Is Epoxy a Plastic?

Find out more about Epoxy, Acrylic, And Polyester Resins

Epoxy resins have been known for several decades by now, and we successfully utilize them in various areas from aircraft to arts. Due to its qualities, this substance can be transformed into a wide range of different materials that possess unique abilities.

No wonder that those who work with epoxy often enough ask whether this substance is plastic or not since knowing that will be handy when working on the creative projects.

So today we will try to figure out what sort of material it is and what basic distinctions it has compared to other related alternatives.

What Kind Of Plastic Is Epoxy?

To begin with, epoxy resins do belong to the plastics family. They are able to change their physical state thanks to which this material is widely used in our homes and daily life:

  • It can be found in the cans of the soft drink and in special packagings as a lining for the content protection and for keeping the flavor inside of the tank.
  • This material is frequently utilized as a protective coating on different objects from beds and garden furniture to bicycles and hospital beds.
  • This substance can be found in special paints that are meant for the surfaces of ships and wind turbines to protect them from bad weather conditions.
  • Epoxy resins can also be applied in paints and coatings, composite materials, and adhesives
  • Industrial tooling, electrical systems, and electronics are other areas of this material usage.

Epoxy Properties

Epoxy resin is a truly miraculous invention. It is able to change its physical state from a low viscosity liquid to a solid with a high melting point. Moreover, this substance can be successfully mixed with different hardeners and curing agents which allows it to form the materials that will have a unique combination of properties.

Epoxies, however, have a list of additional, the same outstanding characteristics:

  • superior adhesion
  • chemical exposure resistance
  • heat resistance
  • mechanical properties
  • electrical insulating properties of high quality

Besides, most of these characteristics can be modified, for instance, if we fill epoxy with silver, it will become a good electricity conductor whereas initially, this material is insulating. This feature makes epoxies irreplaceable for the industry’s needs.

What Kind Of Plastic Is Epoxy
Credits: chonticha, via Canva.com

Distinctions Between Epoxy, Acrylic, And Polyester Resins

When it comes to choosing what substance will be the most suitable for certain purposes, no matter whether in crafting or not, people who are not quite familiar with all those materials may be confused and feel lost: which one to pick up?

Since the three most popular variations are epoxy, acrylic, and polyester resins, we would like to introduce you to the basic distinctions between them to make it simpler to tell the difference next time you will need any casting material.

Distinctions Between Epoxy, Acrylic, And Polyester Resins
Credits: phodopus, via Canva.com

1. Epoxy vs acrylic

Let’s begin with a reasonable question: what is acrylic resin? Clear acrylic resin is a thermoplastic. It means that acrylic casting resin belongs to the plastics that can be heated repeatedly many times.

Liquid acrylic resin is mixed from acrylic polymer. This substance is extremely smelly and makes use of toxic components during the production.

The distinction between the epoxy and acrylic resin is that epoxy belongs to the group of thermosetting plastics which make use of heat to harden into a solid mass that will not melt down under the high temperatures. Besides, it is way less stinky compared to the acrylic casting resins.

Unlike the acrylic resin, epoxy will not be water-clear, moreover, it will not resist the UV degradation.

Is it possible to substitute epoxy for acrylic? Well, generally no, these two can not be used as substitutes for each other.

However, epoxy resin can be shifted to a plastic alternative if you are looking for cheaper casting material.

Repair Broken Plastic Parts with EpoxyRepair Broken Plastic Parts with Epoxy

2. Epoxy vs casting resin

If you have wondered what makes these two substances different, then you can finally get a clear answer.

Several major differences between epoxy and resin exist:

  • Casting resin has a thinner viscosity.
  • Casting resin needs more time to cure.
  • It has way longer working times, unlike the epoxy whose working times are short. Because of this, casting resins will set up much slower if compared to epoxy counterparts that need only 25 minutes to gel.
  • Epoxy resin needs to be poured in a thin layer whereas the casting resin can be applied in thicker covers.
  • Finally, epoxy resin is simpler to mix since it doesn’t need the ratios to be measured super accurately. On the contrary, if casting resin is mixed improperly, it may affect the result dramatically.

Because of these distinctions, casting resin is runnier than epoxy which creates certain problems when using it as a coating material. Besides, casting resin is less hard than epoxy, and is more prone to yellowing when exposed to the UV light.

Also, casting resins normally need between thirty-six and forty-eight hours to cure whereas epoxies will require twenty-four hours at most.

On the other hand, casting resins can be poured in very thick layers (even of several inches) which makes them perfect for certain projects like figurines-making, molds, or river tables.

Epoxy vs casting resin
Credits: SaevichMikalai, via Canva.com

3. Polyester resin vs epoxy

Liquid polyester resin belongs to the thermosetting plastics. It means that both make use of heat to transform into a solid mass resistant to melting.

It is a syrup-like clear liquid that is blended with a small amount of a strong catalyst. This allows the curing mass to heat up but it will also make it craze if we add too much of catalyst.

Polyester resin is rather multipurpose stuff: it can be utilized as a coating, serve as a casting material, and even build up composites.

When comparing polyester vs epoxy resin, there is one more significant distinction, and that is the odor: polyester resin is also evil-smelling stuff, unlike the epoxy which is way less stinky.

So now it will be simpler for any beginning craftsman to figure out which substance to choose when heading for the next creative project.

Written by Melinda Sherween
avatar
Melinda worked as an art consultant and Home Designer for eight years in total. As an art consultant, she was first employed in a local art gallery in San Francisco where she was responsible for picking the most suitable artwork for her clients depending on their goals and budget. At this job, Melinda showed herself as a confident specialist and a true art lover with exceptional taste and artistic sense. Melinda is a passionate author of Housekeeping Bay and we are really happy that she is our Expert.
Our editors independently research, test, and recommend the best products; you can learn more about our review process here.
Which Epoxy is Best for Plastic?  Let's find out!Which Epoxy is Best for Plastic? Let's find out!
13 Best Greige Paint Colors. Ultimate Guide
Paint color greige ultimate guide