Thermoforming materials can be used for many different purposes, from making swimming pools and plastic parts to manufacturing the packaging we use for food and non-food products. When it comes to manufacturing, whether its trays, blister packs or food packaging, thermoforming materials are among the best options on the market and SP Group is here to explain why.
HOW RIGID THERMOFORMING MATERIALS ARE USED IN PACKAGING
There are many different uses for thermoforming materials in the packaging industry; food trays are some of the most common.
The main purpose of these materials in the world of food is to enhance food preservation and the fact that they are employed with foods of all kinds is testament to this. We find thermoforming materials in the packaging that is used for cakes and sweets and for products that have very specific conservation and preservation needs. For example, vegetables, salads, meat, cheese and fish.
Thermoforming materials are also commonly used in other niche markets. In the cosmetics and personal hygiene industry, the pharmaceuticals industry (blister packs, in particular) and a wide range of other non-food sectors, there are some wonderful examples of how rigid thermoforming materials adapt to the needs of a wide range of products.
HOW RIGID THERMOFORMING MATERIALS ARE MADE
The manufacturing process for making thermoforming material varies depending on if the end product is single or multi-layer.
Plastic pellets travel along pipes from a silo to an extruder. Sacks of raw material are poured into trays and transferred into the extruder through suction devices. The temperature in the extruder gets incredibly high (between 210 and 285ºC) and, in conjunction with the inert environment in the extruder, this ensures there is no microbial contamination.
The rigid material manufacturing line at SP Group has two extrusion zones. Raw material is dosed into the first one for the manufacture of PET mono-materials. The raw material travels into a drying oven and remains there for four hours. After this, it travels to the extruder where it is melted, flows along a die and drops down onto cooling grilles where it solidifies into the required thickness. The film then travels to the cutting and reeling station where it is readied for delivery to the client.
The multilayer film manufacturing process involves coating. The film is made by sticking the polyester film manufactured in situ in the first extruder, as explained above, to melted polyethylene from the second zone in the rigid materials extruder. Following this, it travels to the cutting and reeling station where it is prepared as per client specifications and then it is delivered.
When the film also requires a barrier, the film that is manufactured on the flexible products line drops down onto the stabilised polyester film and melted polyethylene is added to it so that the three layers stick together. It then moves on to the cutting and reeling station and is delivered to the client as per the purchase order. A primer is used to improve adhesion.
THE RIGID THERMOFORMING MATERIALS MANUFACTURING PROCESS
Thermoforming plastic film production is a relatively simple process. It begins with a film of plastic material, which should ideally be very recyclable so that the packaging is as sustainable as possible.
The process entails making packaging using a combination of heat and vacuum and, in some cases, with the help of a piston. The film is heated until it reaches the shaping temperature. Force is then applied until it moulds into the required shape. The result is a tray that meets the needs of each product and is made to measure.
Food products are generally packaged on thermoformed trays and sealed with the type of flexible lid that suits the product. This ensures that the product is adequately preserved.
THE MATERIALS THAT ARE NEEDED
At SP Group, we specialise in the manufacture of PET rigid thermoforming films. When it comes to sustainability, plastics made from 100% recycled materials and that are 100% recyclable are ideal. This is why rPET is one of our base materials.
In addition to having the aforementioned characteristics, this material has excellent transparency properties, which help the packaged product and all its features to stand out. Furthermore, not only can our rPET withstand physical impacts during packaging and transportation, it is also entirely safe in terms of food contact, as certified by the EFSA in assessment 2017/4843.
APET PE and others are alternative options. This material is very transparent, which really lets the product stand out, and incorporating a barrier is also an option. In addition, it can be designed as a peelable seal, making it far easier for customers to use.
THE ADVANTAGES OF RIGID THERMOFORMING MATERIALS
Extending food product shelf life should be a food industry priority. It is estimated that a third of all food goes to waste. This includes waste generated in the home, but also waste that is generated when there are cold chain delivery or food preservation issues.
This is where one of the key advantages of thermoforming materials comes into play: the ability to preserve food for longer.
Thermoforming materials help to keep food fresh for longer, in addition to sustaining their appearance and taste. They also help to stop food becoming contaminated by external agents that could affect their quality. They can be a good barrier against light and aromas and they are excellent at creating a watertight environment.
But that is not all! In the food industry, thermoforming materials can help businesses to make their products stand out. Not only does this enhance consumer confidence by making it easy for them to make their choices based on the specific characteristics they are looking for in their food purchases, it also means they can determine if there are any issues with the product quickly and easily. Ultimately, this improves consumer confidence when choosing what to buy.
Furthermore, the ergonomics of these materials improve product presentation and help to deliver them to consumers in good condition.
If you would like to find out more about this material and how to go about using it in your products, simply get in touch. We will be happy to answer your questions.