Food preservation has long been a priority of mankind, from the days before modern refrigeration when salting and dehydrating food were commonplace. 

We explore how thermoforming food packaging not only achieves an extended shelf-life but is an all-around versatile manufacturing technique in food production.

What Does Thermoforming Mean?

Thermoforming is a plastic manufacturing technique that is widely used in many industries, such as aerospace, medicine, and of course, the food sector. This inexpensive technique can be used to make anything from washing machine parts to food packaging. 

To thermoform a component, heat is applied to a plastic sheet to make it pliable. Next, either the air is extracted, or pressure is applied to force the plastic sheet to take the mould’s form. 

The result is a 3-dimensional shape that can be used in a wide variety of applications. 

What Are the Different Methods? 

In general, there are two main methods of thermoforming: 

1. Vacuum Forming: where the air is removed to force the plastic sheet into a mould.
2. Pressure Forming: where compressed air drives the plastic sheet into the mould.

Food packaging thermoforming machinery adapts thermoforming techniques to meet the needs of the food sector, such as food preservation, hygiene, and presentation. Choosing the right method to suit your business ensures you have a high-quality product to meet your consumer’s demands and can help you to make cost-savings in the long term. 

Vacuum Method

In addition to making the container, the thermoformer removes the air within it. By removing the oxygen and moisture from the container, you’ll improve the shelf life of your food product. The vacuum method is ideal for packing meat and cheese products. 

Modified Air Packaging (MAP)

An adaptation to the vacuum method, the Modified Air Packaging or Gas Flushing technique first removes the air from the container. The thermoformer then replaces the air with a modified atmosphere or a preservative gas. This gas helps to preserve food even longer than the vacuum method. 

Skin Packing

The Skin Packing technique is becoming increasingly popular with businesses that produce premium foods where the aesthetic is important. A very tight film is applied around the food container, which enhances the appearance of the food and helps it to retain its juices. This technique is often used for foods such as steak or fish fillets.  

Seal-Only

Where shelf life is not critical, a seal-only thermoforming technique may be useful. Here, the packaging is made and sealed but does not remove the air or apply modified air to preserve food. This technique is common for packaging frozen foods. 

Which Types of Plastics Are Used?

Thermoforming can be used with a wide range of plastics, which all have different properties making them suitable for varying uses.  

The most common type of plastic is Polyethylene Terephthalate (PET), which traditionally has been used to make thermoformed packaging and bottles. Polystyrene (PS) is also commonly used to make thermoformed cups. 

As consumers become savvier about eco-friendly materials, manufacturers are turning to more sustainable plastics such as Polylactic Acid (PLA) and Crystallized Polylactic Acid (CPLA), which are derived from organic sources such as corn starch or sugar cane. These types of plastic are often used to make sustainable plastic cutlery or cup lids. 

Is Thermoforming Environmentally Friendly?

Increasingly, manufacturers are choosing more sustainable materials to produce their packaging. Plastics such as PLA, CPLA, and PET are all widely recyclable. 

Thermoforming techniques are sustainable as they allow you to use and reuse your raw materials, time and again. The plastics used in the thermoforming process are all polymer resins, which means they soften when they are heated – no matter how many times you’ve heated them before. 

Food preservation is one of the main reasons why thermoforming is used in the food sector in the first place. The use of food trays and tray sealing removes moisture and oxygen, helping to keep food on the shelves for longer and reducing food waste.

Which Types of Containers Can You Make?

Thermoforming is a versatile plastic manufacturing technique – you’re only limited by your imagination and your mould!

In the food industry, the main types of thermoformed food containers include:

• Clamshells: ideal for protection and presentation of cold foods.
• Cups: for both hot and cold beverages, depending on the type of material used.
• Trays: used for food packaging and presentation, such as meats, hot foods, or frozen foods.

The choice of food container largely depends on the properties that your product demands, such as heat resistance for products that will be reheated in the oven or microwave, longer shelf-life, or great presentation. 

Which Businesses Can Benefit Most?

Businesses such as frozen food manufacturers, fresh meat and cheese producers, and even takeaway food outlets can all benefit from thermoforming. A key advantage of a thermoformer is the ability to create packaging that extends the shelf-life of food and is convenient for the consumer.

Post-pandemic, it’s more important than ever to present food hygienically and thermoformed packaging is ideal for this purpose. 

Summary

Thermoformers can be a versatile and cost-efficient way of managing your packaging needs. 

With food thermoformers, you eliminate the need for additional machinery to vacuum seal your product. You can design packaging that exactly fits the needs of your product, resulting in less waste, and then modify it efficiently as and when your business needs change.