Low Pressure Die Casting
Low pressure die casting, also known as LPDC for short, is an extremely efficient production process in which molten aluminum alloys are shot under pressure into a mold to create a product. Unlike high pressure die casting, low pressure die casting uses 7T to 10T, while high pressure die casting uses 100 to 3,000T. Liquid aluminum alloys are injected into a hardened steel mold by this pressure from a holding furnace.
The pressure of low pressure die casting allows the liquid aluminum to work well in all corners and crevices of complex molds. Due to the relatively high pressures, the molten aluminum can precisely fill the mold, making it easy to produce complex and thin-walled shapes.
Generally, low pressure die casting is used to produce products that are much larger than those suitable for high pressure die casting. Because the molten material is slowly but under pressure injected into the mold, larger molds can be filled up to 1.80m.
In low pressure die casting, products can be produced on an assembly line basis. This makes series sizes of 2,000 to 100,000 easily achievable. Due to the high numbers of series but the relatively slow production speed of the process, the production costs are higher than in high pressure die casting. A complex mold is required that can withstand more than 70,000 shots.
Advantages
- Stronger and larger products up to 1.80m can be produced due to the slow mold filling.
- The porosity of the products is lower due to the slow mold filling.
- Castings are suitable for heat treatments.
- High shape complexity is possible through the use of inserts or sand cores.
Consequences
- The minimum workable wall thickness for low pressure casting is 4.0mm.
- We recommend using a draft angle between 2.0 and 3.0° to release the product from the mold. This depends on the complexity and size of the product.
- Large series are required to make the process costs attractive; for smaller series sizes or products with other requirements, we can propose alternatives or modifications.