What is plastic turning?

Plastic turning is a machining process used to create and machine plastic materials using a lathe and specific tools.

A lathe is a machine used to machine round workpieces such as rods, tubes and sheets. Rotating them while applying cutting tools to them removes material. Plastic turning is primarily used to achieve complex shapes, precise dimensions and specific types of finishes in plastic parts.

What is turning?

Turning is a machining process used to machine and shape round workpieces such as rods, tubes and cylinders using a lathe. The turning process involves removing material from the workpiece to achieve desired shapes and dimensions. Turning is widely used in metalworking and woodworking but can also be applied to plastics and other materials.

How does plastic turning work?

The process of plastic turning involves several steps:

1. Workpiece preparation: The workpiece to be machined is placed in the lathe and clamped securely. The workpiece must be well aligned with the turning axis to minimize vibration and inaccuracies.
2. Selection of cutting tools: Suitable cutting tools and chisels are selected depending on the type of plastic and the desired operation. These tools have specific cutting edges and geometries to achieve different shapes and finishes.
3. Adjusting the lathe: The lathe is set to the appropriate speed and feed rate depending on the material and desired operation. Speed affects cutting performance and heat generation, while feed rate determines how much material is removed per revolution.
4. Machining the workpiece: Once the lathe is set, the workpiece is set in motion and the cutting tool is gradually guided toward the workpiece. As the workpiece rotates, the cutting tool removes material, achieving the desired shape. The cutting tool can move in different directions to perform various operations, such as turning, flattening, drilling, trimming and threading.
5. Cooling and lubrication: Plastic turning generates heat as a result of friction between the cutting tool and the workpiece. To prevent overheating, coolant or lubrication is often used to regulate temperature and extend tool life.
6. Control and measurements: During the turning process, measurements and checks are made to verify that the desired dimensions and tolerances are achieved. Measuring instruments such as calipers, micrometers and gauges are used to verify the accuracy of the workpiece.
7. Finish: Plastic turning can result in different finishes, depending on the type of cutting tool and operating parameters. These finishes can range from rough to very smooth, depending on the application.

Different types of plastic

There are numerous types of plastics with different properties and applications. Here are five common types of plastics:

1. Polyethylene (PE): Polyethylene is a widely used thermoplastic polymer with high chemical resistance and low density. It is available in several varieties, including low-density polyethylene (LDPE) and high-density polyethylene (HDPE). LDPE is often used for plastic films, bags and coatings, while HDPE is used for bottles, pipelines and industrial applications.

2. Polypropylene (PP): Polypropylene is a versatile thermoplastic with good resistance to chemicals and heat. It is often used for packaging materials, such as bottles, containers and caps, as well as automotive parts, textiles and medical devices.

3. Polyvinyl chloride (PVC): Polyvinyl chloride is a plastic known for its durability, resistance to weathering and chemical stability. PVC is used for a wide range of applications, including pipes, cables, flooring, window profiles and medical tubing.

4. Polystyrene (PS): Polystyrene is a lightweight and easily formed plastic. It has several applications, including food packaging, disposable products, insulation material and also in the form of expanded polystyrene (EPS) for packaging and insulation (known as Styrofoam).

5. Polyethylene terephthalate (PET): PET is a thermoplastic known for its strength, clarity and barrier properties against gases and moisture. It is commonly used for beverage bottles, food packaging and textile fibers, such as those used in clothing and bedding.

What is plastic milling?

Plastic milling is a machining technique in which plastics are machined and shaped using rotary cutting tools. This operation is similar to metal milling but is specifically applied to plastics. Plastic milling is used to produce complex designs.