What is Plastic Injection Moulding?

Ever wondered how the countless plastic parts in your everyday life are made? From your phone case to your car’s dashboard, plastic injection moulding is a powerful manufacturing process that shapes molten plastic into precise and consistent end products.

In this guide we’ll dive into the world of injection moulding and explain:

  • What it is and how it works
  • The benefits it offers
  • The wide range of applications

plastic injection moulding uses

What is Injection Moulding?

Injection moulding takes plastic pellets and transforms them into solid plastic products using a specialised injection moulding machine. The plastic injection moulding process is broken down into the following steps:

Thermoplastic Material Selection

The process starts with choosing the right plastic type (resin) based on factors like strength, flexibility, and heat resistance.

Melting and Injection

The chosen plastic resin is melted until it becomes mouldable. Then, it’s injected into a precisely designed mould under high pressure.

Cooling and Solidification

The molten plastic cools and hardens within the mould, taking on the mould’s shape.

Ejecting the Part

Once solidified, the finished plastic part is ejected from the mould, and ready for use. At this stage, plastic waste from this process can be recycled to create a circular plastic injection moulding process.


everything you eed to know about plastic injection moulding


What are the Advantages of Injection Moulding?

Injection moulding offers several advantages that make it a preferred manufacturing method:

  • High precision and consistency – Produces identical parts with minimal variations, ideal for applications requiring exact fits.
  • Design flexibility – Moulds can be customised to create complex shapes and integrate various features into a single part.
  • High-volume production – Enables the creation of large quantities of parts quickly and cost-effectively.
  • Minimal waste – Modern processes minimise leftover plastic, promoting sustainability. At Fern Plastics we aim to reuse and recycle up to 100% of our plastic and manufacturing waste to be used for future projects with the help of our in-house machines and recycling partners. Our processes mean minimal waste without any compromise on quality.
  • Reduced finishing – Injection moulded parts often require minimal finishing due to the detailed nature of the moulds.
  • Wide range of materials – A variety of plastic resins are available to suit different product needs.

Applications of Injection Moulded Products

The versatility of injection moulding extends to a vast array of products you may come across daily. Some examples include:

  • Automotive parts – From dashboards and cup holders to intricate gear parts.
  • Medical devices – Sterile syringes, medication trays and various medical tools.
  • Consumer goods – Bottle caps, phone cases, toys, storage containers and more.
  • Electronic components – Casings, buttons, switches and internal components.

plastic injection moulded products

Why Choose Fern Plastics for Plastic Injection Moulding?

At Fern Plastics, we offer a high-quality injection moulding service with over 60 years of experience. When it comes to choosing the right plastic injection moulding company, we go beyond basic plastic manufacturing. Our team ensure consistent and high-quality parts for any project, no matter the complexity. As specialists, we are also equipped to handle demanding specifications like leak-proof and pressure-tight designs. We also provide close dimensional tolerances with excellent surface finishes, fire retardant mouldings, transparent moulding or lenses as well as a range of value-added services. For peace of mind, we can guarantee your plastic injection mouldings will be correct and on time every time with 24-hour production.

If you are looking for a dedicated plastic injection moulding service with years of experience and expertise, get in touch with the team here at Fern Plastics. Contact us today to find out more about how we can help you and the range of services we provide.


What plastic is used in injection moulding?

Injection moulding relies on a specific type of plastic – thermoplastics. There are hundreds of options available, but some of the most popular choices include:

What is made from plastic injection molding?

Plastic injection moulding touches almost every aspect of our daily lives. Here are some examples of products using this process:

Automotive Parts:

  • Interior trim
  • Dashboard panels
  • Door handles
  • Bumpers

Consumer Goods:

  • Toys
  • Kitchen utensils
  • Containers
  • Electronic housings

Medical Devices:

  • Syringes
  • Tubing
  • Surgical instruments
  • Pill dispensers


  • Plastic bottles
  • Caps
  • Containers
  • Packaging components


  • Enclosures
  • Cases
  • Connectors
  • Housings for smartphones, computers, and appliances

Aerospace and Defense:

  • Components for aircraft interiors
  • Military equipment
  • Aerospace applications

Can all plastics be injection molded?

No, not all plastics can be injection molded. The process works best with thermoplastics, which can be melted and re-solidified. Thermoset plastics, which permanently harden when formed, are not suitable for injection moulding.


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Plastic Injection Moulding Vs Vacuum Moulding


When it comes to plastic moulded products, two main moulding methods are often discussed, plastic injection moulding and vacuum moulding. But what is the difference between plastic injection moulding and vacuum moulding? We go into the differences between the two plastic moulding types and more.

plastic injection molding vs vacuum moulding

What is Plastic Injection Moulding?

Plastic injection moulding is the process of injecting molten plastic into a pre-designed mould in order to create a plastic moulded product. By injecting molten plastic into a mould at high pressure, the plastic is forced to fill the gaps in the mould and create the shape of the mould design. Once the plastic has cooled, the mould is opened and the plastic injected products are removed from the moulding machine. 

What Type of Products Are Made From Plastic Injection Moulding?

Plastic injected products can be found everywhere in the home and beyond. Plastic injection moulding is often used to produce items such as recycling bins, medical tools, car parts, toys and more with the ability to highly customise the plastic mould meaning that a wide range of intricate designs can be produced in numerous quantities.

What is Vacuum Moulding?

Vacuum moulding, also known as thermoforming, is a process during which a heated sheet of plastic is stretched over a vacuum forming tool in order to form a plastic part. The thermoforming plastic sheet forms the shape of the mould through a vacuum process and as the sheet cools it forms a hard shape before the moulding tool is removed.

Here’s how the thermoforming process works:

  • Preparation – A flat sheet of thermoforming plastic is clamped into a frame. The type of plastic chosen depends on the specific requirements of the part being produced.
  • Heating – The sheet is then heated until it becomes soft and pliable. The temperature and heating time vary depending on the material’s thickness and type.
  • Moulding – After the thermoplastic sheet is heated to the desired temperature, it is quickly moved to the mould or tool.
  • Thermoforming – Once the heated sheet is in position over the vacuum-forming tool, a vacuum is applied beneath the mould, which suctions the plastic sheet tightly against the mould’s surface. This forms the plastic into the shape of the mould. Any excess material is trimmed away.
  • Cooling and Release – After the plastic has taken the shape of the mould, it is cooled. Once it has cooled and solidified, the vacuum is released and the formed plastic part can be removed from the mould.

What Type of Products Are Made From Vacuum Moulding?

Depending on the design of the plastic moulding, vacuum moulding can create a variety of designs and styles. Items such as plastic bathtubs, garden equipment and plastic utensils can be made using the vacuum moulding process.

Plastic Injection Moulding Vs Vacuum Moulding, Which is Best?

When it comes to plastic formed products, each technique is different. For tight tolerances, plastic injection moulding is often more suitable than vacuum forming whilst the plastic injection process can also often work out as cheaper than the vacuum moulding process, particularly for larger projects where a high volume of plastic injected products need to be formed. The process of vacuum forming is sometimes also less controlled than plastic injection moulding die to the heated plastic being stretched over a mould.

What are the Advantages of Injection Moulding Compared to Vacuum Moulding?

There are a few advantages to using plastic injection moulding when compared to vacuum moulding.

High precision and tight tolerances – Plastic injection moulding allows for the production of parts with extremely tight tolerances and high precision. This process is capable of producing complex, intricate parts with consistent wall thickness, intricate details and minimal variations. In contrast, vacuum forming may have some limitations in achieving the same level of precision due to the stretching of the heated plastic sheet over the mould.

Higher production volumes –  Injection moulding is better suited to high-volume production runs when compared to vacuum moulding. The cycle times in injection moulding are typically faster than vacuum forming, and the process can produce a large number of parts in a shorter period of time. This efficiency makes it more cost-effective for long production runs

Material selection – Plastic injection moulding allows for the use of a range of thermoplastic materials including high-performance engineering plastics like Acrylonitrile Butadiene Styrene (ABS), Nylon (PA) and Polycarbonate (PC). This means that injection-moulded parts can have superior properties such as heat resistance, greater strength, chemical resistance and more. Injection moulding is often chosen when the application demands specific material characteristics and performance.

Plastic Injection Moulding Specialists

As plastic injection moulding specialists, we offer a wide range of plastic injection moulding services to help bring your project to life. We have a number of years experience and have faced every challenge there is in terms of plastic injection moulds so are perfectly placed to answer any questions you may have.

Contact our team now on 01902 758282 to find out more about the range of plastic injection moulding services and related services we offer and talk to our specialists.


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