What Is Vinylon?
Vinylon is a synthetic fiber made by acetalizing polyvinyl alcohol.
Vinylon was the first synthetic fiber developed in Japan and has a history of more than 70 years. It is also the second synthetic fiber developed in the world, following nylon, which was developed for the first time in the world.
Characteristics of Vinylon
Vinylon is characterized by its high fiber strength and resistance to friction, as well as its excellent moisture absorbency. Since most synthetic fibers do not have high moisture absorbency, vinylon stands out in this respect. It also has excellent weather and chemical resistance, and is used in many areas of industry and industry. Vinylon is composed of carbon, hydrogen, and oxygen, so it does not produce toxic substances such as dioxin or ammonia when burned.
However, while vinylon has excellent chemical resistance, it is also difficult to dye, making it difficult to use as a fiber for clothing. Although it has a texture similar to cotton, its lack of suppleness (stiffness) is also a disadvantage. It also has disadvantages such as color change when exposed to heat in a damp state, making it unsuitable for use in places where heat is applied or where appearance is a concern.
Uses of Vinylon
Vinylon is used in a variety of situations because of its long history and ease of stable production.
It is a highly durable fiber that is resistant to water, making it suitable for repeated use, and it is often used in familiar applications such as ropes and fish nets.
It is also used for reinforcing concrete because of its excellent chemical resistance and strong resistance to alkali. Because of its resistance to wind and rain, it is sometimes used in applications requiring weather resistance, such as civil engineering and construction and agricultural cold gauzes.
Until a decade ago, vinylon was also used for clothing due to its high moisture absorbency and cotton-like texture, but its use has been declining due to discoloration when ironing.
Currently, vinylon is used for clothes such as work clothes for long hours of sweating, raincoats, and some school uniforms.
Manufacturing Process of Vinylon
Vinylon is a synthetic fiber made by artificially polymerizing chemical substances.
First, vinylon acetate is synthesized from ethylene made from petroleum and natural gas. After polymerization of this vinyl acetate, polyvinyl alcohol, the source of vinylon, is created through a saponification step using sodium hydroxide.
Polyvinyl alcohol has many hydrophilic hydroxy groups (-OH groups) in its molecules, making it easily soluble in water and difficult to use as a fiber.
From here, vinylon fiber is made by using polyvinyl alcohol as the raw material for spinning and acetalizing it with formaldehyde. The spinning process can be divided into dry and wet spinning. In the dry method, the raw material is dissolved in a solvent that evaporates when heated, and the solvent is pressed out of the mouth in a heated atmosphere to evaporate and form fibers. In the wet process, the material is dissolved in a solvent and extruded in a solution called a coagulation bath, where it is chemically reacted and the solvent is removed to form fibers.
By reducing the ratio of hydroxy groups (-OH groups) in this way, a synthetic fiber is produced that is insoluble in water and has moderate moisture absorption.
Other Vinylon
Ordinary vinylon is not degraded by water, but there is an unusual fiber in vinylon called water-soluble vinylon, which has the characteristic of being soluble in water. This fiber contains more hydroxy groups (-OH groups).