Plastic is the most common material used to produce consumer products. It can be seen everywhere and is used across different industries from health care, construction, toys, technology, electronics and a lot more. Plastic is very versatile due to its various polymer options wherein each has its own physical and chemical properties. Its versatility alone makes it a popular material for different products. However, do you know how plastics are most commonly produced by plastic manufacturers? This informative article tackles the step by step process of plastic manufacturing.
Plastic manufacturing has totally evolved and there are now different methods and technology used to manufacture plastics at lower cost than ever. When it comes to high volume manufacturing, the most efficient and effective method for plastic production remains to be the injection molding method (except for bottles and similar voluminous items where you use blow molds). Instead of tackling all of the available methods one by one, let us focus on the step by step process for injection molding since it is the most relevant method for plastic manufacturing of the vast majority of regular plastic parts.
Injection Molding: Step by Step
Just like any other manufacturing process, making plastic products through injection molding always starts by having a design or concept in mind. There is no project to work on if there if there is no design or concept at hand. If the design is still an idea, might as well draw or sketch the product to give it a visual representation. It does not have to be a professional level drawing, as long as the design is clear and understandable.
In the world of plastic manufacturing, basic drawing and sketches are not accepted by injection molding companies. They have to be in CAD or any virtual design file format before manufacturers lay their hands on the potential product. Ask help from professional graphic designers to redraw your sketches in CAD or Adobe Photoshop form. Include specifications and label them in the virtual drawings as the manufacturer will note of these later on during production.
For the next part, you now have to produce a 3D print sample of your plastic product. The sample does not have to be made out of the actual plastic material (but 3D printing material) but must represent the product physically with regards to size, dimension and measurements. The features and product specs also have to be highlighted in the 3D print sample as well. Your plastic product has now progressed as an idea then a visual entity and now has its full 3D physical representation.
The manufacturer will now assess the 3D print sample along with the virtual design files to finalize the mold/s which are going to be created for the plastic product. Depending on how complex the plastic design is, the plastic manufacturing company will decide on the number of plastic molds to prepare for the product. Larger and more complex shapes have to be separated into pieces. The mold is a rigid frame or cavity shaped after the plastic product. The hollow space in the cavity is where the plastic material is going to be injected later on.
Due to complex designs and shapes, some products cannot be completed via a single mold. Instead, the design is broken down into multiple molds and will be held together by a clamp once plastic to keep the design intact. Molds are commonly made out of aluminum or stainless steel and are patented under your ownership and not by the manufacturer. In case you choose to work with a different factory or manufacturer for reproduction of the product, you simply have to bring the molds and design files and you are good to go.
The actual plastic injection happens when the molds are ready. Molten plastic is injected into the molds and sealed through a hydraulic press. The plastic material is allowed to cool until it is solid enough to take the shape of the mold/s. It is later ejected with the help of compressed air and the plastic part will be removed from the molds. The plastic part is now ready and other post-processing actions take place to fully complete the plastic product.
The Magic of Injection Molding
Injection molding can be used to produce any type of plastic part but the more complicated the design also means the more expensive the production costs become. Complex plastic designs require several molds and each mold adds up to your tooling costs. Keep in mind molds take months to complete, make sure you are geared for long term production if you are thinking of making molds for your designs. It is useless to create molds for plastic part which will only serve a small batch of production.
There are a lot more factors covered within plastic manufacturing not mentioned in the article but the step by step process mentioned above simply provides the general gist. Making plastic products is way too complex compared to other types of manufacturing but once you are familiarized with the process then you’d easily get the hang of it.