Worrying about the global ecology- The "Crisis" and "Turning Point" brought by environmental protection regulations for synthetic leather industry
The development of synthetic leather has been more than half a century, from the first generation PVC leather, the second generation of PU leather, the third generation of microfiber PU leather (high-performance polyurethane resin) to the recent market promotion of waterborne polyurethane environmental protection synthetic leather are widely used to replace animal leather. The Global Fashion Agenda and the 2017 PULSE OF THE FASHION INDUSTRY (Note 1) released by the Boston Consulting Group clearly pointed out that the production of synthetic leather is less damaging to the environment, which makes the stakeholders of the fashion industry turn to more ecological options, including synthetic leather. Due to the continuous serious environmental pollution and health hazards in the whole life cycle of traditional PVC artificial leather, the development of recent years has been limited. The market trend has gradually turned to the development of environmentally friendly PU and TPU materials, as well as the process development, and the market competition of synthetic leather is increasingly fierce.
According to the 2020 polyurethane (PU) Industry Research Report of Xincailiao research and online media, China's polyurethane production in 2018 reached 13.06 million tons, accounting for 45% of the world's total production, of which polyurethanes for the synthetic leather industry accounted for about 16% (about 2.1 million tons). In 2015, China's "Key Industries VOC Reduction Action Plan" mentioned that petroleum refining, petrochemicals, coatings, inks, adhesives, pesticides, automobiles, packaging and printing, rubber products, synthetic leather, furniture, footwear and other industries VOCs account for more than 80% of the total industrial emissions, and most are discharged into the surrounding rivers and air, posing a major threat to the living environment and human health.The ecological crisis caused by environmental and climate change has become one of the most concerned topics in the world. Most countries continue to raise the environmental protection threshold for imported products. In the future, the relevant norms of countries around the world will be more stringent. If enterprises do not change, they will cause different levels of impact. In order to completely replace animal leather, the demand for synthetic leather in various industries has increased significantly, and the waste generated is increasing day by day; most leather products have direct contact with the human body, so in the development of synthetic leather, environmentally friendly and non-toxic materials development will be an important trend.
A. PVC artificial leather
PVC is the abbreviation of polyvinyl chloride. It is the only chlorine-containing plastic among the five general plastics (PE, PVC, PP, PS, and ABS), known as "toxic plastic" by the international green peace organization. Its entire life cycle, from raw materials synthesis, finished product manufacturing, end-use and waste treatment of all stages, will cause harm to the living environment and human health.
Raw material synthesis:
Because PVC is poorly stable for light and heat; stabilizers must be added to prevent PVC products from releasing chlorine free radicals under sunlight or high temperature, resulting in materials decomposition. Stabilizer usually contains heavy metals such as lead, cadmium, zinc, which may endanger the brain, lungs and kidneys or even harms the bones in long-term contact.
Manufacture and use of finished products:
After the synthesis of PVC, plasticizers with different contents need to be added according to the required softness of the PVC products. With the influence of time and temperature, plasticizer gradually migrates to the surface of the product, resulting in direct contact with consumers or accidental eating. DEHP (Note 2) (Note 3), which has been proven to cause cell abnormalities and harm fertility, it may also cause thrombus injury to liver and lung.
Waste PVC will produce a large amount of hydrochloric acid and the poison of the century-Dioxin. The plastic skin covered in the outer layer of the cable is chlorine-containing hydrocarbon-PVC. Under the catalysis of the main component of the wire-copper, chloride and hydrocarbon are mixed and burned to form dioxin, which is easy to accumulate in body fat has been confirmed to cause cancer, and in the combustion process to produce a large number of pungent hydrochloric acid gas, which will not only damage the respiratory tract but also accelerate aging the pipeline equipment of factories. As a result, maintenance costs and even the possibility of toxic substances leaking are increased.
B. General PU synthetic leather
PU synthetic leather originated in the 1940s and has the advantages of soft gloss, nice hand feel, animal leather alike and good cold resistance, etc. It is widely used in the fields of clothing, furniture and high-end shoes. However, the organic solvent used in the production process accounts for more than 60% of the entire polyurethane composition, which will cause great harm to the human body and the environment.
The PU synthetic leather produced by the "wet process" (Note 4) is soft to the touch. The principle is to use the miscibility of DMF and water. After being exchanged with water, the content of DMF in the resin will be reduced. The replacement process will produce many micro pores and make the resin solidified; the PU synthetic leather with a realistic feel is finally obtained. This production process has been very mature, but it is gradually eliminated due to the following environmental pollution problems and shortcomings:
The volatilization of organic solvents keeps the concentration of VOCs (Note 5) on the workplace high, the health of workers engaged in in-house production is at risk, and the toxic substances discharged into the environment can also cause serious air pollution.
If the recycling equipment is not sophisticated, the discharge of wastewater containing a large amount of DMF into the environment will cause water pollution and damage the ecological balance.
Since DMF and water cannot be replaced in 100%, more water and energy will be consumed by post-treatment removal, and in fact many of the finished products of PU synthetic leather still have a small amount of DMF residue.
DMF is toxic and is believed to harm the human reproductive system. The EU norms in the finished product DMF content must not be higher than 1 ppm (Note 6), which greatly limits the development of traditional PU synthetic leather.
C. Microfiber PU synthetic leather
The origin of microfibers research can be traced back to the 1940s, and until the 1980s, microfibers were welcomed by consumers, creating a wave of artificial suede. Microfiber PU synthetic leather, referred to as "microfiber leather", the adhesion between the superfine fiber bottom and the surface is very strong. Microfiber leather has chemical resistance, wrinkle resistance, wear resistance, uniformity of quality and is easy to take care of. The bundled collagen fiber structure on the surface is very similar to the mesh layer of the animal leather. Its overall weight is 15% to 50% lighter and its hand feel is also softer than the animal leather, which has been defined as high-grade synthetic leather. Automotive interiors, breathable apparels and footwear, etc., the demand for products continue to increase.
Now we can use the water-based dry coating process to eliminate the doubt of solvent pollution, and the materials can be recycled to extend the life cycle of use to achieve the goal of environmental sustainability.
D. Environmental Friendly Waterborne PU synthetic leather
Driven by the dual pressures of environmental protection regulations and market demand, solvent-free production line has become an important technological innovation and market development direction in the PU industry, so the production technology of waterborne PU synthetic leather came into being. The customized products adjusted according to the buyer's demand are suitable for various industries, with excellent properties such as abrasion resistant, hydrolysis resistant, peeling resistant, cold resistant, flexion resistant, breathable, warm keeping, etc., and the finished product has no solvent residue and non-toxic, to ensure the health of users.
In the international market, waterborne synthetic leather is gradually replacing solvent-based synthetic leather as an industry development trend. In particular, many international brands in the European Union have committed to realize the waterborne synthetic leather products by 2020, accelerating the transformation of the synthetic leather industry. If this technology is widely adopted, it will save millions of tons of organic solvents every year, directly eliminate waste water, waste gas pollution from organic solvents, and 40% reduction in coal consumption for DMF recycling per year, effectively promoting the sustainable development of the environment.
Although waterborne synthetic leather technology has greatly reduced the hazards brought by organic solvents, the production process and equipment of new waterborne polyurethane synthetic leathers are not widespread enough, below are the technical and cost problems to be solved:
At present, the market application is not widespread enough, and most of them are concentrated in the domestic and foreign enterprises with strong scale for production, which has a certain degree of market monopoly, resulting in high product prices.
Compared with the traditional solvent type, the waterborne PU synthetic leather needs higher temperature in the drying process, and the release paper used for coating also needs higher quality. The overall production line will consume more energy.
Due to policies and regulations restricting the addition of organic solvents, the output of traditional processes is reduced. In contrast, the production capacity of solvent-free environmentally friendly synthetic leather must be increased by more than 10% to meet the global market demand.
E. Environmental Friendly Calendering Grade TPU Synthetic Leather
The TPU synthetic leather produced by the calendering process completely solves the environmental pollution problems and disadvantages of traditional PVC artificial leather / PU synthetic leather and has the following five advantages:
1. Environmentally friendly materials:
TPU (Thermoplastic Polyurethane) has the advantages of good physical properties, biodegradability, non-toxic and no plasticizers, is the best alternative to PVC. The production of TPU synthetic leather has always been a key project for leather factories.
2. Friendly process and high qualification rate:
The process is environmentally friendly, and there is no solvent residue in the product, which can effectively solve the VOCs emission problem and replace the existing synthetic leather products directly. It solves the current environmental dilemma faced by enterprises. The raw materials in the production process can be properly recovered, and the overall production yield tends to be stable, which can greatly reduce the production cost of environmentally friendly leather.
3. No need to reinvest in existing rolling equipment:
Verified by many manufacturers that the leather factory with rolling equipment can upgrade the production line at the lowest cost. Through formula research, it can be used under similar processing conditions without reinvestment.
4. Alternative PVC artificial leather/PU synthetic leather:
Calendering TPU synthetic leather has the same production technology as PVC artificial leather. It can also carry out processes such as mixing, calendering, laminating, foaming, embossing and winding, which can directly replace PVC raw materials and processes to produce customized products. TPU synthetic leather adopts dry production technology, without solvent residue, and is the best substitute for PU synthetic leather.
5. Transformation and upgrading to enhance brand value:
Calendering TPU synthetic leather is made of high-value advanced environmentally friendly materials. Calendering TPU can be used in high-end products to further increase consumer recognition and enhance the brand image, transform into a non-toxic environmental protection leather supplier, and avoid the fate of being eliminated by the market. While improving the product performance, it also contributes to the sustainability of the global environment.
According to the latest report of Global Market Insight, the scale of the global PU and TPU synthetic leather market is bullish. By 2024, due to people's environmental awareness and lifestyle changes, the animal leather market will be reduced, and the global synthetic leather market will probably exceed 95 billion US dollars, an increase of more than 5%. Since 2015, synthetic leather has been almost produced from traditional PU as a base. Later, solvent-free water-based PU synthetic leather and calendering TPU synthetic leather have become the key promotion task in the industry because of the processes do not contain toluene, DMF and other organic solvents, the materials can also be recycled and reused. In particular, under the comprehensive consideration of reducing the total weight and improving the fuel efficiency, TPU materials have been gradually selected to replace automobile dashboards, air bags, seat interior trims and car doors. However, there are still many challenges in the production process of petrochemical raw materials, the current domestic and foreign market competition, the enterprise production and operation costs continue to rise, which may lead to high market prices and insufficient supply, and thus have a negative impact on the market scale of synthetic leather.
From the perspective of enterprises, in the pursuit of economic growth, we must also grasp the trend pulse, and actively invest in the transformation of high-value products with the goal of sustainable development, so that the enterprise cannot be eliminated by the market because of stable operation.