Cast PA6 vs extruded PA6: when does it matter?

Cast PA6 vs Extruded PA6: when does it matter?

When working with plastic materials, it is essential to understand the differences between various manufacturing methods. In the case of PA6, also known as polyamide 6, there are two primary manufacturing methods: casting and extrusion. But what is the actual difference between these methods, and when does it matter?

We offer both cast and extruded PA6 on PlastShop.se, and we want to help you understand when to choose one over the other. Let's start by looking at the manufacturing process.

Manufacturing process

Casting of PA6 takes place through a process called casting, where PA6 powder is melted and formed into the desired shape. This process enables the production of complex shapes and thick sections with high crystallinity. Extrusion of PA6, on the other hand, takes place through a process where PA6 pellets are melted and formed into a long, narrow shape, which can then be cut to the desired length.

Extrusion is a more common manufacturing method, and it is used to produce long, narrow shapes such as bars and tubes. But when it comes to thick sections or complex shapes, casting is often the better choice.

Properties

The properties of cast and extruded PA6 differ slightly. Cast PA6 generally has better crystallinity in thick sections, which gives it better mechanical properties. This is because the casting process allows for a more controlled crystallization process, resulting in a more homogeneous structure.

Extruded PA6, on the other hand, often has a slightly lower crystallinity, especially in thick sections. This can affect the material's mechanical properties, such as strength and durability. But extruded PA6 also has some advantages, such as a more constant density and fewer defects.

Another important property to consider is Shore hardness. Cast PA6 can have a Shore hardness of up to 65 Shore D, while extruded PA6 usually has a slightly lower Shore hardness. But what does this mean in practice? How does Shore hardness affect the material's performance in different applications?

Dimensions and tolerances

When it comes to dimensions and tolerances, there are also some differences between cast and extruded PA6. Cast PA6 can be produced in a wide range of dimensions, from small, complex shapes to large, thick sections. Extruded PA6, on the other hand, is usually available in standard dimensions, such as bars and tubes.

The tolerances for cast PA6 can vary depending on the manufacturing process and the material's properties. But in general, cast PA6 can have slightly coarser tolerances than extruded PA6, which usually has more exact dimensions.

Cost

The cost of cast and extruded PA6 also differs. Cast PA6 is usually more expensive than extruded PA6, especially for small volumes. This is because the casting process is more labor-intensive and requires more specialized equipment.

But when is it worth paying the premium for cast PA6? When does the application require material properties that only cast PA6 can provide? For example, in applications where high crystallinity and mechanical properties are critical, such as in the aerospace and defense industries.

When to choose cast PA6?

So when should you choose cast PA6? When you need material properties such as high crystallinity, good mechanical strength, and high Shore hardness. When you need to produce complex shapes or thick sections. And when you are willing to pay the premium for a high-quality product.

But what if you don't need all these properties? Can you use extruded PA6 instead? Yes, you can. Extruded PA6 is an excellent choice when you need a more affordable solution, but still want a quality product.

In the end, the choice between cast and extruded PA6 is a matter of weighing the pros and cons. We hope this article has given you a better understanding of the differences between these two materials. If you have more questions or need help choosing the right material for your application, don't hesitate to contact us for more information.