What is Thermoforming | Different Stages of Thermoforming | Types of Thermoforming | Applications | Advantages & Disadvantages

What is Thermoforming?

What is Thermoforming?

Thermoforming is a manufacturing process in which thermoplastic is heated to a temperature to make it soft and flexible. Then the sheet is pressed and stretched into using a vacuum or compressed air pressure to form the desired shape.

Cooling is crucial in the thermoforming process to manipulate the sheet into the desired shape.

This process is very Versatile in terms of its applications and is utilized in dozens of industries for manufacturing their products.

The thermoforming industry is huge in size and growing by leaps and bounds ( Not kidding ) every year.

The overall thermoformed plastic market was sized at $12 Billion in 2019 and is expected to grow at a CAGR of 4.9 % by 2027.

With a 54% market share, North America ( US, Canada, and Mexico ) leads the chart, followed by Asia and Europe regions.

Different Stages of Thermoforming – 

stages of thermoforming

The thermoforming method is divided into five stages. The typical way of doing it is –

  • Design
  • Prototyping
  • Final tooling
  • Production
  • Shipping

What are the Types of Thermoforming?

There are mainly two types of thermoforming methods – Vaccum Forming and Pressure Forming. Both the methods are quite different in terms of their approach to manipulate sheets into their desired shapes.

Let’s have a brief discussion about them.

#1 Vaccum Forming:

Vacuum forming primarily uses heat and pressure to draw plastic sheets into the desired geometry. The heated sheet is placed on a mold, and then a vacuum is used to shape the sheet into its desired configuration.

The method is generally preferred when shallow parts need to be transformed into cavities.

Almost all the thermoplastics are suitable for vacuum forming. Even HIPS can also be utilized when required.

#2 Pressure Forming:

The pressure forming method is quite similar to vacuum forming only major difference being the added pressure while thermoforming. The extra pressure is a nice touch for additional texturing and detailing.

Although, when it comes to more number users, Vacuum forming takes the cake. However, pressure forming should be given an upper hand for manufacturing complex geometries.

Interesting Read – What is a Plastic Pallet? | The Definitive Guide 

Common Thermoforming Materials – 

thermoplastics for thermoforming

There are several mainstream thermoplastics with great physical properties that are compatible with thermoforming. Below is the of them.

#1 Acrylic (Polymethyl Methacrylate, Plexiglass, or PMMA): This thermoplastic is very transp[arent and one of the prime choices for transparent applications. Being abrasion resistant also makes it easy to fabricate into many shapes and sizes. In addition, it is easily available in impact-modified grades and comes in many colors.

#2 HIPS (High-Impact Polystyrene): The biggest advantage of using this material is that it’s very inexpensive. It is also very brittle, which improves its applicability. It can also be thermoformed easily.

#3 PC (Polycarbonate): Supreme impact strength, easy moldability, good chemical resistance, and high-temperature resistance make this material highly suitable for thermoforming.

#4 PET (Polyethylene Terephthalate): PET has the advantage of being inexpensive and available in abundance. It is transparent but not clear as Acrylic. It is fae for human contact thus extensively utilized in food packaging applications.

#5 PP (Polypropylene): This material is tough, rigid, and highly chemical resistant. It can be thermoformed at high temperatures, but poor dimensional stability might become an issue.

#6 HDPE (High-Density Polyethylene)This material is also impact and chemical resistant. Good cold-temperature properties make it compatible with thermoforming.

#7 PEI (Polyetherimide Ultem): A high-temperature grade material with autoclavability comes with a natural amber color.

Equipements Necessary for Thermoforming –

There are some types of equipment or machines that are necessary for a smooth thermoforming process. The most important equipment needed is either pressure former or vacuum former.

Another major requirement is a station-rotary transformer.

An additional CNC robotic router will make your job easier. The bed for this equipment must be 60” X 120”.

The tooling can be done with composite or temporary molds, aluminum molds, cast aluminum molds, and male/female molds.

Applications – 

applications thermoforming

  • Food Packaging ( Especially where human contact is more )
  • Automobiles
  • Toys
  • Packaging Inserts
  • Pop Displays
  • Medical Packaging
  • Shipping Trays
  • Packing Blisters
  • Retail Packaging
  • Relocating Trays
  • ATM’s
  • Diagnostic Equipment

Advantages – 

Advantages of Thermoforming

  • Very adaptable to consumers’ needs in terms of size and complexity of designs.
  • Figuring out the possible design and fitting issue is easier than other processes.
  • Developing a prototype is also faster than other methods.
  • Its efficiency results in saving time and a lot of money.
  • It is possible to create several fished products with the same material.
  • Aesthetically impressive final designs are the main advantage. The customization options inlined with thermoforming can result in fantastic customer satisfaction rates.

Disadvantages – 

disadvantages of thermoforming

  • Objects can stick to the mold, which can halt the process and consume time.
  • The process is only limited to thin-walled parts.
  • There’s a chance of moisture forming bubbles within the inner layers of the mold.

Interesting Read – Plastic Mold: Information about Male Vs. Female Molds

Future Trends – 

The thermoforming process is quite beneficial for any manufacturer but has certain drawbacks, which can be a problem for its prospects.

It is well-known that the current thermoforming process uses the trial and error method to figure out the heating temperature leading to uneven thickness of parts.

There are multiple research institutes thoroughly researching the prospects of using numerical modeling of heating. With that,  development in heating technologies is bound to happen.

Apart from that, there are several institutions working on developing their proficiency with applications. In the future several, developments will be made for packaging solutions sterilization.

FAQs – 

1. Which thermoforming doesn’t use any mold?

Ans. Billow forming is a seldom-used thermoforming method that doesn’t involve any mold. Still, acrylic sheets are clamped in a frame, and either a vacuum or compressed air draws the material to the desired depth. An electric eye figures out when the specific depth has been reached and decreases or turns off the pressure.

2. What is the difference between Thermoforming and Injection Molding?

Ans. Both thermoforming and injection molding are drastically different from each other. the most subtle difference between them is that the former is used for large designs and smaller production runs. On the other hand, injection molding is used for manufacturing small and medium-sized intricate parts and large production runs.

Talking about both’s working principles, in thermoforming, a flat set of plastic is heated to a pliable temperature then molded to the tool’s shape utilizing suction from a vacuum or both suction and pressure. In injection molding, plastic pallets are heated till they melt and are injected into the mold.

3. Which country is the largest market for thermoformed products?

Ans. China is the largest market for thermoformed products, and it is also the largest supplier of thermoformed plastics and thermoforming equipment in the world.

4. What is the best of someone to use thermoforming?

Ans. Thermoforming has the ability to manufacture several finished parts from the same material. It allows the user to detect any design and fit-related issues before it’s too late. Using thermoforming is advisable when manufacturing large parts. It will be more efficient and save a lot of time and money.

The Takeaway – 

Thus were my thoughts on the thermoforming process and its attributes. Thermoforming can be groundbreaking for any manufacturer to cut costs and boost profits. The process will work wonders for manufacturers looking for a smaller production run that want to make large parts

Kindly share your reviews in the comment box.

Peace Out!!

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