Life Cycle of Synthetic Leather and Raw Materials:
In the production of synthetic leather, the raw materials acquired from the earth are heavily processed to make polyvinyl chloride or polyurethane and excess chemicals during processing are recycled. While currently manufacturers are feeding excess chemicals back into the life cycle to produce more synthetic leather, it doesn’t seem efficient. Product durability seems to be a good solution for waste management by inhibiting the speed of the product life cycle with better raw materials (Blackburn, 2009). However, lowering the product consumption is the best solution. Instead of creating more product life cycles with recycled material, it would be ideal to have a lower demand for the product and thus a lower amount of extracted resources, used energy, and harmful emissions. If people didn’t have a constant demand for newer, more stylish synthetic leather products there would be less resources we must tap into in order to make polyvinyl chloride or polyurethane for synthetic leather.
Polyvinyl Chloride (PVC) Raw Materials and Production:
Polyvinyl Chloride, or PVC, is a type of plastic coating used on fabric to make synthetic leather. PVC is a thermoplastic polymer based on chlorinated hydrocarbons (Baitz, 2004). Polyvinyl chloride requires additives to prolong its life cycle because it is a brittle material in its pure form and susceptible to deterioration under light and heat (Baitz, 2004). Additives include plasticisers, stabilisers, and fillers. For flexible PVC used in synthetic leather, the weight proportions are 53% PVC polymer, 40% plasticiser, 1% stabiliser, 5% filler, and 1% other (Baitz, 2004). PVC can be reduced to its most basic raw materials ethylene and chlorine. These primary materials go through a thermal decomposition that results in ethylene dichloride (EDC) and is then converted to Vinyl Chloride (VCM). Polymerisation takes place creating polyvinyl chloride which is then compounded with additives and processed for the final product.
Ethylene is produced when petroleum is refined to naphtha, cracked with steam power, and then chemically reacted to form ethylene (Baitz, 2004). Petroleum occupies 43% of the polymer weight (Baitz, 2004). Chlorine is taken from rock salt through an electrolytic process that results in chlorine, sodium, and hydrogen (Baitz, 2004). These resulting elements must be kept separately or else they will produce undesirable by products (Baitz, 2004). Rock salt contributes 57% of the polymer weight (Baitz, 2004). When ethylene and chlorine are combined, they chemically react to form ethylene dichloride or EDC (Baitz, 2004). EDC is then subjected to heat and cracking which forms a vinyl chloride monomer and hydrochloric acid (Baitz, 2004). Hydrochloric acid is recycled back into the process by reacting with ethylene to make EDC again (Baitz, 2004). Alternatively, EDC can be produced from the natural gas liquids ethane, butane, and propane (Baitz, 2004). EDC acts as a solvent during an oxychlorination reaction with ethylene, hydrogen chloride, and oxygen that is catalyzed by copper chloride under high pressure and heat (Baitz, 2004). The resulting EDC is cleansed with water and caustic soda which is later evaporated to remove contaminants (Baitz, 2004). EDC is converted to VCM through pyrolysis, a decomposing process initiated with high temperatures (Baitz, 2004). Chlorinated and non chlorinated by products are recycled by combing with the un reacted EDC which yields HCI (Baitz, 2004). The resulting HCI is re used in the oxychlorination process (Baitz, 2004). The by products of this process are less than 2.5% of the final product’s mass (Baitz, 2004).
PVC polymerisation is the process that gives the coating its transparent and glossy qualities. Polymerisation requires light, a liquid monomer, and heat or small amounts of initiators (Baitz, 2004). There are a couple types of polymerisation, but I am going to assume that the most common type, suspension polymerisation, applies to the production of synthetic leather. During suspension polymerisation an impellor agitator is used to distribute a monomer throughout water (Baitz, 2004). This results in large particles that can absorb an ample amount of plasticiser (Baitz, 2004). Plasticisers are typically made from carboxlyic acid and an alcohol (Baitz, 2004). They separate polymer chains, increasing their movement and the elasticity of the product (Baitz, 2004). Plasticisers used in flexible PVC for synthetic leather make up 40% of the product and can reach up to 60% in other “soft products” (Baitz, 2004). After the addition of the plasticiser, the polymer is separated from the water using centripetal force generated by a centrifuge (Baitz, 2004). The centrifuge spins the polymer until the denser material falls towards the middle and the lighter material, or in this case the water moves to the outside. The water is also evaporated with hot air. The VCM is rationed out to a reactor with a suspension stabiliser, a pH buffer, an anti foam agent, and an initiator like organic peroxides (Baitz, 2004). The stabiliser is a significant additive because it protects the final product from damaging heat or UV light. It also protects from thermal degradation and hydrogen chloride evolution during processing (Baitz, 2004). When the VCM reaction is 80% to 90% complete, an inhibitor is added to stop the polymerisation (Baitz, 2004). The suspension is then filtered of the unconverted VCM with water that is later sent to a treatment plant to be stripped (Baitz, 2004). The suspension is processed into dry PVC powder using the same centrifuge and evaporation techniques as earlier (Baitz, 2004). At some point in production, pigments are added to color the final product. One of the most widely used pigments is titanium dioxide because it serves as a base for many colors (Baitz, 2004). Chloride and sulphate processes are used to obtain titanium dioxide from limonite (Baitz, 2004). Titanium dioxide has toxicity potential, requires high energy consumption, and yields chemical waste (Baitz, 2004). Pigments may also have a connection to lead in products because lead makes bright colors last longer (Young, 2012).
After polymerisation takes place, some form of heat is required to bind the PVC particles together and incorporate the additives (Baitz, 2004). The material is then cooled, and left to recrystallize to form a structure process called gelation or fusion (Baitz, 2004).
Polyvinyl Chloride and recycling/waste management:
Industry professionals are trying to increase the amount of recycled PVC entering new life cycles by recycling the raw materials. Only the raw materials that require extraction, intermediate production, and polymerisation substitutes recycled material back into a new life cycle (Baitz, 2004). My first finding was that used hydrochloric acid is recycled to form more EDC in the beginning stages of PVC production (Baitz, 2004). Also, any unreacted EDC and by products are put back into the beginning of a new process (Baitz, 2004). Environmental impacts of EDC and VCM production are fairly low (Baitz, 2004). In the destruction of dioxin containing solid waste, the by product HCI can be re used in PVC production or re-fined to a new commercial product (Baitz, 2004). Moving further along the PVC production process, VCM poses the highest environmental impact. This is because VCM is heavily involved in PVC production and is made up of ethylene which requires intensive energy for production (Baitz, 2004). When VCM is filtered out during the polymerisation process, VCM can be recovered from gas flows using a condenser (Baitz, 2004). When producers are ready to start a new batch of PVC, they rinse the reactor with water to remove any residue from the previous process. With intensive degassing processes throughout polymerisation, they can reduce the amount of wasted residual monomer (Baitz, 2004). This idea of “closed loop recycling”, or putting the by products or unreacted material back into a new life cycle could lower environmental impacts (Baitz, 2004). This recycling process is efficient as long as the amount of recycled material is below its demand (Baitz, 2004). On the other hand, problems are predicted with the continuing enhancement of stabilisers used in PVC manufacturing. New and improved stabiliser systems may not be compatible with the older stabilisers that remain in the recycled material; however, this is not currently a problem as we have not reached this transition in technology (Baitz, 2004). It is hypothesized that recycled material with an outer layer of the enhanced material could fix this possible compatibility issue in the future (Baitz, 2004).
Polyurethane Raw Materials and Production:
Another form of plastic coating attached to a fabric base for synthetic leather is called polyurethane. Polyurethane is composed of isocyanates, polyester polyols, and additives. The isocyanates are methylene diphenyl diisocyanate (MDI) and toluene diisocyanates (TDI) (Lee, 2002). In 2000, 4.4 million tons of MDI and TDI were produced (Lee, 2002). Polyols react with isocyanates and produce polyurethane polymers powered by hydroxyl groups (Lee, 2002). In 2000, there were 850,000 tons of polyester polyols produced with a growing demand of 4-5% per year (Lee, 2002). Polyol blends include additives like catalysts, fire retardents, blowing agents, coloring agents, and fillers.
MDI isocyanate is derived from benzene (Lee, 2002). Concentrated nitric and sulphuric acids and benzene are blended to yield nitrobenzene (Lee, 2002). Nitrobenzene is hydrogenated to aniline by dissolving iron in hydrochloric acid with nitrobenzene (Lee, 2002). The aniline is purified, then reacted with formaldehyde to generate a polyamine mixture called methylene dianiline (MDA) (Lee, 2002). Excess aniline is removed and recycled. The amine groups in MDA must be phosgenated to convert to isocyanates (Lee, 2002). A phosgene molecule reacts with the amine group and emits hydrogen chloride gas that must be boiled off and used as a raw material for other processes (Lee, 2002). Isocyanates are the worlds largest suppliers of hydrogen chloride gas (Lee, 2002). The excess phosgene and solvent are removed and recycled (Lee, 2002). The crude diisocyanate stream and residue is divided into pure MDI and a mixed isomer stream (Lee, 2002).
Toluene is converted into the isocyanate TDI and is processed much like MDI. Toluene is nitrated into dinitrotoluene which produces an isomer mix (Lee, 2002). The isomers are hydrogenated to crude toluene diamine (TDA) (Lee, 2002). TDA is purified by distillation to remove mixed isomers that are disproportional, meaning they have the wrong level of hydrolysable chlorine and acids that would influence rates of chemical reactions (Lee, 2002). Purified TDA is phosgenated similarly to the process in MDI, and excess phosgene is recycled. The isocyanate mixture is distilled to generate a liquid TDI product and a residue (Lee, 2002).
Polyester polyol raw materials include dibasic acids like adipic acid and AGS mixed acids, glycols like ethylene glycol, propylene glycol, 1,4-butane diol, and 1,6-hexane diol, and branching agents like glycerol and pentaerythritol (Lee, 2002). The closer together the ratio of glycols to adipic acid in a polyol results in an extended polymerisation that is desireable for flexible foams (Lee, 2002). I am assuming flexible or elastomer foams are used in synthetic leather due to its more flexible qualities as a plastic. Triols such as glycerol or trimethylolpropane increase functionality of a polyester polyol, which leads to branching of the polyester backbone (Lee, 2002). In the production of polyester polyols, the raw materials are first heated under pressure. Water is distilled off, which wastes some acid groups and slows the rate of polymerisation (Lee, 2002). Azeotropic distillation can be applied to decrease this loss by using a vacumm and or adding nitrogen to improve the polymerisation reaction (Lee, 2002). Pigment additives can be organic or inorganic. Inorganic pigments include titanium dioxide, chromium oxide, carbon black, and iron oxide (Lee, 2002). Fillers are added to they polyol blend to reduce cost, increase stiffness, and increase temperature stability. Glass fibre is most commonly used, although carbon fibre is becoming more popular as its price is dropping (Lee, 2002). Stabilisers are added to prevent microbial attack by enzymatic hydrolysis (Lee, 2002). They are usually composed of metal organics relating to antimony, copper, or arsenic (Lee, 2002). A blend of stabilisers are used for UV resistance. Benzophenone, benzotriazoles, and amines all work as UV absorbers (Lee, 2002). Fire retardants like solid melamine, graphite or aluminium trihydrate and other low viscosity liquid compounds are added to polyols (Lee, 2002). It is typical for fire retardants to contain bromine, chlorine, or phosphorous (Lee, 2002).
Polyurethane Recycling/waste management:
The nitration of benzene to make MDI is a high yield reaction that leaves 10% of the materials weight to be recycled (Lee, 2002). The nitric sulphuric acids mixed with benzene yield water, a process called hydrogenation. The mixture is left to naturally separate and 20% of the benzene will remain unreacted (Lee, 2002). Once the water is distilled it is stripped of the remaining benzene for recycling (Lee, 2002). The nitration process works the same for TDI so the isomer mix and sulphuric acid can be recycled using the same techniques. Also, sulphuric acid can be recycled and excess reaction heat can be recovered as steam (Lee, 2002). In production of both isocyanates, excess phosgene the most important chemical for conversion, is recycled. Renewable materials like sucrose and starch have been used in beginning stages of production of polyurethane (Lee, 2002). Un wanted polyester based polyurethane is recycled using transesterification, a process that shortens the chain extender and breaks down the polyol blend so the material can be re used (Lee, 2002). Using recycled ground flexible foam as a filler mixed into the polyol stream is another way to re use raw materials (Lee, 2002).
Overview of Synthetic leather Production:
To conclude the extensive list of raw materials used and the complex processing, the U.S patent for synthetic leather production gives us an idea of how the raw materials in polyvinyl chloride and polyurethane will serve the final product. The processed raw materials form a polymeric sheet that is fused with a fabric base and all the layers are foamed (Fine, 1982). The initial polymeric layer is attached to an embossed release paper that is heated to a tacky state (Fine, 1982). The fabric base is then added along with another polymeric layer, and soon after that a foam layer (Fine, 1982). The foam layer should have a thin urethane coat that is mechanically embossed to simulate a leather like surface (Fine, 1982).
Baitz, Martin, Dr., Johannes KreiBig, and Eloise Byrne. "Life Cycle Assessment of PVC and of Principal Competing Materials." European Commission, July 2004. Web. 20 Feb. 2013. <http://ec.europa.eu/enterprise/sectors/chemicals/files/sustdev/pvc-final_report_lca_en.pdf>.
Blackburn, R.S., ed. Sustainable Textiles. N.p.: Woodhead, 2009. Print.
Fine, Jerome, and Gene N. Harrington. Production of Synthetic Leather. Cleveland Plastics of Tennessee, Inc., assignee. Patent 4,349,597. 14 Sept. 1982. Print.
Lee, Steve. The Polyurethanes Book. Ed. David Randall. N.p.: Huntsman International LLC, 2002. Print.
Young, Maggie. "CEH Still Finding Lead in Women's Handbags and Wallets." Generation Green. The Center for Environmental Health, 21 June 2012. Web. 11 Mar. 2013. <http://generationgreen.org/2012/06/ceh-still-finding-lead-womens-handbags-wallets/>.
March 13, 2013
Wastes, emissions of Synthetic Leather, and the recycling of wastes.
Synthetic leather has become very popular in the textile industry as well as for furniture, and electronic accessories. It can easily be said that the rise in synthetic leather has been due to its more economical price. Having a substitute for leather enables the textile industry to reach out to more consumers. The purpose of this paper is to report the wastes and emissions of raw materials used in synthetic leather, wastes and emissions during the products life cycle as well as at its end life. Prior to my research I considered synthetic leather to be more eco friendly because it does not involve the killing of an animal. Also I have knowledge that there are certain chemicals used for the curing of hides and skins. I did not exactly know these chemicals but I presumed they were of some toxicity to the environment. In my research I compiled the materials used in the production of synthetic leather as well as the effects of those raw materials in the environment and their waste and emissions. In my overall findings I came to the conclusion that synthetic leather was not as eco friendly as I thought it to be.
The raw materials used in the production of synthetic leather according the United States Patent:
PVC is a type of thermoplastic polymer and it is the dominant component in the production of synthetic leather. The PVC is in the transport sector where leather falls under. I have researched the life cycle of PVC, and have come to the conclusion that at its end life it emits more wastes than I thought it would have. For a product to be eco-environmental friendly it must at least have these four characteristics:
According to my research in PVC synthetic leather is not an eco-environmental friendly product. Firstly synthetic leather is easily flammable as seen in the study done by the Journal of Industrial Textiles, the polyurethane coated knitted nylon fabric was completely burnt out when in a flammability test. Real leathers “were only scorched whilst the synthetics either burnt out or were partly melted.”
Now going back to PVC itself, the raw materials that consist in PVC are:
Ethylene alone has its own waste and its emissions are ethylene and propylene to air, while methanol and propane/butane to water.
Recycling of products can be done in a variety of ways for example, reusing the EVC used in the synthetic leather, or using the energy exerted from recycling the material. Not a great deal of post consumer waste of PVC may be recycled after its use, so unfortunately after a shoe, bag, or accessory reaches it’s end life not much can be taken from the product and in fact it brings toxins in the process of eliminating that product. The journal I researched provided the information about pre-consumer waste, and post consumer waste. Pre-consumer waste was easily recyclable because it could be “collected separately in defined quantities, and hence has a recycling rate in practice.” While post-consumer waste was landfilled with 15% being incinerated.
Wastes during production are not very high due to processing of PVC being very simple. This explains why most recycled material from PVC comes from pre-consumer waste. While in the products use PVC actually release plasticizer to the water and ambient air resulting in higher wastes levels that pollute the environment. Finally, in the PVC’s end life incinerations of PVC are both good and bad. It is good because it reduces waste masses, but it can generate “hazardous waste that have to be disposed accordingly and relatively energy demanding flue gas treatment processes.” As shown in the PVC waste flow chart, PVC waste is collected and separated into mechanical recycling. Chemical recycling, wastes incineration, and disposal. (Picture: Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004)).
While doing the research for this paper I was presented with a number of obstacles. There were not many articles available for the wastes and emissions of synthetic leather, so I decided to research synthetic leather itself and go deeper by finding the wastes of raw materials of synthetic leather. I also found a lot more information on the life cycle of raw materials of synthetic leather, than synthetic leather itself.
1 Jerome Fine, "United State Patent," Production of Synthetic Leather (1982), February 20, 2013.
2 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).
3 bench3, "Characteristics of Eco Friendly Gadgets- How to say a Product is Environment Friendly." Last modified January 19, 2012. Accessed March 12, 2013. http://www.bench3.org/tech/characteristics-of-eco-friendly-gadgets-how-to-say-a-product-is-environment-friendly/.
4 Lacey, P.D.A. "The Flammability and Heat Resistance of Natural and Synthetic Leathers." Journal of Industrial Textiles. .
5 Lacey, P.D.A. "The Flammability and Heat Resistance of Natural and Synthetic Leathers." Journal of Industrial Textiles. Pg. 189.
6 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004). Pg. 50.
7 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).pg. 51
8 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).pg. 80
9 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).Pg. 80.
10 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).Pg. 92.
11 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).Pg. 92.
12 Baitz, Martin, and Eloise Byrne. "Life Cycle Assessment of PVC and of principal competing materials." (2004).Pg. 96.
40A, Winter 2013
10, March 2013
Synthetic Leather: The Real Cost of Fake Leather (Wastes and Emissions)
The goal for this research paper is to develop an understanding of how raw materials are chemically altered into synthetic leather, along with the economic, environmental, and human costs associated with this process. The entire life cycle process of synthetic leather, from the gathering of raw materials to the delivery of finished products to retailers, is broken down into separate categories. Critical environmental issues, such as air pollution, and resource issues, such as electricity expenditure, are explored during each step in the manufacturing process. I found this approach beneficial, as it allowed me to develop not only an understanding of the mechanics of the process, but also an appreciation for the true impact of the process. As a designer, I need to be better informed and more knowledgeable about the materials I choose to create with. This aspect of design is often minimized, as manufacturers must balance environmental responsibility with profit margins and global competiveness. As a consumer, I need to make informed purchasing decisions, and perhaps be willing to pay a higher price for more sustainable products. This method of fully evaluating the process of creating a product, such as synthetic leather, is a must for designers who wish to create products that are environmentally sustainable.
Synthetic leather has hundreds of uses, and is widely utilized in the fashion, furniture, and accessories markets. When visiting a retailer, consumers are faced with an endless variety of products made of synthetic leather, from purses and watchbands to coaches and car seats. Many manufacturers choose synthetic leather over natural leather, as it has a lower manufacturing cost. In addition, synthetic leather can be manipulated into a variety of different textures and molds, unlike genuine leather.
While synthetic leather may be a cheap and convenient alternative to natural leather, there are a number of drawbacks. Concerns related to the synthetic leather market first came to my attention when I began studying the problems related to the manufacture of counterfeit goods, such as handbags and couture goods. These counterfeit goods are made from synthetic materials. When addressing the problem of counterfeit goods, manufacturers and government agencies typically focus on the negative economic effects (e.g. loss of income and tax revenue) and the potential for funneling profits from the sale of counterfeit goods to criminal activity and even terrorism. While these are critical issues, far less attention is given to the environmental impact of the materials, like synthetic leather, used to produce these goods.
Many consumers would likely be shocked and dismayed to learn that the synthetic leather products they buy from malls and chain stores test positive for high levels of chemicals known to cause illnesses and to be toxic to the human body. I first became aware of this danger in Design 40A and 127A classes this semester, and decided to explore this issue in more depth. My research began online with searches on basic materials that are found in synthetic leather, which gave me keywords to search for in journals, articles and books that mention stages of the synthetic leather process. I found the most beneficial information from patents that can be easily accessed through Google Scholar, which provide an explanation of the machinery and energy need to produce this synthetic material. I also utilized online sources to learn how the goods manufactured overseas are shipped to U.S. ports and then trucked to retailers. My online research was supplemented with textbooks available in the university’s libraries.
The first step in the synthetic leather manufacturing process is the gathering of all of the required raw materials, including a variety of chemicals.(As outlined by Alison) I researched several sources to find lists detailing the materials used to construct synthetic leather. The raw materials I found to be most commonly used are Diotctyl Phthalate, Dihexyl Phthalate, Acetone, Sunthene 410, Pliovac Resin M70, Calcium Carbonate, Plasticized Pigments, DOP, VS103, DMF, Mek, Blowing Ration Mixture, and Viscosity. When I first evaluated the list, I did not recognize any of these chemical compounds. I then proceeded to look them up, and learned that they are often known by other names and are found in many products. Many have links to formaldehyde, PVC, and chlorine. Multiple studies have found that these chemicals pose a risk to the health of both factory workers and consumers. The chemicals used during the manufacturing process have been shown to cause severe liver damage, reproductive problems, birth defects, and several types of cancers in humans. This also has been observed in animals. From previous research on chemicals found in nail salons, I know acetone is very absorbent and drying. Liver damage is a factor when an individual is over exposed to this chemical. Other reported chemicals that have been linked to these health problems are dimethylformamide (DMF) and dioxins released from plastics or PVC during the heating phases of manufacturing. DMF is a chemical that is used in the industrial market for reactions. It is a solvent that is an unstable compound and is commonly used as a coating for textiles. It is linked to formaldehyde, which is connected in the name. The other major toxin commonly reported on is dioxin. Dioxins are released when chlorine is introduced to heat. The release of dioxin is associated with air pollution. Dioxin takes time to break down in the environment and the human body, sometimes years. According to Panagiotis Deriziotis’s thesis from Columbia University, being exposed to high levels of dioxin is linked to health problems, and as mentioned in his conclusion, the dioxins can linger in our atmosphere for years. Deriziotis also notes that polyvinyl chloride (PVC) can release this dioxin. Dioxin was also one of the main chemicals linked to mutations seen in the following generation of children, born to those that came in contact with Agent Orange during the Vietnam War.
The process of producing synthetic leather is well documented in United States patents. Synthetic leather started being produced in the U.S. in the early 1900’s. Synthetic leather is now used in virtually all areas of the manufacturing industry to produce goods, and is mass-produced in countries like China and India. China is the king of producing consumer goods, with India in second place. The textile industry uses these countries due to the cheap cost of labor and the volume that can be mass-produced in a quick amount of time. Through my research into the factory machines that produce synthetic leather, I found several websites that sell the machines and give an overview of how the process is supposed to run in order to produce commercial grade synthetic leather. The machines are also well explained in patents filed with the United States Patent and Trademark Office, in which inventors provide detailed outlines of their machines and interpretations of their own version of layers and slight process and chemical changes that they use to manufacture synthetic leather. The outline I found most helpful, and used as a reference when looking up chemicals and different machine parts, is Jerome Fine and Gene Harrington’s Patent number 4,349,597. I attached a copy of their drawings to the poster and to the end of this paper for reference. The overall process laid out in Patent 4.349,597 is described as employing around 109 people operating and overseeing the production. Synthetic Leather appears to be formed from around five layers in order to achieve its leather like texture. This Process is done using heat, machines, human labor, dyes and molds. As a whole just to produce a ream of synthetic leather a factory has to perform in summarized version 6 initial steps before a material resembling leather is formed.
After gathering and combining the required raw materials, the next step in the process, according to the above referenced patent documents, is the heating and curing of the synthetic leather products using industrial infrared ovens and microwaves, at temperatures ranging from 110 c to 250 c. I conducted online research of the manufacturers of industrial ovens, and learned that they are available in two styles, Cylindrical and Planar. Both offer two power levels, 2,450 megahertz, which gives off around 30 kilowatts of energy, and 915 megahertz, which is three times more powerful at 100 kilowatts. The website of one manufacturer, Industrial Molding Supplies (IMS) notes that these methods of heating are most commonly used due to the even distribution of energy. According to the site’s FAQ’s page, these machines have a life span of 6,000-8,000 hours of time in operation, which amounts to 250 days. I was unable to calculate the amount of energy a factory would consume from an outside source when running one of these ovens, as I lacked both data on factory specifications as well as the requisite math skills. However, I did review a thesis on this topic from the University of Texas at Austin, written by Nicholas P. Vasilakos and Jimmy L. Humphrey. The thesis begins with an abstract explanation, then transitions into a more in-depth analysis on heating polymers with microwaves and gives many types of mathematical formulas to calculate these. I learned a great deal from this paper about how the machines run on fossil fuel (oil) or natural gas, due to the high cost of electricity, which can be as much as five times the cost.
Dyes are a completely separate process when it comes to producing synthetic leather. Adding color to the material in the form of dyes demonstrated in patents EP0567975, require a process just as time consuming and labor intensive as producing the synthetic material. This process used embodied energy involving heat, chemicals, machinery, labor, and water. Overall I found this the most difficult to research and comprehend, do to the various ways to dye and cure synthetic fabrics as well as the chemistry involved in mixing dyes and then curing the material.
The next step in the process is the transfer of the product to the marketplace. About 90% of manufactured goods are shipped from the factory to their destination using container ships. After arriving at the port, they are dispersed around the nation by semi-trucks. The fossil fuel used to power these semi-trucks leaves a huge carbon footprint. There are multiple tools available online that can be used to calculate a product’s carbon footprint. The resource I found especially helpful is Green Business Matters “How to Manually Perform a Basic Carbon Footprint Analysis.” You start by looking at how many pounds you need to move from point A to point B, and then you add miles divided by the miles per gallon. Next you factor in the CO2e (carbon dioxide equivalent) for the fuel (their site has a chart with several types of fuel in pounds and kilograms). Once you have the weight in total carbon you can divide CO2e by the amount of products and come up with a solution of the amount of output per item. In the article’s example, there were 17,000 items, moving 2,000 miles by truck and that came to around .62 pounds per item. Two thousand miles by semi-truck is the equivalent of driving from California to Mississippi. The journey of the container ship from China or India to the United States must also be factored in. Boat fuel releases large quantities of nitrous oxide, and at a much higher rate then rail transportation, which according to the chart included in the article, is the least polluting option. Air transportation uses the highest amount of fuel needed to transport items. The equation to calculate the carbon footprint of a manufactured item is simple, and can easily be applied to any type of consumer product or good.
Lastly, the human cost of manufacturing synthetic leather must also be factored in. The embodied energy of the workers is an important factor that counts for a good size portion of what keeps this industry able to turn out large volumes of product. This embodied energy involves workers who move the products, produce the synthetic material, distribute the finished product, and then staff the store that stocks and sells the product. The typical overseas factory employs anywhere from one hundred to several hundred workers, with the size of the labor force dependent on the volume of product being produced and amount of machinery available. It is, of course, much cheaper to produce manufactured goods in the developing world, as they have weak or non-existent health and safety standards and virtually no protections for workers. It is very challenging to obtain information about the true human costs of manufacturing goods in the developing world, as many U.S. companies make a concerted effort to conceal the conditions in their factories from the American public.
Throughout this research process, I have learned to make better use of search tools and resources available to me online and in the library. I learned a great deal about how many things it takes to create what appears to be a simple wallet or wristwatch strap. I feel that this process was worthwhile, in that it opened my eyes to raw materials, how we acquire these materials, the potential dangers associated with using chemicals to create synthetic substances, and the inefficiency of shipping these products across the world. It is also worth noting that this enormous expenditure of resources is for the creation of non-durable goods, most with a useful life expectancy of only a few years. These products expose workers and consumers to potentially toxic chemicals, and leave an enormous carbon footprint across the globe. These hard truths have begun to reshape my thoughts and actions of how I will design and create in the future. I now understand my grandmother’s dissatisfaction with the cheap, disposable and potentially hazardous products of today. I also treasure the antique items I have collected, as they have a lasting quality that I strive to mimic in the future. As a designer, I hope to be able to better research the projects that I am associated with, and to make sure the environmental and human costs of the project are considered at the design stage. As the next generation of designers, we are in a unique position to help ensure that the products of tomorrow are safe and non-toxic, and that they are created in a way that does not harm the workers who produce them or the environment.
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