Thin wall container is very popular in market all over the world. typically, container with a wall thickness less than 0.6 mm is considered as "thin wall". Thin wall container features: thin wall, light weight, high yield, short turnaround period, so the mould requirements are very high.
Thin wall injection molding needs molding speeds 4-6S, so it requires a very good cooling system and high hardness in order to ensure the short cycle and the mold life. For such molding speeds, we should add water channel as more as possible,
strengthen the water circulation. Usually we use chilled water. So our mould steels are stainless steel.
Besides, we always adapt with BeCu to help the mould cooling, because BeCu has good thermal conductivity.
In China, Micon Mould has rich experience in thin wall mold making.
As for the thin wall mould, we always use high speed milling machine and some other high precision tooling machine to tool it, the dimension tolerance should be controlled within 0.05mm. And there will have many inserts so as to maintain the molds.
Regarding the ejection system for thin wall container mould, we usually use air to blow off the cavity. It requires the parts demolding quickly and then use air ejection or air with stripper plate assistance.
Thin wall container design main points:
1. The leakage shall be zero.
2. The container body and cover shall fit properly, leave gap 0.15-0.2mm.
3. There shall leave 0.8-1mm room when design the joint of cover edge and container.
4. The rib design shall be thinner than product, thin wall products are mostly transparent material, too thick rib will bring bubbles.
Thin wall mould design points:
1. If the product shape simple, no any undercut or perforation, for example, plastic cups, about 3 degree or above inclination, in the mould design can use side air, inclined air, air valves etc.
2. If the rib on the stripper plate less than 1mm, the stripper plate can be made as insert in order to machining the rib.
3. Multi cavities mould design points:
a. Individual self-locking: multi cavities independent self-locking is suitable for all shapes of thin-walled mould design, each cavity independent.
b. Entirety mode locking: thickness more than 0.8mm, if machine small, the mould won't fit, so to adopt entirety mode.
4. Core and cavity design points:
a. Cavity plate normally use P20 steel.
b. Should use inserts around the cavity edge to reduce the possibility of steel breaks.
c. Should design cooling water around the gate to reduce the hot runner cooling time.