Injection moulding is one of the most popular plastic products manufacturing technique today. It is a process in which molten plastic is injected into a mould and allowed to cool, forming the desired shape. Today, injection moulding is used to create various products, from toys and games to car parts and medical devices. Almost anything that is made of plastic can be created using injection moulding.
Figure 1: Plastic injection moulding advantages and disadvantages
There are many advantages to using injection moulding, including the ability to create complex shapes, mass-produce products, and the relatively low cost of the process. However, injection molding has some disadvantages, such as the potential for defects in the finished product and the limited range of materials that can be used. In this blog post, we will explore the injection moulding advantages and disadvantages in detail.
What is injection moulding?
Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould. The injection moulding process can be divided into four steps:
- The first step is to heat the plastic pellets until they reach a liquid state. This is done using an injection moulding machine consisting of a barrel heated to a high temperature.
- The next step is injecting molten plastic into the mould. This is done using a screw-type plunger that forces the liquid plastic into the mould at high pressure.
- Once the plastic has been injected into the mould, it must be allowed to cool and solidify. This usually takes a few minutes.
- The final step is to eject the moulded product from the mould. This is done using a hydraulic or pneumatic cylinder that pushes the product out of the mould.
Injection moulding is a very versatile manufacturing process and can be used to create products of all shapes and sizes. The only restriction is that the mould must be able to withstand the high temperatures and pressures involved in the process.
Figure 2: Injection moulding advantages and disadvantages
Advantages of injection moulding
In plastic manufacturing, injection moulding is one of the most popular methods. There are many advantages to using this method, including:
Fast Production & Low Cost
Injection moulding is a fast and efficient way to mass-produce products. The process can be completed quickly and cheaply, making it ideal for high-volume production runs. The molding process to make a plastic product is relatively simple. With a few exceptions, most products can be made using a single mold. The speed of the process is between 15-120 sec per cycle.
It is a versatile process that can be used to create products of all shapes and sizes. The process is ideal for creating complex shapes that would be difficult or impossible to create using other methods, such as machining or casting. In addition, the process can be easily adapted to create products in multiple colors or with multiple components. You can make syringe mould, hanger mould, automobile parts, and more.
High Output and Quality
The process of plastic injection moulding is a highly repeatable, which means that products made using this method will be of consistent quality. In addition, the process can be easily automated, further increasing the accuracy and repeatability of the finished product. Automation also makes it possible to produce large quantities of products quickly and efficiently. No matter what you need injection moulding for, the process can be adapted to create a high-quality product.
Large Material Selection
There are a wide variety of materials that can be used in injection moulding, including metals, plastics, and glass. In addition, the process can be used with both synthetic and natural materials. This vast selection of materials means that injection moulding can be used to create products for a wide range of applications. In injection molding, you can also use abs, polypropylene, nylon, and much more. In steel moulds, you have the option to use stainless steel, hot work tool steel, carbon steel, and much more.
Low Scarp Rates
A highly efficient process of plastic injection moulding produces very little waste. Most of the material injected into the mould is used to create the finished product, with only a tiny amount of material being wasted as scrap. This scrap can be recycled and used to make new products, reducing waste. The raw material used in injection moulding is also relatively cheap, making the process even more cost-effective. You can use recycled materials to create your products which will save you money and help the environment.
In injection moulding, whether the product’s design is complex is not a matter of concern. This is because; the process can be used to create products with consistent dimensions and properties. The result is a product that is very uniform in appearance and performance. Additive manufacturing enables printing the product in multiple colors with different materials.
Enhanced Strength & Durability
Another advantage of plastic injection moulding is that it can be used to create robust and durable products. The process can reinforce the product with ribs or other support structures, increasing its strength and resistance to breaking or deformation. In addition, the material used in injection moulding is solid and resistant to wear and tear. This makes injection moulding products ideal for applications where the product will be subject to a lot of wear and tear, such as in automotive or industrial applications.
Last but not the least, injection moulding can be used to create products with very smooth surfaces. This is because the molten material is injected into the mould under high pressure, which fills the mould entirely and evenly. This results in a product with very few imperfections or surface defects. In addition, the process can be used to create products with multiple colors or finishes, further enhancing the product’s aesthetic appeal.
Disadvantages of injection moulding
As we have seen, injection moulding has several advantages but also some disadvantages to the process. Let’s discuss some of the main disadvantages of injection moulding.
Longer Setup Leading Time
One of the main disadvantages of injection moulding is that it can take a long time to set up the mould and inject the material. This is because the process is exact, and the mould must be created specifically for the product. In addition, the injection process can take a significant amount of time, especially if large quantities of products are being made.
High Initial Tooling Costs
Another disadvantage of injection moulding is that the initial tooling costs can be high. This is because a specific mold must be created for the product, which can be expensive. In addition, if the product is complex or has a lot of detail, the mould may be even more expensive. However, once the initial investment has been made, the per unit cost of the product will be much lower than if another manufacturing process was used.
Limited Design Freedom
Due to the nature of injection moulding, there are some limitations to the product’s design. This is because the product must be designed to fit the mould, which can restrict the overall freedom of the design. In addition, the mould itself must be designed to allow the material to flow through it and fill the mould. This can add complexity to the design process.
Despite the advantages of injection moulding, some potential defects can occur. These defects can be caused by several factors, such as incorrect material viscosity, wrong gate location, or poor mould design. The most common defects include flash, sink marks, warping, and voids. Sometimes the shrinkage of the material can also cause defects.
Figure 4: Molding defects
Temperature is critical in injection moulding, as the material must be heated to a high temperature to flow into the mould. If the material is not heated sufficiently, it will not flow properly, and the product will be of poor quality. In addition, the mold temperature must be kept at a consistent temperature, as fluctuations can also cause defects. It is necessary to know the melting temperature charts of the materials used to maintain a consistent temperature.
The best injection molding service provider in China
With huge market potential, China is one of the fastest-growing economies in the world. Go4mould is a leading injection molding service provider in China with over two decades of experience in the industry. We offer custom plastic injection molding services to global clients in various industries.
The latest injection molding machines and state-of-the-art technology have enabled us to offer our clients the best products and services. We have a team of highly skilled engineers who design and develop customized molds for our clients. We provide a variety of molds, including garbage bin mould, logistics box mould, beer crate mould, and many more. We can make it happen for you if you need any specific design or color. Contact us now for the best injection molding services in China.