380×2428 Screw

Product Introduction:

Several important geometric parameters of screw

1)Screw diameter (D)

A. Relevant to the required injection dose:

Injection volume =1/4πD2*S (injection stroke) *0.85;

B. In general, screw diameter D is inversely proportional to the maximum injection pressure and proportional to the plasticizing capacity.

2) Conveying section

A. Be responsible for the transportation, extrusion and preheating of plastics, and ensure the preheating to the melting point;

B. Crystalline plastic should be long (such as: POM, PA) amorphous material (such as: PS, PU, ABS), the shortest heat sensitivity (such as: PVC).

3) Compression section

A. Responsible for the mixing, compression and pressure exhaust of plastics. Almost all raw materials through this section have melted, but not necessarily mixed evenly;

B. In this area, the plastic gradually melt, the spiral tank volume must decline correspondingly, in order to correspond to the plastic geometric volume decline, otherwise the material pressure is not solid, slow heat transfer, bad exhaust:

C. Generally accounts for more than 25% of the working length of the screw, but the compression section of nylon (crystalline material) screw accounts for about 15% of the working length of the screw, high viscosity, fire resistance, low conductivity, high additives and other plastic screw, accounting for 40%~50% of the working length of the screw, PVC screw can account for 100% of the working length of the screw, so as not to produce intense shear heat.

4) Metering section

A. Generally account for 20%~25% of the screw working length, to ensure that all plastic melting and uniform temperature, uniform mixing;

B. Long metering section is good mixing effect, too long is easy to make the melt stay too long and produce thermal decomposition, too short is easy to make the temperature uneven;

C. PVC and other heat-sensitive plastics should not stay too long, so as to avoid thermal decomposition, which can be used in a shorter metering section or not metering section.

5) Feed screw groove depth, metering screw groove depth

A. The deeper the feed groove depth, the greater the conveyor capacity, but need to consider the strength of the screw, the deeper the metering groove depth, the higher the plasticizing heat, the higher the mixing performance index, but the depth of the metering groove is too shallow, the shear heat increases, the autogenic heat increases, the temperature rise is too high to cause plastic discoloration or scorching, especially not conducive to heat sensitive plastics;

B.Measurement screw groove depth =KD=(0.03~0.07) *D. When D increases, K is selected as a small value.

Zhoushan Jed Machinery Co., Ltd. is located in Dinghai District, Zhoushan City, Zhejiang Province, the screw capital of China, specializing in the production of a variety of plastic extruder, injection molding machine, rubber machine, film blowing machine, drawing machine and other units of single and double screw barrel. Material is made of high quality alloy steel 38CrMoAlA, SKD61, SKD11, after conditioning, qualitative, nitriding, spray welding (bimetal), fine grinding, polishing, waxing and other processes refined, the product has high precision, long service life, wear resistance, corrosion resistance and other characteristics.

Screw material selection of high quality 38CrMoAla, high quality SACM645, high quality SKD11, high quality SKD61, high quality 9Cr18MoV(high stainless steel), CW6Mo5Cr4V2(high speed tool steel), HPT (fully hardened powder alloy tool steel); In order to improve the abrasion resistance and corrosion resistance of the screw surface, the screw surface is nitrized, and fully hardened, sprayed alloy, hard chromium plating or titanium plating.

The company has an excellent technical production management team, in addition to provide supporting facilities for domestic and foreign complete machine factories, but also for customers to undertake sample, drawing processing and design drawing and other business.
We are in the screw city, enjoy the advantages of time, geography and people, committed to the design, manufacturing, service of plastic machine screw barrel continuous improvement. Companies adhering to the “quality is the dignity of the enterprise, customer is the God of the enterprise” purpose, always put product quality and customer interests in the first, we warmly welcome new and old customers to come to inquire and negotiate, create a better future! Customized WhatsApp: +86 135 6767 2668, wechat the same number.Email:[email protected]