Often used for structure reinforcement, ribs allow greater strength and stiffness in molded plastic parts without the need to increase the wall thickness.
Thicker ribs however may cause sink and other cosmetic problems on the opposite side surface to which they are attached.
As a general rule design ribs that are approximately 60% of the joining wall thickness for minimum risk for sink marks.
If you are utilizing glossy materials it is best practice to minimize your rib thickness to reduce the potential for sink.
Keep in mind thin ribs may be more difficult to fill so careful consideration to material and size should be taken when designing your parts that incorporate very thin ribs.
The article comes from China injection mold manufacturer - Mold Best Assurance Company Limited, website is www.mbamoldanddesign.com
