How To Deal With The Problem Of Uneven Wall Thickness Of Rotomolded Products
For the problem of uneven wall thickness of rotational molded products, specific problems must be analyzed in detail. When there is a large wall thickness difference between one part of the product and other parts, if it is caused by structural problems between the rotational molded product and the mold, the structure of the mold must be changed, and the mold corners designed with too small an angle should be replaced with larger smooth arcs. to transition.
For uneven temperatures in the heating furnace, it is necessary to improve and adjust the air volume, angle and circulation path of the hot air to ensure that the mold can be heated evenly in all directions. For parts of the mold that are relatively deep and difficult for heat to reach, you can use an airflow amplifier to add heat. For problems caused by differences in heat absorption in different parts of the mold, such as the flange parts, you can preheat or reduce the heat insulation factor first. In areas where the thickness of the product is expected to be reduced, an additional layer of thin iron sheet can be welded to the corresponding part of the mold to delay the transfer of heat into the mold and reduce the molten material adhering to the mold cavity, thereby reducing the thickness of this area.
As for the uneven wall thickness caused by improper rotation speed ratio or speed control of the mold, the rotation speed of the main and secondary shafts should be appropriately adjusted to maintain a balanced proportion and uniform speed to obtain uniform coverage thickness and appropriate powder trajectory. A constant-torque or constant-speed motor that can be automatically controlled can be used to ensure that the main and secondary shafts rotate at a constant speed. When biaxial rotational molding is performed, the speed ratio of the two axes should not be an integer multiple, so that the spiral material flow traces of each rotation do not repeat each other. The setting of the speed ratio mainly depends on the shape and structure of the product. Generally, the speed ratio of the secondary shaft and the main shaft is 3:10, which is more appropriate.