A thick walled moulding using gas injection
More about Gas Assisted Injection Moulding
Gas Assisted Injection Moulding has improved the quality and cost effectiveness of injection moulded components. By using Gas Assisted Moulding parts can be manufactured with enhanced surface finishes, reduced weight, reducing production costs and material usage.
The principle of this process is that nitrogen gas is injected, during the moulding cycle, either through the sprue or directly into the mould tool. At a controlled high pressure this has the benefit of overcoming sink marks or introducing a cavity without the requirement of a core. During the cooling phase, of normal Injection Moulding, the moulding will shrink away from the mould cavity and a pack of material has to be introduced to counteract the sink. When using Gas Assisted Moulding this pack is replaced by nitrogen, introduced at high pressure while the moulding cools, which helps eliminate sink and improves overall surface finish.
Benefits of Gas Assisted Injection Moulding
- Reduced material requirements – By not having to pack a component the result is a part with a hollow core. In larger components this can save up to 30% in material requirements providing much reduced costs.
- Reduced cycle times – Due to the nitrogen there is no molten core on the part to solidify which causes a major reduction in cycle times.
- Reduced wear on moulds – Gas Assisted Moulding can reduce in-mould pressures by up to 70% meaning a lower press lock force is required. This means larger mouldings can be formed in smaller presses and there is less overall wear on the cavity of the tool. These factors help to reduce overall running costs.
- Improved component quality – The use of gas creates a uniform pressure within the mould cavity. This helps to eliminate sink marks and greatly improves the overall surface finish of the component.
