company news about Why there is uneven wall thickness of rotomolded products

Let's analyze the reasons for the uneven wall thickness of rotomolding products by the rotational molding manufacturers.

It is not easy to process products with concave wall thickness during the rotational molding process. The average wall thickness of the product depends on the amount of material, and its uniformity is related to the structure of the mold itself and the rotational molding process.

In terms of the structure of rotomolding products and rotomolding molds, generally the thickness of the concave corner of the rotomolded product (the convexity of the mold) is smaller, while the thickness of the convex corner of the product (the concave mold) is larger, but if the angle of the convex part is too small, it is easy to cause the material to be unable to fill the mold and bring the corresponding holes and other defects. Therefore, the product should not have sharp corners, and a large smooth arc is usually used for transition.

The melting and adhesion ability of plastics is mainly related to the mold temperature. Where the mold temperature is high, the plastic is easier to melt first and coat layer by layer with the rotation of the mold, and more resin will adhere to it, while the part where the temperature is low will adhere relatively less resin, resulting in uneven wall thickness of the product.

The wall thickness of the product is also related to the rotational speed. The uneven rotation speed is easy to cause uneven wall thickness and irregularity. Therefore, a motor with constant torque or constant speed that can be automatically controlled is generally used to ensure the uniform rotation of the main and auxiliary shafts. When the wall thickness of a part of the product is very different from other parts, and the mold cannot be modified, it is necessary to seek a solution based on the process angle.