FAQ

DMF-Free Eco PU FAQ

What's the difference between OPC's synthetic PU leather and the traditional PU leather (wet and dry process)?
A: The biggest difference is that OPC's WBPU (Water-Based PU) and PPU (Prepolymer PU) have eliminated a large part of the organic solvents and non-environmental / harmful substances which have been used in traditional solvent-based PU manufacturing. This, in turn, leads to new manufacturing technologies that reduce our energy consumption, lower our CO2 emission, and increase production efficiency. It also eliminates the pungent smell of DMF and ensures the health of our employees, customers, and product users.(OPC PU Comparison Chart)

What is Water-Based PU (WBPU), what is PPU (Prepolymer PU), and what's the difference?
In WBPU, water is the medium that disperses PU resin particles, so it's eco-friendly and harmless to the human body. For PPU (prepolymer PU), we synthesize PU prepolymers then process them without adding DMF or water, so PPU is also eco-friendly and harmless. However, PPU is firmer, more durable, and more rebound resilient, suitable for products requiring these physical properties. Meanwhile, WBPU is softer and more breathable, so it can be applied to more lightweight product types. However, with our R&D experience, both can be adjusted to satisfy various applications and physical strengths requirements.

What is organic solvent? What is DMF?
Traditional PU polymerization involves organic solvents like DMF, dimethylformamide, to control PU viscosity so that the PU can be easily processed and coated. DMF is a colorless moisture-absorbing liquid with a pungent odor and high boiling point, soluble in water, alcohol, and acetone. Organic solvents emitted during traditional PU processing would eventually become greenhouse gases, solvent elimination consumes a lot of energy, and the traditional process cannot completely eliminate DMF from the product. Sometimes, residual solvents might induce respiratory disturbances in patients with a weak respiratory system (like asthmatic patients). EU and other nations have listed DMF as a restricted toxic substance. Various renowned European sellers have demanded that the products be DMF-free, which we (Ocean Plastics) can achieve. Note: DMF is also sometimes referred to as DMFA.

What is DMF-free water-based PU leather? What is DMF-free PU leather or water-based PU leather?
PU is short for polyurethane. DMF-free PU leather is any synthetic leather (faux leather / artificial leather) made of polyurethane that is DMF-free. It is made of PU resins that do not have the DMF solvent, and the production process of the synthetic leather does not use the DMF solvent either. See PU Knowledge—>Water-Based PU V.S. Solvent-Based PU. Water-based PU leather is synthetic leather made of water-based PU resins / waterborne PU resin dispersions. Since the water-based / waterborne PU resins do not contain DMF, water-based PU leather is also DMF-free, so it can be called DMF-free water-based PU leahter.

What is DMFu (dimethyl fumarate)? How is it different from DMF?
DMFu is "dimethyl fumarate." Unlike DMF (dimethylformamide--a solvent used in traditional PU synthetic leather processes), DMFu (dimethyl fumarate) is more of an anti-fungal chemical people place in their sofas or leather products to prevent mold from growing. Ocean Plastics' PU products do not use DMFu; they're DMFu-free, and we've made our products DMF-free as well.

What can OPC's eco-friendly PU leather be used on?
Our eco-friendly PU product lines can replace all the products traditional PU leather can be applied on: balls, footwear, furniture, massage chairs, apparel, etc. There is NO limit on what type of product can make use of our eco-friendly PU leather.

Isn’t Water-Based PU’s physical performance property weak?
Ocean Plastics Co., Ltd. (OPC) initiated R&D in Water-Based PU Synthetic Leather in 1998 and began producing Water-Based PU Synthetic Leather in 2001. Moreover, we actually decided, very early on, to synthesize our own Water-Based PU Resin to control to our synthetic leather’s quality. Therefore, we were able to overcome technical hurdles and defy the stereotype that Water-Based PU had weak physical strengths and properties. In fact, we have been delivering our products for sporting goods that require strong physical performance properties, like balls and hockey skates, etc. We can adjust our PU’s physical properties according to our clients’ needs, providing Water-Based PU products with physical properties equal to or even better in strength than traditional solvent-based PU.

What is "hydrolysis-resistance?" What is "non-yellowing?" What is "NOx-resistant?"
PU material is affected by moisture in the air, so PU leather would crack and break down into small flakes that peel off the leather after a time period--this is called "hydrolysis." Our hydrolysis resistance lasts for about 4~5 years, which means that under normal circumstances, it will not break down until after 4~5 years. "Yellowing" refers to the phenomenon where white or light-color PU leather turns yellowish under the effect of sunlight or sources of UV rays in the surrounding environment; our material will pass the non-yellowing test with grade level 4~5 out of 5. "NOx" are chemicals that turn PU reddish brown; our material is resistant to that for a degree as well.

I have heard of Waterborne PU, Wet-Process PU, Wet-Process Water-Based PU. What are they? How are they different from Water-Based PU?
This is a bit technical. Hopefully, the below information gives you a basic picture of the differences and similarities:
(A) “Waterborne PU” is just another word for “Water-Based PU,” where the raw material PU resin particles are dispersed in mostly water. To make synthetic leather, we coat this resin onto a substrate (e.g. release paper), and dry the resin with heat to form a soft, solid PU layer on the substrate. This is how we at Ocean Plastics (OPC) make our PU synthetic leather.
(B) “Wet-Process PU” refers to the traditional solvent-based PU, where the PU resin particles are dissolved in dimethylformamide (DMF), an organic solvent. To make synthetic leather, the manufacturer coats a layer of this solvent-based PU resin on a textile substrate and immerse the coated textile into tanks of water to coagulate the PU resin into a similar soft, solid PU layer on the substrate. Because of this water-tank process, people call this the “Wet Process,” so solvent-based PU with this process is called “Wet-Process PU.” However, during this process, more energy is consumed than the Water-Based system above, and the DMF would migrate from the PU resin to the water in the water tanks, creating chemical waste water problems. Meanwhile, DMF also vaporizes into the air as harmful VOCs for the human body and the environment. We do not use this method.
(C) Sometimes, we hear of “Wet-Process Water-Based PU.” How can water-based and solvent-based PU vocabulary be put together in the same phrase? Well, it’s the production process of synthetic leather again. Some manufacturers use water-based PU resin to make synthetic leather by coating the water-based PU resin on a textile substrate, then immersing the coated substrate into tanks of water filled with acids. Since the water-based PU resin is slightly alkaline, the acid in the water coagulates the PU resin into the soft, solid PU layer. Because water tanks are used again, but the raw material PU resin is water-based, people sometimes call this “Wet-Process Water-Based PU.” However, this process creates salt compounds left in the water, and the water becomes industrial waste water, creating a similar waste water problem like the traditional solvent-based Wet Process. The process also requires more energy consumption and water resource consumption than the Water-Based PU without wet process. We do not use this method

Is it true that water-based PU has a harder, more rigid texture that lacks the suppleness and softness of traditional solvent-based PU synthetic leather?
As with any products, in time with enough R&D, you can overcome technical hurdles. Ocean Plastics Co., Ltd. (OPC) initiated R&D in Water-Based PU in 1998, and we began producing Water-Based PU Synthetic Leather in 2001. We synthesize our own raw material—Water-Based PU Resin—to control the synthetic leather’s texture, strength, and chemical make-up. Therefore, we have made technical headways defying the stereotype that Water-Based PU feels more rigid. With years of experience, we can manufacture Water-Based PU Synthetic Leather whose hand feel, texture, and physical strength properties span from the very soft to the very hard / firm end of the spectrum. For instance, manipulating our Water-Based PU’s softness and creating different degrees of draping, for years, we have successfully delivered very soft Water-Based PU Synthetic Leather for headphone ear covers (hydrolysis-resistant 5+ years) and very firm / strong materials for hockey skates.

What is vegan leather? What is faux leather or synthetic leather? What is bio-based leather or plant-based leather?
The word “vegan” is defined as “not derived from animal.” A thing does NOT have to be plant-based to meet the definition of “vegan.” Therefore, “vegan leather” is simply man-made artificial leather (aka “faux leather”) made of non-animal-derived raw materials. In our industry, such vegan or faux leather is often called “synthetic leather” because it is a man-made material made of synthesized polyurethane polymers coated on top of textile, forming a composite, supple-textured material resembling the texture of genuine leather. It is synthetic because it is man-made and synthesized.

Note that the word “vegan” does NOT mean “plant-based” because “vegan” ONLY means “not derived from animal.” In the synthetic leather industry, “plant-based” leather is a subset of a group called “bio-based” leather, where “bio-based” means the material is derived from “living organisms,” plants or animals. However, since the point of using synthetic leather is to reduce dependence on genuine animal hide and animal skin, “bio-based” leather actually refers to synthetic leather with raw materials from plants or animal shells, etc., not animal hides—the animals are NOT skinned or harmed. Within the “bio-based” group of synthetic leather, “plant-based” leather simply means it is a “bio-based” leather where the “bio-based” raw materials are derived from “plants” instead of animal shells.

Is vegan leather or faux leather or synthetic leather much less durable than genuine leather?
Some might say that vegan leather or faux leather or synthetic leather (all 3 words mean man-made artificial leather) is much less durable than genuine leather, but this is an incorrect stereotype based on the many synthetic leather products made of lower-grade raw materials in the market. With the right polymer formula and manufacturing technology, we can make polyurethane-based synthetic leather with 5-year, 7-year, or 10-year hydrolysis resistance, which, in layman’s terms, represent 5-year, 7-year, or 10-year durability.

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