Polyester resin and epoxy resin: contrast, characteristics and reviews

Epoxy and polyester resins, the differences of which will be considered in this article, belong to the class of thermosetting resins . This means that after the process of solidification they can not 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 review the review 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 capable of self-transition to a solid state. To harden the epoxy resin, add a special hardener in the correct proportions.

For proper use, you need to know the pros and cons of epoxy. A resin of this type is valued for its strength characteristics. It is resistant to aggressive chemical compounds such as acids and alkalis. Advantages of epoxy include: moderate shrinkage, high resistance to wear, as well as excellent strength. The pouring process takes place at a wide temperature range, but the recommended interval is from +18 to +25 degrees. Hot pouring method is used in the manufacture of products of increased strength, capable of withstanding extreme loads.

This type of resin is used both in industry and at home. The scope of their use is growing due to the creation of new compounds with optimized properties. By mixing different types of epoxy resins and hardeners, it is possible to produce an end product with completely different characteristics.

Application of epoxy resin

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

Hardener for epoxy resin

Epoxy material consists of two components, after mixing which begins the polymerization process. The component that causes the curing of an epoxy resin is called a hardener. Depending on the use of different resins and hardeners, completely different epoxy mixtures can be obtained.

The proportion of hardener in the composition can be different and depends mainly on the brand of resin. The polymerization reaction of epoxy resin is irreversible, that is, there is no possibility to melt the already frozen material.

It is a mistake to believe that if the amount of hardener is too high, the hardening will be faster. An effective way to accelerate the process is to increase the temperature of the mixture. Increasing the operating temperature by 10 degrees makes it possible to accelerate the process 3 times. For these purposes, special components are on sale. Also, there are epoxy mixtures that solidify 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 decrease. With a small amount of hardener, the consistency of the part becomes sticky, with excess polymer is released on the surface of the material. The most frequent proportions of resin / hardener are 1/2 or 1/1. Before mixing, it is recommended that you read the instructions for the correct proportion of components.

Polyester resin

Such a resin is formed when processing specialty alcohols. The basis of the material is polyester. To speed up the solidification process, specialized solvents and inhibitors are used. Depending on the scope of the material, it can have a different structure and properties. The resulting product needs additional processing aimed at increasing the protection from water and ultraviolet radiation. The additional coating also enhances the strength characteristics of the product. Polyester resin, in contrast to epoxy, is characterized by low mechanical properties. But the polyester is distinguished by its low price, thanks to which the material is more popular.

Such resins are actively used in the construction of buildings, in the automotive industry, shipbuilding and the process of production of containers for chemical compositions. Polyester components form high-strength joints when mixed with glass. 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. Made with the use of this component, plastic is used in the production of window sills, shower cabins, partitions and decorative elements. Polyester resins, unlike epoxy resins, are easy to color.

The main advantages of polyester resin

Polyester resin, in contrast to epoxy, has greater practicality. After mixing with glass, the composition acquires strength characteristics exceeding the properties of steel. To harden the polyester does not require special conditions and temperatures. Works with it are considered to be less laborious, and the material itself is cheaper.

What is the difference?

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, and the final choice depends on the conditions of use, as well as the type of surface on which the resin will be applied.

Epoxy has a higher cost, but at the same time it is more durable. Possessing excellent adhesive properties, firmly connects different surface structures. Epoxy resin differs from polyester product by slight shrinkage, better mechanical characteristics, and also resistance to wear.

In this case, unlike polyester, epoxy needs more time for solidification, which slows down the process of manufacturing parts from this material. Work with this resin is accompanied by increased safety measures: when working with liquid material, gloves are necessary, a respirator is needed to treat a solid product. The danger is not so much the resin itself, as the components used to give it a solid state. When hardened under high temperature conditions, there is a chance of losing the viscosity of the material, which creates additional difficulties in operation.

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

Advantages of using polyester

Polyester does not emit toxic elements, it is easy to use, and special knowledge for working with it is not required. The composition is used to coat various surfaces, followed by treatment with a strength enhancing agent. According to the adhesive properties of polyester is much inferior to epoxy, and use it for bonding surfaces is irrational. As a material for decorative products is not suitable, because it has low mechanical characteristics. When mixing the composition of polyester, a small amount of catalyst is used. Cures the material quickly, within 2-3 hours.

The finished part has elasticity and resistance to bending. The minus of a product made of polyester resin is flammability. Do not apply polyester resin to a product made of epoxy. To repair a product made of epoxy material, it is better to use it.

How to properly prepare the surface

The resin should only be applied to a previously prepared surface. The first thing to do with a solvent is degreasing. After eliminating dirt and grease, the grinding process is performed. 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 this, you can start applying the working component.

Safety precautions

In order not to cause damage to health when working with resins and hardeners, it is necessary to take all precautions to the maximum. Failure to follow simple rules can lead to skin damage, burns, or lung damage when working with epoxy or polyester resins. Safety features when working with chemicals:

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

Manipulations with epoxy components should be carried out in a well ventilated area.