Unconsciously, today again to the end of November, and as most of the Plastic mold factory in Dongguan boss have to start a headache hair wages and pay factory rent thing. This year, the editor's mold has been very busy, there is no stop rhythm. Today, the editor finally took the time to introduce the basic design rules for plastic wall thickness in products.
Wall thickness depends on the product needs to withstand the external force, whether as other parts of the support, to take the number of columns, the number of protruding parts and the choice of plastic materials may be. The general design of the thermoplastic wall thickness should be limited to 4mm. From an economic point of view, the product is too thick not only increase the cost of materials, to extend the production cycle "cooling time 〔, increase production costs from the product design point of view, too thick product leads to increase the production of holes" Greatly impaired product rigidity and strength.
The optimal wall thickness distribution is undoubtedly the uniform thickness of the cut in any one place, but it is always inevitable to change the wall thickness to meet the functional requirements. In this case, the transition from a thick compound to a thin compound should be as smooth as possible. Too sudden sudden changes in wall thickness can lead to dimensional instability and surface problems due to different cooling rates and turbulence.
For general thermoplastics, when the shrinkage factor "Shrinkage Factor [below 0.01mm / mm, the product allows the thickness of up to up; but when the shrinkage rate is higher than 0.01mm / mm, the product should not change the wall thickness Too often, for too thin a thermoformed product, too thin product thickness often leads to overheating of the product during operation, resulting in waste.Furthermore, fiber-filled thermosets tend to form underfill at too thin a position, but some are easier Flow of thermosetting plastics such as epoxy "Epoxies 〔etc, such as uniform thickness, the minimum thickness of up to 0.25mm.
In addition, in the case of Curing, the runners, gates and components are designed so that the plastic flows from the thick plastic to the thin plastic. This allows the cavity with the appropriate pressure to reduce shrinkage in place of thick plastic material and to prevent the cavity can not be fully filled phenomenon. If the direction of flow of plastic is from a thin plastic material to a place where a thick plastic material is used, a structural foam manufacturing method should be used to reduce the cavity pressure.
Note: The above information from the Jiezheng mold finishing on the Internet, welcome reproduced, indicate the source!