Blow Molding Machine Screw Price

Today, let’s talk about the price of the screw of the hollow blow molding machine. The screw of the hollow blow molding machine is divided into single screw, twin screw and multi-screw. The material of the screw is different, and the use is also different; and the price is also different due to the material and specification of the screw.

The screw is the main core component of the blow molding machine.

 Its function is to convey, compact, melt, stir and apply various pressures to the plastic, which are all completed by the rotation of the screw in the barrel. When the screw rotates, the plastic will produce friction and mutual movement between the inner wall of the barrel, the bottom surface of the screw groove, the screw flight advancing surface, and the plastic and the plastic. The forward advancement of the plastic is the result of this combination of motions, and the heat from friction is absorbed to raise the temperature of the plastic and melt it. The design structure of the screw will directly affect its function and price. So, how do we choose the blow molding machine screw? How should we look at the price of the screw of the hollow blow molding machine?

To understand the price of the screw of the hollowblow molding machine, we must first understand the structure of the screw.

Because the diameter of the screw is related to the required blowing volume; the diameter of the screw is inversely proportional to the maximum blowing pressure and proportional to the plasticizing capacity; the screw is mainly responsible for the conveying, pushing and preheating of the plastic, and it should be preheated to the melting point; crystallization for flexible plastics, a screw with a longer diameter should be used; for amorphous plastics, it is better to choose a screw with the shortest diameter. The second is to look at the feeding groove of the screw. The deeper the depth of the feeding groove, the greater the conveying volume, but the strength of the screw of the blow molding machine should be considered. The shallower the depth of the measuring grooves, the higher the plasticizing heat and the mixing performance index. However, if the depth of the metering screw groove is too shallow, the shear heat will increase, the self-generated heat will increase, and the temperature rise will be too high, causing discoloration or burning of the plastic, which is especially unfavorable for heat-sensitive plastics.

To distinguish from the screw material, the prices are as follows:

The first category is the fully hardened powder alloy screw.
Made of tungsten-cobalt powder alloy tool steel, it is formed by a special process of overall hardening treatment. The internal and external overall hardness of the screw is the same. It is suitable for processing various transparent products, precision products and special high-temperature and high-corrosive plastics such as fiber, magnetic powder, bakelite, etc. The screw quality is very good and the price is high.

The second type is the double alloy screw.

Using SACM645, 38CrMoAlA as the base material, tungsten carbide-nickel alloy based on tooth crest or groove ion spray welding, the film density and strength can reach more than 10000psi, the alloy layer is thick, and the surface hardness of the screw is strong. It is suitable for processing various transparent products and adding fibers and other engineering materials. The screw quality is also very good, and the price is lower than the screw made of tungsten cobalt powder alloy.

The third category is electroplated screw.

Using SACM645 and 38CrMoAlA as the base material, after forming, the outer surface is electroplated with a layer of hard chromium, nickel, titanium and other elements. The thickness of the coating is 0.03-0.06mm, and the hardness is about HRC60°. Suitable for processing PC, PMMA, PET transparent material and corrosive plastic U-PVC material. The screw quality is also very good, but the price is relatively low.

The fourth type is ordinary nitrided screw.

Using SACM645 and 38CrMoAlA as the base material, it is formed by special processing. The depth of the nitride layer is 0.5mm-0.8mm, and the overall hardness is HV980~1080°. It is suitable for processing ordinary plastics such as PP, ABS, PS, AS, PVC and other ordinary plastics. This kind of screw is also of good quality, widely used and relatively inexpensive.

In summary, the price of the screw of the hollow blow molding machine cannot be generalized, and it needs to be treated differently according to the model and material.