The Story of
PLASTIC
Plastic is a byproduct of petroleum and can commonly be classified in Hong Kong into several types: "1" PET, "2" HDPE, "3" PVC, "4" LDPE, "5" PP, and "6" PS. Each type has different characteristics and melting points. Utilizing these properties, various functional plastic products can be made. Generally, hard plastics are formed through injection molding or vacuum forming.
CLASSIFICATION
PVC
(Polyvinyl Chloride)
Softening point: 80°C; Melting point: 260°C
The only plastic with high-strength resistance to chemical corrosion, commonly used for various cleaning products and shampoos packaging.
Usually has a horizontal line at the bottom.
HDPE
(High-Density Polyethylene)
Softening point: 110°C; Melting point: 142°C
PET
(Polyethylene Terephthalate)
Softening point: 70°C; Melting point: 260°C
Commonly found in water pipes, fire-resistant materials, and credit cards.
Clear PVC may appear faintly blue or green when viewed under light.
Commonly found in bottled beverages,
Typically has a small circular dot at the bottom.
PS
(Polystyrene)
Softening point: 80°C; Melting point: 166°C
LDPE
(Low-Density Polyethylene)
Softening point: 70°C; Melting point: 110°C
It has the best flexibility and stretchability among all types of plastics,
Commonly found in plastic bags and soft caps.
It is not resistant to alcohol and oil, has high hardness and low cost, but is also the most brittle plastic. Commonly found in disposable tableware and foam bowl lids.
PP
(Polypropylene)
Softening point: 155°C; Melting point: 164°C
It has the best heat resistance and impact resistance among all types of plastics and is widely used in food containers, stationery, electrical appliances, and various daily products.
BEFORE RECYCLING
Thoroughly cleaned and remove any contaminants like food residue or dirt
The value of recycling plastic lies in the purity of the materials collected!
AFTER RECYCLING
Since the density of plastic No. 2, No. 4, and No. 5 is lower than 1, they can float on water. So these plastics can be seperated by the flotation method.
After classification, the plastic will be melted at high temperature.
The semi-liquid plastic will be pulled into long strips in water, cooled and cut into recycled plastic pellets, that is, plastic raw materials.
Salt will be added to increase the density of water, then No. 6, No. 3, and No. 1 will be floated in turn.