Why Do Rotomolded Products Cause Bubbles?

1. Material issues: If the materials used contain a large amount of volatile substances or moisture, bubbles may easily occur during the heating process. Especially when manufacturing plastic products, toxic substances in the materials may also produce harmful gases. In addition, a melt index that is too low may also lead to the formation of bubbles.

2. Temperature problem: During the manufacturing process, if the heating temperature is insufficient or the heating time is not enough, the material may not be fully heated and it will be difficult to fully fit the mold, resulting in bubbles.

3. Pressure problem: Insufficient or uneven pressure during manufacturing can easily lead to the generation of bubbles. These bubbles may be caused by gas being indented into the material, or they may be caused by insufficient fit between the material and the mold.

4. Mold design: The design of the mold may also affect the generation of bubbles. For example, the diameter of the mold ventilation pipe is too small or blocked, the pressure inside and outside the mold is not balanced enough, the internal pressure increases, and the resistance increases when gas escapes, resulting in residual gas in the raw material, resulting in bubbles in the product. In addition, if the parting surface of the mold is not closed tightly or there are blisters and pores on the cavity surface of the mold, bubbles may appear on the rotomolded products during molding.

5. Gas in the raw material: The gas in the raw material cannot be completely eliminated. During the heating process, it gradually melts, flows and adheres to the mold cavity. During this process, the gas trapped in the raw material is gradually squeezed to the surface, but due to the melting process Due to the existence of body surface tension, if the force of gas pushing outward is insufficient, it will be unable to break away from the melt surface and can only nest in the raw material, thus forming bubbles on the surface of the product.

In order to reduce bubbles in rotomolded products, corresponding measures can be taken, such as selecting appropriate materials, controlling temperature and pressure, optimizing mold design, etc. At the same time, you can try to repair products that have bubbles, such as using hot melt glue, epoxy resin and other methods. However, please note that if the damage to the product is serious or the repair effect cannot be determined, it is best to consult a professional or manufacturer for advice.