Application of Valve Hot Runner

The well-known valve hot runner is mainly applied for precision plastic parts and products with higher demands on appearance.

Advantages of Valve Hot Runner’s Molding Technology

Valve hot runner’s unique technology on process control could highly increase parts’ reliability, making melt faster and smoother flow in three-dimensional cavity, shorter molding cycle, which plays an important role for quality improvement.

1.Ensure cavity smooth filling, and melt balance flow by control of gate’s opening time can remove the melting mark.

Large injection parts’ manufacture usually requires two or several gates for whole injection. To common hot pouring system, the gate opens once the injection starts. In this case, it inevitably results some defects due to incomplete melting of two different flows when their fronts are converged, forming some prints on parts’ surfaces, which generally are called the melting marks. Though it can be improved by temperature and dwell pressure raises, and adjustment of technological parameters, the real effect is limited.

Pouring system formulated by valve hot runner technology not only achieves process control of each valve gate on its opening and closing, but also controls the opening of the valve and the second gate when the first melt just flowing to the second gate. At this time, it could open or close the first gate according to demands that won’t stop until all gates are open and cavities are filled, forming complete melts and traceless parts. Besides, it could achieve balance flow condition via the opening and closing of the valve gate.

2.Parts manufactured by this technology won’t leave mark on gates, so it is applicable to process injection parts with higher demands on surface quality.

Sometimes, the reason why we use valve gate is because its smooth mark on the parts, which only amounts to the mark left by ejector pin. So, compared with marks left by subsurface gate or on top of other hot runners, this one is much smaller.

3. More efficient control of pressure maintaining and molding cycle.

Valve hot runner can use gates with large diameters, which accelerate melt flows in cavity, reduce parts molding cycle, and better maintain the pressure.     

4. Efficiently reduce parts inner stress and improve the stability.

In traditional hot pouring system, after two flows of melt fronts are converged, it will result melting marks that not only affects parts appearance, but also easily generates residual inner stress inside them. The stress concentration will reduce product’s intensity. If it takes valve gate to control melt’s unit order, direct convergence of melt fronts will be effectively eliminated, which avoids the stress concentration happening and improves product’s stability.