Plastics are some of the most common materials used to produce commercial items. Manufacturers use these materials to create everything from medical devices to consumer products.
Plastics can be made from thousands of types of polymers, each of with its own unique mechanical properties. Engineers have created plastic manufacturing processes that cover a wide variety of part geometries and applications.
Top Methods for Manufacturing Plastics
Many methods are used to create plastic products. Some of the most efficient plastic manufacturing techniques include:
Injection Molding (IM)
Injection molding works by injecting a mold with molten thermoplastic. Because molds can be custom designed, and because the plastic conforms completely to each mold used, this process can create large amounts of highly intricate products. This is the most common process used to mass manufacture plastic parts.
Manufacturers use this technique to create hollow plastic parts. To build desired shapes, manufacturers inflate a heated plastic tube inside a mold. This process is continuous and can be completely automated, which results in low unit costs and high rates of production.
Manufacturers perform thermoforming by using air-based or mechanical processes to mold plastic sheets into the desired shapes. Air pressures used can range from nearly zero psi to several hundred psi.
When thermoforming at 14 psi, which is equivalent to the Earth’s atmospheric pressure, manufacturers instead create pressure by removing the space between the sheet and the mold. This process is referred to as vacuum forming.
Manufacturers use extrusion to create products such as:
- Continuous sheeting
- Profile shapes
Similar to injection molding, extrusion refers to a process in which workers feed dry plastic material into a hopper, which conveys it into a long heating chamber. The difference between these two processes, however, lies at the end of the heating chamber: During extrusion, the plastic is forced out of a die or small opening in the desired shape. After the material leaves the die, manufacturers move it to a conveyor belt, where it cools.
Unlike more common plastic manufacturing processes, CNC machining is a subtractive process. Plastic is removed by either by milling (using a fixed part and spinning tool) or lathing (using spinning parts with fixed tools). Machining is best suited for building low-volume plastic part applications that require geometries that are hard to mold but still require tight tolerances.
Infinite Applications for Plastic Parts
Manufacturers can draw from thousands of types of polymers when designing plastic products. Each polymer has its unique derivatives, base chemistries, and additives that suit it to unique aesthetic and functional requirements. Most plastics shake out into one of two categories: thermoplastics and thermosets.
Thermoplastics are the most widely used type of plastic. They’re durable enough to withstand many melting and solidification cycles without significantly degrading.
Thermoplastics normally come in the form of sheets or small pellets. Workers heat and form these into the required shape using a number of manufacturing processes. Since no chemical bonding occurs, the process is wholly reversible, which makes it feasible to recycle or melt thermoplastics for reuse.
After curing, thermoset plastics permanently remain in a solid state. Polymers in thermosetting plastics cross-link during the curing process, which is induced by suitable radiation, light, or heat. Because the curing process forms an irreversible chemical bond, thermoset plastics will not reform upon cooling and not melt when heated. Instead, they will decompose when exposed to extreme heat. This makes it nearly impossible to recycle thermosets or turn the plastic back into its base components.
Industries that use thermoset plastic parts daily include:
- Electronic and electrical
- Home products
- Medical and pharmaceutical
Quality Plastic Parts from Mardek
Mardek leads the field in offering high-quality, custom plastic manufacturing and machining services. Our long-standing relationships and ISO 9001–certified manufacturing facilities guarantee the highest level of quality for your products.
Contact us today to request a quote on our quality plastic manufacturing services.
Plastic injection molding allows manufacturers to produce large quantities of plastic parts in a fast, efficient, and cost-effective manner. This process injects molten plastic into stiff molds or frames and then applies pressure as the plastic cools.
Using this technique, plastic part manufacturers enjoy a high degree of design flexibility and can create parts of almost any size, shape, or function. This process can also build complex designs with multiple intricate elements. Beyond its versatility and efficiency, plastic injection molding offers manufacturers a number of important advantages by reducing costs as well as the environmental impact of production.
Key Advantages of Plastic Injection Molding for Part Manufacturing
Plastic injection molding brings a long list of benefits to any plastic manufacturing project.
Once the molds are created and equipment programmed, manufacturers can produce large quantities of parts that fit precise specifications. The molds used for plastic injection don’t need to be replaced or adjusted as often as those used for other manufacturing processes. This ensures that more parts are produced in less time without sacrificing precision.
Other advantages of plastic injection molding include:
- Enhanced strength: Hard plastic parts must be strong and durable to function effectively. Manufacturers that use other plastic forming methods usually cannot modify or reinforce their products; however, during the plastic injection molding process, fillers can be added to the molds to reduce the plastic material’s density. After molding is complete, these parts exhibit greater resistance to pressure, which makes them more reliable in heavy-duty jobs.
- Customization potential: Plastic part manufacturing companies can customize the material and color of their products when they use plastic injection molding. This process also supports the use of a wide variety of polymers and resins.
- Longer service lives: Products made from plastics have longer service lives than their metal counterparts. Plastic reacts less with chemicals than metal does, which makes it an ideal solution for use in hazardous environments. Using plastic also eliminates the threat of rust and corrosion. Environmentally conscious companies can more easily reuse plastic components in their own operations or recycle them for different purposes.
- Lower-cost products: Plastic injection molding’s inherent speed and ease reduce its dependence on human operators and attendants. Companies that use this method often see a noticeable drop in labor-related costs.
Plastic injection molding saves money and time while improving quality and output. Plastic injection molders can use either stock molds or create customized molds with clients to achieve high-quality product outcomes.
Learn More from the Mardek Manufacturing Team
Using plastic injection molding, manufacturers can produce large volumes of products quickly, efficiently, and with less resources than what other techniques require. This process delivers parts in a finished state that often doesn’t require any additional steps.
Plastic injection molding also supports efforts to protect our common natural resources. Scraps of plastic material that fall off during the production process can be ground up and reintegrated into the production material. Using this technique, manufacturers produce less waste and reduce their expenses.
Mardek offers plastic injection molding for manufacturers of food products, consumer goods, packaging, and appliances. Our processes allow companies to produce any quantity of plastic parts to their exact specifications while incurring lower financial and temporal investments than those required by other manufacturing processes.
In addition to plastic injection molding, Mardek offers a variety of blow molding, machining, structural foaming, and thermoforming services. Contact us to learn how Mardek can help with your company’s next project.