Design Guidelines: Plastic Injection Molding
Our basic guidelines for plastic injection molding include important design considerations to help improve part moldability, enhance cosmetic appearance, and reduce overall production time.
|SIZE||18.9 in. x 29.6 in. x 8 in.|
|VOLUME||59 cu. in.|
|DEPTH||4 in. from parting line|
|Up to 8 in. if parting line can pass through the middle of the part|
|PROJECTED MOLD AREA||175 sq. in.|
|SIZE||480mm x 751mm|
|VOLUME||966,837 cu. mm|
|101mm from parting line|
|Up to 203.2mm if the parting line can pass through the middle of the part|
|PROJECTED MOLD AREA||112,903 sq. mm|
Typically, Protolabs can maintain a machining tolerance of +/- 0.003 in. (0.08mm) with an included resin tolerance that can be greater than but no less than +/- 0.002 in./in. (0.002mm/mm).
|PM-F0||non-cosmetic, finish to Protolabs' discretion|
|PM-F1||low-cosmetic, most toolmarks removed|
|PM-F2||non-cosmetic, EDM permissible|
|SPI-C1||600 grit stone, 10-12 Ra|
|PM-T1||SPI-C1 + light bead blast|
|PM-T2||SPI-C1 + medium bead blast|
|SPI-B1||600 grit paper, 2-3 Ra|
|SPI-A2||grade #2 diamond buff, 1-2 Ra|
|MINIMUM FOR SHUT OFF||3°|
|MINIMUM FOR LIGHT TEXTURE (PM-T1)||3°|
|MINIMUM FOR LIGHT TEXTURE (PM-T2)||5°+|
Maximum Side Core Dimensions
|< 8.419 in.||< 2.377 in.||< 2.875 in.|
Maximum Side Core Dimensions
|< 213.84mm||< 60.38mm||< 73.66mm|
|MATERIAL||RECOMMENDED WALL THICKNESS|
|ABS||0.045 in. - 0.140 in.|
|Acetal||0.030 in. - 0.120 in.|
|Acrylic||0.025 in. - 0.500 in.|
|Liquid Crystal Polymer||0.030 in. - 0.120 in.|
|Long-Fiber Reinforced Plastics||0.075 in. - 1.000 in.|
|Nylon||0.030 in. - 0.115 in.|
|Polycarbonate||0.040 in. - 0.150 in.|
|Polyester||0.025 in. - 0.125 in.|
|Polyethylene||0.030 in. - 0.200 in.|
|Polyphenylene Sulfide||0.020 in. - 0.180 in.|
|Polypropylene||0.035 in. - 0.150 in.|
|Polystyrene||0.035 in. - 0.150 in.|
|Polyurethane||0.080 in. - 0.750 in.|
Table is adapted from manufacturingcenter.com.
RECOMMENDED WALL THICKNESS
1.143mm - 3.556mm
0.762mm - 3.048mm
|Acrylic||0.635mm - 12.7mm|
|Liquid Crystal Polymer||0.762mm - 3.048mm|
|Long-Fiber Reinforced Plastics||1.905m - 25.4mm|
|Nylon||0.762mm - 2.921mm|
|Polycarbonate||1.016mm - 3.81mm|
|Polyester||0.635mm - 3.175mm|
|Polyethylene||0.762mm - 5.08mm|
|Polyphenylene Sulfide||0.508mm - 4.572mm|
|Polypropylene||0.635mm - 3.81mm|
|Polystynene||0.889mm - 3.81mm|
|Polyurethane||2.032mm - 19.05mm|
Table is adapted from manufacturingcetner.com.
Some part corners will have a radius rather than a sharp edge since we use an automated CNC milling process to make the mold for your parts. This typically does not require a change to your model, but resulting radii are identified before the mold is milled.
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