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What is Thermoforming?
Thermoforming is a manufacturing process in which a thermoplastic or glass sheet is heated to a temperature where it becomes soft and flexible. Then the sheet is pressed into and stretched over the mould using air (both vacuum and compressed) pressure or pressed between moulds using mechanical force to form into the desired shape.
It’s very similar to vacuum forming but faster and used extensively for higher volume manufacturing of thermoplastics. Depending on the material, mould type, sheet thickness, and quantity, it might need trimming to create the final part.
Plastic thermoforming can be divided into the following two categories according to the material thickness.
- Thin gauge thermoforming (< 5 mm)
- Thick gauge thermoforming (> 3 mm)
The thin gauge process, as the name implies uses thin plastics and is used to manufacture rigid or disposable packaging items such as plastic cups, food containers, lids, blisters while the thick-gauge process is typically used to form more durable cosmetic permanent parts such as vehicle door inside panels and electronics packaging.
The most common thermoplastics used in the thermoforming are;
- Acrylic (PMMA)
- Acrylonitrile Butadiene Styrene (ABS)
- Cellulose Acetate
- Low-Density Polyethylene (LDPE)
- High-Density Polyethylene (HDPE)
- Polypropylene (PP)
- Polystyrene (PS)
- Polyvinyl Chloride (PVC)
Thermoforming glass is a fairly new manufacturing process and came into prominence when Samsung introduced it through its flagship handset Galaxy S6 edge. Thermoforming glass is very similar to thermoforming plastics but differs in that the glass is already cut to the right size including the allowance needed for formed edges. It differs from glass blowing and is better suited for making flatter glass parts such as phone screens, glass tables and countertops.