Gas-Assisted Injection

Adding nitrogen gas during the plastic injection process presents several significant technical advantages. First, it helps reduce internal stresses in the part during cooling, contributing to minimizing warping and deformation. Additionally, gas-assisted injection promotes better plastic material distribution in the mold cavity, improving part homogeneity and reducing defects like flow marks and weld lines.

Furthermore, using nitrogen gas also optimizes production cycle times. By partially filling the mold cavity with gas, the plastic’s cooling time is reduced, accelerating the overall injection process and increasing production yield.

Using gas-assisted plastic injection with nitrogen has specific implications for tooling design and manufacturing. Here are some important specifics to consider for tooling:

Mold Design:

The mold design must include specific channels for gas passage in the mold cavity. These channels must be dimensioned and positioned to ensure uniform gas distribution throughout the cavity. Additionally, it is essential to design the mold to minimize gas losses and avoid dead zones where gas could become trapped.

Mold Materials:

Materials used for mold manufacturing must be carefully chosen to withstand high temperatures and gas pressures. Special wear-resistant and corrosion-resistant steels are often used to make molds for gas-assisted injection.

Effective Cooling:

As the gas-assisted injection process reduces plastic cooling time, the mold must have an efficient cooling system. Specific cooling channels must be integrated into the mold to quickly and evenly dissipate heat, allowing for optimal operating temperatures and uniform plastic solidification.

Pressure Control:

The mold must be equipped with pressure control systems to monitor and regulate gas pressure during the injection process. This ensures gas pressure is maintained within specified limits to avoid part defects like excessive plastic shrinkage.