Which Plastics Are Recyclable?

Which plastic materials can and cannot be recycled? How can different types of plastics be recognized? We are far too familiar with these and many other related questions. Luckily for you, we have the answers to your questions!?

In our previous?blog post, we introduced you to our recycling journey and the mini-series we created for you on our?YouTube?channel. If you missed it, we recommend you check it out first before continuing on with this blog.?

As you probably know, there are different types of plastic materials, and not all can be recycled. In this blog post, we are going to dive deeper into the different types that are out there and how you can recognize them.?

Types of Plastics?

There are 7 types of plastic materials; PETE or PET, HDPE, V or PVC, LDPE, PP, PS, and?Other / Miscellaneous Plastics. For most plastic consumables, you can recognize the type of plastic used by an indented icon of each plastic code stated below.?

PETE or?PET – Polyethylene Terephthalate

PET is the most common plastic material name nowadays. It’s used in mostly beverage bottles, oven–tray detergent, and cleaning product bottles. It is also used for the finishing of objects such as liquid crystals, displays, carpets, clothes, guitars, and pianos. Therefore, this material is suitable for recycling into filament, however, it absorbs odors and flavors from foods and liquids stored in it, which can prevent you from being able to recycle PET into filament. Furthermore, the plastic is designed for blow-molding, not extrusion (it does not flow easily inside an extruder).?

HDPE – High-Density Polyethylene

Another common plastic material is HDPE, which is known for having a low risk of leaching into foods and or liquids. This material is mostly used in the making of children's toys, yogurt cups, milk jugs, shampoo bottles, and other similar products. Recycled HDPE is mostly turned into pens, plastic lumber, plastic fencing, picnic tables, and bottles. This material is suitable for recycling into filament, however, it is not easy to turn into filament; it flows easily but requires special cooling.

V or PVC – Polyvinyl Chloride

PVC plastics contain very harmful chemicals that have been linked to various diseases. This material is usually used for the making of plumbing pipes, tiles, windows, and medical equipment. Due to the fact that this material has harmful chemicals, it is not recommended to recycle it yourself. PVC only gets recycled by specialized programs that recycle it into flooring, paneling, and roadside gutters.?

LDPE – Low-Density Polyethylene

This material is a very safe and clean plastic. It is recognized by its flexible and thin texture. It is commonly found in household items like grocery bags, plastic wraps, frozen food containers, and food-holding bottles. LDPE is recyclable but not recommended to recycle into filament, due to its behavior in molten state and the shape of the items it usually comes in (grocery bags being a good example of something painful to shred). Recycled LDPE is usually found back in garbage cans, paneling, furniture, flooring, and bubble wrap.

PP – Polypropylene

Another known safe plastic is PP. This material has a sturdy texture and it is commonly found back in Tupperware, syrup bottles, medicine bottles, and yogurt containers. It is also heat resistant as it is also used in making microwavable food containers. PP is suitable for recycling into the filament (depending on the item you want to recycle), and it is usually recycled into heavy-duty items like pallets, ice scrapers, rakes, and battery cables.?

PS – Polystyrene

This material is your everyday plastic, it is found in beverage cups, plastic utensils, insulation, packing materials, egg cartons, and disposable dinnerware. Although some would say that it is notorious for leaching and poor recyclability, we actually managed to recycle it into filament. Polystyrene is the material we used in our recycling video and therefore, we can recommend you to recycle your PS objects into filament. However, it is a possibility that random PS items could react differently and therefore, work differently as well,?

Other / Miscellaneous Plastics

SPI 7 is seen as all kinds of plastic that do not fall in the 1 to 6 category. Miscellaneous plastics are usually found back in nylon, baby milk bottles, sunglasses, computer casings, and compact discs. This is actually the most important category since it contains all of the interesting plastics. All of the cool engineering and high-performance ones would correspond to 7. It consists of an immense variety (Nylon6 and other types of nylon, PEEK, PEKK, PEI, TPU, PC, and many more). This category is a lot harder to define, but there is a lot of potential.

No matter what plastic you choose (PEEK, PET,….), they each come in dozens of grades (versions). We might be able to extrude and print one LDPE, but not another one. The challenge with all commodity plastics (1 to 6, + a few in 7) is that the parts were originally injected. Injection-molding grades do not work well with extrusion. Moreover, despite which material, the recycling challenges are almost always the same, and so is the methodology (purity of the batch, shredding to an even size, finding good settings,….). In other words, we can’t always predict how recycling will go, but if it is doable, we will manage.

Now that we know how to recognize the different types of plastic, we can move on to the next step, which is how to shred the plastic correctly to be able to extrude it. That step will be explained in the next video and blog post so keep a lookout for that.?

If you are still left with some unanswered questions, we recommend you visit our webpage which is dedicated to the?polymer pyramid.?You can also download all material guides in just one PDF file on that same webpage. It is also always possible to contact us and to speak with one of our?material experts.?

We hope to see you back next week. In the meantime, sort out your collected plastic so we can move on to the next step together!?