Types of plastics and general introduction.

In the last post, we have learned about plastics and their classification based on their reaction to heat treatement. The main two types were thermoplastics and thermoetting polymers. Let's continue it further.

We use vast numbers of plastics and these plastics are often blended with each other to get desirable properties which makes them complex in structure and to identify which type of plasti it is. Still. there are some plastics which are identical in nature and their tructure and are used widely across the globe. Since, it is necessary to identify what type of plastic is, their identification should be easy. That way, it can be easily used and also to recycle used material.

The Society of the Plastics Industry introduced the Resin Identification Code (RIC) system in 1988 as a growing number of communities were implementing recycling programs. In order to address the concerns of recyclers across the U.S., the RIC system was designed to make it easier for workers in Materials Recovery and Recycling facilities to sort and separate items according to their resin type. Plastics must be recycled separately, with like materials, in order to preserve the material’s value and enable its reuse in other products after being recycled.

RIC was developed originally by the Society of the Plastics Industry (now the Plastics Industry Association) in 1988, but has been administered by ASTM International since 2008.

Following are the seven types defined by the RIC system:

♳ Polyethylene Terephthalate (PET)

♴  High-density polyethylene (HDPE)

♵  Polyvinyl chloride (PVC or V)

♶ Low-density polyethylene (LDPE)

♷  Polypropylene (PP)

♸  Polystyrene (PS)

♹ Other plastics (OTHER or O)  

Let's get the primary introduction and uses for each of them.

#1 Polyethylene Terephthalate (PET)  ♳

PET is indicated by #1 in the resin identication code system and it is used for Polyester fibres (Polar Fleece), thermoformed sheet, strapping, soft drink bottles, tote bags, furniture, carpet, paneling and (occasionally) new containers and bottles. It can be recycled easily.

#2  High-density polyethylene (HDPE) ♴

HDPE is indicated by #2 in the RIC system and is used in Bottles, grocery bags, milk jugs, recycling bins, agricultural pipe, base cups, car stops, playground equipment, and plastic lumber. HDPE is also recyled. 

 #3 Polyvinyl Chloride (PVC) ♵

PVC is indicated by #3 in the RIC system and is extensively used for pipes, window profile, siding, fencing, flooring, shower curtains, lawn chairs, non-food bottles, and children's toys. It contains Chlorine which makes it hard to recycle but still, it is extensively recycled in Europe. 

 #4 Low-density polyehtylene (LDPE) ♶

 LDPE is indicated by #4 and is used for plastic bags, six pack rings, various containers, dispensing bottles, wash bottles, tubing, and various molded laboratory equipments. Apart fron plastic bags, most of the things are accepted by the recycling centres.

#5 Polypropylene (PP) ♷

PP is indicated by #5 and is used in auto parts, industrial fibres, food containers, and dishware. Some recycling centres accept PP for recycling.

#6 Polystyrene (PS) ♸

PS is indicated by #6 and is exclusively used in desk accessories, cafeteria trays, plastic utensils, toys, video cassettes and cases, clamshell containers, packaging peanuts, and insulation board and other expanded polystyrene products (e.g., Styrofoam)

#7 Other plastics (O) ♹

 All the other plastic are indicated by #7. It can include other plastics such as acrylic, nylon, polycarbonate, and polylactic acid (a bioplastic), and multilayer combinations of different plastics. As these can be used to indicate a single plastic or mixture of different plastics, it is hard to recycle them but if manufacturer provide the plastic properties and type of plastic used, it can be recycled depending upon the type. It is used in bottles, plastic lumber applications, headlight lenses, and safety shields/glasses.

These seven types of plastics can be easily identified by checking their RIC system number and you can easily segregate different plastics. Segregation of plastics makes it easy task for the recycling centre to identify and recycle them. This way, you can save energy and time. Also, you help nature and environment from pollution and global warming.

We'll discuss these plastics in detail in next few posts.

Keep recycling :)