Even though metal-to-plastic injection molding conversion has been around since the 1950s, many companies are unaware of its benefits. Because of the necessity to decrease weight and enhance fuel economy, automotive and aerospace businesses have been the most active in converting current metal components to plastic injection molding. Engineered plastics may be as robust as metal with the right design.
They can also be more chemically resistant and have superior heat resistance, making them ideal for fuel systems, fluid handling configurations, and other high-temperature applications. Moreover, engineered plastic that is thermally and electrically conductive can be utilized as EMI or RFI shields or in automotive electronics.
What are the benefits?
The cost of manufacturing is a significant driver of change in every sector. If there are lower-cost alternatives that produce the same or better benefits, a corporation should naturally seek them. Regarding metal-to-plastic conversion, plastic components’ most significant advantage is their potential cost savings of 25-50% over metal. Also, the use of plastic generally minimizes the number of secondary procedures often associated with metal parts and the number of assembly stages necessary.
Additionally, OEMs may integrate various components into a single molded part design with plastic instead of producing numerous discrete metal components and welding or riveting them together. Using scientific molding procedures, OEMs may even make complicated plastic components with strict tolerances that do not require additional machining. Fewer production stages and shorter assembly duration can result in considerable cost savings and increased design flexibility.
In addition to speeding assembly, injection molding provides producers with the time-saving benefit of having the color and surface finish ready to go right out of the mold, rather than needing to add time-consuming procedures afterward, as with metal components. Furthermore, injection molding offers shorter cycle times (more parts produced per machine hour) than metal components, generating predictable and durable parts.
Plastic components are generally 50% lighter than metal parts and have a higher production quantity – you get more pieces per pound with plastic vs. metal.
1. Design flexibility: Converting to plastic components allows producers additional flexibility in product design, including increased material diversity and the ability to build more complicated shapes. Plastic injection molds enable under-cuts, threads, ports, and tight tolerances, making a net form to the finish level standards, making it considerably easier to produce complicated shapes than metal.
2. Material preference: Polymer technology has progressed to the point that suppliers may combine a range of plastic materials with precise fillers and reinforcements to give enormous structural stability. With correct material selection and design optimization, plastic may be as robust as metal while weighing significantly less. Based on the job, selecting suitable plastic might take some time. The availability of over 25,000 designed materials for manufacturing purposes is one of the most significant advantages of plastics. Custom-designed, higher-performance mixes and hybrids can also be developed to satisfy particular performance needs. The following are vital factors for plastic-type:
- Chemical resistance, impact, flow, processing, and other needs should be considered while choosing between crystalline and amorphous materials.
- Additives impact strength, stiffness, temperature performance, aesthetics, packaging requirements, and cost.
- Fillers made of carbon and stainless steel increase conductive or shielding qualities.
- Lubricant fillers increase the wear and friction characteristics of lubricants.
- Mineral fillers increase dimensional stability, electrical performance, weighted feel, sound dampening, and specific gravity.
- Impact modifiers increase toughness.
Making the switch
The first stage is determining whether the project is appropriate for metal-to-plastic conversion. This involves extensive thought and is not always a fast decision. End-use application, environmental circumstances, material assessments and analyses, manufacturability, and economic feasibility must be thoroughly understood. The design engineers must be able to properly analyze the product’s real-world environment, comprising chemical exposure or contact solutions, temperature variations, shielding, and forces (including worst-case scenarios). This information must be assessed together to select the optimum material decision.
The most spectacular achievements in metal-to-plastic conversion are almost certainly still to come, especially with developments in tailored polymers. The creative freedom provided by metal-to-plastic conversion is perhaps the most intriguing advantage. Manufacturers may think more creatively about complicated geometry, harsh environment performance, shielding concerns, weight, and structural restrictions, thermal management, and product differentiation—both in terms of performance and how the product appears on the shelf.