Imitation leather

There are several types of alternatives to genuine leather. The more popular materials, including thermoplastic polyurethane (TPU), polyurethane laminate (PUL) and polyvinyl chloride (PVC), are often used for jackets, handbags, shoes and upholstery, and were developed as inexpensive alternatives to leather. These materials are man-made synthetic products.[1]

Benefits and potential impacts

	DESCRIPTIONS	BENEFITS	IMPACTS
Thermoplastic polyurethane (TPU)	Heat bonding lamination process where no solvents are necessary. Two types of TPU are common: polyester based and polyether based.	• Can be waterproof and weigh less than genuine leather. • Can be constantly reused, which is why it’s often used for disposable diapers. • Could be considered “animal friendly” since it is not derived from the hide of a cow. • These products have the visual aesthetics of genuine leather, but at substantially less cost.	• Less durable than genuine leather. • The base material used to form polyurethane compounds is a by-product of the oil refining process. • Almost all commercial grade polyurethanes available are based on two different isocyanates: TDI (toluene diisocyanate) and MDI (methylene bisdiphenyl diisocyanate). • TDI is considered a volatile organic compound (VOC) and has acute and chronic effects on humans.[2] • Not biodegradable. • Not recyclable.
Polyurethane laminate (PUL)	A polyurethane coating is laminated onto fabrics such as polyester or cotton, and uses solvents in a chemical bonding process.	• Durable, waterproof, flexible. • Can be constantly reused. • These products have the visual aesthetics of genuine leather, but at substantially less cost. • Could be considered “animal friendly” since it is not derived from the hide of a cow.	Impacts are the same as TPU above.
Polyvinyl chloride (PVC)		• Polyvinyl chloride (PVC) is a versatile plastic that can take on a variety of characteristics—rigid, filmy, flexible and leathery—with relatively limitless applications. • Could be considered “animal friendly” since it is not derived from the hide of a cow. • These products have the visual aesthetics of genuine leather, but at substantially less cost.	• Less durable than genuine leather. • Dioxin (the most potent carcinogen known), ethylene dichloride and vinyl chloride are emitted during the production of PVC and can cause acute and chronic health problems, including cancer, endocrine disruption, and reproductive and immune system damage.[2,3] • Chemical stabilizers are necessary in the creation of PVC, including lead, cadmium and organotins. Phthalates are used to soften PVC. Certain phthalates have been banned in the European Union, such as DEHP, BBP and DBP, and are known to cause acute and chronic health problems, and are possible carcinogens.[4,5] • During use, dioxins and phthalates can leach, flake or outgas from PVC over time, again emitting dioxin and heavy metals into the air, water and land. • Fibre is less breathable than polyurethane. • Not biodegradable.

Other substitutes to genuine leather

Pu split leather

Pu split leather, also known as “pu split,” comes from the same hide as 100% genuine leather. The hide is prepared and tanned. Since the hide is too thick to use on its own, it is split into layers: the top layer is of the highest quality, and is considered pure leather. The lower layer, called “split,” is also considered 100% genuine leather and looks like suede. For the processing of pu split leather, the tanner applies a thin layer of polyurethane (pu) with foil or extrusion that hardens on top. A hair cell pattern can be embossed on the pu layer so that it looks like genuine leather. Pu coated split leather is not considered 100% leather.

Bonded leather

Bonded leather also comes from the same hide as 100% genuine leather. The hide is prepared and tanned. Small pieces of leather that are cut away from the final usable piece are combined with composite materials and spread out in sheets. Foil is put on top to resemble the top layer of leather. Bonded leather is to 100% genuine leather as particle board is to wood. Bonded leather is not considered 100% leather.

Optimize sustainability benefits

• Promote suppliers who use alternatives to PVC.

• Promote suppliers who use water-based solvents for Polyurethane laminate (PUL).

• Investigate “vegan leathers” made out of polyester or polyamide microfibre, which could allow them to be recyclable.

• Consider using 100% genuine leather that utilizes low-chrome tanning, non-chrome tanning or vegetable tanning processes.

Availability

Vegetable, low- or -no-chrome tanned leather is readily available. Water-based solvents for PUL are currently being researched. Microfibre made out of synthetics, such as polyester, are readily available.

Application

Chrome tanning still provides the softest quality leather most suitable for high end clothing.
Vegetable tanned leather is applicable to bags, belts and some shoes.
Bonded leather is applicable for belts, shoe soles and furniture upholstery, though it could be creatively applied to bags.
Microfibre for leather substitutes made out of polyester is applicable for shoes, handbags and upholstery.
Microfibres for leather substitutes made out of 100% chemically recycled polyester is available through Toray in the United States.[7]

Marketing opportunities

vegetable tanned leather or “naturally tanned” leather If vegetable or naturally tanned.
post-consumer recycled leather If from used garments.
100% recyclable If polyester or polyamide microfibre is used, and infrastructure to collect products and garments is in place.

NOTE: Simply saying “vegan leather” is not enough to substantiate sustainability claims, since these processes are generally derived from petroleum and can be toxic.

Innovation opportunities

1. At the product design stage, consider what will happen to imitation leather products at the End of Use stage of the lifecycle. Design products that address longevity, recyclability, biodegradability, disassembly for reuse, etc.

2. Explore innovative imitation leather fabrications that specifically address toxicity during production and use.

3. Work with partners to develop closed loop recycling of imitation leather products.

4. Design completely recyclable products where all materials and component parts recycle fully and safely. Partner with textile recycling facilities to guarantee effectiveness of recycling ability. Set up infrastructure to collect products. Communicate the proper route of disposal to consumers through POS and hangtags.

5. Use recycled leather collected from tanneries to create modular accessories or patchwork pieces; or use in trims on garments.