Analysis the reason of cow excrement grain and clamp water grain of thick PVC injection parts become a big problem

August 15, 2017

 

 

In toy manufacturing, thick PVC injection pieces with thicknesses of 10mm to 50mm are often encountered. As the cavity inside space is too large, when the adhesive from the inlet into the large cavity, the extruded adhesive will be folded, wavy or spiral from the inlet into the cavity. After these linear melt rendezvous, will give the injection pattern in the inlet position left cow excrement grain, in other place with clamp water grain.

 

In addition, in the wide cavity, the middle part of the melt will go faster, but because of the influence from around the die wall cooling and friction will go slow, resulting in melt shunt, shunt after joined  format of the clamp water grain. If the cavity between the various obstacles, through the melt will cause the melt after the shunt caused clamp water grain.

 

Due to poor fluidity of PVC material, welding ability is not very good, so the PVC melt usually formed after shunting obvious thick clamp water grain.

 

According to the formation mechanism of cow excrement grain and clamp water grain we not difficult to understand, the faster the speed of injection, the cavity space is larger, the situation of folding or spiral into glue and shunt is more obvious, cow excrement grain and clamp water grain is more serious. This is cow excrement grain and clamp water grain is extremely difficult to eliminate.

 

So to solve these two problems, we must reduce the injection speed, melt to make no longer folding or spiral into the cavity. At the same time, it is necessary to ensure the smooth flow of melt, no diversion. We also need to take effective measures to ensure that the adhesive can be filled smoothly under the condition of slow injection, so as to prevent the injection molding parts from being out of order.

 

In fact, it is easy to say and hard to do. For a long time, countless injection technicians do not know how much effort, still do not have a complete set of effective measures and techniques to overcome them, most people treat this kind of problem will not have too much confidence and certainty, which can be known as the number one problem of toy industry injection "".

Others such as ABS, PP and other materials will be the same as large thick, thick problems bcow excrement grain and clamp water grain, size is too thick will also become difficult. Therefore, measures and adjusting machine skills will mention is also suitable for thick hard rubber a problem.

Tongxiang Longcheng Plastic Co., Ltd. has nearly 20 years of PVC granular research and development, granulation production experience. Professional and technical service team can provide one-stop system solution for customers. For more information about products, please visit our website: www.lcpvc.com, consult online customer service or call the hotline:+86 573 88618523. Fixed line: 0573-88618323 mailbox: sales@lcpvc.info, we will serve you wholeheartedly.

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