LCA Rebirth:: custom fit // dissolvable thread jeans by unspun & resortecs pollutes 50% less than average denim
Textile overproduction, unsold inventories and difficulties of disassembly renders sorting and recycling complicated, imposing polluting disposable options such as landfill and incineration. Producing Eco-sensible garments demands innovation technologies to tackle the issues that are facing textile industry at each step of the manufacturing process. Unspun produces garments on demand utilizing 3D printing technology and to ensure sustainability, the product must be recyclable. Rebirth is an unspun digital fit jeans produced with Resortecs soluble sewing thread that aims to close the sustainability loop of circular fashion. The objective of this white paper is to conduct a comparative Life Cycle Assessment (LCA) between a rebirth pair of jeans and a benchmark jeans. The LCA will quantify the magnitude of the environmental impact (as kg equivalence of CO2 emission per item) of producing one pair of jeans under both rebirth and classical textile production approaches.
What is LCA?
The Life Cycle Assessment stems from the increasing need to protect the environment and evaluate the impact of a product on the ecosystem and human health. Consequently, International Standard Organization (ISO) described the principle and the framework to conduct LCA. LCA studies the environmental aspects and potential impacts throughout a product’s life, i.e cradle-to-grave (Figure 1), from raw material acquisition through production, use, until disposal (ISO 14040)[1].
Figure1: garment life cycle stages covered by the LCA.
Why we need LCA ?
LCA is an environmental management tool that provides a better understanding of the product’s impact at each stage of its life cycle. The increasing consumer awareness and the right to take informed choice necessitates to know what is behind the product they buy, what is the pattern of the supply chain and what is the fate after usage. The LCA reveals the unanticipated consequences of the approaches green industry is claiming by testing the actual environmental impact via overarching evaluation of product’s life phases including transportation. Deep diving into the manufacturing processes in a factual manner based on scientific methodology will verify the ecological credentials of the product by allowing numbers to speak for itself. Consequently, the LCA outcome provides the required knowledge to have well informed decisions for consumers, management policies, production strategies and further highlights opportunities to improve process and implement potential tradeoffs [2].
LCA verifies the ecological credentials of the product by allowing numbers to speak for itself.
Jeans Life Cycle Assessment
ISO 14040 framework is followed to conduct this LCA. Direct applications of LCA relies on several parameters that should be identified and well characterized to allow appropriate data collection, inventory analysis and interpretation.
Figure 2: Flow chart of jeans life cycle for data collection during assessment.
LCA goal: the objective of this LCA is to provide a comparative analysis of the environmental impact of a jeans produced using two different manufacturing approaches (benchmark jeans vs. rebirth jeans).
Functional unit: Since the goal of the LCA is for comparative purposes therefore the products should use the same definition of the functional unit[3]. The functional unit of this LCA is the mass of one pair of jeans = 500 g.
LCA scope: The LCA covers the CO2 emission (equivalence of Kg of CO2 /item) during raw material acquisition (cotton, nylon, polyester, and Brass) , raw material processing (cotton spinning, weaving, yarn dying, zipper/button molding), garment manufacturing (sewing, washing, drying and finishing), marketing as finished product, disposal (either incineration, landfill or recycling) along with all the stages of transportation routes between the different points of the life cycle. This LCA excludes the product use as the environmental impact of the usage is considered equivalent for both products.
Data collection: The life cycle inventory is crucial for the accuracy of the LCA. Data availability, updated inventory, detailed and comprehensive processes will provide better resolution of the outcome. Conducting LCA is limited by data availability and complexity of the environmental system, therefore all the assumptions and choices taken throughout the project should be reported to ensure that the final result of the LCA remains within the appropriate context (Curran, 2008)[4]. Ecoinvent database (2012) was used as life cycle inventory to calculate the CO2 emissions from the different stages of jeans life cycle.
Modelling
After data collection for each step of the jeans life cycle for both rebirth jeans and benchmark jeans, excel software was used to calculate the environmental flows of the input and output of the jeans life cycle model. The data input for this LCA was based on the required raw material to produce 500 g of pair of jeans and the required energy associated for each processes. While the output of the activities is translated by quantitative amount of equivalent Kg of CO2 emissions per jeans as depicted in Figure 2.
Unspun disclosed their production/manufacturing processes to Resorteces, while available assumption were used for the benchmark pair of jeans[5].
Inventory analysis
Raw Material acquisition of both products are represented in Figure 3. Rebirth Jeans utilize BCI cotton (Better cotton initiative), by which recent assessment showed that BCI cotton’s primary energy demand is 2510 MJ compared to conventional cotton system of 5375 MJ (Shah et al., 2018[6]). Additionally, rebirth uses recycled polyester for the zipper. Sourcing the raw material to manufacture a product requires transportation of the material from the different countries as shown in Figure 3.
Once the raw material is obtained, further processing is required, and based on the particularities of the processes, the different steps takes place in different countries (Figure 4). Raw material processing and production is different for rebirth in comparison to the classical processes utilized by the benchmark jeans. Namely, rebirth relies on 3D method were cutoffs are reduced, and the objective in the near future is to have zero cutoffs (as considered for the assumptions of this LCA) and adopt eco plating technology for the buttons [7].
figure 3: raw material acquisition flow chart.
figure 4: material processing flow chart.
Garment sewing, washing, drying and finishing is taking place in Dongguan China for rebirth jeans while for the benchmark jeans it is assumed to be in Tunisia.
It was assumed that there is 15% of every jeans’ total mass is wasted as cut-off during the classical benchmark production methods by which the fate of the cutoffs is incineration. Unspun is targeting zero cutoffs thanks to it’s on-demand 3D weaving process – currently in development.
Hong Kong was considered as the final market for both the rebirth and benchmark jeans after the finishing stage of each manufactured product.
For disposal, different scenarios were applied to have comparative analysis for this particular step of the product’s life cycle. The fate of the benchmark jeans can be either incineration or landfill (Figure 1), which is considered to take place in mainland China. While for rebirth jeans, since disassembly of the jeans is feasible due to Resortecs sewing thread, the jeans will be shipped to Belgium to be disassembled using Resortecs heat disassembly methodology. This heat disassembly approach permits to keep the integrity of the different textiles and conserve their qualities that will allow further recycling or even upcycling. The dissembled textile will be shipped to the Netherlands for material sorting.[8] There are two scenarios of recycling after material sorting, either mechanical recycling (Netherlands) or chemical recycling (Sweden) [9]. The recycling process will allow the recovery of the raw material which in turn will be utilized for 60% as an input for rebirth jeans LCA.
Regardless the disposal fate of the benchmark jeans (i.e. landfill or incineration), or the recycling method of the rebirth jeans (mechanical or chemical), emissions of CO2 of one benchmark jeans is 2 folds higher compared to one rebirth jeans.
Data interpretation
Each pair of jeans manufactured using classical processes releases more than 28 Kg of CO2 into the atmosphere. Both Table 1 and 2 show that the manufacturing of the material in both cases is the most polluting step of a jeans lifecycle almost 50% of the total CO2 emission. Further, the disposal of the unsold inventory (estimated to be 20% of the benchmark jeans inventory) represents ~16% of the total emission/item (Table 1).
On the other hand, CO2 emissions from landfill disposal of 1 benchmark jeans is slightly higher (28.61 kg/jeans) than incineration of the same jeans (28.35 kg/jeans) see Table 1.
Table 1: LCA comparing the mechanical to chemical recycling of rebirth jeans. 
Table 2: LCA comparing the incineration to landfill disposal of benchmark jeans. 
Producing one pair of jeans following rebirth manufacturing, releases ~13 kg of CO2 to the atmosphere compared to 28kg of CO2 emitted during classical benchmark jeans production. The CO2 emissions from mechanical recycling of rebirth (13.09 kg CO2/jeans) is compareable to the chemical recycling (13.37 kg CO2/jeans) table 2.
Regardless the disposal fate of the benchmark jeans (i.e. incineration or landfill), or the recycling method of the rebirth jeans (i.e. mechanical or chemical), the emissions of CO2 of one benchmark jenas is 2 folds higher compared to rebirth jeans.
figure 5: comparision chart.
conclusion
The LCA of production and end-of-life of rebirth custom-fit dissolvable thread jeans in comparison to benchmark jeans showed reduction of CO2 emissions at the different life cycle stages of the product. Overall CO2 reduction is estimated to be reduced by 53% including 25% reduction in transportation. 58% reduction of raw material and 99% reduction of waste generation.
figure 6: summary final results.
About the author
Rawaa Ammar joined Resortecs® on March 2019 as the sustainability manager. Rawaa holds a Ph.D in Earth and Environmental Sciences from University of Brussels (ULB, Belgium).
She has more than 9 years of experience in scientific research, field work and environmental risk assessment. Her research was focused on anthropogenic pollution, remediation, heavy metals impurities, Fe biogeochemistry in ocean and the link to atmospheric CO2 emissions.
Rawaa is a visiting professor at the Lebanese University (Beirut). Here are the contact details of Rawaa if you like to discuss further the LCA
TEL: +32 (0) 488 41 07 48
@: rawaa@resortecs.com
Sources:
[1]International Standard Organization (2006) Environmental Management -LCA- Principles and Framework. ISO 144040 Geneva.
[2] United Nations Environment Programme (2004), Why Take a Life Cycle Approach? New York: UNEP(ISBN 92-807-24500-9).
[3] European Environment Agency, Environmental Issue Series no.6. Life Cycle Assessment (LCA). A guide to approaches, experiences and information sources 2016.
[4] M. A. Curran Life-Cycle Assessment. Human Ecology, pages: 2168-2174, 2008
[5] Brut Nature France (https://www.youtube.com/watch?v=U9xoi7RSOwo )
[6] P. Shah, A. Bansal, R. K. Singh, Life Cycle Assessment of organic, BCI, and conventional cotton: A comparative study of cotton cultivation practices in India. Designing Sustainable Technologies, Products and Policies, pages: 67-77 2018.
[7] http://www.dorlet.fr/en/index.html
[8] https://smartfibersorting.com/
[9] https://renewcell.com/
