Synthetic polymers sheet formation

The chemistry is both wide ranging and interesting. It involves carbohydrate chemistry, the chemistry of inorganic pigments, organic resins —both natural and synthetic—and many other organic and polymeric additives. The sheet formation process also involves a considerable amount of colloid and surface chemistry. Polymer chemistry and environmental and analytical chemistry also play an important part. 

The two major secondary structures found in nature— the helix and the sheet—are also major secondary structures found in synthetic polymers. The helix takes advantage of both the formation of intermolecular secondary bonding and relief of steric constraints. Some materials utilize a combination of helix and sheet structures such as wool, which consists of helical protein chains connected to give a pleated sheet. 

Nonwoven fabrics are flat, porous sheets or web structures that are made directly from separate fibers or from molten plastics or from plastic films by entangling fibers or filaments mechanically, thermally or chemically. Nonwovens can be produced from both natural and synthetic fibers or directly from polymers by a variety of techniques that involve web formation and bonding. Different polymers/fibers are more suited for one process than the other. All of the different techniques available for web formation and bonding are discussed in sufficient detail. 

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