Advantages and disadvantages of injection molding
The advantages
1. It is fast and efficient
Injection molding machines are fast and efficient. Depending on the size and complexity of the mold, the machine can produce more parts per cycle than you would achieve manually. With each cycle taking between 15 and 120 seconds, the output is quite significant.
2. Low labor costs
The molding process is fully automated, where one operator is enough to monitor, control, and manage the machines and robotics. No additional manual labor is required during the production process, reducing manufacturing costs even further.
3. Design flexibility
The molds are compacted under high pressure to produce the desired shape or design. Such makes it possible to imprint fine details onto the part, as well as produce complex shapes.
4. High output
Injection molding machines are built to produce thousands of parts before requiring replacement. This means you will be raking in profits years before a replacement is needed.
5. Wide selection of materials to choose from
Most types of polymer resins can be used as raw materials for injection molding. You can also use several different plastic materials simultaneously as well.
6. Minimal waste
The controlled and precise molding environment produces very little to no waste during production. Post-production scraps are also on the lower side too compared to traditional manufacturing processes. Any scrap or waste from runners and sprue can be ground and recycled in future molds too.
7. Allowance for inserts
Plastic injection molding allows for inserts to be added into molds when needed.
8. Excellent color control
Plastic injection molding provides excellent color control. One can achieve the desired color through compounding or masterbatches.
9. Product uniformity
Injection molding produces identical and uniform parts. With the same mold used in every process, you will be able to produce products and parts with a high tolerance rate and reliability. It is often used for medical components due to its precision visit https://www.plastechgroup.com/injection-moulding/medical-components.
10. Little to no post production finishing required
The extreme pressure used for compression helps produce almost perfect pieces. The parts thus come out already refined, requiring very little to no post-production finishing.
11. Stronger parts
Pieces and parts produced through injection molding are sturdier than if produced via the traditional methods. Fillers can also be used within the molding material to improve the end product’s quality and strength. The fillers reduce the plastic’s density during the molding process, making it stronger.
Disadvantages of plastic injection molding
1. High upfront costs and long set-up time
The upfront cost of acquiring an injection molding machine is a bit on the higher side. This is because the equipment has to be designed with precision and tested before it can be ready. Aside from the equipment, the prototype tool may have to be designed via a CNC or 3D printed to produce the exact replica of the intended part. It’s only after extensive testing is done that the equipment can be ready for use. Set up time for this equipment can be an issue for many people.
2. Part design restrictions
Several basic rules and restrictions have to be followed in injection molding. These include:
Avoid sharp edges and undercuts: The mold needs to be of the same wall thickness for uniform cooling and prevent defects (such as sink marks).
Draft angles are commonly recommended for better and easier de-molding. These molds are commonly made of aluminum or steel. This makes it almost impossible to make slight or significant design changes to the mold. One would thus have to add metal or aluminum to the cavity if/when looking to reduce its size.
The size and weight of the part determine the size of the tool and the press as well. Large parts will thus need a larger tool and press, hence more expensive.
3. Producing small runs of parts can be expensive
In addition to the lengthy setup times, injection molding can be too expensive for small runs of parts. This is because tooling is quite complicated and expensive, and one would have to remove all the previous material before they can start producing the next product. Injection molding isn’t thus a viable investment if looking to produce parts on a small scale.