Polyester resin and epoxy resin: difference, characteristics and reviews

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Epoxy and polyester resins, the differences of which will be considered in this article, belong to the class of thermosetting. This means that after the solidification process, they can no longer be returned to the liquid state. Both compositions have different characteristics, which determines the scope of their application. To understand the purpose of these materials, it is useful to read the overview of polyester and epoxy resins.

Epoxy resin

Epoxy refers to materials of synthetic origin. In its pure form, it is unsuitable for use, since it is not able to go into a solid state on its own. For hardening, a special hardener is added to the epoxy resin in the right proportion.

For proper use, you need to know the pros and cons of epoxy. Resin of this type is valued for its strength characteristics. It is resistant to aggressive chemicals such as acids and alkalis. The advantages of epoxy include: moderateshrinkage, high wear resistance, and excellent toughness. The solidification process occurs over a wide range of temperatures, but the recommended range in everyday life is from +18 to +25 degrees. The hot curing method is used to produce high strength products that can withstand extreme loads.

This type of resin is used both in industry and at home. The scope of their use is becoming wider due to the creation of new compositions with optimized properties. By mixing different types of epoxy resins and hardeners, you can get a final product with completely different characteristics.

Epoxy resin application

Epoxy type resin is primarily used as a material for bonding surfaces: wood, leather, metal and other non-porous. Such a composition is in demand in electronics, mechanical engineering and aviation. Fiberglass, which is actively used in construction, is also made from epoxy. The resin is used for waterproofing floors and walls, including external ones. Finished products made of fiberglass after grinding and additional processing are popular in decorating interiors.

Epoxy hardener

Epoxy material consists of two components, after mixing of which the polymerization process begins. The component that causes the epoxy to cure is called the hardener. Depending on the application of various resins and hardeners, it is possible to obtain completelydifferent epoxy mixes.

The proportion of the hardener in the composition may be different and depends mainly on the brand of resin. The polymerization reaction of epoxy resin is irreversible, that is, it is not possible to melt an already solidified material.

It is a mistake to assume that by overestimating the amount of hardener, hardening will be faster. An effective way to speed up the process is to increase the temperature of the mixture. Increasing the operating temperature by 10 degrees allows you to speed up the process by 3 times. For these purposes, special components are commercially available. There are also epoxy mixtures that harden at low temperatures.

Incorrect selection of the amount of hardener adversely affects the quality of the finished product. First of all, its strength and resistance to chemicals are reduced. With a small amount of hardener, the consistency of the part becomes sticky, with an excess, the polymer is released on the surface of the material. The most common resin/hardener ratios are 1/2 or 1/1. Before mixing, it is recommended to read the instructions for the correct ratio of components.

Polyester resin

This resin is formed during the processing of special purpose alcohols. The basis of the material is polyester. To speed up the hardening process, specialized solvents and inhibitors are used. Depending on the scope of the material, it may have a different structure and properties. The resulting product needs additional processing aimed at increasing protection against water andultraviolet radiation. The additional coating also enhances the strength characteristics of the product. Polyester resin, unlike epoxy, is characterized by low mechanical properties. But at the same time, polyester is distinguished by a low price, due to which the material is more popular.

Such resins are actively used in the construction of buildings, in the automotive industry, shipbuilding and the production process of containers for chemical compositions. Polyester components, when mixed with glass, form high-strength compounds. Thanks to this, the resulting material is used in the manufacture of canopies, roofs for buildings and lighting fixtures.

Polyester resin is also part of the artificial stone. The plastic produced using this component is used in the production of window sills, shower cabins, partitions and decorative elements. Polyester resins, unlike epoxy resins, can be easily dyed.

The main advantages of polyester type resin

Polyester resin, unlike epoxy, has more practicality. After mixing with glass, the composition acquires strength characteristics that exceed those of steel. Polyester hardening does not require special conditions and temperatures. Work with it is considered less laborious, and the material itself is cheaper.

What's the difference?

When asking the question: "Which is better, polyester or epoxy?", you need to understand why and where the resin is needed. Both materials have their pros and cons, andthe final choice depends on the conditions of use, as well as the type of surface to which the resin will be applied.

Epoxy has a higher cost, but it is more durable. Possessing excellent adhesive properties, it firmly connects surfaces of various structures. Epoxy resin differs from the polyester product in low shrinkage, better mechanical characteristics, and wear resistance.

At the same time, unlike polyester, epoxy needs more time to harden, which slows down the process of manufacturing parts from this material. Working with such a resin is accompanied by increased safety measures: gloves are required when working with a liquid material, a respirator is needed to process a solid product. The danger is not so much the resin itself, but the components used to give it a solid state. When cured at high temperature, there is a chance of losing the viscosity of the material, which creates additional difficulties in work.

Which resin is better, epoxy or polyester? Reviews indicate that in most cases the first is used in the form of glue, since its properties are much higher than those of a polyester-based material. In other situations, it seems more rational to use polyester-type resin, which, firstly, will save money, and secondly, will simplify the work.

The benefits of using polyester

Polyester does not emit toxic elements, is easy to use, andspecial knowledge is not required to work with it. The composition is used to cover various surfaces, followed by treatment with a strength-enhancing agent. In terms of adhesive properties, polyester is significantly inferior to epoxy, and it is irrational to use it for gluing surfaces. As a material for decorative products, it is not suitable, as it has low mechanical properties. When mixing the composition of polyester, a small amount of catalyst is used. The material hardens quickly, within 2-3 hours.

The finished part is elastic and resistant to bending. The downside of polyester resin products is flammability. Do not apply polyester resin to an item made from epoxy. To repair an epoxy product, it is better to use it.

How to properly prepare the surface

Resin should only be applied to previously prepared surfaces. The first step is degreasing with a solvent. After removing dirt and traces of fat, the grinding process is carried out. The top layer is removed from the surface of the material using sandpaper or a special tool. Then the dust removal process is carried out. After that, you can start applying the working component.

Safety

In order not to cause harm to he alth when working with resins and hardeners, it is necessary to take all precautions to the maximum. Failure to comply with simpleregulations may cause skin injury, burns or lung damage when handling epoxy or polyester resins. Chemical safety considerations:

• Do not use containers designed for cooking.
• All manipulations must be carried out in special clothing and gloves. Before carrying out work on the hands should be applied with a protective cream. Grinding of finished products is carried out in a respirator and special glasses.
• If resin comes into contact with skin, wash immediately with soap or alcohol.

Epoxy components should be handled in a well ventilated area.