A Guide to Understanding How Injection Molding Works
Injection molding is a process that creates parts by injecting material into a heated, closed mold. The part can be made of many different materials, including plastics, rubber, and metals.
Injection molding has been around for over 150 years and continues to grow in popularity as the demand for plastic products increases. It’s time to get to know injection molding better!
Injection Molding Advantages
Injection molding is used in industries such as automotive, medical, and construction.
What exactly is an injection mold? An injection-molded plastic part will first start on a metal plate called the “tool.” When heated by an electric current or steam pressure from the water, two silicone halves from around the tool’s shape over a hollow cavity- creating what’s known as a closed mold (so no air remains inside).
The molten material is then injected into this cavity through small openings at high speed to force all of the material into the cavity. When the material cools down and hardens, it creates a finished product- typically in just seconds!
The advantages of injection molding are that it allows for more complicated shapes to be created in a single part while maintaining high precision. It also produces parts with smoother surfaces than other manufacturing techniques.
Injection Molding Disadvantages
The major disadvantage of injection molding is that sometimes you can see seams on an injection-molded plastic part left by where two halves of silicone came together to form one shape. This effect is called parting lines because they are often visible at points where two different pieces meet (or “part”).
To minimize these effects, manufacturers will try to make sure their tool design has as few shapes as possible so that there’s less chance for seam lines to show up when they close their molds around them. Another downside of injection molding is its tendency for some materials like PVC to shrink and warp when they cool.
Injection molding can be used with a wide range of materials, but the process isn’t easy for plastics that don’t have high melting points like PVC (which is why it’s not often seen in injection molded products). The two halves of an injection-molded part are made by injecting heated liquid plastic into steel molds that keep the molten material from cooling too quickly to hold its shape.
You can calculate how big your tool needs to be based on what size you want your finished product to be. Just remember that the longer or wider something is, the more expensive it becomes per unit because more raw material has been wasted due to oversizing.
Injection Molding Parts
The parts that go into injection molding include the raw materials, a mold for each half of the finished part (usually steel or aluminum), and mechanical devices such as clamps to hold everything tightly together while it cools.
During injection molding, molten plastics are injected into molds made from a metal called “tools.” These tools can be expensive because they have to be machined out of high-quality material with tight tolerances. The larger the tool size is, the more costly per unit production cost will become because more plastic has been wasted due to oversizing to make that particular sized product.
The two halves then need time to cool before separating so that their shape won’t deform during removal from the tool.