Screw head combination


Injection molding machine over the rubber head with apr […]

Injection molding machine over the rubber head with apron and meson series introduction: over the plastic head, (reverse ring) through the rubber ring through the meson, the material can be selected from fully hardened powder alloy steel, Japan's Hitachi SKD61, domestic SACM645 alloy steel, domestic 38CrMoALA alloy steel, tungsten steel, 45# steel, H13 and other materials. The role of the rubber head meson: the plastic head group mixes the plastic melt in the plastic injection process, so that the molten plastic is evenly mixed. The rubber head defines the action distance before and after the rubber ring. The screw head. The meson combines with the function of the sealant. If the two are bad, the plastic will flow backwards, causing the injection molding products to be inaccurately measured. In severe cases, the product will appear yellow and produce black spots.

Introduction to the rubber ring: The rubber ring can be divided into two types according to the style. One is with a fork and the other is without a fork. The apron with a fork is stuck in the groove of the screw head during pre-molding. In the middle, the rubber ring rotates with the rotation of the screw. The advantage is that the two end faces are less worn and plasticized. The disadvantages are: the outer diameter wears fast and the inner hole tolerance of the cylinder is small or the debris falls into the cylinder. It is easy to cause the entire screw to rotate and the like. This kind of apron will accelerate the wear of the inner hole of the cylinder. The outer diameter of the apron without the fork wears slowly because it does not rotate during the pre-molding. However, the wear on both ends is faster. If you want to make PVC or PC material and make other plastics, it is better to use the rubber ring because the dead angle generated by the fork can be avoided to avoid black spots in the dead corner.

Screw head transparent product injection molding requirements for the rubber head ring meson: The three small parts of the screw head are required to have a smooth overall surface. Except for the assembly part, any place that can be seen from the front cannot have a right angle acute angle. All angle parts should be Sleek transition. Because the right angle sharp corners are easy to crack, it is easy to accumulate material, so that the raw material flow is not smooth. It is easy to have black spots and yellow when the time is long. Usually three small pieces are the most prone to yellowing, and many make transparent PC. .PMMA products are all due to the three-piece design is not good, resulting in a yellow screw head