Plastic Injection Molding Part Design Guidelines

UpMold has provided these plastic part design guidelines because we strive to produce your molds and parts perfectly according to your designs. In order to assure that your parts are moldable, please examine the basic guidelines laid out on this page and follow these basic design steps when designing  your plastic parts.

Wall Thickness by Resin Material Guidelines

The proper material selection and observing uniform wall thickness in injection molded plastic parts, helps avoid potential issues such as sink marks and warpage. We recommended using the plastic part design guidelines in the table to the right as thicknesses vary by material:

Material Available Wall Thickness(inches)
ABS  0.045-0.140
Acetal 0.030-0.120
Acrylic 0.0025-0500
Liquid Crystal Polymer 0.030-0.120
Long-fiber Reinforced Plastics 0.075-1.000
Nylon 0.030-0.115
PC(polycarbonate) 0.040-0.150
Polyester 0.025-0.125
Polyethylene 0.030-0.200
Polyphenylene Sulfide 0.020-0.180
Polypropylene 0.025-0.150
Polystyrene 0.035-0.150
Polyurethane 0.080-0.750
Resin Available Wall Thickness(inches)

Minimum acceptable wall thickness and layer height

Overall wall thickness should be greater than or equal to the ideal amount, but thinner wall sections greater than or equal to the acceptable minimum are achievable. Wall thickness is geometry and application dependent. We recommend designing load bearing surfaces with ideal thickness or greater.

Plastic part  of wall thickness and layer height relationship with resin

Thickness Optimized design guideline

Such as below charts showing that you can according the corrected solutions to optimize your plastic injection molded products

Rib Optimized design guideline

Such as below diagrams showing that you can according the corrected solutions to optimize your plastic injection molded products

Boss Optimized design guideline

Such as below charts showing that you can according the corrected solutions to optimize your plastic injection molded products

Draft Optimized design guideline

Such as below charts showing that you can according the corrected solutions to optimize your plastic injection molded products

 

 

Draft
A taper applied to the faces of the part that prevent them from being parallel to the motion of the mold opening is called draft. This keeps the part from being damaged due to scraping as the part is ejected out of the mold. Recommended draft:
0.5 degrees on all vertical faces is strongly advised.
2 degrees works very well in most situations.
3 degrees is minimum for a shutoff (metal sliding on metal).
3 degrees is required for light texture.
5 or more degrees is required for heavy texture .