Hot-filling products has numerous benefits for a wide variety of industries. It streamlines production, sterilizes packaging, and is a more economical way of approaching filling. However, not every plastic packaging solution offers the benefits of hot-filling. In this blog, we’ll examine whether PET bottles can withstand hot-filling and what you can do if you want to use PET for your own filling operations.
Polyethylene Terephthalate (PET, PETE or polyester)
Commonly used for carbonated beverages, water bottles and many food products. PET provides very good alcohol and essential oil barrier properties, generally good chemical resistance (although acetone and ketones will attack PET) and a high degree of impact resistance and tensile strength. The orienting process serves to improve gas and moisture barrier properties and impact strength. However, this material does not provide resistance to very high temperature applications—max. temperature. 200 °F (93 °C). So can you hotfill PET?
Hot fill packaging
The hot fill packaging process offers a number of advantages to many industries, especially in the food and drinks sectors. The heat can act as a sterilising agent, preventing the growth of bacteria. This means that it is sometimes possible to avoid the need for additional chemicals or preservatives in order to make sure that the product has a decent shelf life and doesn’t spoil. The process of hot filling will often also allow for shorter product runs, meaning that it is more accessible to smaller businesses.
The process works best with low PH products that have been chemically neutralised. When the products are hot filled, they are capped and then inverted so that the cap and neck are also sterilised. The bottles are then immediately cooled down.
But can you hot fill PET bottles?
The short answer is no, you cannot. It’s a shame because PET bottles can have the look of quality glass, bringing elegance to a product and adding market value because it looks so good and is lighter to transport than glass. However, standard PET plastic is not suitable for normal hot fill. The usual recommendation is that PET plastic containers are tolerant of being filled with products up to 40°C. Some people say that you can get away with slightly higher temperatures than this, but it is important to test each product for chemical and heat compatibility.
What are the alternatives?
Unfortunately, hot-filling PET is not an option, and filling plants will have to use alternative forms of sterlization. However, other forms of plastic have various hot fill temperatures for plastic bottles and jars:
- PET (polyethylene terephthalate) 50°C / 120°F
- PS (polystyrene) 65°C / 150°F
- HDPE (high density polyethylene) 62°C / 145°F
- LDPE (low density polyethylene) 50°C / 120°F
- PP (polypropylene) 73°C / 165°F
- PVC (polyvinyl chloride) 60°C / 140°F
The choice is yours
Ultimately, you will have to choose which plastic bottle or jar will be best suited to your production. Plastic packaging that enables hot filling could have many benefits, but you must be aware of what is possible and what is not for the packaging in question. If you would like to find out what’s possible for your own plastic packaging needs, contact us today. Our experts on standby to help you identify the perfect plastic packaging solution for your business.