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Polyacetal resins are important engineering resins used in industrial, transportation, agricultural, construction and consumer markets. They possess excellent chemical, thermal, electrical and mechanical properties; as a result, they have replaced metals and other plastics in many applications.
Polyacetal resins are highly crystalline polymers characterized by their good hardness, strength and stiffness. In addition, they exhibit good lubricity properties under a wide variety of environmental conditions of moisture and heat, good fatigue resistance, a low coefficient of friction and springiness. They also have good chemical resistance to most solvents. Disadvantages of polyacetals include relatively high specific gravity and the inability to be flameproofed. Polyacetal resins also cannot be painted, although they are available in a variety of molded-in colors. The high crystallinity of polyacetal resins results in high mold shrinkage, which must be compensated for when designing parts.
Production of polyacetal resins is highly concentrated with only a few world producers. In 2008, Ticona and DuPont were the largest producers, followed by Mitsubishi Gas Chemical Company. Ticona, through direct or partial ownership, accounts for 41% of world capacity, DuPont accounts for 19% and Mitsubishi Gas Chemical accounts for 13%.
The following pie chart shows consumption of polyacetal resins by major region:
While one of the oldest engineering thermoplastics, polyacetals continue to be successful substitutes in traditional metal markets, at costs that are lower than those of many other engineering thermoplastics. Polyacetals continue to replace die-cast zinc, brass, aluminum, steel and other metals in various end-use industries.
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