Injection molding is the most common manufacturing method for producing plastic parts in the world. The purpose of these parts can range from a picture frame that is never touched to a gear that is used in a moving assembly every day. Many times, the stiffness of a part must increase due to the load applied to the part design. When designing strength into an injection molded part, considerations must be made to accommodate for the manufacturing process. This is where ribs and gussets come into the design.

Ribs are thin wall protrusions that extend perpendicularly from a wall or plane. Gussets are triangular shaped ribs that support a main wall. Ribs and gussets add strength and rigidity to primary walls without the dangers and high costs caused by excessive wall thickness.

If a wall is too thick, sinking and warpage may occur on the part, resulting in a rejected design. Ribs solve this problem by providing additional support for thin walls, and are in fact, more effective structurally than just a thick wall. Along with being stronger, ribs also require less material than thick walls making them the economical choice as well.

Ribs increase the durability and quality of your part while reducing material cost, but if used incorrectly, can have negative effects on the aesthetics of your molded part. The area where the rib intersects with the main wall will experience a thicker plastic section. If the rib is too thick it will cause a sink mark in the main wall due to inconsistent cooling rates. To avoid this there are several rules to follow when using ribs in your design:

Feel free to call me at 770-901-3200 to discuss your upcoming project and how ribs may benefit your design. Click Here to request a FREE molding sample that shows rib and gusset usage.

Just a reminder:

The Chinese New Year is the longest and most important of all Chinese holidays. This 2-week holiday falls on different dates each year between January 21 and February 20. During this holiday, the working people of China take leave from working so that they can celebrate the New Year with family. Quickparts Chinese manufacturing facilities will be closed during this period to honor these traditions.