Automation in Remanufacturing : Robots flexibility and usage

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Linköpings universitet

Linköping University | Department of Management and Engineering

Master’s thesis, 30 ECTS | Manufacturing Engineering

2020 | LIU-IEI-TEK-A--20/03836--SE

Automation in Remanufacturing

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Robots ﬂexibility and usage

Automation inom återtillverkning

- Robotars ﬂexibilitet och användning

Johan Eklund

Supervisor : Martin Hochwallner Examiner : Erik Sundin

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Abstract

In the modern world, remanufacturing is a growing sector where automation is more and more requested. To be able to improve automation in remanufacturing, simulations are getting more and more used. This thesis is a part of a Swedish research project where one part is carried out at Linköping University. The case comes from one of the partici-pants in the research project. For this thesis, the research will be focusing on how to get the system as flexible as possible with the help of theoretical analysis, simulations and real tests. Studies of the given parameters will also be an important part to find which com-ponents that fit in the selected concept. Through simulations and real tests from a parallel project carried out by year three students at the University validation of the concept will be achieved. Other simulations more relevant for this study will also be carried out to validate the selected concept idea.

The main focus of this thesis has been to come up with flexible concepts that could fit in to remanufacturing. This has resulted in a deep analysis of different gripping techniques that could be used when handling different products. Analysis of different dispensers are also carried out to find which best suits to the model and robot cell used for testing. To select component Ulrich and Eppinger’s method for developing of product design has been used. Beyond this analysis of different mounting solutions of the components are a very central thing. The result of this analysis is, by enabling the robot to grip the product and move to different fixed tools, high level of automation can be achieved together with high flexibility and low setup time.

Focus in this thesis is also to show how to handle the variety of products remanufac-tures can face and how to get it as flexible as possible. The last area investigated is how the programming of the system should be done. The focus was to interfere minimum on the existing process and give the best flexibility as possible.

From the result of simulations and real test, the selected concept with a fixed mounted dispenser and letting the product movie between the different stations that is needed to carry out the process is proven to work. The real test that has successfully been carried out test the accuracy of off-line programming and how accurate the robot can be while handling the product instead of the dispenser.

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Acknowledgments

I would like to begin by expressing my most sincere gratitude to the two parallel projects that has helped me with designing some of the products used as well with some of the the simulations and the real testing of dispenser on a 3D printed model.

I would also want to thank Martin Hochwallner who has been my supervisor that helped me doing progress in this project and always been ready to discuss different question I have had.

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List of Figures

1.1 The process steps listed above. . . 2

1.2 How the setup looks today at Megalans. . . 3

2.1 The way of working for this thesis. . . 6

2.2 The general black box according to Ulrich et al. (2008). . . 7

3.1 All areas that need to be covered before selecting an adhesive/sealant according to DaSilva et al.. . . 11

3.2 When fixating a object to three points the rotation around two axis get lost as well as the movement in one direction according to Pollack. . . 13

3.3 When two points on another side is added the rotation around the last axis get lost as well as the movement in another direction according to Pollack. . . 14

3.4 To fully constrain the placement of the object a new point is needed perpendicu-larly to the previous five according to Pollack. . . 14

3.5 A picture showing the different levels of automation related to variety and volume of the products according to Groover. . . 18

3.6 The seven process step for remanufacturing according to Johansson et al. and Sundin. . . 20

3.7 Different types of flexibilities according to Shivanand et al. . . 23

4.1 The product gripped by the robot with a fixed mounted dispenser. . . 27

4.2 Dispenser mounted on the robot. . . 29

4.3 One type of automatic feeding of lids with help of a vertical storage. . . 30

4.4 Traditional robot cell which require the robot to switch tool to be able to pick up the lids. . . 32

4.5 A robot cell which collaborates with a human operator to mount the lids. . . 33

4.6 A robot cell with two robots collaborating to apply sealant. This concept requires that the robot with the dispenser switch tool to be able to mount the lids. The supply of lids can also be carried out with a storage similar to the one in figure 4.3. 34 4.7 A robot cell with two robots collaborating to apply sealant and an operator to apply the lids. . . 36

5.1 The black box for the formed concepts according to Ulrich et al. (2008). . . 44

5.2 The scoring table of the different concepts. . . 50

5.3 The gripper in Process Simulate. The gripper model is downloaded from Zim-mer’s web page [GH6140-B]. . . . 51

7.1 The test bed for the early tests with the dispenser. . . 58

7.2 The used dispenser designed by Daniel Larsson from the parallel project Jetté et al (2020). . . 58

7.3 The controller used to control the pneumatic’s to the dispenser. . . 59

7.4 An overview of the simulation carried to prove the concept created based on the theoretical result. . . 60

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7.5 The overview of the real robot cell. . . 60 7.6 The result from the real test carried out by the student project run in parallel. The

pictures are from Ryman et al. (2020). . . 61 8.1 Hardpoints on the electromechanical part. . . 65 9.1 A simple program that can be executed by a Yaskawa robot. . . 68 10.1 A picture showing the different levels of automation related to variety and volume

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List of Tables

3.1 Properties for TSE392. . . 12

3.2 Properties for RTV5243. . . 12

3.3 Properties for RTV11. . . 13

4.1 Concept of the different process layouts. . . 31

4.2 Screening of concepts layouts. . . 40 5.1 Description of the rating 1-5 for the scoring matrix according to Ulrich et al. (2008). 50

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Acknowledgments

Adhesive A type of silicone used primary for holding two or more surfaces together.

ARR Automation in Repair and Remanufacturing

CAD Computer-Aided Design

CNC Computer Numerical Control

Curing agent A chemical substance used to harden the silicone.

DBT Dibutyl tin dilaurate which is a curing agent

DfA Design for Assembly

Dispensing System Used to control the outflow of sealant material from its storage.

Dispensing Valve Is a part of a dispensing system that takes a sealant material on to a work piece.

Electrorheological fluid A fluid that change its properties when a current is applied.

FDA Food and Drug Administration

Fixture A tool which is used to support, locate and hold the work piece during a manufacturing operation.

FMS Flexible Manufacturing System

Granular Jamming When the friction between the particles creates a hard solid object.

Green strength The amount of force the silicone can handle direct after application before curing has taken place.

Hardpoints Features or geometry on objects that do not change during the evolution of different generations of products.

LiU Linköping University

LMPA Low Melting Point Alloy

Magnetorheological fluid A fluid that change viscosity when subject to magnetic field.

Off-line programming Creating a robot program in a model

On-line programming When the programming of the robot take place in the real world

PC Personal Computer

Remanufacturing When a used product are taken back to industry to get new upgraded properties.

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RTV Room Temperature Vulcanizing

RTV11 White FDA Silicone Rubber + DBT 1lb

RTV5243 Black Electronic Silicone

Sealant A type of silicone used for primary providing a barrier or protective coating.

Tack free time How long time it takes for a silicone to get a non sticking surface.

TCP Tool Center Point

Teach pendant A handhold computer used for on-line programming of a robot.

TSE392 Clear Paste Silicone

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1 Introduction

This chapter will give the background for this project and present the focus and aim with it. It will also define the research questions and the delimitations for this thesis.

1.1 Motivation

Today in remanufacturing, more or less everything is done by hand to ensure the flexibility that is required due to problems with controlling the incoming product flow [55]. But since more manufactures moves towards a more sustainable image, new markets are found for remanufactured and repaired products. The requirements are high to satisfy both customers as well as the companies in the remanufacturing sector [1]. With the help of robots the quality may be improved of the product, a higher volume can be handled, improved lead times and increased efficiency for repair and remanufacturing companies can be achieved [1, 6, 17, 61, 68]. Since the technology today more or less have taken over the ordinary mass production of goods with help of robots and other automated solutions, the next step in the development of remanufacturing should be to automate this process as well.

For mass production or big batches it is for sure easier to automate the production com-pared to remanufacturing since the step is always the same [55]. This makes it possible to handle a setup time when changing product and still be profitable. In remanufacturing the product flow is much more uncertain which could lead to more time spent on setting up the machines than actually remanufacturing products. To get ride of setup times the flexibility could be built in to make it more smooth [34]. Spending to much time on setting up the system is not a preferable situation and therefore a research project has started which this thesis is a part of. The Swedish research project is about Automation in Repair and Reman-ufacturing (ARR) and one part of it is carried out at Linköping University [1]. The project at Linköping University is carried out together with Yaskawa Nordic who is a robot manufac-turer and Megalans remanufacturing which is a company that focuses on remanufacturing of electronics and electric-mechanical parts for automotive industries. Yaskawa help this thesis by providing equipment such as one HC10 robot and other equipment related to the robot. Megalans remanufacturing provides the case and parts so that tests can be carried out with real products as well as with the specific sealant. The focus for this research is to define how robots can be used in remanufacturing [1, 17].

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1.2. Aim

1.2 Aim

The aim for this master thesis project is to investigate if a robot can take over some of the easier tasks from human operators and contribute to companies working in remanufacturing. This is done with help of literature studies, computer simulations and real tests. The aim is also to find a solution with the optimal flexibility for sealant applications with help of a robot.

1.3 Project case

Today’s sealant is applied manually with a hand hold dispenser driven with compressed air at Megalans remanufacturing. The object the sealant is applied to is an electromechani-cal throttle house with the requirement that no water or dirt should enter the product and harm the electronics. Therefore, a sealing process in several steps is carried out with different sealants for protection of the electronics. The process today for Megalans remanufacturing is as listed and can be visualized in figure 1.1:

1. Placing the part in a fixture in figure 1.2. 2. Applying clear paste sealant (TSE392).

3. Applying sealant in the grove for the small lid and put on the lid. 4. Apply primer (4004) on electronic contacts and let dry.

5. Fasten the black cable with sealant (5243).

6. Stir together silicone rubber + DBT (RTV11) and apply to electronic contacts. 7. Apply sealant (5243) for lid of throttle house.

8. Place the lid on the throttle house in position and press it down.

The amount of TSE392 used per product is around 4 mL to 6 mL and is stored in cartridges of 310 mL. The TSE392 is applied in step two. For RTV5243 around the same amount is used and it is stored in the same way. It is dispensed in both step five and step seven. Nearly all RTV5243 is applied in step seven around the outer edge. The RTV11 is a two component sealant which stores the cure agent and the sealant separately and before application it is mixed by hand.

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1.4. Research questions

Figure 1.2: How the setup looks today at Megalans.

By applying the sealant by hand great flexibility in the process with low investments is ac-cived. This is often required in the remanufacturing sector. But problems occur when a task should be repeated multiple times with the same quality. Here the advantage of a robot ex-ists compared to a human. Robots can without problems repeat the same task over and over again with the same result without flaws. To apply a perfect seal is very hard and to do it repeatedly is nearly impossible according to Sprovieri [17, 58].

1.4 Research questions

For this thesis the objective is to show how robots can be used in remanufacturing and repair. As well as proving the flexibility that can be built in if necessary with help of simulations and models. From this the research questions have been created.

RQ 1: How should the dispenser/dispensers be mounted to ensure the flexibility required in repair and remanufacturing? Is a solution with a robot the best way for applying sealant material in remanufacturing?

RQ 2: Is the variation due to wear on products a problem when automating system in remanufacturing? If a problem with wear, what can be done to minimize it? RQ 3: How should the robot be programmed so it support the required flexibility in

remanufacturing and repair?

The first RQ is very specific for the project where focus is on applying liquid seals but nonetheless important to be answered. The behavior of this could be translated to other operations such as screw tightening or loosing. The followup question is to challenge the whole topic of this research. If a robot would not be suitable for remanufacturing the whole research will be wasted.

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1.5. Delimitations

The second RQ focuses on a big part of remanufacturing, where parts that should be identical are not because of wear. This could lead to problems when trying to automate the system where similarity is important. The followup question is important to answer for repair and remanufacturing companies. To find a solution where wear and other damages affect the automation.

The third RQ is a more general question for building flexible systems for all manufacturers but nonetheless very important for this research project and thesis.

1.5 Delimitations

To reduce the size of this project some delimitations are set to get a clear boundary of what will be investigated for this thesis.

Only one robot model will be considered when doing the simulations and for the real tests since the process and behavior should be more or less similar for every robot.

Only application of silicone paste will be considered in this thesis for testing the flexibility. Applying silicone paste on different products and paths will show the flexibility.

Tests will only be carried out on two different products. The process for implementing more products should be the same as for the first and second product if not even more simple. The geometry of the part are restricted to length and/or width are equal or under 200 mm and the weight is less than 5 kg. The part that Megalans remanufacturing today works with has the size of length=177 mm, width=86 mm and weight=1.6 kg.

The dispensing will only be focusing on the one component sealant RTV5243 and therefore no analyze of dispensers for two components be investigated. The technique to dispense is similar but the requirements are higher for this type.

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2 Method

This chapter will present the different methods used through out this project. It contains a description how the way of working has taken place along with other methods used.

The theoretical part will contain theory about remanufacturing, automation, wear and flex-ibility to cover the motivation and answering the research questions. To find answers and information of the mentioned areas literature studies will be carried out. The base of the lit-erature study will be from scientific publications such as journals and articles but also books and theses will be used. The theory chapter will also contain knowledge about programming industry robots and how to make them flexible. Another important part of the project will also be to select a dispenser which will be done with help of a modified version of Ulrich and Eppinger’s traditional method for selecting concepts. The selection will be based on studies about sealants and their behavior and requirements from the remanufacturer Megalans. An investigation on grippers is also done to see if this is a way to increase the flexibility for this process.

The practical part will consist of simulations done in Tecnomatix which is a system from Siemens and maybe some other software that can provide information about dispensing the sealant. The simulation part will also consist of some modeling of parts required in the sim-ulation model. To verify the model real test will be carried out to both see accuracy and behaviour of the sealant. The tests will be a very important part in the verification on all areas.

2.1 Way of working

This work has basically been carried out with theoretical research which are later validated with help of empirical studies in form of simulations and real tests. The steps can be seen in figure 2.1. The theoretical research has been divided into keywords which have a very central part of the research. Keywords that have been used are automation, remanufacturing, flexibility, hardpoints, and off-line programming. From the basic theory gained from this combinations of keywords gave a base to find articles and literature connected. The search engines that were used are google scholar and the internal database from Linköping University’s library.

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2.2. Theoretical part

The information received through the literature study of the keywords resulting in concept generations where an evaluation of which concept that suites remanufactures best.

The best concept according to the theory research are then tested in simulations. The soft-ware used for the simulations is Process Simulate which is a part of Tecnomatix delivered by Siemens. In the software a model of the reality is created with the same components and own designed models to create an accurate model as possible. The simulations give the possibility to do changes before building up the cell and find problems that can be taken into account before real tests. From the simulation robot programs are created and exported to the robot for tests. The programs are then modified online with help of the robot motion to get it as accurate as possible.

Figure 2.1: The way of working for this thesis.

2.2 Theoretical part

2.2.1 Literature analysis

The planned method to find articles and journals will be through internet searches on data bases like google scholar and other similar internet pages with help of key words like the ones mentioned before such as automation, remanufacturing, flexibility and wear separately as well as in combinations. Other search engines will be Linköping University library page and data bases connected to it. By using key words a broad spectrum of knowledge will be given to cover the theory chapter as well as giving knowledge to the rest of the work. Also previous studies and reports in this area will be used for help and inputs to the work.

2.2.2 Select gripping solution

The method for selecting products and/or creating new concepts that is required for this project will be done according to Ulrich and Eppinger’s book “Product Design and Develop-ment” [62]. In general, the concept development consists of seven parts; identifying customer needs, establish target specification, generate product concepts, select product concept(s), test product concept(s), set final specifications, and last plan downstream development. The last two steps will not be considered since those are aiming for products and not relevant for this thesis.

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2.2. Theoretical part

To find a suitable gripping solution that fits the process, the first step is to identify the cus-tomer needs. This is done by evaluating what the gripper will do in the process. The next step is to establish target specification. Here the existing products that will be handled are analyzed together with the customer needs specified in the previous steps. From this a list with all needs are gathered as well as how important different needs are. This will be the main criteria’s that will be focused on when evaluating the concepts.

To start forming concepts on gripping solutions a black box technique was used to see what was needed. The black box serves to decompose the problem so that an easier solution can be found [62]. From the black box the difference between input and output can be seen for energy, material, and signals. This can be seen in figure 2.2. The black box can also be divided even more to show subfunctions. When all functions are divided into subfunctions that are simple enough, the research of external and internal concept starts. From that a concepts start to take form systematically [62]. To end the concept generation phase reflections of the concepts brought forward are carried out.

Figure 2.2: The general black box according to Ulrich et al. (2008).

Some of the subfunctions brought up sounds good in theory but not practically. This results in that some subfunctions are rejected and concept containing them is not considered. To find which concept is the best, an evaluation of the concept created is carried out where the pros and cons for the different processes are stated. From this the concepts that performs best in the screening process will be further investigated and scored.

The concepts that scored best in the screening process will then be scored based on the re-quirement stated in the beginning with a score between 1 to 5. All criteria have also got a weight parameter so that the areas that are more important affect the total score more than the less significant criteria [62]. The total score is then summarized for all concepts and the concept with the highest score is the one which fits the process best. To end this phase re-flections of the winning concept is good enough to keep or if the process should be restarted with new requirements and customer needs [62].

2.2.3 Selecting dispenser

This method is used to select a dispenser for this project. It follows the same step as for selecting of gripping solution in section 2.2.2 but with some modifications. First the customer needs are specified. From that the requirements for the product are set according to Ulrich and Eppinger [62]. To help to set the requirement the black-box presented earlier from Ulrich

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2.3. Simulation part

and Eppinger can be used [62]. When the requirements are set the search for existing products on the market starts in order to find products that can support the requirements. If several similar products are found, some are neglected since the market is big of dispensers. The solutions that are found are then evaluated with pros and cons to find the dispenser that fits best for the process.

2.3 Simulation part

From the information and knowledge that been put forward during the theoretical part of this thesis a simulation model will be built. This is done to verify that the theory presented is correct. The model will be based on Yaskawa’s HC10 robot and the electromechanical part from Megalans. The simulation will be done in the Tecnomatix Process Simulate. From Tecnomatix the robot program can be exported to the real robot for real tests.

The model is created with as accurate products to get it to match the reality. Some parts are collected from the internet like the robot to get the right settings on limitations and motions. Other parts like the product are 3D-scanned to get the right geometry in the model. Some parts in the real cell are created by some students at Linköping University which gives the possibility to just import these parts to the model. Parts that are not as important are created in the simulation program just to create the environment.

Most of the simulations were carried out by the candidate project that has been run in parallel with this theses. The concepts they have tested is the same as the one found through theory in this report.

2.4 Verification part

The real tests will be used to verify both simulation models and theory with help of the robot present in the robot lab at Linköping University.

The the first test will be to carry out just a simple with the dispenser dispensing on a plate with the printed line to see the movements accuracy and the width of the sealant. When the result here is good enough tests with the real part can start to be tested without sealant until this result is satisfying. The final test is that test the whole cell together with the electrome-chanical product with sealant.

Also most of the tests are done by the candidate project on the same terms as for the simula-tions.

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3 Theoretical foundation and

research

This chapter will contain the theory that is necessary for understanding this work. This chapter con-tains general knowledge about: Liquids/silicones, Fixtures, gripping techniques, automation, remanu-facturing, and flexibility in manufacturing.

3.1 Liquid

For thousands of years, adhesives and sealants been an important part of the construction and for the human mankind [11, 51]. Today it is nearly impossible to find products in the society that does not uses adhesives [11, 51]. Adhesives and sealants can be found in three stages during the formation according to [11]. The first stage is the spreading of the sealant on the surface applied to, forming good wetting to create a good connection between the liquid and the surface [11]. The second stage is the hardening so the liquid can support the forces acting on the joint [11]. The third stage is all factors that need to be considered that can affect the durability and lifetime of the adhesive and sealant [11]. To get a good joint knowledge, knowledge in many areas are required. From surface chemistry and chemistry to material engineering and mechanical engineering [11, 51].

The reason for the increased use of adhesive joints over conventional fasteners can be found in many areas [11].

• More uniformed stress distribution.

• Shows an increased damping effect thanks to the polymeric nature of adhesives. • High fatigue stress.

• Can bond dissimilar material with different thermal expansion.

• It creates smooth surfaces since no holes are needed for bolts and rivets.

3.1.1 Viscosity

Sealants can be found in many different viscosities. Adhesives and sealants exist in the range from watery to pasty but also with a description of how easy it flows [10]. Non-flowable

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3.1. Liquid

liquids cannot change its shape without external forces applied to it while other sealants that have low viscosity and good flowability will keep spreading until found the lowest energy state as possible [10]. To compare with solids, viscosity can be seen as Young’s modulus but for liquids [11]. The viscosity of material shows the internal resistance between the molecules affecting the flow and deformation of a material [11]. The definition of viscosity is the ratio between shear stress and the shear strain rate [11].

3.1.2 Sealant

On the market, two types of materials are used to create products that should be protected from the outer environment. One is adhesives and the other is sealants [51]. Both are used in a lot of areas, from the aerospace industry to the automotive industry to more simple usage in your home when putting up tiles in the bathroom. The behavior is quite similar as well even though the primary area where they are used differs [11, 51]. According to [51] the definition for both adhesives and sealants are.

“Adhesive: A substance capable of holding at least two surfaces together in a strong and permanent manner."

"Sealant: A substance capable of attaching at least two surfaces, thereby filling the space between them to provide a barrier or protective coating.”

(Petrie 2007, ch 1.6)[51]

3.1.3 Sealant properties

A lot of parameters influence the selection of a sealant as can be seen in figure 3.1. From joint performance and fabrication issues to cost and aesthetics [11, 51]. The most important factors to consider according to [11] are:

• Substrate type(s) • Adhesive form • Application requirements • Manufacturing needs/constraints • Aesthetics • Costs • Fabrication issues

For one process the obvious key parameters can be superseded of some other less important parameter [11]. This could be the form of the sealant that either could be applied in the form of a paste or a film. The past sealant can be cheaper and simpler to apply per unit volume but to get it accurate, additional cost will appear to automate and dispense it. Then a more complicated form of the sealant could give a simpler way to apply it which could save money in the long run [11]. Because of this, all parameters need to be evaluated to make sure that nothing is missed out in the selection. The key parameters are often linked together. This results in a good performance in one area but will result in reduced performance in another area [11]. Often the most important starting point for analyzing at the beginning of the selection phase is, what is the requirements of the structure and joints [11]. This often results in the elimination of a lot of families of sealants according to da Silva et al. In the end it is very uncommon that just one type of product is left to select from [11].

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3.1. Liquid

Figure 3.1: All areas that need to be covered before selecting an adhesive/sealant according to DaSilva et al..

Some of the more important physical properties that need to be considered when a sealant is selected are the ability to flow and wet the bed applied to. This to ensure an even and tight seal [11, 51]. The density of the sealant is also important to consider since the range for sealant goes from 0.6 g cm´3up to 2.28 g cm´3[11]. Even though the density by itself is not very important, it can tell a lot of the polymer’s nature, chemical family, morphology, filler, and void content [11]. Also, modulus and viscosity are important physical properties affecting the idealization of the solid and liquid behavior[11]. Furthermore, the viscosity of the sealant defines which equipment can and can not be used when mixing, pumping, and dispensing the material. But it can also give more knowledge about the polymer itself [11, 51]. To apply sealant with a robot a high viscosity of the sealant is preferable. Robotic application is commonly used in industries such as automotive and consumer products to increase quality and to reduce labor and material costs [51].

3.1.4 Sealants used by Megalans

Megalans works with three different types of sealants to isolate components, create a safe environment for the electronics, and hold components in the right place. This section will describe the three types used and what purpose they have.

TSE392

TSE392 is a one-component thixotropic paste used for protecting the components and circuit board inside the electromechanical throttle. This paste has a fast curing time as well as good properties against corrosion [33]. It cures to atmospheric humidity and forms an elastic sili-cone rubber [10, 29, 33]. The TSE392 is also an excellent adhesion to many different materials such as copper, plastics, ceramics, glass without the need of a primer [33]. During curing and alcohol is released and the tack-free time for TSE392 is 5 min [10, 29, 33]. Tack-free time is how long time it takes to get coat on the sealant.

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3.1. Liquid

Table 3.1: Properties for TSE392.

Properties TES392-Clear Paste Silicone Property Value

Density 1040 kg m´3

Tensile Strength 1.6 MPa

Tack free time 5 min

RTV5243

RTV5243 is a black alkoxy neutral cure, non-flowable, one-component adhesive sealant with high strength creating strong bonds that withstand exposure to moist environments [31]. This sealant is used to enclose the top lid to ensure that no moist can harm the electronic compo-nents. The sealant is also neutral during curing releasing methyl alcohol when exposed to the normal environment (no heat or pressure or extra dry air is required) [31]. RTV5243 is also good since it does not get metals to start to oxidize, giving good green strength fast, and have short curing time compared to other alkoxy sealants [10, 31, 29]. Curing time to a depth of 3.2mm is 6 hours and tack-free time is 45 minutes [10, 31, 29]. It does not require a primer to create strong bonds to metals and plastics [10, 31, 29].

Table 3.2: Properties for RTV5243.

Properties RTV5243-Black Electronic Silicone Property Value

Tensile Strength 2.2 MPa

Tack free time 45 min

Curing time 6 h

Viscosity 0.82 Pa s

RTV11

RTV11 is a two-component sealant often used for potting and encapsulation of connectors and electronic coils [30]. The two components are white FDA silicone rubber mixed with 0, 5wt% DBT as a standard curing agent leading to a curing time at 25 degrees estimated to 24hours [10, 29, 30]. 0, 5wt% DBT means that 0, 5% of the total weight should be the DBT curing agent. It is a measurement of the mixture. By changing the curing agent and/or the amount used will result in changed curing time [30]. The RTV11 cure at room temperature with excellent adhesion with the help of a primer [10, 29, 30]. Before curing it is easily pourable with a viscosity of 11000 cps [10, 29, 30].

According to the datasheet from Momentive [30] can the agent be changed to better suit an automatic process. In the datasheet RTV9811, RTV9950 or RTV9910 are seen as possible exchanges when an automated solution is requested [30, 32]. The general difference between DBT and RTV9910 or RTV9950 curing agents is that the RTV agent are a pre-blended DBT mixture [32]. 10wt% of RTV9950 is equal to 0, 5wt% DBT and while fore RTV9910 the curing time will be longer with 10wt% [32]. For RTV9910 the curing time will be longer compared to the one used today and the others which have a moderate curing speed quite similar. The amount of cure agent RTV9811, RTV9950 and RTV9910 applied to the mixture is around 5 ´ 10wt% [30].

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3.2. Fixture

Table 3.3: Properties for RTV11.

Properties RTV5243-Black Electronic Silicone Property Value

Tensile Strength 236 MPa

Curing time 24 h

Viscosity 11 Pa s

3.2 Fixture

The fixture’s purpose in manufacturing is to accurate position and secure parts location. To be able to do this the fixture must be locked in the three linear motion directions (X, Y, Z) as well as restrict the rotation around these axes so it cannot move. Another requirement for a fixture is that independent of the workpiece the result of the machining is inside the tolerances. It should also be easy to switch workpiece without complicated setups. To be able to fixate one part, the geometry of it is very important [48, 46, 52].

To create a fixture for an easy geometry (block), a point connection with three points not placed on a line on one side of the block will restrict the linear movement in one direction as well as the rotation around two axes which can be seen in figure 3.2. The reason for three points not placed in a line guarantees that all points will have contact independent of the surface roughness [52].

Figure 3.2: When fixating a object to three points the rotation around two axis get lost as well as the movement in one direction according to Pollack.

By adding two new points on another side that is not opposed to the first, a restriction of the second linear motion and the third rotation are restricted as in figure 3.3. If just one point would be added the rotational movement would not be hindered.

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3.3. Gripping techniques

Figure 3.3: When two points on another side is added the rotation around the last axis get lost as well as the movement in another direction according to Pollack.

Now it can just move linearly in one direction. To strain this a single point perpendicular to the two other sides will result in that the block will be fixed in all directions, both linear and rotational. This can be seen in figure 3.4 where the orange/yellow colour symbolize that the block is fixated.

Figure 3.4: To fully constrain the placement of the object a new point is needed perpendicu-larly to the previous five according to Pollack.

3.3 Gripping techniques

For handling objects with a robot some external device is necessary. A wide range of tech-niques exist and some of them are presented in this subsection.

To be able to create products with the help of robots in a good way without problems good precision is required on both systems as well as the products handled [13]. This puts pressure on the equipment that handles parts and the tools used to fixate and grip objects during as-sembly [13]. For objects that are fixated the requirements are on the position and orientation to be correct. For the part that is gripped the requirement is similar, both orientation and position are key aspects, but when moving objects dynamic forces start to interfere. For a light object, this does not affect the process significantly but for a heavier object at high speed, this could be a problem. What this means is that both the fixture holding the fixed object and the gripper handling the part that moves need to be designed so it can handle both static and dynamic forces that occur during assembly [13].

For assembly with robots, two different systems need to be considered. The first is the tolerances from the component manufactured. The second system is handling the system

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3.3. Gripping techniques

tolerances that come from fixtures and handling equipment. Often for separate components, the manufactured tolerance is more than enough, but when adding up all tolerances prob-lems can appear when assembly. This means that both the accuracy of the system and the tolerances of parts need to fit together.

The two different systems, system tolerance, and component tolerance can also be divided into two subareas. For the component tolerance, it is divided between tolerances on the functional surface, the surface in contact with components, and the tolerance on the surface that is gripped and fixated. For the gripping and fixation system, the tolerance related to location, shape, and surface roughness of the areas in contact during handling must be as accurate that it does not create problems when handled.

System tolerance is also affected by two subareas. The first sub-area is the tolerance on the equipment, handling the objects, like the accuracy of the gripper. The other area is the tolerance on the fixture that could affect the position of relevant geometry. In the intersec-tion between the system tolerance and component tolerance, the actual tolerance appears when everything is summed up. When using industry robots in assembly to form flexible automation a very heavy system which in its nature is very dynamically unstable can affect the system tolerance. More than static and dynamic flaws the material and techniques used to create parts can also create problems with the tolerances. Especially when molding the surface roughness can be a problem when gripping and fixate products.

3.3.1 Impactive Gripping method

This is the most common gripper, using mechanical movement to create contact and holding force between the jaws and the object gripped. The movement of the jaw can be done with many different technical solutions the most common is pneumatic, hydraulic, or electrical movement. The drive chain contain motors, gears, brakes, and sensors to read the location of the jaws. The design of this type of grippers contains between two to four jaws that often move synchronized. The advantage with this tool type is that it often allows the special design of the jaws which means it also can position the object without a specific alignment station. Even though impactive grippers often are very technical mechanically they allow very high reliability, give enough force to grip and move heavy object. It can also adapted the jaws for different handling operations. [44]

3.3.2 Adaptive Gripping method

A gripper with controlled stiffness could be a solution for gripping and moving different types of objects with different shapes without harming it. This gripping method works by controlling the shape of the gripper. When no object is gripped the gripper is in a soft state and when an object is grasped the state is set to stiff [8, 43, 56]. This type of gripper can use different techniques. The granular jamming technique uses a vacuum and a filling like ground coffee beans, plastic granules, or other material that shows the property of granular transition. The vacuum here compresses the filling to a locked state like a vacuum-sealed package of ground coffee which feels like a brick and is very stiff and hard, but as soon as the pressure is released the behavior becomes very similar to liquids [8, 43, 56]. Other techniques that could be used for controlled stiffness are low-melting-point alloys (LMPAs) which works by changing the temperature to get a stiff and soft state. Tools with this require having a cover to contain the LMPA when in the liquid state. The LMPA is often seen in finger solutions that could adapt to the material [56]. Some other methods to create grippers with controlled stiff-ness are electrorheological fluid and magnetorheological fluids which can change viscosity

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3.4. Automation

when exposed to electromagnetic fields. Also, shape-memory materials could be used [56]. The last three techniques have not yet shown the possibility to lift objects heavier than 1 kg [56].

3.3.3 Astrictive Prehension Gripping method

Astrictive prehension grippers are the gripping type that can grip without using compressive stress which are vacuum grippers, magnetic grippers, and grippers using electrostatic fields [44]. Vacuum grippers are very versatile and can handle everything from heavy objects to small semiconductors by applying a relative vacuum of 70% or lower which in absolute residual pressure is 300mbar [44]. The negative pressure gives the holding force and is de-pendent on the contact surface area. The principle of this technique is very simple, cheap, and easy to implement but with simplicity, some areas start to lack. The vacuum technique cannot by it self handle centering in the prehension step [44].

To calculate holding force(F)for a vacuum gripper the equation below can be used:

σ= F ´ m ˆ(g+a)

A (3.1)

where(σ)is the contact pressure,(a)is the acceleration of the robot,(g)is acceleration due to gravity and(A)is the prehension surface area [44]. The suction cups can also be modified dependent on the object that should be handled as well as the possibility for exact positioning can be built in even, though it is very uncommon [44].

Magnetic grippers can either use permanent magnets or electromagnetism to create the pre-hension for moving magnetic objects. For permanent magnet grippers, the requirement is that the object is of ferrous material. To release the object a mechanical switch is often im-plemented to divert the flux [44]. This way the long term deterioration is avoided. Another possibility to release the object is with mechanical force by simply pushing the object away from the magnet [44]. Electromagnetic grippers instead work with a magnetic field generat-ing with the help of electricity and coils. To release the object the electricity is simply shut off and the gripper is no longer magnetic and can not hold it. This technique is a little simpler than for permanent magnets [44].

3.4 Automation

Manufacturing is today divided into three different levels of automation [16, 26]. It can either be carried out by humans and it is seen as a manual system or it can be automated in two different levels: semi-automatically or fully automatically [16, 26]. The definition of automa-tion in manufacturing is when a product is formed without the same influence of workers as for manual operations, this means the products are instead formed with the help of ma-chines running autonomous [26]. Some automated system that is listed below is brought up by Groover:

• Transfer lines with machines to modify the product • Machine tools processing parts

• Assembly system

• System using industry robots • Automatic inspection

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3.4. Automation

The two different levels of automation can be found in manufacturing today. Semiautomatic where an operator should be present during the operation even though not all steps are manually, and fully automatic systems where an operator should not need to interfere with the process [16, 25, 26]. It can also be divided into three categories: fixed automation, flexible automation, and programmable automation. The semi-automated level is often present in the programmable automation. Dependent on product variety and annual production volumes the different classes of fixed, flexible, and programmable automation [26].

Fixed automation works with very high volumes and low variety like light bulbs. The se-quence for the operations is a set of equipment and cannot be changed without rebuilding the system. The operation at the different stations is often very simple with linear, rotary, or plane motion [26]. Features for this type of automation are often high investments for specially designed equipment, high production rate, and very inflexible for both the line and products that are handled [26]. To be economic justify a very high production rate is required but also big products like a car can justify this investment [26].

The programmable automation tries to be as flexible as possible with the help of equipment that can be adjusted for the different products that should be handled [26]. To control this system, programs are used where new programs are needed for all new products that should be handled. This automation class works in batches to ensure efficiency since a new product that should be handled results in downtime to setup the system. The reason for this are the need to setup the fixtures and change tools [26]. The characteristics of this system are high investments for machines that are very general. They can produce low quantities and can handle big variety. This is the result of long setup time between different products. These machines are very useful for production in batches [26].

The last one, flexible automation, is something in between fixed and programmable automa-tion with not the same variety as programmable automaautoma-tion but instead without setting up time [26]. This gives the possibility to mix a variety of products without time losses and no restrictions on which order the products comes in. The reason this is possible is the low variety of the parts handled reducing the amount of changeover needed. Features that characterize this system are a high investment for special design equipment, a non-stopping production with a variety of products, a medium production rate and can handle a variation of products [26].

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3.4. Automation

Figure 3.5: A picture showing the different levels of automation related to variety and volume of the products according to Groover.

3.4.1 Why Automation?

The reason for using automation today can be found in multiple areas. Reasons often seen are improving labor productivity and reduce labor cost but the effect of automating the man-ufacturing can be found in more areas [6, 26, 53]. Other reasons than just the one mentioned already are listed here according to [6, 7, 26, 53, 70]:

• Reduce the problem of finding workers since some advanced countries have a shortage of workforce.

• Get rid of repetitive moments in production which are not very good for humans and can injure workers.

• Improving safety by letting robots work in hot, dirty, toxic, or other dangerous environ-ments that humans cannot without special equipment.

• Improved quality on products since robot’s repeatability is better than humans over long periods. It also guarantees that the products are made with the right quality. • Reduced lead time is also something that can be achieved with automation, meaning

that the time from that the customer place the order to it is delivered is shorted. • Carry out tasks humans cannot do requiring very good precision, miniaturization, or

complexity of geometry that a human cannot achieve.

• Avoid high cost for not automating since the competitive advantages for automating are very big.

3.4.2 Robot automation

The different levels of automation mentioned previously can be achieved in many different ways, the most common for a fully automated system is to have dedicated machines with pre-defined steps in a sequence [26, 53]. To build systems that could handle variations of product this type of setup cannot be used and instead, robots are used [7]. Robot’s ability to be repro-grammed and the ability to do more than one task increase flexibility in assembly. For high automated lines all steps need to be carried out in the pre-defined order while for industry robots the sequence can be changed and other products can be handled without rebuilding the system, just by adding or changing some code [7]. This gives increased flexibility for the

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3.5. Remanufacturing

system but for fixtures and grippers, changes might be needed to be able to handle different products [7]. A robot also gives greater flexibility in production volumes since it can operate with much longer cycle times compared to a high automatic system [7, 25]. Other advantages using robots are the possibility to handle defect products and avoid the problem that might occur as well as the part that does not need to be picked at the same place every time, the parts can the stored on patterns or arrays on pallets or part trays [7].

3.5 Remanufacturing

Remanufacturing is one of the more important areas in the industry that need to be consid-ered to get a sustainable life with the increased consumption of technique, gadgets and other products that are thrown away at the end of life stage for a product. Since the wealth is im-proving for all in the world and consumers buy more and more stuff the amount of material available on the earth will run out [50]. But the first appearance of this concept came during the second world war due to material scarcity [34, 60]. The definition of remanufacturing in this report is:

A process that in several steps transform a product (core) from its end of life condition to a like-new condition. The different steps used are inspection, cleaning, disassembly, improving parts, reassembly, and testing and is based on statements from [34, 39, 60].

Remanufacturers in different areas are not always seeing themself as remanufacturers, in the car industry it is called ‘rebuilding’, in the tire industry it is called ‘retreaters’ and for laser toner cartridges ‘recharger’ [60]. Other terms used are refurbishment or reconditioning. but then often the condition is just restored to when the product was new[28].

3.5.1 Remanufacturing process

The remanufacturing process consists of a maximum of seven different steps depending on the product that is remanufactured [60]. Since every type of products is different, no prede-fined path can be designed for remanufacturing [34]. What is clear though is that these seven steps are included according to Sundin and Johansson et al. which is illustrated in figure 3.6:

• Inspection • Cleaning • Disassembly • Storage • Reprocess • Reassembly • Testing

Often seen as the process of remanufacturing is that the inspection is the third step carried out after cleaning and disassembly [34, 59, 60]. The risk of doing it in this sequence is that during the inspection fatal errors can appear resulting in unnecessary work [34]. Some products require cleaning to be able to be inspected even though it can result in finding out that the core is unusable. Because of this, no general sequence can be defined for remanufacturing. But during remanufacturing all listed steps are included. The step that always finishes a process is the final testing to verify that the product performs as good as a new one [34, 59,

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60]. And compared with newly manufactured products, all products are tested to verify the quality.

Figure 3.6: The seven process step for remanufacturing according to Johansson et al. and Sundin.

3.5.2 Benefits of remanufacturing

Remanufacturing is something that can benefit the environment but also companies carrying it out. The environmental benefits from remanufacturing are both from the waste handling as well as energy consumption. By remanufacturing products the energy consumption lowers to around 60 percent compared to newly produced products [38]. The main energy saved is from the embodied energy in the core that is recovered in remanufacturing. This means that a remanufactured product uses energy already consumed when forming the product at first. An estimation is that for every kilowatt-hour spent in remanufacturing between 4-5 kilowatt-hours are saved according to [38]. Also the amount of material that can be recovered have great potential. According to Lund about 80 percent of the material can be recovered during the remanufacturing process but with the potential to increase up to 90 percent. This is very important for countries lacking in domestic resources [38].

Another driver for remanufacturing are the future where the global population grows and the estimation is that around 70 percents will live in urban areas. With increased wealth the consumption will increase leading to lack of resources, energy, water, and land areas [50]. Climate change can also create problems with supply chains to Europe according to Parker et al. Consumers are also estimated to affect the market in the way of requesting products that are more sustainable [50].

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3.5.3 Motivation for companies

According to Parker et al.[50] these motivators can be the reason why manufacturers start to remanufacture.

• Business Model: The economic margins can be increased by changing the business model from ’make and sell’ to service-based. Service-based models also increases the possibility to take back products when they are worn out. The remanufactured products are sold for 40-80 % of the price of a new product.

• Access to used product: Legislation today forces companies to collect products that enable remanufacturing to grow.

• Reduced lead times: The lead times of products can be minimized thanks to less failure of key systems.

• Alternative businesses models: By enabling rental and service-based offering, the product is never sold which means that the company always ensure that the core comes back to remanufacturing.

• A reduced risk of resource insecurity: Ensuring that products do not take more dam-age than expected through leasing and rental long supply chains can be avoided. • Environmental legislation: The ELV Directive put pressure on vehicle manufacturers

that 95 % of the material must be reused or recovered. This opens up an opportunity for remanufacturing.

3.5.4 Problems with remanufacturing

Parker et al. have also put forward a list of barriers against remanufacturing in the published report [50].

• Lack of information on third party products: Since not all remanufacturers are the original manufacture of the product, lack of information can be a problem.

• Legal ambiguity: Since remanufacturing is a very broad term and unclear what it stands for, it cause problems. Can a remanufactured part be assembled in a new product or must it be declared that it is a ’second hand’ product? Also, problems with ambiguity legislation affect remanufacturers.

• Definition of waste: Is a product waste just because of reaching end-of-life or can it be seen as a resource. If remanufacturing is seen as ’waste processing’ extra cost will be added to administration and controls.

• Competition from low-cost products: The biggest problem for remanufacturers ac-cording to multiple sources is the cheap replacement products. This results in lost mar-ket shares for remanufacturers.

• Lack of technically skilled engineers: Lack of well-educated employees results in a similar problem as the manufacturing sector faces.

• Poor design for remanufacturing: Products not designed for remanufacturing can cre-ate big problems. When disassembling and reassembling joints can be damaged if not designed for remanufacturing as well as components might not be designed for re-use. • Technology shifts: When new techniques and materials appearing on the market re-manufactured products will also need to adapt to match the new products on the mar-ket. This will result in compromises where a purely mechanical product gets combined with electronics to improve performance.

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3.6. Flexibility in manufacturing

• Reverse logistic costs: To take care of large and bulky products results often in signifi-cant cost that might result in less likely to remanufacturing of this type of product. To collect parts from sparsely populated areas will also result in increased cost.

• Cost and availability of storage space: remanufacture will need to have big storage areas to ensure the availability of reused parts.

• A lack of remediation techniques: To be able to take care of products in some sectors is required to be able to achieve similar performance as new products.

Lund mention also other problems according to energy consumption. Most of the remanufac-tured parts consume energy like diesel engines, cars, refrigerators, and a lot of other products [38]. By remanufacturing the life of an old and not as effective product will be extended re-sulting in higher energy consumption than for a new product [38]. He also asks himself if this then is not a waste of energy to keep old products running with old techniques instead of an upgrade to new ones.

3.6 Flexibility in manufacturing

The idea of a flexible manufacturing system (FMS) was born from the increased competition on the market around 1960 to 1970 were often cost was the primary concern [36, 57]. This leads to improvements in quality but also to a more complex market where also delivery times became a more central requirement [36, 57]. From this, the new strategy about Cus-tomization was formed which meant that the manufacturers needed to be more flexible in the production [36, 57].

Shivanand et al. say that FMS is, first of all, a manufacturing technology but also states that it is a philosophy that strives to be as agile as possible [57]. This means that the manufac-turer producing with the lowest total cost, delivers fastest to the market, and can make the customer happiest perform best [57]. Manufacturers can achieve this with the help of FMS as one of the tools according to Shivanand et al.. Often seen is that FMS is used by the producers with small batch sizes or work with a job shop environment [36]. Also, different focuses can be found for FMS which can be seen in 3.7 where everything cannot be achieved at the same time and require different layouts and setups.

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Figure 3.7: Different types of flexibilities according to Shivanand et al.

3.6.1 Definition of FMS

A common view of FMS is that it is a combination of machines connected with some type of transport system where both machines and transport system is controlled by a central computer [40, 57]. In a more general way, it is defined in [57] on page 2 as:

"FMS consists of a group of processing work stations interconnected by means of an automated material handling and storage system and controlled by integrated computer control system."

The reason for FMS being seen as flexible is the ability to produce a variety of products si-multaneously with the ability to adjust the quantities based on the demand [57].

3.6.2 Basic components for FMS

As stated earlier, an FMS consists of at least three basic components. They are workstations, automatic material handling and storage system, and computer control systems.

Workstations

According to Shivanand et al. the typical workstation consists of computer numerical control (CNC) machine tools used for machining of families of parts [57]. Other stations also exists in a flexible system. From the load and unload station, assembly stations, inspection stations, forging stations as well as sheet metal processing.

Automated Material Handling system

To get the part to the different stations some carriers are required to get it fully automated. The handling can be carried out with different automatic handling systems with various func-tions [57]. The listed various funcfunc-tions from the book of Shivanand is:

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• Random and independent movement of work parts between workstations. • Handling of a variety of work part configurations.

• Convenient access for loading and unloading of work parts. • Compatible with computer control.

Computer Control Systems

This is the part of the system that controls and coordinates the operations taking place in the system. The different functions that a computer control system consists of are [57]:

• Control of each work station.

• Distribution of control instructions to work stations. • Production control.

• Traffic control. • Shuttle control.

• Work handling system and monitoring.

• System performance monitoring and reporting.

3.6.3 Other ways to create flexibility

By allowing products to have similar hardpoints the flexibility can also be increased. Hard-points are very common for vehicle manufacturers who uses them for handling parts and references in assembly [14]. In the automotive industry, the car has one main reference sys-tem, as well as all components that has its own. The specific hardpoint for every component is used for the alignment in the assembly [14]. By keeping it the same, it is possible to mount the same component in different vehicles, while a change of reference system would result in requirements of new tools and models [14].

The hardpoints can also be used as handling points in manufacturing. They can serve both as fixtures and as help with transportation during manufacturing but might not be used in the final assembly [14]. By creating similar handling points the same tool can be used for multiple components in handling and transportation without needing a flexible carrier. The handling points in the vehicle industry is used to handle heavy components but also for automated assembly [14].

The importance of equipment is also a key to achieve flexibility in manufacturing and assem-bly [65]. Vos states also that the equipment is the key to get an economically justified process for flexible assembly [65]. Furthermore, without the right equipment, it is stated that it is impossible to get an automated assembly flexible [65]. Also with planning in the early stage of a product life much can be gained. Especially when considering automated assembly [65]. It is of course still possible to get a flexible assembly without doing all this but complexity will increase according to Vos. By emphasizing design for assembly (DFA) the pressure of the equipment would be reduced resulting in cheaper equipment and the justification on the economical level will increase [65].

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4 Concepts for the process

This chapter will contain how different steps in the process can be carried out. It also contain the different concepts formed and a screening of them. In the end one of the concepts will be selected to go further with.

The process investigated is as the one shown in figure 1.1 where the idea is to automate the whole process instead of as it is done today, manually. The concept that will be put forward will be considered so that automation, remanufacturing, and flexibility will be achieved. The different steps in the current process are: apply three types of sealants and one primer as well as provide one lid to cover the circuit board and one to close the top of the throttle valve. The different steps to consider are: should the product be fixed or moving, should the dispenser be fixed pr moving, and how will the different lids be supplied and mounted. With one selected method restriction on how the other steps can be carried out can appear.

4.1 Mounting of product

The product can either be fixed in a stationary fixture or it can be gripped in some way by the robot and moved to the location of the stationary dispenser.

4.1.1 Fixed position for product

With a fixed position in the system, the mounting of the products property will not affect the system which is very good for an automatic solution. With help of a fixture that lock the product in place further improves the precision which is positive from an automation point of view. Another positive thing with a fixed position of the product is that the product weight does not needs to be considered and gives the possibilities to handle heavier products than otherwise. The reason for this is that a structure that can withstand the load and fixate the object is easier to build than a robot that can handle the same weight. One problem with a fixed position is how the supply and mounting of the products will take place. The mounting of the product would be best suited for a human to carry out for a realistic concept which then reduces the level of automation but increase the flexibility. Worth to consider with a human is that the robots environment should be avoided which will result in some sort of supply system with a rotating table or similar is needed. But a supply system will affect the

Automation in Remanufacturing : Robots flexibility and usage

Linköping University | Department of Management and Engineering

Master’s thesis, 30 ECTS | Manufacturing Engineering

2020 | LIU-IEI-TEK-A--20/03836--SE

Automation in Remanufacturing

Robots ﬂexibility and usage

Automation inom återtillverkning

- Robotars ﬂexibilitet och användning

Johan Eklund

Upphovsrätt

Copyright

Acknowledgments

Contents

List of Figures

List of Tables

Acknowledgments

1

Introduction

1.1

Motivation

1.2

Aim

1.3

Project case

1.4

Research questions

1.5

Delimitations

2

Method

2.1

Way of working

2.2

Theoretical part

2.2.1

Literature analysis

2.2.2

Select gripping solution

2.2.3

Selecting dispenser

2.3

Simulation part

2.4

Verification part

3

Theoretical foundation and

research

3.1

Liquid

3.1.1

Viscosity

3.1.2

Sealant

3.1.3

Sealant properties

3.1.4

Sealants used by Megalans

3.2

Fixture

3.3

Gripping techniques

3.3.1

Impactive Gripping method

3.3.2

Adaptive Gripping method

3.3.3

Astrictive Prehension Gripping method

3.4

Automation

3.4.1

Why Automation?

3.4.2

Robot automation

3.5

Remanufacturing

3.5.1

Remanufacturing process

3.5.2

Benefits of remanufacturing

3.5.3