Understanding Injection Pressure in Molding

Quiz by: How Does Injection Pressure Affect the Properties of Molded Parts? — Refer to this article for more details.

What is the effect of high injection pressure on molded parts?

High injection pressure indeed reduces shrinkage marks as it ensures the mold is filled completely. However, too much pressure can lead to defects like flash and even deformation of parts.

How does low injection pressure affect the appearance of molded parts?

Low injection pressure can lead to weld marks as the plastic may not flow properly at confluence points. A smooth surface finish typically requires adequate pressure.

What is a common issue caused by excessive injection pressure?

Excessive injection pressure can lead to poor dimensional stability as it induces residual stress in the material, increasing the risk of warping or deformation.

Why is achieving the right injection pressure crucial in molding?

Achieving the right injection pressure is crucial because it directly impacts both the mechanical properties and the visual appearance of molded parts, ensuring they meet quality standards.

How does injection pressure affect internal quality in molded parts?

Injection pressure significantly improves the internal quality by reducing porosity and increasing density. Properly compacted melt results in fewer internal defects.

What happens if injection pressure is too low during molding?

If injection pressure is too low, it can create weak spots in molded parts as trapped air leads to porosity and structural weaknesses.

What is a consequence of high injection pressure on mechanical properties?

High injection pressure can lead to an increased risk of cracks or deformation due to higher residual stress within the molded part, affecting long-term reliability.

Why is it important to balance injection pressure during molding?

Balancing injection pressure is crucial to ensure consistent wall thickness and stability of molded parts. Uneven pressures can lead to defects and inaccuracies in the final product.