BMC Motor Accessories Has Good Physical Properties, Electrical Properties

BMC Motor Accessories is a glass fiber reinforced unsaturated polyester thermosetting plastic short, is the most commonly used class of enhanced thermosetting plastic.

(1) the characteristics and application of BMC Motor Accessories

BMC Motor Accessories has good physical properties, electrical properties and mechanical properties, so it is widely used, such as the production of such as transmission components, intake pipe, valve cover, bumper and other mechanical parts; in the requirements of seismic, Durable aerospace, construction, furniture and other aspects have also been widely used; in its traditional areas of electrical appliances, its use is also more and more widely.

(2) BMC Motor Accessories injection molding equipment

In the BMC Motor Accessories, due to the addition of glass fiber, so the equipment used and the general thermosetting plastic injection molding equipment is somewhat different, the use of injection molding machine, plunger and screw can be.

1) feeding system. Whether screw or plunger, must be attached to a squeeze feeding device to force the material into the barrel, the feeding device to use plunger-type pressurized feed.

2) Injection molding system. As the plunger injection molding machine injection volume is accurate and constant, so that the glass fiber less damage dispersed in the melt, so the plunger injection molding machine use more, but the exhaust inconvenience.

3) heating system. In the BMC Motor Accessories injection molding, the control cylinder temperature is very important, there must be a set of control system to control the temperature, to ensure that the feeding section to the nozzle temperature is the best. At present, more use of constant temperature water or constant temperature oil for heating. Electric heating can also be used.

4) clamping device. More use of mechanical, hydraulic and full hydraulic and other mold clamping device.

5) mold. BMC Motor Accessories injection mold and the usual thermoplastic, thermosetting injection is somewhat different, mainly BMC Motor Accessories shrinkage is low, so the design of mold cavity size should be changed.

(3) BMC Motor Accessories injection molding process

1) barrel temperature and mold temperature. Processing, requires BMC Motor Accessories at the cylinder temperature, a long time to maintain a low viscosity flow, the general cylinder temperature should be able to meet the BMC Motor Accessories low limit. Cylinder temperature is generally divided into two or three control, near the hopper end is low, near the nozzle temperature is higher. Generally difference between 20 ~ 60 ℃, mold

Temperature is generally controlled at 135 ~ 185 ℃.

2) Injection pressure. As the BMC Motor Accessories's poor mobility, fast curing, mold structure is complex, so the injection pressure should choose a higher pressure, generally 80 ~ 160MPa.

3) Injection speed. The increase of injection speed will help to improve the surface quality of plastic parts, shorten the curing time, but not conducive to exhaust, and increase the degree of glass fiber orientation. It should ensure that the quality of plastic parts under the premise of the use of lower injection speed, usually 1.8 ~ 3.5m / min.

4) screw speed and back pressure. If the use of screw-type injection molding machine, injection of BMC Motor Accessories, the screw on the glass fiber damage, in order to minimize the damage of glass, screw speed should choose low value, usually 20 ~ 50r / min. According to the viscosity of BMC Motor Accessories, to use low back pressure is appropriate, generally 1.4 ~ 2.0MPa.

5) forming cycle. As the size and complexity of the plastic parts of the different sections of the process time is also different, the general injection time of 2 ~ 20s, holding time of 10 to 20 (thickness).