Leather softer

Polyvinylchloride (PVC) is a hard, amorphous polymer which softens at about 85 °C. Also in PVC rubbers are sometimes added in order to improve the impact strength. The main applications of PVC are pipes, gutters, front panels of buildings, cables, bottles, floor tiles. A much softer and more flexible material is obtained by blending with plasticizers soft or plasticized PVC is being used in artificial leather, tubes and hoses, footwear, films, etc. 

The development of new softening materials is considered to be a high priority by the international leather industry. Research to find materials that give softer leather for garments without the drawbacks of greasy feel, odor, and cost that attend... 

An increasingly widespread use of acrylates in the leather field is as a component of water-based finishes. In such cases, the acrylate improves tho adhesion, flexibility, and leveling of the finish, and depending upon the amount and type used, improves the washability. The softer t q)es are often used as plasticizers for aqueous disperrions of other resins which are too brittle, without modification, for flexible coatings. 

Polyvinyl chloride (PVC), also called poly(vinyl chloride) and polychloroethylene, is a widely produced synthetic polymer. It is used in pipe construction, for doors, windows, etc. and has the chemical formula (C2H3Cl)n. This polymer can be made softer and more flexible by the addition of plasticizers. In its softer form, the plastic can be used in plumbing and imitation leather. Figure 5 shows a model of polyvinyl chloride [16]. 

An alternative to using the fully thermoplastic TPU is to use two-component (two-pack) types for the coating of fabrics. The technique is as follows the fabric may be coated either directly or, more usually, by prior coating on to release paper and subsequent transfer of the film on to the fabric. Direct coatings are generally cheaper to apply but they produce composites which are stiffer. Transfer coating provides softer composites, which are easily embossed and simulate a leather look, but the costs are higher. 

Proteases are used in dehairing and dewooling of leather, and improve its quality (cleaner and stronger surface, softer leather, less spots). Lipases are used in this phase or in bating phase to specifically remove grease. The use of Upases is a fairly new development in leather industry. 

While many proteins have been in long use, modern polymer science can be employed to make them better, or serve additional uses. Graft copolymers of wool and leather, now under investigation, yield softer and/or more water-resistant materials. 

The requisite hiding performance is achieved through the partial use of the polybutadiene dispersion. Furniture leathers are softer than automotive leathers. Embossing is accordingly done under less pressure. Since the fastness requirements are lower, the top coat is less crosshnked and the appHed amount is lower. For aesthetic reasons, the leather is briefly plated after the appHcation of the top coat. 

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