Side wall design of injection mold cavity is often an important issue encountered in mold design, especially for large injection molds. In actual production, we require the injection molding mold to be strong enough to avoid damage and at the same time have good rigidity to avoid deformation. Therefore, the design of injection mold cavity should be carefully considered, generally considering the following aspects:
In the injection molding production, the force that the mold cavity of injection molding mold is subject to is mainly the pressure of plastic melt. Under the pressure of plastic melt, the cavity will produce internal stress and deformation. If the thickness of the cavity side wall is not enough, it will inevitably cause damage during use. In practical applications, for large-sized cavities, insufficient rigidity is the main problem and should be calculated according to the rigidity conditions; for small-sized cavities, insufficient strength is the main problem and should be calculated according to the strength conditions.
When high-pressure plastic melt is injected into certain mating surfaces of the injection mold cavity, if the rigidity of the mold is insufficient, it will cause elastic deformation and produce gaps large enough to cause overflow. In this case, we need to consider the non-overflow gap of the plastic used.
Because the deformation of the injection mold cavity under high pressure will reduce the accuracy of plastic parts, especially small ones. Therefore, the influence of cavity deformation on the accuracy of plastic parts should be considered in the design and corresponding measures should be taken to ensure the accuracy.
The elastic deformation of the cavity should be less than the shrinkage value of the plastic part. Otherwise, after injection cooling and mold opening, the cavity will tightly wrap the plastic part, making it difficult to demold. If forcibly ejected, it will cause damage to the plastic parts. When designing the side wall of the injection mold cavity, material and process costs should be minimized under the premise of meeting the strength and rigidity requirements.
Different types of injection moulding are important process equipment used for manufacturing various plastic parts. With the rapid development of the plastic industry and the promotion and application of plastic parts in aviation, aerospace, electronics, machinery, shipbuilding and automobile industries, the requirements for injection molding molds are getting higher and higher. Traditional mold design methods cannot meet the requirements of today's plastic products. Compared with traditional mold design, computer-aided engineering technology not only has great advantages in shortening the injection molding cycle and ensuring the quality of plastic parts, but also reduces the cost of injection molding and reduces labor intensity.