November 2022

Polymers help automotive manufacturers save weight and reduce costs. Readily formed into rigid shapes and complex geometries, they play important roles in the interior, exterior and the engine compartment. Making automotive components takes materials expertise and the right manufacturing processes. C-Plex has both. Here’s a closer look. Polymers For Automotive Applications Polymers divide into two groups: thermosets and thermoplastics. The thermosets are rigid and can’t be remelted. They’re used in applications like steering wheels. Thermoplastics on the other hand are flexible, although they can be formed into stiff shapes. They have a wide range of automotive applications. The polymers we use most for automotive applications are: Manufacturing Processes At C-Plex we carry out vacuum forming, thermoforming and reaction injection molding (RIM). These processes are ideal for producing automotive components in a wide range of shapes, sizes and quantities. We can also machine plastics, both to trim and finish molded parts and to produce complex geometries as one-offs and in small quantities. Thermoforming and vacuum forming are closely related. Both are used to produce plastic shapes from sheet material. In thermoforming the sheet is heated and then pressed between two halves of a mold. In vacuum forming there’s only a single mold half and the sheet material is pulled down over it by vacuum. Hollow forms are possible with these processes. One approach is to bring two halves together after molding, another is to blow air between two sheets clamped inside a mold tool. A big advantage of thermo and vacuum forming is that the mold tools are far less expensive than those for injection molding. What’s more, it’s possible to produce much bigger parts than is practical by injection molding. (Alternatively, many small parts can be molded from one sheet in a single cycle.) Thermo and vacuum forming are usually performed on thermoplastics like HDPE, ABS and acrylics. The RIM process is used for making large plastic shapes in thermoset materials. It entails mixing two polymer components and then pouring or pumping them into a 3-dimensional mold. In this sense it’s a little like injection molding but with less expensive tooling, (because the pressures are much lower,) and the ability to make very large shapes. Automotive Applications of Polymers Vehicle manufacturers strive to maximize the amount of plastic used in every car, truck and SUV because it reduces weight. Unless there’s a need for high strength, high temperature resistance or optical clarity it’s very likely an automotive component will be made from one of the polymers discussed above. Another major benefit of plastic molding is that it helps reduce piece count. Molding a part as a single piece rather than assembling it from smaller components saves time and money and improves quality by eliminating tolerance stack up issues. External uses of polymers on vehicles include: In addition, a growing number of body panels are being produced as single piece moldings rather than by using metal or joining smaller parts. Front and rear bumpers are prime examples. Inside the vehicle polymers are everywhere. Applications range from seat cushions (poylurethane foam) to tray liners, door panels, glove box doors and inners and even the steering wheel. Underhood applications present some particular challenges. High temperatures and potentially corrosive liquids are the biggest. However, lower thermal conductivity gives polymers an additional advantage over metals in some situations. Polymer applications in this part of the vehicle include: Producing Automotive Components in Polymer Materials Without extensive use of polymers, modern vehicles would be far heavier than they are now, and probably a lot more expensive. C-Plex uses thermo and vacuum forming processes as well as RIM to produce large and small parts for automotive and other customers. Our formal quality management system ensures high levels of consistency, whether the need is for prototype quantities or high volume production. Contact us to learn how we can meet the needs of automotive customers.

It’s lightweight, doesn’t corrode, comes in a limitless range of colors, and can be formed into an infinite variety of shapes. By “it” we are of course referring to plastic. Though it’s not yet a century since polyethylene was first created, it, and the many other plastics invented since, are used in just about every industry. Plastics and Polymers “Plastic” refers to the ability of a material to deform. Materials scientists and engineers prefer to talk about polymers rather than plastics. Polymers are long chains of molecules that consist mostly of carbon and hydrogen atoms. They’re made from liquids, sometimes gases, and the manufacturing process turns them into liquids and solids. Solid polymers are usually sold as granules and melted for molding shapes. Polymers can be either thermoplastics and thermosets. Thermoplastics can be remelted and formed into other shapes while thermosets are formed once and can’t be melted. Thermosets tend to be stronger and more rigid than thermoplastics. Today there are many types of polymer besides polyethylene. ABS, PVC, Nylon and PEEK are just a few. These were developed with specific properties, like strength at elevated temperatures and chemical and UV resistance. Reasons for Preferring Polymer Materials Polymers can often substitute for metal, glass, ceramics and to an extent, wood. As a general class of products their useful properties include: Of course, there are exceptions. Some polymers are dense. Others are brittle rather than flexible. Many break down when exposed to UV light. Although polymers are not as strong as metals, clever design and manufacturing process selection can create rigid polymer shapes. And not every application needs high strength anyway. Forming Methods for Polymer Products Polymer materials are turned into useful products by first producing them in sheet form or as extrusions, or molding them directly into the final shape. Sheet material can be vacuum and/or thermoformed. These closely-related processes involve cutting the required shape from sheet, then pushing or pulling it onto a former that reproduces the geometry needed. In thermoforming the polymer is softened by heating so it deforms with less load and conforms better to the shape underneath. After forming, the part is trimmed, holes or slots drilled and milled, and components added as needed. The extrusion process creates long lengths with a uniform cross-section or profile. Extruded lengths of polymer are called extrusions and are sawed to length, drilled and milled as needed before being assembled. Molding processes come in many types. Injection molding is the best-known, but needs mold tools that are complicated and therefore very expensive. This is why it’s only appropriate for very high volume production. Other molding techniques include Reaction Injection Molding (RIM), blow molding and rotational molding. Applications for Polymers Unless the application needs load bearing strength, thermal or electrical conductivity, or extremely high temperature resistance there’s almost certainly a polymer that’s up to the task. Common applications include: Industries using polymer products in applications like these include: Most of these industries use polymer materials in their manufacturing processes as well as in what they make. Polymers like nylon make excellent guides for conveyors and chutes, they absorb impacts, provide damping and generally help reduce product damage while extending equipment life. Meeting the Need for Quality Plastic Products Compared to wood, ceramics, glass and most metal alloys, polymers are still a relatively new class of materials. Despite that, they have become essential in both the products we buy and use and the processes that make them. Without polymers everything would be heavier, bulkier and more expensive. At C-Plex we can work with almost every polymer to produce a wide variety of plastic products for customers in a diverse set of industries. With vacuum, thermoforming, RIM, and machining and assembly, we give demanding customers the quality, precision and service they need. Contact us to learn more. Sources https://www.sciencemuseum.org.uk/objects-and-stories/chemistry/age-plastic-parkesine-pollution#