Plastic injection molding is a process that forces liquid plastic into a mold to make custom plastic name plates, plaques, signs and product branding elements. Once the plastic cools and solidifies, it releases from the mold to form a variety of plastic parts for any industry. Popular uses of injection-molded include appliance name plates, name plates for industrial equipment, car emblems, vehicle branding and license plate holders, as well as product identification for recreational products.
Injection-molded plastic name plates and other components are produced by a machine that consists of three basic components:
A mold which can be made to manufacture any size and shape that is needed
A clamping unit that clamps and holds the mold together throughout the whole process
An injection unit will then inject molten plastic into the mold, where it will remain until it has sufficiently cooled and released
The molten plastic used for injection-molded products is produced by melting small plastic pellets, which are fed into an injection machine heating the pellets to a molten or liquid form.
Once the now molten plastic pellets reach a predetermined temperature the semi-liquid is forcefully injected into a mold. The speed and pressure of this process are controlled by a hydraulic cylinder that, once engaged, forces the liquid plastic into the mold.
In “dwell” phase of the plastic injection molding process, the plastic is left in the mold to ensure that it completely fills the mold and then allowed it to cool to the point where it solidifies, and the desired object is produced. It is then ready for secondary processes as decoration, sub-assembly, or shipment.
The injection-molded plastic process allows manufacturers to produce custom plastic nameplates and components that would be too costly to make as intricately by utilizing traditional machining methods. Injection-molded plastics also saves time and money by allowing many pieces of the same component to be made at the same time, from the same mold; each copy identical to the one before it. This process also reduces labor costs by minimizing the need for manual labour from employees. There is also nearly no wasted material, as any unused or left-over plastic can be recycled to be reused in the process.
The Past
Plastic injection molding originated with chemists in Europe and The United States who were experimenting with plastics. Originally it was done by hand and pressed into a mold using Parkesine, but it proved to be too brittle and flammable. John Wesley Hyatt is the official inventor of plastic injection molding and the process has a rich history with brilliant minds.
John Wesley Hyatt was a creative inventor and developed the processing of celluloid plastics. This was an amazing feat for a young printer from Illinois who took on the challenge from the New York Billiards Company to replace the ivory that was used in billiard balls.
So began his career in plastics engineering as he and his brother Isaiah started making several mixtures for checkers and other objects. After some time trying various mixtures, John mixed nitrocellulose, camphor and alcohol together. He pressed these ingredients into a circular steel mold that was heated and allowed it to cool. When the material was removed from the mold, he realized that he had successfully created a billiard ball composed of plastic. Thus began the process of plastic injection molding.
John and his brother Isaiah patented this process of producing celluloid in 1870 and continued by making dentures from their new material which replaced dentures made of rubber. Thus began the manufacturing process of celluloid plastics. John was quite like the Da Vinci of industrial invention because he also was credited with the invention of the sewing machine and roller bearings all of which contributed heavily to manufacturing.
Today, Celluloid and Cellulosic plastics can be found almost anywhere including screwdriver handles, toothbrushes and utensils. Celluloid can be found in Hollywood, California today and is used for the production of your favorite films.
The Present
Today’s version of the plastic injection molding equipment is computer controlled and the plastic raw material is injected into steel and aluminum molds to produce the custom plastic nameplates, plastic components and many of the plastic products we use every day. The molding equipment injects hot plastic into the mold and cools the plastic and extracts the parts. The molding equipment of today makes mass production of plastic components easy and cost-effective.
Today, plastic injection molding companies use vertical and horizontal presses, injection screw presses, electric presses and hydraulic presses for whatever rate of pressure is needed to complete the product pressure to form. This process produces everything from car parts to license plates and even toothbrushes.
The Future
Plastic Injection Molding is a very innovative process that has created many useful products that we use every single day in our households. While the history of plastic injection molding is quite full of creativity and innovation, the future is filled with even greater possibility as more creative minds add new ways to improve plastic injection molding equipment and process.
While the improvements in the plastic injection machinery continue, the future of injection molding is now turning its attention to the molds and mold components.
The invention of 3D printing gives us a glimpse of how far plastic injection molding can travel into the future. 3D printing is a process of making a three-dimensional solid object of virtually any shape from a digital model. With the integration of 3D printing in the plastic injection molding process, concepts and samples can be produced with far less expense.
There was some insight into the past present and future of this injection molding industry, and if you are looking for such products that are also reliable, be sure to check this out!