Acrylonitrile Butadiene Styrene (ABS) Polymers History
Acrylonitrile-Butadiene-Styrene has been available since the 1940's. In attempts to produce bulletproof plastic sheets during the last years of World War II, polymer systems were developed from special butadiene acrylonitrile copolymers and styrene acrylonitrile copolymers with high molecular masses.
These materials have a high impact resistance on account of their low thermoplastic flow, but they can only processed using extruders. Semi-finished Products were the first parts to be made from ABS polymers and had dull or matt surfaces.
ABS polymers have greater toughness over styrene, this made them suitable for many applications, and its limitations led to the introduction of a rubber (butadiene) as a third monomer and hence was born the range of materials popularly referred to as ABS plastics. These became available in the 1950's and the variability of these copolymers and ease of processing has led to ABS becoming the most popular of the engineering polymers. ABS (Acrylonitrile-Butadiene-Styrene) is an opaque thermoplastic polymer material made from the monomers Acrylonitrile, 1,3-Butadiene and Styrene. Strong and durable even at low temperatures, it offers good resistance to heat and chemicals and is easy to process.
ABS is the generic name of a family of engineering thermoplastics produced by a combination of three monomers: acrylonitrile, butadiene, and styrene. The overall property balance of the terpolymer is a result of the contribution of the unique characteristics of each monomer. Polymer chemical resistance and heat and aging stability depend on acrylonitrile, while its toughness, impact resistance, and property retention at low temperature are developed through butadiene. Copolymer rigidity, glossy surface appearance, and ease of process ability are contributions from styrene. The terpolymer properties are controlled by manipulation of the ratio and distribution of the three components.
Systematic research into ABS polymers has led to the development of other multiphase plastics with a chemically different makeup. These contain other monomer units in addition to or as a replacement for acrylonitrile, butadiene, or styrene.
Aramid Fibers/Polymers: History, Synthesis, Properties, Applications/Uses
The Federal Trade Commission definition for aramid fiber is: "A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85% of the amide linkages, (-CO-NH-) are attached directly to two aromatic rings."
Synthesis of Acrylonitrile Butadiene Styrene (ABS) Polymers
ABS is made by emulsion or continuous mass technique. Globally, the most important is the emulsion process. ABS can be processed by injection moldings or extrusion technique.
Why do fabrics shrink? Shrinkage in Fabrics!
During the manufacturing process of fabric or we call it fabric processing, fabric comes in lot of tension and stretches when it moves from one machine to another which causes stretching in fabric structure and when this tension is removed, and fabric is relaxed it tends to get back in its original structure causing shrinkage.
Worsted Yarn Manufacturing Process
A fine smooth yarn spun from combed long staple wool. Worsted yarns are more tightly twisted than the bulkier woolen yarns. The soft, heavy yarn is strong and durable and is often used for sweaters. Worsted yarns are also used for fine dress fabrics and suit materials.