The Differences between thin-walled moulds and general moulds

- Apr 11, 2018-

Thin-wall products are widely used in food packaging. When we go to restaurants and want to take away food, we will use thin-walled containers to package foods. It is clean and very easy to pack. Thin wall products are more and more popular with merchants. But make Thin wall mould the cost is very high,The differences between thin wall mould and general mould are mould structure, gating system, cooling system and exhaust system and release system.

1.Mould structure: In order to bear the high pressure of molding, the rigidity of the thin wall molding is need larger and stronger. Therefore, the dynamic and fixed template of the mould and its supporting plate are heavier, and the thickness is usually thicker than that of the traditional mold. The support column should be more, the internal lock may be set in the mold, so as to ensure accurate positioning and good side support to prevent bending and deviation.

2. Gating system: Shaped the thin wall products, especially the thickness of the products, should be used with large gate and the gate should larger than the wall thickness. If the direct gate, the cold well should be set to reduce the stress of the gate, assist in filling, and reduce the damage of the product when removing the gate. In order to ensure sufficient pressure filling thin cavity, the pressure drop should be reduced as far as possible in the runner system. For this reason, the flow design is larger than the normal one, and the residence time of the melt should be restricted to prevent degradation of the resin.

3. Cooling system: the thin wall products are not able to bear the residual stresses due to the uneven heat transfer in the traditional wall thickness. In order to ensure the dimensional stability of the products, the shrinkage and warping can be controlled within acceptable range, and the cooling of the mould must be strengthened to ensure the cooling balance.

4. Exhaust system: thin - wall injection molding mold generally needs good exhaust, it is better to vacuum operation. Due to the short filling time and high injection speed, the full exhaust of the mold, especially in the flowing front area, is very important to prevent the gas from burning. The gas is usually discharged through the core, the top rod, the reinforcing rib, the stud and the parting surface.

5.Release system: because of the thin wall products wall and reinforcement are very thin, very easy to damage, and contraction along the thickness direction is very small, make it easy to reinforcement and other small structure adhesive, at the same time high pressure maintaining pressure make less shrinkage. In order to avoid the top and sticky mold, the thin wall injection molding should be used more than the conventional injection molding and the larger size.

The above 5 points cause the special characteristics of thin-wall mould, which leads to the increase of mold price.