HaiYi  Plastic

1, screw diameter (D)

a, and the required injection quantity related to:
Injection volume = 1 / 4 * π * D2 * S (Injection trip) * 0.85;
b, In general, the screw diameter D with a maximum injection pressure is inversely proportional to, with plastics capacity in direct proportion.

2, conveyor paragraph
a, is responsible for the delivery of plastic, push with the warm-up, should ensure that pre-heating to the melting point;
b, crystalline plastic should be long (such as: POM, PA) followed by amorphous nature of materials (such as: PS, PU, ABS), the shortest heat-sensitive (such as: PVC).

3, compression paragraph
a, the mixing is responsible for plastic, compression and exhaust pressure through this period, almost all the raw materials have been melting, but not necessarily uniformly mixed;
b, In this region, the gradual melting plastic, spiral chute must be a corresponding decline in the volume to the corresponding decline in the volume of plastic geometric, or material false pressure, heat slowly, bad exhaust;
c, accounting for more than 25% of the general work of the length of screw, but the nylon (crystalline material) of the compression screw above the work of about 15% of screw length, high-viscosity, fire resistance, low conductivity, high plastic additives, such as Lo stroke, accounting for 40% of \'50% screw working length, PVC screw screw can work 100% the length of the shear in order to avoid intense heat.

4, above the measurement
a, usually accounts for 20 \'25% of screw length work to ensure that all the molten plastic as well as temperature uniformity, uniform mixing;
b, the measurement duration is good mixing effect, is easy to make the melt is too long to stay too long and have a thermal decomposition, is too short so that the temperature inhomogeneity is easy;
c, PVC and other heat-sensitive plastic should not stay too long in order to avoid thermal decomposition, the measures can be shorter or not the measurement above paragraph.

5, the depth of the feed trough Lo, Lo groove depth measurement
a, Lo feed trough deeper depth, the greater the throughput, subject to the screw strength, measuring the depth of spiral groove more shallow, then Plasticating fever, mixed performance index higher, but the measurement of spiral groove is shallow depth of cut increase in heat-cut, since heat increases the temperature rise too high, resulting in discoloration or burning plastic, in particular, is not conducive to heat-sensitive plastic;
b, groove depth measurement Lo = KD = (0.03 \'0 .07) * D, D increases, then choose a small value of K