In multi-cavity molds, ensure that the flow path distance from the main sprue to every single cavity is identical. Unbalanced runners cause uneven filling, flashing, and dimensional variations across parts.
The feed system acts as the plumbing network, delivering molten plastic from the injection machine nozzle into the mold cavities.
For textured surfaces, add an extra 1° to 1.5° of draft per 0.025mm (0.001 inches) of texture depth. Ribs and Bosses
Before cutting steel, designers use CAD and CAE (Computer-Aided Engineering) tools to simulate the molding process.
Your material dictates steel type, vent depth, and surface finish.
Before cutting steel or aluminium for a mold, the plastic part itself must be optimized for the process to avoid defects like sink marks, voids, and warping. Plastic Injection Mold Design Guide | PDF | Polyethylene
Draft is the taper applied to the sides of a part to facilitate its removal from the mold.
: Harder and more expensive to tool because the mold maker must machine away all the surrounding metal to leave the letters standing in the mold. This style is often used when text needs protection from surface wear or for a specific aesthetic. Best Practices Summary Recommendation Font Type Bold Sans Serif (e.g., Arial, Verdana) Minimum Size 20 points (~5 mm height) Height 0.3 mm – 0.5 mm (raised) Placement Facing the "pull" direction of the mold
Cooling constitutes 70-80% of the total cycle time.
The design must allow for machining, usually via CNC milling or EDM. 2. Fundamental Injection Mold Design Rules
The gate is the opening through which molten plastic enters the mold cavity. Choosing the correct gate type affects part appearance, structural integrity, and production cycle time.
Identifying defects early allows engineers to modify the tool geometry before cutting steel.