Many customers report that the plastic box will find a hollow inside when it is used. If it is worried about whether it will affect the quality of the packaging, here we will tell you why the plastic box is hollow or collapsed inside:
1. The gel and foaming reaction rate are not balanced. We all know that the foaming process is indispensable in the production process of plastic boxes. In the final stage of foaming, a large amount of gas is generated, and the viscosity of the bubble membrane wall is larger. At this time, its elasticity is also very poor. In the case where the gas in the bubble is continuously increased, it cannot withstand the stretching of the film wall, and thus the bubble may be broken and the gas may overflow, thereby forming a phenomenon of opening. When it occurs, the wall of the foam membrane is broken and further extended, which will cause the foam collapse phenomenon. If the crack spreads and stops, it will cause partial hollowing or cracking of the plastic box. To improve this situation, it is necessary Increasing the amount of the gel catalyst in the plastic box raw material, or reducing the amount of the foaming catalyst, thereby reducing or improving the hollowness or collapse of the foam.
2. The amount of foam stabilizer is low. Stabilizer is one of the indispensable raw materials in the plastic foaming process. It can reduce the surface tension of each raw material component during the whole process, and can stabilize the foaming process and make the foam. The pores become finer and more uniform. When the system is in the low viscosity stage, the pores of the plastic box are grown to a thickness suitable for the opening, creating conditions for the final opening, and the stability of the foam pores is small when the amount of the stabilizer is small. Will become worse, premature opening will cause collapse or partial hollow, the appropriate amount of stabilizer is mainly used to coordinate the opening period, but the plastic box opening must be in the foaming reaction and the gel reaction When it is completed and reaches equilibrium, it will appear, otherwise there will be central control or collapse.
The hollow inside of the plastic box is not only the above two phenomena, the occurrence of these defects is closely related to the influence of the raw material formula, the state of the tooling mold and the production process parameters, so it is necessary to pay more attention in the production process. .