BMC Parts It Is Important To Control The Cylinder Temperature

BMC Parts features and applications

BMC Parts 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 earthquake, fire, Durable air, 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.

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 more plunger-pressure 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 Parts 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 type of several mold clamping device.

5) mold

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

BMC Parts injection molding process

1) barrel temperature and mold temperature

Injection molding process, requires BMC Parts at the cylinder temperature, a long time to maintain a low viscosity flow state; general cylinder temperature should be able to meet the BMC Parts low limit. Barrel temperature is generally divided into two or three control, near the hopper end is low, near the nozzle temperature is higher. Generally difference between 20-60C, mold temperature is generally controlled at 135 ~ 185C ;.

2) Injection pressure

As the BMC Parts's poor mobility, fast curing, mold structure is complex, so the injection pressure should choose a higher pressure, generally 80 ~ 16OMPao

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. - should be used to ensure 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 Parts, the screw on the glass fiber damage, in order to minimize the damage of glass, screw speed should choose low value, usually 20 ~ 5Or / min. And according to the viscosity of BMC Parts, to use low back pressure is appropriate, generally 1.4-2.0MPa.

5) forming cycle

As the size and complexity of plastic parts of different sections of the process time is also different, the general injection time of 2 ~ 20s, holding time of 10-20s / mm (thickness).