Venting in Crate Mould

Injection Mould Venting System is needed in every mould, but most of us do not know why venting problem appear and how to solve such problem?

First, let’s figure out why it appears: When plastics material enters an impression, air is displaced. Normally the air can escape between mould cavity and mould core. However, if these two plates have a very fine lapped finish, the air may be trapped within the impression so that mould defects, such as discoloration, sinks incomplete filling, scorch and so on.

Second, we must learn how to solve venting problem? Usually we design vents in the mould to allow air (and other gases when present) to escape freely. It is really hard to predetermine where the vent will be required, so the vent is normally machined into the mould plate once the mould has been tested. The vent is normally a shallow slot, not more than 0.05mm deep by 3mm wide, tooling on the plate surface. But if the slot is too large, when the plastics material pass through the slot and resultant undesirable flash mark being left on the moulding.

Finally, we take crate mould to explain how to solve venting problem. Plastic crate moulds’ handle area will appear venting problem, since it has a very fine lapped finish and do not have ejector pin or sleeve eject system. We have three ways to solve this problem: 1. Make Logo insert around the handle area. 2. Add venting ejector pin. 3. Add small blank insert. Compare with add Logo inset or small blank insert around handle area, add venting ejector pin will be more accept and nice, but the first two have better venting effect. So before make decision, you must communicate with customer and choose best solution for them.

In a word, every kind of mould has different venting problems, we must consider such problems when design mould design and try to figure out best solution to solve it. Until now, we have accumulated rich experience in how to solving venting problems, so if you meet such problem, do not hesitate to contact me, Iam glad to discuss with you and help you deal with it.

Post by Miss Mandy

Email: auto@sinomould.com

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