Plastic injection moulding Services offers excellent precision, repeatability, speed, low cost per item, and a wide range of plastics. Some disadvantages include greater startup costs and longer lead times.
Plastic Moulding Pros:
Plastic injection moulding is ideal for highly detailed items. Molding, as comparison to other processes, allows you to include more elements with very small tolerances. Take a look at the illustration on the right. This moulding fits in the palm of your hand and features bosses, ribs, metal inserts, side cores, and holes created by a tool with a sliding shut off feature. That’s a lot of features packed into a short space! Making it with plastic fabrication would be impractical, and making it with the vacuum forming procedure would be impossible.
Once your mould tool is created, you can make identical things over and over again. And once more. A well-made mould tool will last a long time if it is properly cared for by the moulding machine setters!
Low cost per part:
While the plastic injection moulding tool has a hefty initial investment, the cost per part is extremely inexpensive after that. Other plastic processing procedures, such as polishing, may take multiple operations, whereas injection moulding can handle everything at once. It would cost hundreds of pounds per part to CNC machine the portion described above. Injection moulding is the way to go if you want to go into full production.
Cycle times as short as 10 seconds are possible. When you combine that with a multi-impression injection moulding tool, you can swiftly produce a large number of products. Because it’s a specialty material with a lot of characteristics to mould correctly, the portion above takes a little longer, but at roughly 50 seconds each cavity per hour, you’d still produce 70 pieces per hour. A one-off CNC machining would take half a day, and 3D printing would take much longer!
For plastic injection moulding, there are a plethora of materials to choose from. A variety of more conventional materials, as well as antistatic plastic, thermoplastic rubber, chemical resistant polymers, infrared, biocompostable…and with colour compounding or masterbatch coloration, you have an almost limitless palette of colours. The moulding above has a dull black colour, but it’s composed of PPO, or poly(phenylene oxide), a stiff and flame-resistant polymer.
Special Surface Finishes, Engraving & Printing:
The injection moulding tool can be created with a particular finish that will show on the moulding in addition to a variety of colours. You can choose from a variety of finishes, such as leather look, soft touch, sparking, high shine, and so on. Logos or other text can also be etched on the tool. Finally, you may have your mouldings printed because there are a variety of inks that work well on plastic.
Little plastic waste:
Injection moulding has a high level of reproducibility. Sprues and runners (leftover bits of plastic formed by the ‘tunnels’ through which the plastic material reaches the actual mould) can also be reground and reused. You can learn more about the environmental impact of injection moulding by visiting our website.
Plastic Moulding Disadvantages:
Doesn’t it sound fantastic? Of course, there are some drawbacks as well:
High Initial Cost:
Before the go-ahead or production is given, numerous rounds of designing and modelling are often required. The injection moulding tool required to make the mouldings must then be designed and manufactured. The mould tool is a complex piece of equipment that requires a lot of people, material, and machining time to create, and it is the most expensive part of acquiring injection mouldings. Of course, once it’s all done, the cost of parts is quite low, and the repeatability for hundreds of thousands of mouldings is very high.
Initial lead time:
Design, testing, and tool production might take months from product conception to completed item. However, if you know exactly what you want, you can get the finished mouldings in as little as six weeks. (The Chinese Mould Tools Flowchart from Toolcraft demonstrates how this might operate.) And, as indicated under benefits, once the tool is in place, running the mouldings takes very little time, especially if you have a multi-impression mould tool. (A list of Mould Tool Types may be found here.)
Large Part Size Limitations:
In order to create plastic injection mouldings, massive machines are required. Large pieces necessitate a massive mould tool and are therefore highly expensive to produce; in this situation, depending on the type of product required, a technique like Plastic Fabrication may be a better option.
Careful planning is required:
To minimise tooling concerns such as undercuts (which will drive up tooling costs dramatically), locked-in features, and insufficient draught (What Draft Angles for Plastic Mouldings? ), plastic mouldings must be carefully designed. The material and temperature must be considered when designing the wall; otherwise, the mould may not fill completely. To guarantee that the product is aesthetically acceptable, the positioning of ejectors and cooling lines will need to be addressed.
Should I go with plastic injection moulding for my product?
Well, it depends on a variety of elements, including design considerations, material, size, and quantity requirements, as well as your budget. Each product proposal will be evaluated by an expert to determine the most efficient and cost-effective manufacturing method.
Toolcraft provides injection moulding, vacuum forming, and plastic fabrication services, as well as finishing, printing, and packaging. Our extensive experience allows us to assist you in selecting the most appropriate production procedure for your new project. On our plastic moulding guidance pages, we also offer our knowledge.