China mold maker and supplier

Overview Runner design dictates part quality and productivity. The design rules that follow provide general guidelines for runner design. Runner size Runner cross section The cross-sectional area of a runner should not be smaller than that of the sprue, to …

Importance of balanced flow Balanced flow into the cavities is a prerequisite for a quality part. This can be achieved by changing the runner size and length. Changing the gate dimension may give a seemingly balanced filling. However, it affects …

Overview The ideal injection molding system delivers molded parts of uniform density, and free from all runners, flash, and gate stubs. To achieve this, a hot runner system, in contrast to a cold runner system, is employed. The material in …

Factors you’ll need to consider The diameter and length of runners influence flow resistance. The higher the flow resistance in the runner, the higher the pressure drop will be. Reducing flow resistance in runners by increasing the diameter will use …

Common designs There are several common runner cross-sectional designs. They are illustrated in Figure 1. l   Full-round runner l   Trapezoidal runner l   Modified trapezoidal runner (a combination of round and trapezoidal runner) l   Half-round runner l   Rectangular runner Recommended cross-sectional …

china plastic injection mold company

china plastic injection mold company

Factors involved The number of cavities depends on the available production time, product quantity required, machine shot size and plasticizing capacities, shape and size of the moldings, and mold costs. Formulas Following are simple formulas for determining the number of …

Helping the melt flow A runner system directs the melt flow from the sprue to the mold cavities. Additional pressure is required to push the melt through the runner system. Shear (frictional) heat generated within the melt while the material …

Design for assembly Molding one part vs. separate components A major advantage of molding plastics parts is that you can now mold what were previously several parts into one part. These include many of the functional components and many of …

Boosting structural integrity with ribs Structural integrity: the goal of every design The major component of designing for structural integrity, in many cases, is to design the structure to be stiff enough to withstand expected loads. Increasing the thickness to …

Part thickness Part thickness drives quality and cost Many factors need to be taken into account when designing a part. These include functional and dimensional requirements, tolerance and assembly, artistic and esthetic appearance, manufacturing costs, environmental impacts, and post-service handling. …