Question

Over the world, humans consumed up to million of plastic water bottles per minute. Plastic water bottles are generally made from polyethylene terephthalate (PET), which is non- biodegradable in nature. Thus, most of these plastic bottles are end up in either the ocean or in a landfill. Then, the plastic bottles waste caused a serious issue to our environment. For this reason, many beverage packaging companies are planning to replace their plastic bottle that 100% made from recycled PET material. Currently, the plastic resin company is going to produce a food grade plastic from recycled PET material due to high market demand from beverage industry. As you are an engineer in plastic resin company, you may need to

compare the difference of recycling method

the question 3

Answer 1

Okay so we need to compare the different methods of recycling of thermoplastics :

As we know broadly there are 3 types :

• Primary
• Secondary
• Tertiary

Primary recycling means that the plastic product shall be REUSED as it is, no alteration neither mechanical nor chemical. It is the least expensive.

Example : Reusing a plastic bottle as a storage container.

Secondary recycling means that the plastic is mechanically altered such as by cutting or shredding but no chemical alteration of the plastic shall happen. This can be also stated that changes happen at an Extrinsic level. This requires a certain initial investment.

Example : Cutting a bottle into half and using it as a flower pot. In case the plastic is shredded into granules or pellets , these can be then extruded or injection moulded into desired shape.

Tertiary recycling means that the plastic is altered chemically such that changes happen intrinsically at a molecular level such as breaking of chains or removal of certain molecules through heat or a chemical reaction such as Hydrogenation - Glycolysis - Gasification - Hydrolysis - Pyrolysis. This is most expensive. Mechanical methods can be used as a compliment

Example : breaking down bottle into brand new products

In very brief:

RECYCLING MECHANICAL CHEMICAL PRIMARY x SECONDARY x TERTIARY