Plastic gears are moving towards larger sizes and more complex geometries, the direction of higher strength, while high-performance resins and long glass fiber-filled composites play an important role in promoting.
   Plastic gears in the last 50 years has undergone a change in course from new materials to an important industrial material. Today they are already deep into many different application areas, such as cars, watches, sewing machines, structures and missile control facilities, etc., play and exercise in the form of transfer torque effect. In addition to the existing applications, new applications harder gear machining will continue to appear, this trend still further development.
   Automotive industry has become the fastest growing plastic gears a large field, this success is encouraging change.

   Automotive manufacturers are trying to find a variety of cars driven auxiliary systems, they need to be and other motor and gear rather than power, hydraulic or cable. This change makes the plastic gear depth applied to many applications, from lifting doors, seats, headlights track to brake actuators, electric throttle body, turbo mediation devices.

   Application of plastic power gear is further widened. In some applications the large size requirements, plastic gears are often used to replace metal gear, such as the use of plastic washing machine gear, etc., which is changing gears in size application limits.

   Design a gear configuration, while maximizing power transfer so that transmission errors and minimize noise, but also faces many challenges. This pair of concentric toothed gear and other characteristics of a very high precision machining requirements. Some helical gear, may require a complex molding operation to produce the final product, other thicker portion of the gear teeth of the core is required to reduce shrinkage.

   Precision Gear of tolerance is generally difficult as illustrated by the Society of the Plastics Industry (SPI) "good" to describe. But today most experts use the latest molding process with the molding machine control unit in a complex window, control precision molding temperature, injection pressure, and other variables to molding precision gears. Some experts in the use of more advanced gear molding method, temperature and pressure sensors placed them in the cavity in the molding to improve consistency and repeatability.
 
   Manufacturer of precision gears also need to use professional testing equipment, such as to control the double flank gear rolling mass detector, assessment of gear tooth surface and other features of the computer-controlled detector. But having the right equipment is just the beginning. Those trying to enter the precision gear industry molders must adjust their environment to ensure that they produce molded gears, in every injection, every cavity as far as possible consistent. Since the production of precision gear when the mechanic behavior is often the deciding factor, so they must focus on staff training and operation of controls.
 
   Common plastic gear teeth are straight, cylindrical worm and helical gears, almost all made of metal gears can be used to manufacture plastics. Gear commonly used to split the mold cavity molding. Since the injection must be allowed when the helical gear machining gear or ring gear teeth are formed is rotated, it requires attention to the details.
 
   Noise generated by the worm runs straight teeth than small, after forming a cavity by a spin or slide out of multiple agencies. If you use a slide mechanism must operate with high precision to avoid apparent parting line on the gear.
 
   Now, in the manufacture of precision gears, a series of engineering thermoplastics processing staff appears to provide more

choice than ever before. Acetal, PBT and polyamide, etc. The most commonly used materials, can produce excellent fatigue resistance, abrasion resistance, smoothness, high performance tangential stress intensity, can withstand shock loads such as reciprocating motor operation caused by the gear apparatus. For crystalline polymer to be molded at a sufficiently high temperature to ensure adequate crystalline material, since otherwise the temperature is raised to the molding temperature used above, the occurrence of secondary crystallization of the material resulting from dimensional changes gears.