With the progress of science and technology, as well as the requirements of environmental laws and regulations related to the stricter the development of environment-friendly adhesive is receiving increasing attention. Environmentally friendly water-based adhesives are solvent-free adhesives with the two. Solvent-free adhesives generally referred to as hot melt adhesives, thermoplastic resin 100% by the composition does not contain any water or solvent, can flow in the molten state, and the cooling performance of a bond can be easily used for automated production process to provide high productivity, and does not produce any environmental pollution, not human-induced toxicity. In addition, there emulsion / dispersion adhesives, reactive adhesives and natural polymer adhesives.
environment-friendly footwear adhesive glue adhesive in addition to requirements of the shoe has a solid, durability and softness, but also must be environmentally friendly nature,UGG boots clearance, and compatibility with different materials, to ensure the quality of shoes.
environment-friendly polyurethane adhesive glue footwear primarily reactive polyurethane hot melt adhesive without solvent and water-based polyurethane two.
a, solvent-free polyurethane reactive hot melt
hot melt adhesive as regular contact with the surface of the material is sticky, poor infiltration, has been shown to not be generally applicable to outer end of the adhesive, Therefore, reactive hot melt adhesives have been developed through the efforts of the last 10 years,Discount UGG boots, and now has developed a low viscosity and temperature conditions in the appropriate product can be applied. Reactive hot melt adhesive with water or heat the role of cross-linking, and finally to achieve better adhesion. Use of solvent-free polyurethane reactive hot melt adhesive should be supporting the specialized equipment, more stringent operating conditions, therefore, promote the use of a certain degree of difficulty. Footwear factories overseas have been applied in bulk hot melt adhesive polyurethane soles, has research units in the development of such adhesives, adhesive strength from the reports is not high enough to see, is still at the laboratory stage.
b, water-based polyurethane water-based polyurethane Buhan
NCO groups, which contain carboxyl, hydroxyl group, under suitable conditions, for example, isocyanates in the presence of water can make adhesives The molecules cross-linking reaction. Most water-based polyurethane is the polar groups by the generation of intramolecular cohesion and adhesion to curing. Polyurethane with polar groups, such as urethane and health, urea bond, ionic bond, etc. Therefore, many synthetic materials, especially in polar materials, porous materials have good adhesion.
waterborne polyurethane compared with the solvent polyurethane adhesive, polyurethane adhesive without solvent odor, non-toxic, non-polluting, easy to operate, easy to clean adhesive residue, solid content, safe and convenient storage, but the water-based adhesive to be a longer drying time and higher drying temperature, drying process was demanding, in order to ensure complete evaporation of water. Water-based adhesive on the substrate wetting ability, the adhesive will reduce the water-soluble polymer thickener, in addition, has not yet developed the necessary use of water-based surface treatment agent (in the laboratory research stage), still need to use solvent-based surface treatment agent,UGG boots cheap, so even if rubber outsole with water-based, are still unable to achieve eradication of organic solvents.
Polyurethane Adhesive 50's began in the 20th century, the real attention by people in the 60-70 years, but then the water-based polyurethane adhesive bond strength is not high, with plastic used for packaging and some low- adhesive strength of the occasion. The mid-70s began to water-based polyurethane for bonding rubber soles, due to poor performance, coupled with the strict environmental regulations, to the late 80s, is basically still in the experimental stage. Early 90s, Europe and the United States to the increasingly stringent environmental regulations, the amount of the shoe began to control VOC, waterborne polyurethane dispersion synthesis and application technology research efforts have been strengthened, the performance of water-based polyurethane adhesive is basically meet the requirements of footwear. For example, the production of Dispercoll U Bayer Desmodur D together with Nike and Adidas brand sports shoes has reached an industrial scale use. Use water-based polyurethane production of leather shoes is still in trial production in bulk, but also a number of multinational companies in the shoes, such as Bally Company, Bata company, Clarks companies, etc, in bulk trial, is said to have made significant progress. Water-based polyurethane leather shoes behind, the reasons why are: sports shoes soles are basically new materials, material quality is relatively uniform, and large-scale sports shoe, the level of quality of personnel and equipment are of excellent in the shoe industry; The shoe bottom material complexity, it is difficult to ensure that new materials are used, small scale leather products, more emphasis on personalized,Bailey UGG boots, even the manufacturers of the products are not mass products like shoes so much.
According to the Bayer Company in 1998, the amount of the global number of tonnes of waterborne polyurethane soles scale, the scale of 5,000 tons in 2000, it reached 2001 million tons, China's water-based polyurethane outsole rubber in the research Progress is slow, only a few institutions in the present work. Shoe production and use of water-based polyurethane is basically a foreign brand-name sports shoes for foreign processing, according to the requirements of the use of foreign companies in 2000, the processing factories of these water-based polyurethane adhesive for the 2500-3000 tons, has reached 4,000 tons in 2001 so, using water-based polyurethane adhesive glue is basically from the Taiwanese company. But the water-based polyurethane
a longer drying time and higher drying temperature, drying process was demanding, and therefore appropriate for transformation of existing process equipment. Affected to some extent the rapid spread of its applications. In addition, water-based polyurethane over the price of organic solvent-based polyurethane nearly 4 times higher, and its solid content of only 3 times higher, compared to the price is still expensive.
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