Master of Science in Mechanical Engineering June 2020
Replacing waste streams in the healthcare industry by applied technology
Developing technology for a circular economy
Adam Backman and Marcus Skoog
Contact Information:
Author(s):
Adam Backman
E-mail: adbc15@student.bth.se Marcus Skoog
E-mail: maiz15@student.bth.se University advisor:
Tobias Larsson
Department of Mechanical Engineering
This thesis is submitted to the Faculty of Engineering at Blekinge Institute of Technology in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering. The thesis is equivalent to 20 weeks of full-time studies.
The authors declare that they are the sole authors of this thesis and that they have not used any sources other than those listed in the bibliography and identified as references. They further declare that they have not submitted this thesis at any other institution to obtain a degree.
Keywords: Waste streams, Circular economy, Innovation, Recycling, Remanufacturing, Healthcare
Abstract
Background
Waste has been around since humans started to create products. Today, it is a growing problem in the world; humans keep producing waste at a faster pace than we can handle. The world is becoming more conscious of our actions, and new solutions to manage and utilize the waste are desired. Medical waste lacks a global definition, which results in a lack of standardization for medical waste management.
The rapid development of medical science and technology has led to increased use of medical consumables. Single-use gloves are the most commonly used consumable within healthcare. They are not recycled due to fear of contamination, which results in a big load on the environment by not preserving the value of the material.
Objectives
The objectives with the research have been to understand the waste industry and identify where waste streams have the opportunity to be replaced with circular systems through new technology. From the findings, design and propose a new technology that fits into a circular economy.
Method
Design Research Methodology and MSPI Innovation process worked as frameworks for the design process for the researchers during the thesis work. Inspiration from company visits, interviews, job shadowing, and literature research initiated the project and was used to clarify the problem. Prototypes, testing, and literature research were used to validate the design progress and followed up by lab experiments and mechanical design of a fully circular system.
Results
Through tests and experiments, a circular system for single-use protection gloves was designed.
The proposed technology would eliminate the need for raw material extraction, manufacturing, and transportation. The system is based on making protection gloves from Polyvinyl Alcohol. Due to the unique properties of the material, it is possible to dissolve the gloves in water, sterilize them and remanufacture them into new gloves. The gloves proved to have similar mechanical properties to the current options on the market. The system includes many elements from the manufacturing process of nitrile rubber and latex gloves, but the introduction of cleaning and sterilization steps will question the main reason consumable protection gloves are used in the first place, to ensure sterility.
Conclusion
Optimizing, automating, and implementing this system will make the healthcare industry more environmentally friendly. Introducing a system to remanufacture and sterilize single-use gloves is a statement to prove the possibility to replace linear life cycles with circular ones, by questioning the reasons behind unsustainable behavior and solving those problems. Contaminated waste is incinerated today. Some argue that energy recovery classifies as recycling, but this system will focus on preserving the value of the material by reusing it in multiple cycles. Similar work will be necessary to keep up with the increased production of waste. Circular systems may enable humans to fulfill their needs with a significantly decreased environmental load. Before implementing this solution in the healthcare industry, more research must be carried out. However, the innovation of an in-house system and a more direct approach to manufacture – recycle – reuse, has presented to create new value of waste and further technological development to enhance the waste management and recycling industry.
Nyckelord: Avfallsströmmar, cirkulär ekonomi, innovation, återvinning, hälsovård
Sammanfattning
Bakgrund
Avfall har funnits sedan människor började tillverka produkter. Idag är det ett växande problem i världen, människor fortsätter att producera avfall i en snabbare takt än vad vi kan hantera. Världen blir mer medveten om åtgärderna men nya innovationer för att hantera och utnyttja avfallet behövs.
Medicinskt avfall saknar en global definition som resulterar i brist på standardisering för hantering av medicinskt avfall. En snabb utveckling av medicinsk vetenskap och teknik har lett till en ökad användning av medicinska engångsartiklar. Engångshandskar är de vanligaste förbrukningsvarorna inom sjukvården och återvinns inte på grund av rädsla för förorening, vilket resulterar i en stor belastning på miljön eftersom materialets värde inte tas vara på.
Syfte
Målet med forskningen har varit att förstå avfallsindustrin och identifiera var avfallsströmmar kan ersättas med cirkulära system genom ny teknik. Utifrån resultaten, utforma och föreslå ny teknik som passar in i en cirkulär ekonomi.
Metod
Designforskningsmetodik (Design Research Methodology) och MSPI:s Innovationsprocess användes som ramar för designprocessen för forskarna under avhandlingsarbetet. Inspiration från företagsbesök, shadowing, intervjuer och litteraturforskning initierade projektet och användes för att klargöra problemet. Prototyper, tester och litteraturforskning användes för att validera designframstegen. Följt av laborationer och mekanisk design av ett komplett cirkulärt system.
Resultat
Genom tester och experiment designades ett cirkulärt system för skyddshandskar avsedda för engångsbruk. Den föreslagna tekniken skulle eliminera behovet av råmaterialutvinning, tillverkning och transport. Systemet är baserat på tillverkning av skyddshandskar från polyvinylalkohol. På grund av materialets unika egenskaper är det möjligt att lösa upp handskarna i vatten, sterilisera dem och åter tillverka dem till nya handskar. Handskarna visade sig ha jämförbara mekaniska egenskaper som de nuvarande alternativen på marknaden. Systemet innehåller många element från tillverkningsprocessen av nitrilgummi- och latexhandskar, men införandet av rengörings- och steriliseringssteg kommer att ifrågasätta den främsta orsaken till att förbrukningsskyddshandskar används i första hand - för att säkerställa sterilitet.
Slutsats
Optimering, automatisering och implementering av detta system kommer att göra sjukvårdsindustrin mer oberoende och mer miljövänlig. Att införa ett system för att återvinna och sterilisera skyddshandskar för engångsbruk, bevisar möjligheten att ersätta linjära livscykler med cirkulära, genom att ifrågasätta orsakerna bakom ohållbart beteende och lösa dessa problem. Förorenat avfall förbränns idag, somliga hävdar att energiåtervinning kan klassificeras som återvinning, men energiåtervinning saknar egenskapen att bevara materialets värde. Detta system har materialvärdet i fokus genom att återanvända det i flera cykler. Liknande arbete kommer att krävas för att hålla jämna steg med den ökade avfallsproduktionen. Cirkulära system kan göra det möjligt för människor att uppfylla sina behov med en avsevärt minskad miljöbelastning. Lösningen behöver ytterligare forskning och måste förbättras före implementering. Men innovationen i ett internt system och ett mer direkt tillvägagångssätt för tillverkning - återvinning - återanvändning har presenterats för att skapa nytt värde för avfall och ny teknisk utveckling för att förbättra avfallshanteringen och återvinningsindustri.
Acknowledgment
A special thanks to Tobias Larsson, our supervisor for the thesis, Christian Johansson Askling, and Ryan Ruvald for providing guidance and support during the whole ME310 Global Design Innovation project. In times of struggle and confusion, they would always take time to give the researchers a nudge in the right direction. We would also like to give thanks to Peter Blaschke and Ulf Pettersson for helping with the manufacturing of the mechanical parts, providing tools, workspaces, and support during the whole research process.
We would also like to thank Jenny Elfsberg, Martin Frank, Bobbie Frank, Julie Wright, and the whole Volvo Group team for providing us with their experience and expertise from the industry. Every time we needed support, they would find time to meet and guide us forward.
We would also like to thank the environmental department of Region Kalmar, for taking the time to meet with us and give feedback on our concept of sustainable systems for the healthcare industry.
T ABLE OF CONTENTS
1. INTRODUCTION ... 1
1.1 BACKGROUND ... 1
The world’s waste ... 1
Medical waste ... 2
Single-use gloves ... 3
Personal Protective Equipment ... 4
Nitrile and vinyl glove manufacturing ... 4
1.2 SUSTAINABLE TECHNOLOGY IN THE HEALTHCARE INDUSTRY ... 5
1.3 RESEARCH QUESTION ... 5
1.4 DELIMITATIONS ... 5
1.5 VOLVO GROUP ... 6
1.6 STANFORD UNIVERSITY ... 6
2 METHOD ... 7
2.1 RESEARCH APPROACH –DESIGN RESEARCH METHODOLOGY ... 7
Research Clarification (RC) ... 9
Descriptive Study Ι (DS-Ι) ... 9
Prescriptive Study (PS) ... 9
Descriptive Study ΙΙ (DS-ΙΙ) ... 10
Detailed stages into an overview process ... 10
2.2 INNOVATION PROCESS ... 11
Initiation ... 11
Inspiration ... 11
Ideation ... 12
Implementation ... 13
Design sprint ... 13
Six thinking hats ... 14
2.3 DATA GATHERING ... 14
Company visits and job shadowing ... 14
Interviews ... 15
2.4 LABORATORY EXPERIMENTS ... 16
2.5 MECHANICAL DESIGN ... 16
2.6 ENERGY CONSUMPTION CALCULATION ... 16
2.7 LITERATURE RESEARCH ... 17
3 THEORY ... 18
3.1 DESIGN THINKING ... 18
3.2 KNOWLEDGE ENABLED ENGINEERING ... 19
3.3 CIRCULAR ECONOMY ... 20
Recycling: Focus on material recovery ... 22
The art of remanufacturing ... 23
3.4 MATERIAL ASPECT:PVA AND HYDROPOL ... 23
Recovering PVA from water ... 23
3.5 THEORY OF DRYING PROCESS WITH HEATED AIR ... 24
4 RELATED WORK ... 26
Recycling WEEE plastics ... 26
Circular material – PET recycling ... 27
5 LABORATORY EXPERIMENTS ... 29
5.1 PVA RECOVERY FROM WATER SOLUTION ... 29
5.2 HUMIDITY TEST ... 30
5.3 STERILIZATION TEST ... 31
5.4 GLOVE MAKING ... 32
Puncture resistance ... 33
Tensile strength ... 34
6.1 NEEDFINDING -COMPANY VISITS AND RESEARCH ... 36
Company visits ... 36
The “ick” factor ... 37
6.2 LABORATORYEXPERIMENTS ... 37
PVA recovery from water solution ... 37
Humidity test... 37
Sterilization test ... 39
Glove making ... 40
Puncture resistance test ... 41
Tensile strength test ... 41
6.3 PROPOSED TECHNOLOGY ... 42
Circular system ... 42
Cleaning and dissolving ... 43
Sterilization ... 46
Glove molding unit ... 46
Drying process ... 50
Full system ... 51
6.4 ENERGY CONSUMPTION ... 52
7 DISCUSSION ... 54
7.1 NEEDFINDING ... 54
7.2 RELIABLE SYSTEMS IN TIMES OF CRISIS ... 55
7.3 LAB EXPERIMENTS ... 55
PVA recovery from water solution ... 56
Humidity test... 56
Sterilization test ... 56
Glove making ... 57
Puncture resistance test ... 57
Tensile strength test ... 57
7.4 PROPOSED TECHNOLOGY ... 58
Cleaning and dissolving ... 58
Glove molding unit ... 58
Drying process ... 59
Sterilization unit ... 59
Alternative sterilization methods ... 59
7.5 FULL SYSTEM ... 60
7.6 SUSTAINABLE TECHNOLOGY IN THE HEALTHCARE INDUSTRY ... 60
7.7 ENERGY CONSUMPTION CALCULATION ... 61
7.8 AGENDA 2030 ... 61
8 CONCLUSION AND FUTURE WORK ... 62
8.1 CONCLUSION ... 62
8.2 FUTURE WORK ... 63
9 REFERENCES ... 64
10 APPENDIX ... 68
List of Figures
Figure 1: Environmental impact at Swedish hospitals [8]. ... 3
Figure 2: Sectioning of single used products at Swedish hospitals [7]. ... 3
Figure 3: Relationship between design research methodology, design research, and design ... 7
Figure 4: A representation of the Design Research Methodology framework. ... 8
Figure 5: Description of the work process of Design Research Methodology. ... 8
Figure 6: Detailed description of Design Research Methodology framework. ... 10
Figure 7: Performance of the Needfinding process. ... 12
Figure 8 - Design Thinking micro-cycles [23]. ... 18
Figure 9 - Double diamond [23]. ... 18
Figure 10 - Knowledge pyramid [36]. ... 19
Figure 11: Circular economy concept [38]. ... 20
Figure 12: Factors that are linked together in a circular economy [40]. ... 22
Figure 13: Dissolving time connection to temperature for hot (left) and warm (right) Hydropol [44]. 23 Figure 14: Visualization of the theoretical drying process. ... 25
Figure 15: Visualization of a dismantling strategy with the option to implement a post-shredder process. ... 26
Figure 16: A overview of a super-cleaning recycling process for PET bottles. ... 28
Figure 17: Processed solution of recycled PVA. ... 29
Figure 18: Testing the effect of a humid environment for PVA. ... 30
Figure 19: Reconstruction of an Autoclave's sterilization process. ... 31
Figure 20: First iteration of creating a glove from recycled PVA. ... 32
Figure 21: Second iteration of creating a glove from recycled PVA. ... 33
Figure 22: Testing the puncture resistance of recycled PVA. ... 34
Figure 23: Tensile strength test setup. ... 35
Figure 24: Early created PVA sheet of recycled PVA. ... 37
Figure 25: Humidity test visual results. ... 38
Figure 26: Data of the variance in temperature. ... 38
Figure 27: Data of the variance in humidity level. ... 39
Figure 28: Result of before and after a sterilization (autoclave) process of recycled PVA. ... 39
Figure 29: Results of glove creation with a 3D-printed hand mold. ... 40
Figure 30: Results of glove creation with a ceramic hand mold. ... 41
Figure 31: Tensile strength test: PVA vs. Nitrile. ... 42
Figure 32: Overview description of the created solution. ... 43
Figure 33: Description of components of the cleaning unit. ... 44
Figure 34: Description of the complete cleaning system. ... 44
Figure 35: Description of included components for the dissolving process. ... 45
Figure 36: Visualization of enabling the dissolving process. ... 45
Figure 37: Presentation of a CAD model of an autoclave [59]. ... 46
Figure 38: Constructed movement possibility for the manufacturing process. ... 47
Figure 39: CAD model of the manufacturing process. ... 48
Figure 40: Physical prototype of the molding unit. ... 49
Figure 41: Enlargement visualization of how the heated air is generated. ... 50
Figure 42: Detailed description of the designed drying process. ... 50
Figure 43: Process diagram of each step in the created circular system. ... 51
Figure 44: Final visualization of the created system in a CAD model. ... 52 Figure 45: The proposed solution to switch to an automated process for the clean and dissolve steps. 58
List of Tables
Table 1: Generated MSW in the USA in 1960 and 2017 ... 1
Table 2: Generated MSW recycled in the USA in 1960 and 2017... 2
Table 3: AEIOU method [23]. ... 15
Table 4: Overview table of the amount of recycled MSW between 1960 - 2017 [2]... 22
Table 5: Different strategies to recover plastic and their categorization of output quality. ... 26
Table 6: Data of recollected PET bottles. ... 27
Table 7: Result of PVA material puncture resistance test. ... 41
Table 8: Parameters to calculate the energy consumption of the autoclave. ... 52
Table 9: Parameters and result of energy consumption calculation of a sterilization process with an autoclave. ... 53
Nomenclature
HMW – How Might We - Questions MSW – Municipal Solid Waste PP – Polypropylene
PVC – Polyvinyl Chloride PE – Polyethylene
PET – Polyethylene terephthalate PPE – Personal Protective Equipment PVA – Polyvinyl Alcohol
Resin – Mixture of two substances (Water + PVA or Water + Hydropol) VFE – Vacuum Flash Evaporation
DRM – Design Research Methodology EXPE – Experience
E – Energy (kJ)
C
p– Specific heat capacity (Jg
-1K
-1) m – Mass
SEK – Swedish krona
1. I NTRODUCTION
1.1 B ACKGROUND T
HE WORLD’
S WASTEWaste is something that has existed since humans started to create and build products. Waste is a topic that has increased in human consciousness during the past decades, and it is beginning to be clear that it is a world size problem.
Waste can be divided into four major categories [1]:
• Municipal solid waste
• Industrial waste
• Agricultural waste
• Hazardous waste
A common word for waste is Municipal Solid Waste (MSW) and includes waste that is used by consumers and then thrown away. In MSW is not every source (table 1) involved, and the ones that are missing from tables are construction and demolition waste, municipal wastewater sludge, and other types of non-hazardous waste generated from similar actors [2]. A study from EPA [2] shows that MSW in the US has increased since 1960. Table 1 presents data of different MSW categories from 1960 and 2017.
Table 1: Generated MSW in the USA in 1960 and 2017
Material Tonnes - 1960 Tonnes - 2017 Difference
Glass 6,720,000 11,380,000 + 4,660,000
Paper & Paperboard 29,990,000 67,010,000 + 37,020,000
Food 12,200,000 40,670,000 + 28,470,000
Metals 10,820,000 25,050,000 + 14,230,000
Misc Inorganic Waste 1,300,000 4,040,000 + 2,740,000
Plastics 390,000 35,370,000 + 34,980,000
Rubber & Leather 1,840,000 9,110,000 + 7,270,000
Textiles 1,760,000 16,890,000 + 15,130,000
Wood 3,030,000 17,990,000 + 14,960,000
Yard Trimmings 20,000,000 35,180,000 + 15,180,000
Other 70,000 5,100,000 + 5,030,000
In correlation to the increase of generated MSW, it is also essential to understand the development of recycling during the same period, to completely understand both sides of the industry. The data show that it was a small percentage of the generated MSW in 1960 that was recycled compared to the recycled MSW in 2017. Table 2 presents data of recycled MSW in the year of 1960 and 2017.
Table 2: Generated MSW recycled in the USA in 1960 and 2017
1960 Tonnes - 1960 Tonnes - 2017 Difference
Glass 100,000 3,030,000 + 2,930,000
Paper & Paperboard 5,080,000 44,170,000 + 39,090,000
Food 0 2,570,000 + 2,570,000
Metals 50,000 8,330,000 + 8,280,000
Misc Inorganic Waste 0 0 0
Plastics 0 2,960,000 + 2,960,000
Rubber & Leather 330,000 1,670,000 + 1,340,000
Textiles 50,000 2,570,000 + 2,520,000
Wood 0 3,000,000 + 3,000,000
Yard Trimmings 0 24,420,000 + 24,420,000
Other 0 1,450,000 + 1,450,000
The data shows that when the generated MSW has increased has also the recycling of MSW increased. Other factors of managing generated MSW has increased in correlation to the increase of MSW. The incineration process where waste is converted to energy recovery has increased drastically between the years 1980 to 1990 and has been steady until 2017.
The study shows that the volume of waste is increasing as well as the amount of recycled material.
The world bank [3] says that the world's waste generation rates are rising and that due to rapid population growth and urbanization. The expected increase of generated waste intends to increase by 70% in 2050.
M
EDICAL WASTEThe term “medical waste” is defined by the United States Medical Waste Tracking act of 1988 as
“waste that is generated in the diagnosis, treatment or immunization of human beings or animals, in research pertaining thereto, or in the production or testing of biologicals.” The problem is that there is no global definition of medical waste, which also results in a lack of standardization for medical waste stream management [4].
The progress in medical science and technology and health services has developed rapidly during the last couple of years. It has led to increased use of medical consumables. New materials and solutions for consumable medical equipment are continuously developed [5]. Medical waste management is a very complex and tricky challenge that the world is facing due to the increased demand for medical services and the world population growth. Medical waste that is mishandled poses a high risk of infection or injury for any workers in contact with it, according to the World Health Organization (WHO). It may also cause harm to the public through the spread of microorganisms from medical facilities [4].
The USA is the largest creator of medical waste in the world with the production of 3,5 million tonnes of waste each year; the consequence of this production comes with a price of $790/tonne of waste [4]. Therefore, circular systems for medical waste management is of high relevance.
Single-use products are one of the biggest environmental threats in hospitals according to data collected by Swedish hospitals. These products are responsible for 49,5 % of the environmental impact in the hospital industry [6] (figure 1). Eight hundred thirteen million single-use products are consumed annually in the healthcare industry in Sweden. From these single-used products, almost everything is burned with some exceptions where products are recycled. The most common materials used are PP, PVC, and PE [7].
Figure 1: Environmental impact at Swedish hospitals [8].
S
INGLE-
USE GLOVESGloves are the most consumed single-use item in healthcare settings. They equal to 44 % of the total number of produced products according to the buying history of six regional hospitals in Sweden (figure 2). Three hundred fifty-eight million gloves are consumed in Sweden each year, which equals 2100 tonnes. [8].
Figure 2: Sectioning of single used products at Swedish hospitals [7].
The most common materials for single-use gloves are nitrile rubber, latex, and vinyl. Today, the recommended choice is nitrile rubber [7]. The selection of gloves is also affected by the desired properties and possible allergies. Latex gloves have beneficial properties, they are comfortable, soft, provides a good fit and proper protection, but people have latex allergies and are advised to use other types of gloves. The most common latex-free alternatives are nitrile, neoprene, and polyisoprene. These gloves lack the elasticity that the latex gloves provide, and the lower tensile strength results in gloves tearing up more frequently [9]. A risk assessment can be used to choose the correct glove for the task.
The evaluation will usually explore the following factors [10]:
• Nature of the task
• Type of contamination
• Sterility requirements
• Allergies
These factors will affect the decision in which the best gloves are for the task and situation.
P
ERSONALP
ROTECTIVEE
QUIPMENTPersonal Protective Equipment is used in many businesses for different reasons. The primary purpose behind the medical PPE is to prevent the spread of infections between patients and to protect the healthcare workers from being infected.
Any healthcare employer is forced by law to provide the appropriate PPE for their workers; also, the healthcare worker is legally required to wear it appropriately according to the specific rules for their job [11].
N
ITRILE AND VINYL GLOVE MANUFACTURINGThe manufactured process of single-used gloves is dependent on the purpose of using the gloves Medical gloves usually have a similar manufacturing process, regardless if they are nitrile, vinyl, or latex gloves. Nitrile rubber is a copolymer, which is a substance created by the bonding of molecules.
This process is called copolymerization. Vinyl gloves are made of sole polyvinyl chloride (PVC), which makes it a polymer. When manufacturing vinyl gloves, a plasticizer must be added to make the glove flexible. PVC is cheap compared to latex and is a better option when the consumption of gloves is high [12].
The simplified process runs as follows [12], [13]:
1. Usually, a ceramic hand mold is used because of a suitable surface. The glove mold gets cleaned by running through water and bleach. This step is to remove particles that got stuck or any residue from the previous round of manufacturing. The gloves are very thin and therefore sensitive to even the smallest particle
2. The mold is dipped in a tank filled with the desired material, in this case, either PVC or nitrile rubber.
3. Heat the material to a high temperature to form the glove and expose it to dry air to rapidly dry the solution on the ceramic mold to create a glove.
4. Surface treatment of the glove. For nitrile gloves, the glove surface will either be treated by exposure to chlorine to make the material harder and slicker or a polymer coating to lubricate the surface.
5. The gloves get stripped from the mold. This can be different depending on the gloves. Some gloves can be removed by a puff of air; others require human interaction.
6. Laundry and drying, the gloves are cleaned in a washing machine and then dried with dry air.
7. The gloves process through the testing stage according to ATSM standards and FDA regulations. It includes testing for holes by either using air or water. A leaking medical glove will expose the healthcare worker and the patient for the risk of infection.
8. Packaging - usually packed in thin cardboard boxes and shipped in packs of 100+ pairs, but this step depends on the manufacturer.
1.2 S USTAINABLE TECHNOLOGY IN THE HEALTHCARE INDUSTRY
This is a pilot project and has not been scaled and tested in an industrial setting. This system is more than a machine as it is intended to prove a statement; that waste streams can be eliminated and replaced with circular systems. Circular systems like this solution eliminate transportation and reduce material waste, resulting in a significantly reduced environmental impact. Three hundred fifty-eight million single-use gloves are consumed each year at Swedish hospitals, if this number can be cut in half, by recycling the gloves, using this thesis’s proposed technology it will result in a reduction of 1050 tonnes of plastic consumed each year in the Swedish healthcare industry. This data excludes the reduced need for transportation.
Most single-use gloves used in Sweden are manufactured in Malaysia, which is a long trip by itself, but the system will also eliminate the need for waste transportation and hazardous waste management [7].
1.3 R ESEARCH QUESTION
- How can waste streams in the healthcare industry be replaced with circular systems by the application of new technology?
- How can this technology be designed to fit a circular economy?
1.4 D ELIMITATIONS
The suggested solution for an in-house recycling and manufacturing system is in the first iteration phase. The idea is built of a vision of the next step of a waste and recycling industry. The researchers chose to focus on the most critical subsystems due to the time limit. Proving the function of the essential subsystems will inevitably show that the full system has a good chance of working.
This thesis is focused on the technological aspect of a circular system. The material used to manufacture products in the designed system is developed during recent years and requires knowledge in chemistry to research appropriately. The researchers had limited knowledge about chemistry and plastic structure before this thesis. To proceed with the suggested solution, it requires further investigation in the material and its part of a system with a combination of recycling and manufacturing.
This thesis is focused on the manufacturing and recycling on medical protection gloves. The system is formed and inspired by a glove manufacturing process, which implies it is limited to making gloves.
Still, the same principles of the remanufacturing process can be adapted into other products as well.
This thesis presents a fully circular system on a theoretical basis and involves some testing and basis of the manufacturing design. The focus has been on constructing the manufacturing process, and the other subsystems have theoretically described and designed in a CAD software.
The current solution is aiming towards the healthcare industry, but protective gloves are being used widely in many industries, but they must be tested for those purposes to be allowed.
The presented idea of a circular system is designed through an innovative process to change how we use a traditional manufacturing model today, to a more circular economy model. The presented solution is therefore designed through a first take of the solution to eliminate waste streams. The research in this thesis orients towards the technological aspect of the system and not the economical. The economic analyses are only conceptual. The thesis does not include a Life-Cycle Analysis comparison between the current glove manufacturing industry and the proposed technology.
1.5 V OLVO G ROUP
The project work and research were done in collaboration with Volvo Group. Volvo Group is a company focused on transport solutions, offering trucks, buses, construction equipment, and power solutions for marine and industrial applications. They are committed to shaping the future with sustainable transport and infrastructure solutions. Volvo has a vision that the future of waste and recycling will be safe, optimized, and sustainable during the whole life cycle. They believe that waste is a valuable resource with many unknown application opportunities. Volvo’s zero vision strives for a future with zero accidents, zero-emission, and zero unplanned downtime, and much higher productivity in the waste and recycling business [14].
1.6 S TANFORD U NIVERSITY
The research and product development process were carried out in conjunction with the ME310 Design Innovations at Stanford University. ME310 is a project course available for first-year master’s students in mechanical engineering. In the course, two groups of students collaborated and together to solve a problem. The collaboration was between one group of students from Stanford University and another group from a global partner, in this case, Blekinge Institute of Technology. The two groups converged on one solution and presented it during Stanford Design EXPE 2020. The task for this year was to solve a problem within the waste industry and create a technical solution to bring value within the sector [15].
2 M ETHOD
The following section describes how the research and project development process was carried out.
The Design Research Methodology was used for the research work, and the project work is described as an “Innovation process” in section 2.2, this includes the work that was carried out before the final concept was chosen, to iterate and explore different problem areas within the prompt. Data gathering and interviews are described as methods to gather quantitative and qualitative data during the project work. The laboratory experiments, mechanical design, and energy consumption calculations were used to examine and design the final solution. Finally, everything was tied together using literature to confirm the validity of the research work.
2.1 R ESEARCH APPROACH – D ESIGN R ESEARCH
M ETHODOLOGY
The foundation of this thesis is product-development and design. Design Research Methodology is used as a structure for the work process throughout the thesis work [16]. The DRM is focusing on supporting research in design, methods, and guidelines. Design can be divided into three parts with different approaches to design. The relationship between these areas is presented in figure 3
Figure 3: Relationship between design research methodology, design research, and design.
Design Research Methodology framework consists of four stages that are presented in figure 4.
The structure consists of Research Clarification (RC), Descriptive Study Ι (DS-Ι), Prescriptive Study (PS) and Descriptive Study ΙΙ (DS-ΙΙ). Each stage has an input of necessary means and outcomes. The correlation between the stages implies that each stage is not accomplished only one time; instead, it represents iterative work progress. The DRM in figure 4 shows that the starting point can be any of the four stages. It also means that it is not necessary to work through every stage. For example, in an individual project can be preferable to go through only one or two of the stages. Research shows that attempts to follow the DRM linearly and in “order” will develop a result with lower quality in comparison to a project that strives for a goal-oriented, but flexible approach [16]. The method of the DRM framework is shown in figure 5. The outcome is that the work has followed the framework
“linearly” but reverted to earlier stages when it has been necessary to examine other problems and solutions.
Figure 4: A representation of the Design Research Methodology framework.
Figure 5: Description of the work process of Design Research Methodology.
R
ESEARCHC
LARIFICATION(RC)
The research clarification (RC) is a stage where the researcher focusses on formulating a research goal. The process is to find evidence or indications that can support the assumptions and set the desired research goal. The process consists mainly of searching in literature for two factors. The search is for factors that influence task clarification and product success. From the work of finding relevant material in the literature, descriptions of the existing situation and desired situation is developed to state the assumptions clearly for each classification. To improve the intended clarification, the researcher may formulate some criteria that can provide as measures to be meet the outcome of the research. It can be used to support task clarification [16].
At the beginning of the project, only a brief description of the whole project area was presented from Volvo. A summarized description of the project is presented in section 1.4. The description is used as a starting point for the project. Currently, the focus area was too broad and almost covering every part of the waste management industry. The first important decision of the project was to select a focus area within waste management. The focus area for this thesis should align with the ME310 project goals.
The researchers decided to focus on technology development and how technology can change the waste industry towards more sustainable production. The approach to validate the focus area and pursue a research goal, the RC stage clarifies the first step is to find support within the literature that can describe the situation and validate the meaning of the research area.
D
ESCRIPTIVES
TUDYΙ (DS-Ι)
Initiating DS-1 implies that the researcher has stated a clear goal and focus area and has reviewed the literature to discover more influencing factors to evolve an initial description of the situation. The purpose of deciding a goal and focus is to make the description detailed enough and select which factors the researcher should proceed to investigate to make the task as clear as possible. The research shows that an inadequate problem definition in task-clarification is related to a significant amount of time spent on modifications in stages that follow after this stage [16].
The descriptive study Ι is entered after the RC stage. At this point, the research has mainly consisted of literature studies to clarify the research question. The literature study has shown the overview rise of generated waste and new technology to meet the needs to recycle the world's generated waste. The study provided a good understanding of how technology can apply to waste management. Still, it has not created enough understanding of which problems that mediates that an innovative solution can be used to improve the industry. To expand the knowledge and exploring the factors that can improve the research question and as well choose a problem statement for the ME310 project, the researchers conducted company visits to explore the waste management industry.
P
RESCRIPTIVES
TUDY(PS)
In the prescriptive study is the focus on increasing the understanding of the existing situation to elaborate and correct the initial description of the desired situation. The story should represent the vision of how one or more factors can be addressed in the present case to proceed to a realization of the desired situation [16].
At the prescriptive study, knowledge has been collected through literature research and company visits. These findings are set parallel to the initial problem statement and evaluated to rephrase the initial problem statement into a problem statement for the collected data and knowledge of existing problems within the industry. The focus is to elaborate on the findings and against the initial description of the research area and elaborate on the research area if it needs to changes.
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ESCRIPTIVES
TUDYΙΙ (DS-ΙΙ)
The final presented stage is the descriptive study ΙΙ where the effect of the support is explored. An example from the research is that an empiric study can increase the understanding of the intended support [16].
The researchers can improve their knowledge and discover impacts that did not enlighten before the DS-ΙΙ stage. It is done through iterations of prototyping and evaluations from the testing [17].
At this point, a problem statement is established from the findings in literature studies and company visits. The problem statement is used as the focus area to build and test prototypes. The execution of building and testing activities complement to evaluate the result and test if it meets the needs of the problem statement. It also discovers impacts that were not thought about before entering this stage and increase the knowledge of applying technology into waste management. The DS-ΙΙ is used as an iterative process within prototyping and testing sessions. A gateway to either proceed or revert to the DS-Ι stage.
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ETAILED STAGES INTO AN OVERVIEW PROCESSThe Different stages presented in figure 4 are explanations of the stages in DRM. Each stage shown in figure 4 presents in detail from section 2.1.1 – 2.1.4. As mentioned earlier in the text, it is not mandatory to include every stage, and in the same way, it is not compulsory to spend an equal amount of time on each planned stage. The abnormalities from linear work progress depend on the case of the research project and time restrictions.
The detailed figure 6 presents three different studies. A review-based study relies on a literature study. The comprehensive study includes the literature research, and the result is presented by the researcher in the form of empiric study, develop support to bring out the result or evaluate the support.
The last study is an initial study that closes the project. This study includes the previous stages and shows the outcome of the result to be prepared to be used for others [16].
The work process included all four stages, and the desired outcome of the research is that others can use the result. This desired outcome and description of each stage imply that work process 5 (figure 6) is suitable for this thesis, and it also unites with the usage of RC, DS-Ι, PS, and DS-ΙΙ.
Figure 6: Detailed description of Design Research Methodology framework.
2.2 I NNOVATION PROCESS
The progress of a product development process can often be intangible; thus, it is crucial to have a structured innovation process to follow and always document the design rationale. The researchers used Design Research Methology for the research. The MSPI Innovation Process was utilized for the project work together with the ME310 team, a process based on the Design Thinking framework (see 3.1). The process is divided into four main blocks: Initiation, Inspiration, Ideation, and Implementation. These blocks are broken down further into subprocesses. It is essential to understand that an innovation process is concurrent, nonlinear, and iterative. It is possible to perform multiple tasks simultaneously, go back and forth, or loop the stages when needed [17], [18].
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NITIATIONThe Initiation phase is the first stage of the project process. Setting up the team for an effective product development process. The Initiation is divided into three sub-blocks: Framing, Teaming, and Planning. These blocks performed during the first weeks after the ME310 virtual kick-off.
Framing
The first part of the Initiation phase is framing the problem and stating an end goal. The researchers set an end goal of what the desired outcome would be. The group used “How Might We”- questions to frame the problems correctly. “HMW” questions can put the researchers into a problem-solving state of mind, by allowing the problems to be open and the solutions to be independent [17].
Teaming
Another critical stage of the Initiation phase is to plan the collaboration and get to know your team members. It was done in two parts, since two authors are conducting research together, resulting in this thesis, but are a part of a bigger team of nine students, five from Blekinge Institute of Technology and four from Stanford University. The researchers signed one contract between each other and filled in a teaming canvas with the whole project team to make sure everyone in the group was on the same page and to reduce the risk of any future conflicts. It included the division of roles by expertise, setting goals, defining purposes, and values within the teams [18].
Planning
The next stage of the phase is planning the work. The researchers scheduled the year carefully to make sure the research and the project work can run smoothly. The planning was done in collaboration with the whole project team to make sure that the time was used efficiently. Essential goals and milestones were set to get an idea of how to conduct the research. The plan should be agile and include short iteration cycles, daily coordination sessions, and should be revised often [18].
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NSPIRATIONNeedfinding
The Needfinding process is a stage that was ongoing during the whole project. Needfinding is to study people’s needs, qualitative research that can be done in many forms. The goal was to define unmet needs that should build a foundation for the problem you are trying to solve. Conducting Needfinding research requires awareness, preparation, and curiosity. The researchers used interviews, observations, and company tours for the Needfinding process. In the end, it’s crucial to translate the collected data into needs correctly; this allows for reframing and iterations [18].
Through this thesis and combined with the ME310 project, the research consisted of literature research, company/industry visits, interviews, and email conversations. Under the headline method and in the section of Research approach – Design Research Methodology explains the design process with a combination of the different steps in DRM and our performance of those steps. Figure 7 presents a detailed process of the Needfinding and our performance of the Needfinding process.
Figure 7: Performance of the Needfinding process.
Trendwatching
Trendwatching was used early on in the research. It is a reality check for the current market and societal trends in the world. It is a way of benchmarking the current state to predict where the future is heading [18]. It was done in the form of research on the internet.
Techwatching
Techwatching was crucial when working with applied technology in the waste business. Instead of analyzing the social and market trends, Techwatching is a way of benchmarking arising technology in the world. It can and should be done both inside and outside the research subject to get a broader perspective and allow for innovative applications of new technology [18].
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DEATIONThe ideation stage was performed in many ways to embody creativity through the whole research process. It is where the double diamond strategy comes in, to use convergent and divergent mindsets to maintain the correct focus during the process. When faced with a significant, complicated problem, it encourages you to explore many areas and apply different solutions. This stage was emphasized many times during the project.
Brainstorming
During the brainstorming sessions, it is crucial to have a divergent mindset early on. It means expanding the possibilities rather than narrowing them. To let everyone in the team contribute with ideas, regardless of how radical they may seem at the time. The researchers made sure to focus on the number of ideas rather than quality. Open brainstorming can be useful, but using methods and tools to generate a large number of ideas can be helpful to prevent it from being solely a discussion [18].
Convergence
The continuation after the idea generation is to enter the convergent mindset, to evaluate the generated ideas. To make sure that the ideas are feasible, desirable, and viable enough to continue exploring. Here is another stage where tools, such as the Six Thinking Hats, can be used to get a better perspective of which ideas should be explored further and to highlight some key questions to be answered in the prototyping stage [18].
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MPLEMENTATION PretotypingThe researchers used pretotyping to answer the most straightforward questions asked in the convergence phase. Pretotypes are rapid prototypes that require between a few minutes to a few hours to build. They are built to make sure that you are building the right thing rather than building it right.
Technical questions answered in the prototyping phase, where more time was put in to answer more complicated questions [18].
Prototyping
To answer more technical questions, the researchers built more advanced prototypes, provided the prototype indicated that the idea was worth exploring. The prototypes were designed in Autodesk Inventor and then developed with an appropriate manufacturing method. Often 3D-printing for rapid prototyping as it provides high precision and short lead times. For more durable prototypes, wood and metal were the primary materials.
Test
Testing is the last step of the implementation process; testing includes the actual text of the prototype and the evaluation. Evaluation and reflection after testing are crucial to speeding up the learning about the problem. The tests were always carried out with an experiment question, visual documentation, data collection, and reflection.
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ESIGN SPRINTA design sprint is a method for product design to increase your chances of fulfilling people’s needs drastically. The researchers used this method in collaboration with the project team to move the product development forward. The technique requires intense work by a small group, isolating a problem, and solving it in a few days. The framework takes practical and theoretical scientific elements to combine with a compressed design process and wrapping them with an agile philosophy. The process represents a short timeframe (usually 1-4 weeks) where the team is focused on accomplishing a specific goal. This process is meant to be flexible and allows the team to adapt the steps to fit their own specific goals, and it tends to be effective in most projects [19].
The design sprint process is divided into five different phases. These steps can be iterated as many times as necessary [19].
1. Understand and review background and user insights. This step is supposed to bring the team to a greater understanding of the problem and make sure that every member is on the same page with it. This step if further broken down into setting goals, conducting research, interviews, mapping, discussions and creating personas.
2. Divergent thinking, brainstorming new solutions. Once the team has an initial understanding of the problem, it is time to enter the solution space. It can include various brainstorming techniques, depending on the goals and preferences of the team. The goal is to generate as many ideas as possible without criticizing them too early.
3. Convergent thinking, to rate the solutions generated and converging on one. Once the team has generated enough ideas, it is time to narrow them down. The converging phase includes difficult decisions that may originate from debates within the team as well as idea selection tools. Here, the Six Thinking Hats may be applied to help you ask the right questions about the solution.
4. Prototype. Once you have converged on what to build, it is time to create a minimum viable prototype to demonstrate a solution to the problem. The building phase should take as little time and effort as possible, but enough to provide some detail in the upcoming tests. The team should use the prototype to break assumptions made in previous steps.
5. Test the solution. The last stage of the sprint is to test the solution, either on users, to test a function. Usually, the best way to get rapid feedback is to evaluate the solution to users. Testing the prototype might bring unexpected reactions, which is what you want. This stage is not only to answer the questions asked by the team but also to highlight new questions that might originate from tests or the customers themselves.
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IX THINKING HATSWhen evaluating concepts and problem statements, there is a powerful tool that project teams can use called the Six Thinking Hats. The tool is meant to enable critical thinking for the designers. This method was used in collaboration with the project team to evaluate the concepts. It includes asking the right questions about the concept, finding relevant information, and unveiling assumptions. The fundamental purpose of the method is to raise awareness of multiple points of view by looking at the solution or problem space with different mindsets. [20]
There are six different colors of the hats: White, Yellow, Black, Red, Green, and Blue, each color represents a separate way of thinking with different logical and philosophical approaches of problem- solving [20].
- The White Hat is the facts hat. The wearer of this hat is supposed to state facts, what you know, and do not know what information is needed. The wearer is supposed to ask questions like: What do we know? What information do we need?
- The Yellow Hat is the optimistic hat. It is a symbol of optimism, positivity, and possibility.
The wearer should ask questions like: what are the benefits of this solution? What are the positive impacts? What opportunities do we have?
- The Black Hat is the skepticism hat. The wearer is expected to identify problems and difficulties with the solution. Questions like: what are the downsides? What might go wrong?
What are the negative impacts of the solution?
- The Red Hat is the feelings hat. It represents emotion and intuition; this hat can seem a bit more philosophical compared to the other hats. Questions asked by the wearer could be: What do we like about this, and why? What do we dislike, and why? This hat emphasizes the gut feeling about the solution.
- The Green Hat is the creativity hat. This hat is supposed to find solutions to the skepticism from the black hat, to improve the concept with new ideas, by thinking outside the box. Possible questions to ask could be: What alternatives are yet to be considered? Are there any creative possibilities?
- The Blue Hat is the process hat. The wearer is supposed to manage the whole process. To make sure that the method is carried out correctly. Questions for this hat could be: Are we following the process correctly? What obstacles do we have during the procedure? Learnings?
The creator of the method encourages teams to use this method to think about what a solution “can be,” instead of only what “it is.” It enables exploration of the limitations and possibilities with a solution.
[20]
2.3 D ATA GATHERING
An essential part of a successful Needfinding process is to understand the industry in which the problem is applied and understand the needs of the consumers [21]. The problem statement from Volvo was intentionally broad; they wanted the researchers to give them a nudge in the direction in which new unexplored value could be found. The focus area of the research was technology in waste management and recycling, which implied multiple areas to explore.
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OMPANY VISITS AND JOB SHADOWINGTo get an understanding of the latest technology used in the industry, the researchers went on field trips to many different companies. The industrial processes were observed and analyzed in conjunction with interviews with both managers and workers. The researchers got the opportunity to ride along with garbage trucks to gain insight into how a regular day looks for the workers in the industry. This process is called “job shadowing,” which refers to a youth joining an employee for a workday or more, doing their regular daily working routine [22]. This process is used to get a more in-depth insight into the user behavior, which in the case of the garbage truck rides, was the driver and his companion. The qualitative data collected when using this method can be translated into creating a user persona. The AEIOU method (Activities, Environment, Interaction, Objects, User), was used to lay a base foundation of the desired
environment, which also results in a more accurate persona [23]. The prepared questions for each shadowing occasion were based on the questions in table 3. Specific questions were adjusted according to the company’s business.
Table 3: AEIOU method [23].
Activities What happens?
What are the people doing?
What is their task?
What activities do they carry out?
What happens before and after?
Environment What does the environment look like?
What is the nature and function of the space?
Interaction How do the systems interact with one another?
Are there any interfaces?
How do the users interact with one another?
What constitutes the operation?
Objects What objects and devices are used?
Who uses the objects and in which environment?
User Who are the users?
What role do the users play?
Who influences them?
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NTERVIEWSInterviews and meetings were another essential part of the data collection. Both structured and unstructured interviews were used on several occasions. An unstructured interview is a conversation about one or a few topics but without specific questions. The idea behind the method is to gather data around the topic without setting any constraints on what the participants can express. The structured interviews are the opposite method; it’s an interview with prepared questions. This technique was used when consulting experts within a specific area [24]. The prepared questions aimed to encourage storytelling at the meeting. The scientific reason behind trying both techniques was mostly experimental, to understand which kind of interview gathered the best results in different situations and with different people. There was always some preparation before each visit. The researchers made sure to gather an understanding of what the company was doing, who will be attending the meeting, and which background they had. Based on this information, the decision could inform about which technique was most appropriate.
2.4 L ABORATORY EXPERIMENTS
To be able to optimize the parameters of the glove and find out the feasibility of all stages of the system, countless lab experiments had to be carried out. The research took place during the COVID-19 pandemic, which resulted in a temporary closure of universities in Sweden [25]. In turn, most lab experiments were performed in a kitchen environment using the available lab equipment. The tests in this research could be performed in a kitchen with safety measures. It is, however, essential to consider that there might be more errors in the data collection.
The experiments were performed in many iterations to optimize each result. The most critical iterations are covered in the result.
2.5 M ECHANICAL DESIGN
The mechanical design of the system was done in iterations together with the whole project group.
The parts were designed in Autodesk Inventor and divided between the members of the group. The researchers of this report were both involved in the mechanical design. The parts were initially designed to fit the purpose and then exchanged with standardized parts available and predesigned for building custom made CNC machines. The parts are designed for machines using linear movement with high precision. 3D-printing was used frequently to physically test the prototypes before putting in time and resources to manufacture them in more suitable materials.
2.6 E NERGY CONSUMPTION CALCULATION
The energy consumption for the system can be calculated by collecting numbers for each stage of the process and adding them together. To find out how many gloves are consumed per day in one facility, the researchers were in contact with Kalmar Regional Hospital.
Autoclave
To calculate the energy consumption for an autoclave process, the first thing to do is to calculate the energy consumption for heating the PVA-water solution to the right temperature.
Energy consumption can be calculated using (1).
𝐸 = 𝐶𝑝∗ 𝛿𝑡 ∗ 𝑚 (1)
The heat capacity for the PVA solution can be calculated by using the rule of mixture [26], described in (2).
𝐶𝑝𝑡𝑜𝑡= (𝑚 𝑚1
𝑚𝑖𝑥𝑡𝑢𝑟𝑒) 𝐶𝑝1+ (𝑚 𝑚2
𝑚𝑖𝑥𝑡𝑢𝑟𝑒) 𝐶𝑝2 (2)
2.7 L ITERATURE R ESEARCH
The focus area of applied technology into waste management has a broad impact area. Waste management consists of different sections, for example, waste collection, waste sorting, material recovery, and recycling. New technology can be applied to all these types of areas to increase efficiency, control, and establish closed-loop recycling.
The recycling process has a starting point at people’s homes, industries, or companies. Today, it is common that a garbage bin has multiple compartments to ease up the waste sorting process [27]. This approach increases the availability to sort, but it does not establish control over incorrect sorting. An approach to increase the awareness and control of what is thrown away is connected to the smart city concept [28]. One method to raise awareness is to collect data about what types of waste have been placed in the garbage bin. The proposed technology is RFID, small readers that collect data from tags inside the waste product [29]. Together with multiple compartments and data collection, it is possible to increase recycling efficiency and especially the effectiveness of sorting waste.
As mentioned at the beginning of this section that it is common to have multiple compartments in a garbage bin today. Another standard option used today is that all waste is thrown in one compartment and then sorted out by the waste management company.
The ascent of AI has opened new possibilities to improve recycling. Multiple actors are developing robots that use AI to sort waste. MIT [30] has developed a robot that uses touch-based sensors to identify what material it is and if there are electronics within the product. They believe that touch is a better measurement than sight, but it has its disadvantages compared to other sensor measurements. The robot needs to touch each product to detect what it is, and it is not an optimal option for an industrial scale.
Other measurement sensors that increase productivity are visual systems to identify different products, and it is planned to be installed to complement the touch sense.
AI technology could change the way we today sort waste and make it possible to recover material that is not recoverable today. Ferrovial and EIT Climate-KIC are partnering with ZenRobotics to implement AI and robotics into municipal solid waste plants. Countries in Europe are encountering a change in laws where a new regulation forces the European countries to recycle a minimum of 55% of municipal waste [31]. This new regulation change how we today look at recycling and how new technologies can create a reality where regulations and our needs are met.
Each of the above subjects is contributing to higher controlled and accurate recycling and waste management. The first section is for collecting the waste, how it can be monitored and controlled. The second section is a technology that enables a better accuracy of separating different waste materials.
These technologies are improving the collection and sorting of waste. Collecting and sorting are some of the first steps of recycling, and the end goal is to reuse the collected material and change model from the traditional linear life cycle to a close loop.
Today’s material recovery is often recognized with urban mining. A company that has developed technologies to recover valuable metals such as gold, silver, palladium platinum, with others. is Umicore [32]. Umicore has developed a technology that enables material recovery without releasing toxic pollution [33]. The company’s technology and business model allows the material to remain in a closed loop. The technology and business model can shift the need for raw material and instead utilize the material that is above the ground. The direction can have a positive effect on the environment and in an economic aspect.
The literature research presents innovative solutions that might change how we today manage waste. The purpose of presenting these areas is because it is an inspiration source of new technologies within waste management and innovations to enhance the industry. This thesis intends to introduce a similar new technology as the ones mentioned above and, therefore, improve the readers’ understanding of this thesis.
3 T HEORY
The following chapter will describe the theory used in the research work. In the beginning, an explanation of the design thinking framework will be presented, as it is utilized in the innovation process (see section 2.2). It will be followed by the thought process of the researchers and the theory behind circularity and the materials used.
3.1 D ESIGN THINKING
When conducting the research, the Design Thinking framework was used. MSPI:s Innovation Process is based on the Design Thinking framework. Design Thinking encourages the researcher to create a deep understanding of the user affected by the problem you are trying to solve. It is called Human-Centered-Design. The working process is divided into many smaller iterations, called micro- cycles (figure 7). It means that the researcher must be willing to reiterate or take a step back in the process when needed. When focusing the micro-cycle on the user, it will help the researcher to create a deeper understanding of the problem [23].
Figure 8 - Design Thinking micro-cycles [23].
The double diamond strategy was used to keep the correct mindset when doing every iteration. To expand your perspective, you should define if you are in a divergent phase, which means generating ideas or convergent phase, where you try to limit yourself to the ideas you have and try to improve and explore them further. This process takes the shape of a double diamond (figure 9) [23].
Figure 9 - Double diamond [23].
This way of thinking can be an important part of a successful product development process as it makes sure that the developers are focused on the right things at the right time, and it keeps the perspective broad [23].
