Plastic Additive Manufacturing

Plastic Additive manufacturing, also known as 3D Printing, is a process that manufactures components by building up layers of polymer to form the required shape. This manufacturing technique can produce complex items that are impossible to replicate using more traditional methods. Items can be manufactured from CAD files, or by scanning and digitising an existing product.

Technology in this sector has developed massively over the last few years. Initially, 3D Printing was used primarily for producing prototype parts, which had a relatively rough finish. In today's market, there are high-speed and high-quality printers used for low and sometimes medium volume production. In some cases, this process can be used as an alternative to injection moulding. Many plastic moulding companies have now installed 3D printers to manage the production of prototypes, and low volume runs.

Inserts can be 3D printed in a range of materials suitable for tooling applications, including some more durable polymer grades. The inserts are then placed into a bolster ready for injection moulding. Customers supply CAD files of the component they require, and this data is converted to produce the insert for the injection mould tool.

This process can result in a much faster turn around than is possible with traditional metal tools that are 'machined' from solid. Production runs are limited, but this technique is ideal for quickly producing prototype components in the same plastic material as will eventually be used in full production.

There are many types of software packages that support the 3D printing industry. These include CAD packages, reverse engineering software and numerous design programs.

These range from very low-cost units to complete high quality, high production commercial systems. Machines are now available to make parts up to 2metres long. The technology is improving at a tremendous rate, and due to its popularity, prices are falling in line with the volume of supply.

There are presently many different types of 3D printers. The most common types used with polymer based materials:

1. Stereolithography (SLA)
2. Material Jetting (MJ) Polyjet
3. Fused deposition Modeling (FDM)
4. Selective Laser Sintering (SLS)
5. Digital Light Processing (DLP)
6. Binder Jetting (BJ)
7. Laminated Object Manufacturing (LOM)
8. Material Jetting (MJ)

3D scanners analyse objects and collect data based on their shape and dimensions. This data can be captured and converted into accurate 3D models. In manufacturing, 3D scanners are often used for reverse engineering, prototyping, industrial design and inspection.

Depending on the type of 3D printer being utilised material can be supplied in the form of polymer-based filaments, pellets or powder. In some cases, e.g. the Arburg Freeformer, actual plastic material pellets are used. ABS is presently the most commonly used 3D printing plastic, although many different materials with different properties are now on the market.