Injection Mold Design Guide Jun 2026

When molten plastic (300°C) rushes into a cavity, it compresses the air in front of it. Compressed air heats up—sometimes to 600°C. That burns the plastic, creating “dieseling” marks: black, carbonized spots.

. This technical manual is widely used as a reference source for engineers and covers the relationship between part geometry, material selection, and the mechanical design of the mold. Essential Design Guidelines injection mold design guide

: This is the "golden rule." Constant wall thickness ensures even cooling and reduces the risk of sink marks , internal voids, and warping. Recommended Range : Generally between , though parts can be as thin as for specific resins. When molten plastic (300°C) rushes into a cavity,

The solution was a vent: a shallow groove (0.02mm deep) along the parting line, just deep enough for air to escape but too shallow for plastic to flash. It’s invisible to the naked eye but as critical as the heart to a body. Recommended Range : Generally between , though parts

He turned the page. A crude drawing showed a fortress wall—thick at the base, thin at the battlements. The caption read: “Uneven walls create ghosts: voids, sinks, and residual stress.”