Gas-assisted and water-assisted injection molding based on similar technology, and therefore its scope is similar. So, what is the difference between the two techniques in? What are the applicable scopes for both technologies?
Gas-assisted injection molding, as a very mature technology has been applied for many years of history in the injection molding industry. Gas-assisted molding technology one of the most important field of application is the production of thick-walled plastic parts, such as the production of handles and similar products.
Correspondingly, water-assisted molding technology is a new technology, since IKV announced the preliminary results of water-assisted injection molding up to now has only six years, but this technology has been rapidly developing. During the actual production, water-assisted technologies are more and more used in the plastic parts that have functional space or flow channel.
Gas-assisted injection molding techniques are used to produce rod-shaped parts can be reduced part weight and the cycle time. GAIM will also help significantly reduce or completely eliminate the wall thickness of the plastic parts of the regional plane, deformation and shrinkage marks, thereby improving the quality of plastic parts.
The thermal conductivity of water is approximately 40 times than the nitrogen gas, the heat capacity is four times as nitrogen. Apart from ordinary mold cooling, cooling water will cause internal cooling, compared with gas, so cooling time can be reduced by up to 70%. At the same time, water is also a non-compression and inexpensive medium.
Water instead of nitrogen cavity surface quality will be better. In addition larger parts can be processed and water-assisted injection molding to form a more uniform wall thickness, reducing the residual wall thickness.
Water-assisted injection molding and gas-assisted injection molding process can be used in different methods. They did not differ in terms of the use of machinery but differ in mold design and process control. Water-assisted injection molding is a two-step process similar to gas-assisted injection molding: firstly the cavity is filled completely by melt; in a second step, the injection water to form a cavity.
Water-assisted injection mold is generally more expensive than gas-assisted mold, the reason is all the higher manufacturing mold steel village quality (sturdy nickel plating or titanium nitride coating for the protection of water-assisted injection mold from corrosion is essential)