Conventional wisdom has said that metal is better than plastic when it comes to making parts. However, manufacturers are learning that is no longer the case. With the development of new advanced materials, plastics today have tensile strength comparable to metal. While plastics have gotten stronger, they have retained their characteristics of being lighter weight, corrosion resistant, and more flexible. Injection molders are finding that using plastic means manufacturing costs are lower, production speeds are higher, material costs are more stable, design flexibility is greater, and there is less scrap material left over to deal with.

Plastic parts can be just as tough as metal
With the proper engineering, plastics can have physical and chemical characteristics that are better than metal. And with proper part design, plastic parts can actually perform even better than metal parts. If more strength is needed, features to increase strength, such as gussets, ribs, and bosses can be molded into the part when produced. With metal, these features (fastening, welding, and gluing) must be added after the piece is produced.

Switching to plastic can save a lot of money
Manufacturers can expect a 25 to 50% savings by converting from metal to plastic. This is possible due to the following reasons:
1) Multiple metal parts can be combined into one plastic part. This means less production time, the elimination of fasteners and assembly. If multiple pieces are required, the plastic parts can be designed to snap-together eliminating the need for fasteners and reducing time for assembly.
2) Color can be added to the melt, eliminating the need to paint. Textures can also easily be incorporated.
3) Metal must be welded, ground, and enhanced with dent and scratch resistance. Plastics do not require such steps
4) Lower packaging and shipping costs due

Other benefits:
• High dimensional stability
• Tight tolerances can be achieved
• High strength-to-weight performance
• Improve product performance and longevity
• Up to six times longer tool life

When possible, manufacturers are now switching from metal to plastic. The first step in finding out if this is the right move for your company is to analyze and fully understand the end-use application. Other considerations are material evaluations and analysis, manufacturability, economic feasibility, environmental conditions, and more.

The Polymers Center is here to help. We have the engineering expertise needed to help manufacturers analyze and test to make the best decisions possible. We can help make the switch from a metal product to plastic.