What is a plastic injection molding machine?
Plastic injection molding machines are used to manufacture large quantities of plastic parts. People use them in various industries, including automotive, aerospace, medical, and consumer products. Injection molded parts are made by melting plastic pellets and injecting them into a mold cavity. The desired part shape is formed, the part is cooled, and is ejected from the mold.
There are many different types of plastic injection molding machines available, each with unique features and capabilities. Some machines are better for high-volume production, while others are ideal for small runs and prototyping. The size of the machine can also vary depending on the size of the parts that you produce.
Below, the parts of an injection molding machine are labeled.
How do plastic injection molding machines work?
Plastic injection molding machines work by melting plastic pellets and injecting them into a mold cavity. The machine has a hopper where you load the plastic pellets, a barrel where the plastic melts, an injection unit where you inject the molten plastic into the mold, and a mold where the plastic cools and solidifies.
The injection molding process starts with the plastic pellets being fed into the hopper. The pellets are then heated and melted in the barrel, which is equipped with a screw that moves the plastic forward. Once the plastic melts, you then inject it into the mold cavity at high pressure, where it cools and solidifies into the desired part shape.
How big are plastic injection molding machines?
The size of plastic injection molding machines varies depending on the size of the parts you produce. Small tabletop machines can produce parts that weigh only a few grams, while large machines can produce parts that weigh several kilograms. The machines can range in size from about 1 ton to more than 1000 tons. Pictured below is a 165 ton injection molding machine.
The size of the machine required for a particular application depends on the size and complexity of the part, as well as the required production volume. Larger machines are generally more expensive to purchase and operate than smaller machines.
How much does a plastic injection molding machine cost?
How much a plastic injection molding machine costs can vary widely depending on the size, features, and manufacturer of the machine. The smallest machines can cost a few thousand dollars, while larger machines can run for hundreds of thousands of dollars or more.
In addition to the initial cost of the machine, there are also ongoing costs associated with operating the machine, such as electricity, maintenance, and materials. However, the investment in a high-quality machine can pay off in the form of increased production efficiency and reduced waste. It all varies based on what the needs and scale of an injection molding operation are.
Below: a machine operator at Rex Plastics removes a fresh part from an injection molding machine.