How To Prevent Serious Deformation Of Rotomolded Products When Cooling After Molding

Deformation of rotational molding products is a common problem, mainly due to many factors such as temperature control, cooling method, mold design, and raw material properties during the rotational molding process. In order to overcome the deformation of rotomolded products, improvements can be made from the following aspects:

1. Optimize cooling methods

Choose low-intensity cooling methods: Try to choose low-intensity cooling methods, such as forced cooling by fans or natural cooling, and avoid using rapid cooling methods such as direct water spraying to reduce deformation caused by too fast cooling rates.

Keep the mold rotating: Continuing to rotate the mold during the cooling process will help to cool all parts of the product evenly and reduce temperature differences, thereby reducing the risk of deformation.

2. Control the demoulding temperature

Extend the cooling time in the mold: The longer the cooling time in the mold, the smaller the shrinkage rate of the product and the lower the risk of deformation. Therefore, on the premise of ensuring easy demoulding, the cooling time in the mold should be appropriately extended.

Control the demoulding temperature: On the premise of ensuring that the product can be demoulded smoothly, the lower the demoulding temperature, the better, which can further reduce the risk of deformation. The demolded products should avoid being placed in an environment with large temperature differences, and should be fixed as soon as possible.

3. Adjust mold and process parameters

Correct the mold structure: Correct the structure, narrow space, sharp angle, etc. in the mold that may cause product deformation to ensure the rationality of the mold design.

Adjust the rotation speed: Adjust the rotation speed of the main and auxiliary shafts to balance the rotation speed ratio and the rotation speed to ensure uniform wall thickness of the molded products and reduce deformation caused by uneven wall thickness.

Keep the mold vents clear: Make sure the mold vents are unobstructed. If necessary, inert gas can be introduced into the mold to reduce the occurrence of bubbles and deformation.

4. Optimize the selection and use of raw materials

Master the shrinkage rate of raw materials: Understand and master the shrinkage characteristics of the raw materials used. For products with high quality requirements, raw materials with relatively low shrinkage rates can be selected.

Reasonable use of additives: Use pigments, additives, and release agents with caution, and avoid using additives that can cause large deformation of the product. At the same time, the amount of release agent should be appropriately reduced to avoid negative effects on the product.

5. Improve product design

Avoid unreasonable structures: Where possible, try to avoid designing large and flat product surfaces to reduce shrinkage deformation caused by large surface areas. At the same time, the interior can be appropriately reinforced to improve the rigidity and stability of the product.

Optimize the wall thickness of the product: Reasonably design the wall thickness of the product to avoid deformation problems caused by too thin or too thick wall thickness. At the same time, it is necessary to ensure that the wall thickness of each part of the product is uniform.

To sum up, overcoming the deformation of rotomolded products requires starting from many aspects, including optimizing cooling methods, controlling demoulding temperature, adjusting mold and process parameters, optimizing raw material selection and use, and improving product design. By comprehensively applying these measures, the risk of deformation of rotational molded products can be effectively reduced and product quality and stability improved.