Nylon (Polyamide PA) Plastic Injection Moulding
Nylons are a part of the group of plastics called Polyamides (PA) and are available in a variety of material types each with very different properties. Polyamides are generally tough thanks to their semi-crystalline structure. This synthetic thermoplastic polymer is widely used in plastic injection moulded products and can be blended with other engineering plastics to improve certain aspects of performance.
Some of the types of nylons include:
Nylon 6 (PA6)
Nylon 66 (PA 66)
Nylon 6,12 (PA 6,12)
Nylon 4,6 (PA 4,6)
Nylon 12 (PA12)
Nylon is formed in two ways, either through a condensation reaction between diamines and dibasic acids or by a process of opening a lactam monomer. The numerical identification of nylon relates to the way the nylon was produced. For example, Nylon 66 is created using a condensation reaction and produces a nylon type with two identifying numbers. The first number relates to the number of carbon atoms in the diamine and the second number represents the number of atoms in the acid. Nylon 6 is produced by opening a lactam monomer and the numerical identification of 6 represents the number of atoms in the lactam monomer.
This page is for informational purposes only. Fern Plastics provides injection moulding services and does not supply the material.
Properties of Nylon (Polyamide PA)
The most common forms of nylon used to create custom moulded plastic parts are PA 6 and PA 66. The main differences between these types of nylon material are in their structure. Nylon 6 (PA6) exhibits lower mould shrinkage which results in a stable final product, while nylon 66 (PA66) has greater mould shrinkage when it cools and solidifies, so this needs to be taken into account as the shape of the final product will differ. While PA6 and PA66 have slightly different characteristics, they do have similar properties.
- Good thermal and chemical resistance
- UV resistance
- High strength and stiffness at high temperature
- Good abrasion and wear resistance
- Good impact strength, even at low temperature
- Lighter and cheaper than aluminium
- Excellent fuel and oil resistance
- Very good flow for easy processing
Benefits of Using Nylon Material in Plastic Injection Moulding
Nylon has very high durability and is lighter and cheaper than aluminium making it a great choice for many applications. Using nylon materials for injection molding results in an end product that is easy to paint and has an excellent surface appearance. Polyamides are extremely hardwearing and strong and are often used to replace metal parts. Additives like fibreglass are often introduced to create a more robust end product.
- Has useful electrical insulating properties
- Corrosive resistant
- Works well in environments with high temperatures
Common Nylon Uses
Polyamides are very commonly used in many polymer injection mouldings to create plastic products for a wide range of applications in a variety of industries. Nylon injection molding can be used to create a variety of products like electrical insulation and product packaging.
- Exterior: Grills, Door Handles, Wheels covers, Mirror
- Interior: Airbag canisters
- Engine Covers
- Radiator grills
- Electrical & Electronic applications
- Switches and other electrical components
- Terminal blocks
- Industrial plugs and sockets
- Castors and wheels
- Packaging films
- Housings and internal parts for power tools
Nylon Material Disadvantages
Although there are many advantages to nylon injection moulding, there are some nylon disadvantages to consider that can affect the results of your injection moulded product.
- Non-resistant to strong acids and oxidants
- Prone to shrinkage
- High water absorption
- Subject to gassing in poorly ventilated which results in aesthetic defects in nylon products
Using Nylon Materials for Your Plastic Injection Moulded Project
With its extreme versatility and strength, nylon material makes an excellent alternative to metal products. At Fern Plastics we specialise in the manufacturing of plastic injection moulds. We create bespoke nylon parts using custom injection moulding processes.
What are the challenges associated with Nylon in injection moulding?
Nylon PA absorbs moisture from the atmosphere and this moisture can affect the material’s properties and lead to issues like surface defects and reduced strength. It is essential to dry the raw materials before moulding. Nylon can also exhibit significant shrinkage and warping during cooling which can lead to unstable parts so it is important to use appropriate extended cooling times.
Is Nylon recyclable, and how is it typically recycled?
Nylon (Polyamide or PA) is recyclable through mechanical and chemical recycling methods, as well as upcycling techniques. Mechanical recycling involves collecting and processing Nylon waste into new products, although the material may experience some degradation with each cycle. Chemical recycling breaks down Nylon into its constituent monomers for the synthesis of new Nylon, potentially yielding higher-quality material, but it is more complex and may require greater investment.