The Classifications of Plastic - plastic, plastics, buy, sell, recycle, compounding, manufacturing, resins, polymers

The Classifications of Plastic

Plastic can come in all shapes, sizes and forms. They are used in countless categories of products that we use on a daily basis. We use plastic for safety, security, health, sports and leisure, shelter and transportation just to name a few. Plastic can be used to form pipelines that keep our soil and water safe to drink and protect our wildlife. Plastic is utilized in the manufacturing of bullet proof vests used to save the lives of thousands of police and military personnel. Shatter-proof plastic bottles cut down on household accidents and spills.

With a wide variety of products and uses comes a variety of methods to manufacture and recycle plastic. Plastics can be made of natural or synthetic materials. Natural substances can be chemically modified, or organic/inorganic raw materials are synthesized to make plastic. Since plastic is used in a wide variety of aspects of our modern life, they are classified into three general categories according to their chemical composition: Thermoplastics, Thermosets and Elastomers. These categories differ largely due to their molecular structure. The molecular structures of each of the three categories create a different reaction when exposed to heat. The following information will give you a better look into what each of these types of plastic consist of and how they are formed.

Thermoplastics

Thermoplastics are plastics that are usually produced in one step and later become products in a second step. They become soft and flexible whenever they are exposed to heat (usually 120-180o C), and can be formed into the desired shape during this process. Once thermoplastics cool significantly below a softening point, the material will become firm and sturdier.

Because thermoplastics can be reheated and reshaped, they are highly recyclable. Heat allows the linear, branch-like molecular structure to break down allowing the conditions needed to remold the plastic into a different shape without causing a chemical change. Although most thermoplastics become liquid-like when exposed to heat, when they are frozen most become like glass and can shatter.

Thermoplastics make up a large portion of the everyday plastic we use everyday. They are generally light-weight, sturdy and inexpensive to allow for a variety of uses. Polyethylene (PE), a thermoplastic, is one of the most widely used consumer plastic. It is used in the production of food wrap, food storage containers, most personal hygiene bottles and plastic bags among others. Another thermoplastic, Polyvinyl Chloride (PVC) is also a widely used plastic. It is manufactured largely for piping, but is also manufactured for other uses like window frames and drinking bottles. Polystyrene is a thermoplastic that also has a variety of uses including disposable sliver wear and CD/DVD cases. Polystyrene can also be foamed to make packaging and drinking cups. Acrylic is another thermoplastic that is commonly used. Acrylic is used in the production of lacquer, adhesives, gloss paper, sinks and some parts of automobiles.

Be sure to contact Malvern Plastics Group for all your plastics resin buying and selling needs as well as plastic compounding, plastic manufacturing and plastic recycling requirements.

Thermosets

Thermosets are plastics generally produced and formed during the same step, unlike thermoplastics that are made in separate steps. Thermosets are usually made by heating a liquid or powder inside of a mold and allowing the plastic to cure. Once the molecules have merged, the process is irreversible. Any further shaping generally occurs by machine. This means that a thermoset cannot be reshaped or reformed, but rather reheating the product actually will cause the molecules to burn and disintegrate. This occurs because reheating does not release the bonds of the molecules due to the hard, very tight-knit branched molecular structure. However, this is seen as a positive effect in regards to a thermoset’s increased strength, durability and the means to maintain shape when exposed to heat.

The curing process for thermosets can be done several ways. One curing process is called vulcanization, which produces vulcanized rubber. Vulcanized rubber differs from natural rubber in that it is not as sticky and more resistant to heat.

There are many other products that are classified as thermosets, in an array of industries. Some of the uses of thermosets include: polyester fiberglass systems, electrical insulators, car bodies, and epoxy resins. Epoxy resins are made for use in several products like adhesives, paint and coatings, industrial tooling, and electrical systems.

Be sure to contact Malvern Plastics Group for all your plastics resin buying and selling needs as well as plastic compounding, plastic manufacturing and plastic recycling requirements.

Elastomers

Elastomers are composed of polymer chains with a mesh-like structure. These cross-linked molecules are very long but are much looser than the mesh structure of a thermoset. Like thermosets, once elastomers are cured, they cannot be reshaped from heating. Actually, many elastomers can also be classified as thermosets but some elastomers may also be classified as thermoplastic.

The mesh-like structure of elastomers allows the elastomer to have an increase in elasticity and an increase in product longevity. Thus, this can prevent deformation when the product is being used because the molecular structure allows the product to “bounce back”. Rubber products are considered elastomers for this reason. One of the most common and popular rubber products is automobile tires.

Because elastomers cannot be reshaped from heating, this does not mean elastomers cannot be recycled. Many elastomers are used to serve an alternate purpose like fuel or civil engineering projects. Elastomers can be grinded up and used as part of roads and athletic tracks, or as landscape mulch for gardens. They can also be used for truck bed liners, floormats, picnic tables and benches, and flooring. Some elastomers are even used as the soles of tennis shoes and as insulation covering speaker cables and phone wires.

Be sure to contact Malvern Plastics Group for all your plastics resin buying and selling needs as well as plastic compounding, plastic manufacturing and plastic recycling requirements.