Injection molding machine first fast and slow injection method

Injection molding machine first fast and slow injection method

Fast first and then slow, that is to say, use the first level of fast injection, and when it reaches a certain set position, then the second level of slow injection. This secondary starting point is generally set at the late stage of injection and filling, that is, close to the end of filling.
What problems can it solve?
The use of one-stage fast glue injection can maintain the melting temperature, overcome the cavity resistance, and facilitate smooth filling. The second-level slow-spray glue is conducive to the exhaust and the inhalation of the melt to solve the trapped air and prevent the problem of sharpening and shrinking. Using this technique can also solve many difficult and conflicting problems for us:
1. It can be used to solve the air trapping problem of injection molded parts. Including "dead corners" trapped air and "return package" trapped air problems.
2. It is used to solve the problem of not only a sharp front but also shrinkage or uneven feeding in the same mold caused by the imbalance of the water in the mold cavities.
3. It can also be used to solve problems such as censorship, whitening or shrinkage.
4. It can also be used to solve the problem of difficult filling.
Of course, the adjuster in production can also add several injection levels to the injection process of "fast first and then slow" according to the actual situation, in order to solve other problems in the filling process, or before the fast injection Adding a slow level to solve problems such as the air mark of the nozzle position, all of which are higher and more advanced applications of this technique.
In fact, in a complex multi-stage glue injection process, the two techniques of "slow first and then fast" and "fast first and then slow" may actually be combined into one, but each is still working on its own. When there are relatively few problems, there are actually more obvious differences and emphasis, so they are divided into two techniques to discuss, so that we can understand differently and use them in a conflicting way.