PET & rPET
What is PET?
PET (or PETE, PETP, PET-P, Virgin PET) is polyethylene (or polythene) terephthalate. A form of polyester, it’s a plastic resin made from a combination of two monomers, ethylene glycol, and purified terephthalic acid.
Virgin PET is made through crude oil and natural gas extraction from the Earth’s core. It is heated to form a molten liquid then moulded and solidified to create PET plastic containers.
It is the most recycled plastic worldwide because so many waste management systems accept it. PET is also easy to identify for recycling through clear embossment and good labelling. It is regularly used for soda bottles, water bottles, and food jars.
Through both stretching and blowing, the rPET is moved in two directions. This method is responsible for giving rPET it’s glass-like clarity while having excellent barrier properties and strength.
Intrinsic Viscosity (IV) in PET
IV is the measure of the polymers molecular weight which indicates the strength and functionality of the PET. The higher the IV, the better the tensile strength, the higher the melting point, and the lower the freezing point, so a high IV is best.
Qualities and benefits of PET bottles and jars
The following qualities and benefits of using PET are also all applicable to rPET, bar one: 100% pure rPET bottles may have a slightly cloudy appearance due to impurities and a lower IV. This could be an acceptable trade-off for consumers, but if not, it can be easily corrected by using a slightly less sustainable mix of rPET and PET.
- Shatterproof: making them ideal for use in surroundings where glass can be a potential hazard, like bathrooms, kitchens, and retailers, and perfect for on-the-go consumption
- Good Barrier properties mean a longer shelf-life: PET packaging has excellent gas and moisture barrier properties and is resistant to penetration from microorganisms and O2, meaning it can keep food and beverage and products containing oxygen or carbon dioxide, alcohols, oils, and diluted acid fresher for longer when compared with other plastics
- Lightweight: 10% of the weight of the equivalent glass packaging meaning it is convenient to use and incredibly efficient to transport, therefore lowering carbon emissions
- Transparent: with the same clarity and appeal as glass packaging to display contents
- Thermostable: most common cold-fill PET bottles and jars can withstand temperatures from -40 to 60degrees. If using CPET or a double ISBM process it is possible to make hot-fill bottles that can withstand the heat of a conventional oven up to 230degrees celsius. PET also has a higher heat distortion temperature (HDT) than other plastics
- Reusable, resealable, and fully recyclable: the bottles and jars can be reused and the polymer can be reprocessed to granulate and reinserted back into its original supply chain to create new PET feedstock
- Easy to recycle: widely accepted by recycling plants across Europe, and easy to distinguish with the #1 recycling embossment and label: 90% of Virgin PET has been recycled in countries such as Finland.
- More sustainable than other plastics: PET has a lower manufacturing carbon footprint than other plastics
- Customizable: Especially with the Single-Stage injection blow moulding process it can be formed into many non-circular shapes and varying volumes
- Inexpensive: there is a high supply of PET and so it has a lower cost than other plastics
PET vs. Glass
- PET is up to 40x lighter than glass
- PET is 5x less expensive than glass
- PET is more durable than glass due to being shatterproof
- PET is safer as it doesn’t grow microbial biofilms including bacteria, fungi and protists that are very bad for health like glass does
- PET manufacturing process is better for the environment than glass production
- Glass can be clearer, although high-quality PET can have a glass-like look
- PET extracts crude oil from the ground whereas glass uses sand
Analysis shows that the overall environmental impact of PET as a packaging material is lower, and this is mostly due to the weight of glass. PET is much lighter and uses far less CO2 to transport. Furthermore, PET is fully recyclable (like glass) and it doesn’t break so the production leads to a much higher level of used products and far fewer breakages/damages.
PET vs. Aluminium
- PET uses half the amount of greenhouse gases to produce than aluminium, with a 330ml PET bottle using 330g vs. an aluminium can of the same size using 1300g of CO2 emissions
- PET costs 20-30% less than aluminium
- PET is more consumer convenient as it is resealable, whereas cans cannot be closed
- PET has more options for shapes, volumes, and colours
- PET production has more existing infrastructure set up, therefore costs less to produce than cans which have less
- Less power is needed to chill aluminium cans than PET bottles
- Less space needed to transport aluminium cans than PET bottles due to their being so lightweight
PET is a far more sustainable choice when considering the CO2 emissions produced by Aluminium production, the food and beverage waste that can occur from non-resealable packaging, and the cost of changing a lot of manufacturing infrastructure.
What is rPET?
rPET is recycled polyethylene terephthalate. The key impact of rPET is in its creation – reducing greenhouse gas emissions by 71% when compared with Virgin PET and requiring 79% less energy to produce. This gives rPET a far smaller carbon footprint, at under a quarter of regular PET, 0.45 of CO2 per kg vs. 2.15 CO2 per kg. rPET bottle and jar production grew by 29.5% in 2017.
rPET is produced by collecting and sorting industrial waste and post-consumer PET, refining the material into flakes, then cleaning and drying them to form a granulate that can be turned into new products. rPET can be produced in two ways:
Means PET that has been used by consumers before being disposed of. It can be collected from recycling bins, the ocean, or landfill. Post-Consumer recycling is effective in removing plastic from the environment and reprocessed to form rPET.
Is the PET that is collected as waste during the manufacturing process. This can be reused, making manufacturing more efficient and sustainable. It is also reprocessed to form rPET.
The benefits of rPET
rPET has all of the benefits of PET bottles and jars, with some added extras. From a business perspective, introducing more rPET into packaging means a business can identify with a broader customer base and increase sales by meeting the demand for recycled packaging and sustainable efforts. In addition, rPET use leads to greater demand and market for recycled plastics which will increase material supply and lower costs – a win-win for business and the environment.
In addition to having all of the benefits of pure PET bottles – rPET has many environmental gains:
- Uses 79% less energy plus less water to produce than virgin PET
- Reduces transport carbon emissions: as demand grows, there is also a more local and reliable supply of rPET, limiting the need to transport rPET internationally
- Less plastic going to landfill: through recycling and stopping the material entering landfill, no toxic chemicals are leaching into the groundwater during the years that they can take to break down
- Reducing the need to extract resources from the earth, using rPET offsets the need to create new PET
- Encouraging bottle return schemes and post-consumer recycling programs and establishing them as a norm within the industry – less likelihood of plastic waste ending up in the ocean
- Lowering costs – the consumer demand for recycled materials has risen and so is pushing the prices and transport costs down, plus a focus on good design means lowering costs and waste through reducing the amount of plastic used during the bottle and jar production process
- Fulfilling consumer demand for recycled packaging, increasing sales, and lowering costs through progressing the market of recycled materials
Cold-Fill bottles and jars
The food and beverage, personal, health, and home care industries, especially pharmaceuticals, are now using cold-fill PET bottles and jars due to their many benefits and the development of aseptic processing.
Before cold-fill was created, hot-fill bottles and jars were used. This meant that the contents had to be heated to 90 degrees Celsius to kill any bacteria and then cooled. This process took up a lot of energy and also changed the flavour of the product.
Cold-fill PET bottles and jars are suitable for:
- vitamin shots
- energy shots
- nutritional products
- drinkable yoghurts
- drinkable probiotics
- energy drinks
- non-carbonated products
- fruit juices
- pharmaceutical liquids
Now, instead of having to heat their products to get rid of bacteria etc. they can now use cold-fill bottles which help retain the natural flavour, freshness, and nutritional value of the product. It also saves energy. This is partly due to the development of High Pressure Processing.
It is still possible to use hot-fill bottles and jars for products that need pasteurising by using CPET or the Double ISBM process, but if you’re using the High Pressure Processing method you don’t need to.
High-Pressure Processing (HPP) Method
Cold fill bottles can go through an extra process to make the shelf-life of the product longer, called high pressure processing, or HPP. This is a cold pasteurisation technique whereby sealed products are placed into water and pressurised in order to inactivate bacteria, virus, yeasts, mould and parasites. As the contents is never heated, it retains the original taste and nutrients.
All of Embaco’s bottles and jars are HPP suitable.
HPP vs. UV Pasteurisation Methods
UV light can be used in the food, beverage, and pharmaceutical industry for sterilisation of produce prior to filling bottles and jars; however, this method is not as effective as HPP as it can significantly damage the nutritional content of the product.