Burn testing 

• A simple technique where you cut a small piece of plastic and light it on fire (although this produces toxic fumes, so we don’t recommend doing this one regularly!) the unknown plastic and light it up observing the flame color, nature and smell.

Hand sorting 

• A manual process where plastic comes in on a conveyor belt and people identify common plastics or using the SPI codes. The problem with this process is that some items can look and feel the same, but are made from different materials 

Volatile Organic Compounds

• Volatile Organic Compounds (VOCs) are a large group of chemicals that are found in many products we use to build and maintain our homes. These chemicals released or “off-gas,” and there are many health risks from inhaling.

Plastic Types: 

Thermoset

• Plastics that are synthetic materials that strengthen when heated but cannot successfully be remolded or reheated after initial heat-forming or molding. 

Thermoplastics

• A thermoplastic is any plastic material with a low melting point that becomes molten when heated, solid when cooled, and can be re-melted or molded after cooling. The curing process is completely reversible, and doing so will not compromise the material’s physical integrity.

• Thermoplastics are usually stored as pellets to facilitate easy melting during the injection molding process. Common examples of thermoplastics include acrylic, polyester, nylon, and PVC.

🔴 Do not use with the machines

🟡 Try other plastics first (these plastic are harder to work with)

🟢 Great for the machines

1. PET (1): Polyethylene terephthalate 🟡

• PET is a very strong plastic that can be easily recognized for its transparent look - all water and soda bottles are made from PET as well as some jars, combs, bags, tote bags, carpets and ropes, and is recycled more commonly. It is more complex to deal with, so start off with other plastics.

2. HDPE (2): High-density polyethylene 🟢

• HDPE is often used for food and drink containers, as well as milk bottles, motor oil, shampoo bottles, soap bottles, detergents, bleaches, toys and bottle caps. Products of this plastic types are often easier to collect sorted and clean. 

3. PVC (3): Polyvinyl chloride 🔴

• PVC is toxic and is commonly found in plumbing pipes and releases chloride when heated up. Not recommend for Precious Plastic!

4. LDPE (4): Low-density polyethylene 🟢 

• PET is a very strong plastic that can be easily recognized for its transparent loo

• LDPE is largely used for plastic wrap, sandwich bags, squeezable bottles, and plastic grocery bags. Usually LDPE is not commonly recycled, as it is often not labeled, it’s too light and tends to be more difficult to clean. A popular recycling technique for plastic bags is ironing them into a more durable textile.

5. PP (5): Polypropylene 🟢

• PP is one of the most commonly available plastics on the market, it is strong and can usually withstand higher temperatures. PP has a wide variety of uses but is consistently used for products that get in contact with food and drink - tupperware, yoghurt boxes, syrup bottles etc. 

6. PS (6): Polystyrene 🟢

• PS is most commonly known as Styrofoam, but also appears in many more products. PS can be recycled, but not efficiently - recycling it takes a lot of energy which means that few places accept it. It is one of the more toxic plastic types, but at the same time offers great aesthetic and haptic properties as it is comparable with glass and can be polished. 

7. MIX (7) 🟡

• This label is used to identify other types of plastic that are not defined by the other six plastic types. Plastics such as. ABS, Acrylic or Polycarbonate are included in this category and can be difficult to recycle. Precious Plastic can work with some of this.