The shape of rotomolded products affects the forming of rotomolded containers

- Mar 30, 2021-

The shape of rotomolded products affects the molding of rotomolded containers, but it is generally a shell structure. In order to facilitate demolding, split molds are generally used.

   1. It should be as thin as possible (to save power) and have a direct impact on the wall thickness and performance of the product (too thick will easily lead to different temperatures in the mold cavity). It is also related to the rotomolding method and heating system, such as: hot liquid conduction heating mold δ should be thickened = 12-15mm to ensure that the liquid quickly heats the mold and the temperature is uniform. For molds heated by hot air circulation, δ is thinner (5-7mm).

  2. The rotomolding container should have an exhaust port to expel the decomposition of low-molecular compounds due to the increase in pressure in the mold. The exhaust port is a thin-walled metal plastic tube extending to the center of the mold cavity. In order to prevent the powdery resin from overflowing from the exhaust port during rotation, the hole is filled with glass wire, graphite powder and other materials.

  3. The material requirements are not high. Good thermal conductivity, extensibility, solderability, and heat resistance are sufficient. Steel and aluminum are common. The mold material affects the time required to heat the rotomolding container is the main part of the heating cycle, so the mold material has a great influence on the heating cycle. For example, a nickel mold with δ=3.2m and a lead mold with a thickness of 614mm are heated equally at 205°C, and the time h1 is smaller than h2. Rotomolding container mold: mold rotation and revolution speed, etc. To produce a product with uniform wall thickness, the rotation of the mold And revolution speed and speed ratio are very important factors.

   The rotational speed of the rotomolding container should not be too fast, and the centrifugal force will cause the material to fly out of the cavity. The proper speed should ensure that a layer of material sticks to the wall of the mold every one revolution. Mainly depends on the resin viscosity. The viscosity is high, and the cavity can be covered evenly at a slow speed. The revolution speed is less than the rotation speed, usually 1:4, sometimes 1:1 or 1:8. The speed ratio depends on the shape of the product and the way the mold is suspended.

   The above content is to give you a detailed explanation about the shape of rotomolded products affecting the forming of rotomolded containers. I believe that everyone has further learning and understanding. If you want to know more inquiries, please continue to pay attention to us.