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Have you ever wondered how to design parts for injection molding?

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This video will walk you through the essential design for manufacturing rules for injection molding,

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so your parts are strong, accurate and ready for production.

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Decrease the maximum wall thickness of a part to shorten the part cooling time and reduce

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the part volume. Keep walls as uniform as possible. Uniform wall thickness will ensure

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uniform cooling and reduce defects such as warping, sink marks and porosity.

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Round corners to reduce stress concentrations and fracture. Round corners also smooth

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and plastic flow and mitigate unfilled gaps at corners. The inner radius should be at least

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the thickness of the walls. Apply a draft, also known as taper, of one degree to two degrees

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to all walls parallel to the parting direction. This improves part ejection from the mold.

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Proper draft angles also increase mold life. Use ribs instead of thick walls for structural

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support rather than increasing the wall thickness. This increases stiffness without excess material.

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However, remember to orient ribs perpendicular to the axis about which bending may occur

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to properly utilize their strength. The thickness of ribs should be around half of the walls

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to which they are attached. Round the corners at the point of attachment of ribs to the structure

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and apply a draft angle of at least 0.25 degrees. Bosses should be supported by ribs that connect

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to adjacent walls or by gussets at the base, as standalone thick bosses can cause sink marks or warping.

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Similarly, if a boss must be placed near a corner, it should be isolated using ribs instead

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of being merged with the walls. Minimize the number of external undercuts. External undercuts

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require side cores which add to the tooling cost. Some simple external undercuts can be molded by

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relocating the parting line. Sometimes redesigning a feature can remove an undercut. This can often be

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used in part designs that include hinges. Minimize the number of internal undercuts. Internal undercuts

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often require internal core lifters which add to the tooling cost. They can also be avoided with

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clever design if it does not interfere with parts functionality. Lastly, minimize the number of

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side action directions. Additional side action directions will limit the number of possible

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cavities in the mold, reducing the production rate. Thank you for watching the video. For more

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information, please visit CustomPartNet website.