Which Type Plastic Is Easier To Be Recycled?

It is well known that plastic products can be recycled. However, the process of plastic recycling is not as simple as many people might think. On one hand, the difficulty of recycling varies with different types of plastics. Without precise recycling facilities and technology, many areas can only recycle plastics like mineral water bottles and boxed beverages, while the plastics used in products like yogurt cups, plastic cutlery, and coffee pods will ultimately be incinerated or landfilled due to a "lack of recycling capacity." On the other hand, the heating process shortens the polymer chains, thereby reducing the quality of the plastic. Therefore, even if a plastic water bottle can be effectively recycled, it cannot simply be "reborn" as another plastic water bottle. The vast majority of plastic products will be "downcycled," becoming products of lower quality than their original form.

Currently, according to the ASTM International's D7611 standard (the resin identification code for plastic products), plastics can be divided into seven common types.

1# Polyethylene Terephthalate (PET or PETE)

Polyethylene terephthalate (PET) is the most common variety of thermoplastic polyester and is one of the easiest types of plastics to recycle. It is typically used for transparent beverage bottles and food containers. Due to its porous structure, this plastic can absorb bacteria over time, which is why it is not recommended for repeated use, especially for holding beverages.

Recovered PET is commonly made into tote bags, furniture, carpets, panels, fibers, or flocking, and can withstand 2 to 3 recycling processes. However, it's important to note that whether products made from recycled PET can be recycled again depends on the overall recycling capacity of the industry they are in. For instance, since the textile industry's ability to recycle on a large scale is not high, once recycled PET is turned into polyester fibers, it may not have the chance to enter a second recycling cycle and may instead be incinerated.

2# High density polyethylene (HDPE)

High-density polyethylene (HDPE) is typically opaque, and due to its lower leaching risk, it is considered one of the three safest types of plastics. It is commonly used in products such as milk jugs, cleaning agents, juice bottles, and shampoo bottles. In terms of recycling efficiency, HDPE is comparable to PETE, and both are easy to recycle. Recycled HDPE is often used in products like ballpoint pens, drainage pipes, toys, and wood-plastic composite materials.

Thanks to its certain thickness and durability, HDPE can better withstand repeated recycling processes. A European experiment testing the recyclability of HDPE found that, under precise and highly controlled conditions, HDPE plastics can be recycled up to 10 times. However, current everyday recycling conditions do not yet reach this level.

3# Polyvinyl chloride (PVC)

Polyvinyl chloride (PVC) is commonly found in products such as synthetic leather, vinyl flooring, and pipes. This type of plastic contains Phthalates, DEHA, and other harmful substances that can be harmful to human health under long-term contact or high-temperature conditions. Moreover, this plastic is much more difficult to recycle compared to PETE and HDPE because it contains many different compounds and additives, making the challenge of decomposition and processing significant.

Currently, through some complex processes, some PVC can be separated and re-manufactured into new PVC products, such as panels, flooring, cables, fences, carpet backing, and decking, or turned into pipes again. However, due to the difficulty and cost of the re-manufacturing process, the regrind PVC products often have reduced durability and are difficult to withstand multiple recycling processes.

4# Low-density polyethylene (LDPE)

Low-density polyethylene (LDPE) has good chemical stability and is most commonly found in squeezable bottles and bags (such as those for ketchup), shopping bags, film injection molded products, medical instruments, pharmaceuticals, and food packaging materials. After collection, sorting, cleaning, and removal of impurities, LDPE waste can be melted into pellets and used to produce new products such as trash bags and trash cans, but it is typically only recyclable once.

LDPE is rarely involved in traditional plastic recycling systems, but with the development of sustainable development concepts, people have gradually realized that the production energy required for recycled LDPE is less than that of the virgin version, and the price is generally lower than that of virgin LDPE, offering good environmental and economic benefits. Therefore, an increasing number of recycling companies are now including LDPE in their recycling scope.

5# Polypropylene (PP)

Polypropylene (PP) has excellent durability and ease of processing, with low production costs and high safety, making it a widely used general-purpose material. It is commonly found in products such as medical bottles, yogurt containers, bottle caps, automotive parts, and clothing. Due to its strong plasticity, PP can be repeatedly heated, shaped, and cooled without losing its properties, which is why it is one of the types of plastics that many professional plastic recycling companies focus on.

According to data from AZoCleantech, PP can be recycled about 4 times. The specific recycling process includes collecting and sorting plastic waste, crushing it into small pieces, melting it, and molding it into various products such as plastic pallets, garden furniture, storage boxes, car battery cases, bicycle frames, and more.

6# Polystyrene (PS)

Polystyrene (PS) is a common type of foam plastic and a major component of "white pollution," often used in the manufacture of instant noodle containers, disposable meal boxes, disposable plastic cups, and the like. Traditional PS material is formed from liquid hydrocarbons, which cannot be broken down by standard recycling methods, and the processing costs are too high, so the recycling rate of PS is far lower than that of other plastics.

Relatively speaking, a subcategory of PS, expanded polystyrene (EPS), has a higher probability of being recycled, but it can mostly only be recycled once. Common recycling methods involve processes such as heating densification, cold crushing, or cold compression to regrind the material, which is then directly used to mix with other materials and process into products such as coat hangers, flower pots, videotapes, furniture, building materials, or insulation materials.

7# others

From polycarbonate (PC) used in CDs, laptop screens, and shatterproof windows, to to ABS for car dashboards, doors, bumpers, body shells, to biodegradable "plastics" like polylactic acid (PLA) made from cornstarch or sugarcane, all plastics that do not belong to the other six types fall into the seventh category.

Plastics in this category are mostly engineering-grade materials, each with unique characteristics, uses, and recycling methods. Therefore, when recycling these plastics, a case-by-case analysis is required to ensure they are used most appropriately. For example, after professional recycling, some types of PC plastics can be repurposed for use in appliances, automobiles, and sheet materials. PLA, on the other hand, can be composted in certain facilities, addressing the issue of plastic products not being degradable at the source.

Kitech Machinery, specializing in the manufacturing of waste plastic recycling machine, it has over 20 years of plastic recycling experience. We have developed specific recycling solutions based on the characteristics of different waste plastics, such as physical form, chemical structure, and processing difficulty. With professional technology and customized methods, we ensure that waste plastics can be efficiently recycled and reused. We are committed to reducing environmental pollution, promoting a circular economy, and helping our clients achieve sustainable development goals.