When it comes to manufacturing parts metal has traditionally been the material of choice, but over the last 50 years plastic engineering technology has moved on and there are now solid reasons to consider plastic as a first choice.
It is a common misconception that plastic parts are of inferior quality to metal. This is not the case, engineering-grade plastic resins regularly equal, or outperform metal in both scientific tests, and practical everyday experience.
Key to the success of manufacturing in plastic is choosing the right plastic for your purpose. Polymer science has progressed to the level where plastic materials can be combined with reinforcements and fillers to produce a structural integrity that can exceed metal.
Plastics can offer similar tensile strengths to metal, they can be thermally conductive, and they are able to resist chemicals and heat.
Perhaps the greatest benefit which plastics can bring to the manufacturing process is their low weight.
Reducing the weight of a part will have a significant impact on the bottom-line of your company. Think about the amount you spend on packaging, shipping costs, installation costs etc.
In addition to being lighter than comparable metal parts, plastic parts are cheaper to produce. Plastic is a cheaper raw material than metal, and production times are usually quicker as well. In many cases it is possible to incorporate multiple part components into one extrusion or mould. This approach reduces the production costs and can increase the final durability of the product. It is also worth noting that plastic often needs less finishing work than metal components. Plastic can be coloured prior to fabrication, so unlike metal there does not need to be a separate stage for painting, or treating the material after production.
As Ken Glassen, vice president of engineering at Kaysun Corporation, says:
“Plastics can be made to flow to produce thin-walled parts with uniform wall dimensions, replacing the more costly thicker-walled design features of most die-cast metal parts,” … “Multiple metal parts can be replaced by one injection-molded part made of tough engineered plastic, eliminating the need for fasteners and assembly.”
Overall, many companies have achieved cost savings of 25% to 50% simply by switching to plastic parts.
The cost savings are not the only reasons to consider using plastic parts. In many cases plastic can be used to create parts with more complex geometries that would be difficult to manufacture in metal. The injection moulding process allows for threads, ports, under-cuts, and tight tolerances that would be difficult to replicate in metal. The end result can be a finished product that is not only more complex an an equivalent metal part, but will last longer as well. Key to the success of this process is choosing the right plastic for your purpose. Polymer science has progressed to the level where plastic materials can be combined with reinforcements and fillers to produce a structural integrity that rivals or exceeds metal.
As Glassen says:
“With plastic, you can prove it out using finite element analysis before ever molding a part and investing in tooling,” … “With analysis of the entire system up front (system loads, temperatures, chemicals, and UV considerations), you can be sure that plastic is the right choice for your application.”