Vacuum forming is one of the most common methods of processing plastic materials. It is the process of heating a sheet of plastic at a forming temperature and it will be stretched into a single mold and forced against the mold by a vacuum. This vacuum formed products are all around us and play a major role in our daily lives like helmets, paper cups, plastic cans, packaging materials, masks, and other enclosures. This is like the process of thermoforming. This process is done to form plastic into permanent objects such as covers and other things.
Why is Vacuum Forming Used?
Vacuum Forming is used to make different products from thermoplastic sheets which include the things we use daily. The plastic is placed over the mold and it is heated to make it flexible and then it will be formed over a mold and then it would be cooled to make it hard again.
- Density fiberboard which is also known as MDF can be shaped by using hands or by using computer-controlled machines, the sides of the mold must be a slope which should allow the plastic product to be pulled out, the corners of the mold must have a radius which should be small.
Steps Involved in Vacuum Forming:
There are three steps involved in Vacuum Forming. They are:
Step 1: Plastic is placed over the mold
Step 2: The plastic is heated well
Step 3: The air in the mold will be removed
- The process involves heating a plastic sheet until it becomes soft and then it should be draped over a mold.
- A vacuum is applied in the sheet into the mold. The sheet is then taken out from the mold. This process uses cultured air-filled, hydraulic and heat controls. So, it enables higher production speeds and a detailed vacuum formed applications.
Type of Materials Used in Vacuum Forming:
The materials used in Vacuum Forming are Acrylonitrile Butadiene Styrene, Acrylic PMMA, Polyester Copolymer, Polyvinyl Chloride, Polystyrene, Polypropylene, Polyethylene, and Polycarbonate.
Difference Between Thermoforming and Vacuum Forming:
Vacuum forming is a type of thermoforming. Both thermoforming and Vacuum forming processes require heating plastic to a flexible temperature. It then requires cooling the plastic into a new form. In vacuum forming, there is an additional process. During thermoforming vacuum pressure is used to adapt plastic to the mold during forming and this is the main difference between the two.
Advantages of Vacuum Forming:
The advantages are as follows
- Vacuum forming offers many advantages over other forming processes. Here low forming pressures are used, and it enables relatively low-cost tooling.
- As it uses low pressure the molds can be made of low-cost materials
- The mold fabrication time is also sensibly short.
- Many refined machines and molds are used for the automated production of plastic things which is used in our daily life. As the operation is less complex to execute the production is easier.
- Vacuum forming has a short lead time and initial project costs are usually much lower
- There is a huge freedom of design and small details can be added which can be pre-colored
- Plastic is available with an extensive choice of patterns, textures, and finishes, and provides an excellent quality ratio.
Disadvantages of Vacuum Forming:
The disadvantages are as follows
- Highly detailed parts are very difficult to achieve.
- Absorbed moisture can expand which forms bubbles within the plastic.
- Webs tend to grow around the mold from the process of overheating.
Vacuum forming is important for processing plastic material and mold them in a usable form.