Injection molding is one of the most widely used plastic manufacturing process. If you look around you can find countless injection moulded products. In this article we will discuss injection moulding’s advantages and disadvantages.
Advantages of Injection Molding
Injection molding process is very fast compared to other plastic manufacturing methods. High production rates can be achieved using injection molding. Injection cycle time for a part depends on part size, geometry and material used.
- Complex Part Design
Very complex parts with consistency can be manufactured using injection molding. Plastic part design guidelines shall be followed during part design and process need to be controlled effectively.
- Design Flexibility
Wide variety of material from clear, opaque to flexible are available.
- Ability to use multiple plastic materials simultaneously (Overmolding)
Multiple plastic materials can be used simultaneously to achieved desired results. For example TPU is overmolded over plastic parts to achieve design ergonomics. This is not feasible with other plastic manufacturing processes.
- Flexibility in Colors
Plastics parts can be manufactured in any required colors. Even multi color parts are also feasible using overmolding.
- Reduced Waste
Excess plastic after injection molding can be reused as well. But designers should consider the degradation of material properties once it is molded.
- Good dimensional consistency and control
If tool design is good and process is controlled. Good dimensional consistency and control can be achieved with injection moldiing.
- Ability to insert molding
With injection molding a metal / plastic insert can be insert molded.
Disadvantages of Injection Moulding
Followings are the disadvantages of injection molded plastic parts when compared with metal parts.
- High initial tooling Cost
Initial tool cost for injection molding is very high. Therefore injection molding for small volumes is not recommended.
- Part Design Restrictions
Plastic part design guidelines need to be followed to achieve good quality and consistency during production.
- Not economical for low volumes
After tool manufacturing, initial setup cost for injection molding tool for production is also very high.