Water injection molding introduction

The water-assisted injection molding technology is an advanced injection molding process that injects high-pressure water into the melt through a pressurizing device and a water auxiliary controller after a portion of the melt is injected into the mold cavity; finally, the water is incompressible. Thus, the water front end forms a solid interface, and the inner wall of the product is squeezed into a cavity. The front end of the water also plays a role of rapid cooling. Therefore, the water auxiliary has many advantages that are unmatched by gas. Research and application show that the water auxiliary energy generates a thinner and more uniform cavity wall, and the surface of the inner wall of the flow channel is very smooth. Especially for thick-walled workpieces, the cooling time can be significantly reduced compared to water-assisted and gas-assisted. The thermal conductivity of water is 40 times higher than that of gas, and the heat capacity of water is 4 times larger than that of gas. For thick-walled parts, cooling time can be reduced by 30-70% compared to water-assisted and gas-assisted

Water-assisted injection molding (WIT) is a new method of forming hollow or partially hollow injection molded parts. Water-assisted injection molding can not only form thick products, form a very smooth inner surface, but also cool the products from the inside out. The cooling time is only 1/3 or 1/2 of the gas-assisted injection molding. The demand for this technology comes mainly from suppliers of automotive hollow products.

Suncenter's water-assisted injection molding integrated system has the following features:

◎ Maximum output pressure up to 400b15l/min adjustable;

◎ can control two injection molding machines at the same time, each ar;

◎Output flow rate at 400 bar pressure 0 - Injection molding machine can be individually pressure and flow control;

◎ Injection curve can be set arbitrarily.

Water injection molding features

The design of water-assisted injection molding equipment must meet the conditions similar to gas-assisted injection molding. This is because most process technologies are based on gas-assisted injection molding. However, water-assisted injection molding also has its own characteristics. From the point of view of plastic parts, except that drainage is more complicated than the removal of nitrogen gas, it is necessary to complete the “drainage” of plastic parts through gravity and the introduction of compressed gas. To prevent corrosion, water must not come into contact with the mold surface.

Water-assisted injection molding requires extremely high water injection capacity to ensure uniform wall thickness distribution and high surface quality. For this reason, suitable pressure control mode. The water supply operates at an extremely high flow rate and can reach a pressure of 350 bar. In order to inject water into the melt, an injection assembly with a larger cross-sectional area than gas-assisted injection must be used, which is essential for water to penetrate into the melt at a sufficient speed.

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