Polyester Resin vs Epoxy Resin: All You Need To Know

A huge range of resins exists in the market– every resin has its own characteristics and applications. Polyester and epoxy resins are popularly used types of resins due to their many great features – Strength, durability, thickness while curing, and many more. Everybody says ‘resins’ without mentioning the type of resin they use or come across. 

However, when it is about your project, you need to know the best and choose between the resins. Polyester resin and epoxy resin are the most popular resins ideal for business applications. This blog post gives you a detailed overview of Polyester resin vs Epoxy resin and their respective applications. 

Why Resins are in demand among industries 

Resins are viscous elements and they transform into strong polymers when you let them undergo a curing process. When you consider two monomers that combine to form a copolymer, one among them is called resin whereas the other one is known as a hardener. 

Resins occur naturally, however, you can also make them synthetically. Certain synthetic resins exhibit behaviour similar to that of natural resins, but most of them are different. There are numerous classes of synthetic resins. 

The polyester suppliers and Epoxy Resin suppliers in India serve customers with quality resins for a wide variety of applications like adhesives, coatings, moulding, vehicle components, and so on. 

Also Read: What is Polyamide? – Properties and Uses of Polyamide

Epoxy Resin- An Overview

Epoxy resin is a highly durable and adhesive resin that you come across in many major industry-specific applications such as construction, aircraft components, boat building, etc. 

When you use epoxy resin with Carbon, it can create rigid and compact structures, making it ideal for industrial applications. 

Epoxy resins also play a significant role in both commercial and industrial flooring, and massive segments like aerospace, space, etc.

Also Read: Properties And Uses Of Xanthan gum 

Properties of Epoxy Resin

Being the ideal choice of customers and businesses, businesses largely depend on Epoxy Resin Suppliers in Delhi for their Epoxy resin needs. Here are the physical properties of Epoxy resin that makes it a popular resin. 

 

• Epoxy resins are strong and incorporate high-end flexural strength.

 

• They have a huge shelf life and can last for at least a year if they are stored appropriately on the shelf.

 

• The cure time of epoxy resins demands ambient temperature based on hardener, adding too much hardener can turn the epoxy rubbery.

 

• You can minimise the epoxy cure time by increasing the temperature of the epoxy resin. But, make sure that you don’t raise the temperature above 100 F.

 

• Epoxy resins are expensive compared to polyester resins. 

 

• Epoxies usually have little to no odour, and they have non-flammable properties.

 

• When you apply epoxy as a thin film, it cures completely and holds perfection while you use it for adhesive applications. 

 

• They don’t shrink after they undergo curing.

 

• Epoxies offer resistance to cracking, wear, corrosion, peeling, or damages from both environmental degradation, and chemical degradation.

 

• Epoxy remains moisture resistant after the curing process.

 

• They are not UV resistant on their own. The ideal way to make sure that the epoxies don’t yellow with UV rays is to use UV resistant transparent Urethane as the top coating. 

 

• Epoxy usually has a bonding strength of about 2000 psi. 

 

• They don’t bond to polypropylene, Teflon, Anodized Aluminum, Polyethylene, or Tedlar.

Also Read: Application and Properties of Zinc Phosphate

Polyester Resin- A quick look

Polyester resin is the most abundantly used resin and is popular in the global market. Due to the surge in demand, businesses and individuals work with the best Polyester Resin Suppliers In India to fetch the materials for their business operations. 

The global market value for Polyester resin would hit $20 billion in 2026 with a 5.1% CAGR compared to 14.9 billion in 2020.

The core benefit of Polyester resin is its stunning chemical and mechanical stability, and also the low cost. You can integrate it with glass fibers for a composite structure known as fibreglass. 

This is a lightweight, strong, and durable material that exhibits excellent abrasion resistance, waterproofing, and protective features. Being affordable and easy to use, they are more flexible than carbon fibre. 

They are highly used in pond linings, bund wall linings, boat building industries, and various waterproofing applications. 

Also Read: Niacinamide Uses: The Complete Beginner’s Guide

Properties of Polyester resin

Businesses rely on the best Polyester Resin Suppliers In Delhi since Polyester resin has many superior properties when you consider the other competitor resins in the market. Here is a glance at the characteristic features of Polyester resins. 

 

• This type of resin is brittle and subject to micro level cracking.

 

• The polyester resin has about 6 months to over 1-year shelf life.

 

• You can add a catalyst and change the cure time of the Polyester resin.

 

• It usually costs slightly less when compared to epoxy resin.

 

• The off gases of Polyester produce strong and flammable fumes.

 

• It does not cure perfectly when it is a thin film, hence not a great adhesive.

 

• When the pour is large, the polyester resin tends to shrink after curing.

 

• The polyester resins offer UV resistance and need not be top coated to avoid degradation or yellowing due to sunlight.

 

• Polyester resins are water permeable after curing; this means that the water can pass through the resin gradually.

 

• Polyester resin has a bonding strength of about 500 psi or less.

 

• They don’t form bonds with epoxy resin.

 

• Polyester resin needs a catalyst for curing and the time you need to cure is about 12 hours. They are easy to use and UV resistant.

 

• They are affordable compared to epoxy resin and include great heat resistance.

 

Also Read: Important Properties and Uses of Urea Formaldehyde Resin

 

Major Differences between Epoxy and Polyester Resins

 

Bonding Strength

The Polyester resin can hold less than 500 lbs. for every square inch. However, epoxy resin has enhanced bonding capabilities. The relative strength of epoxy is 2000 lbs. for every square inch.

Wear and Crack resistance

Epoxy resin offers high resistance to cracking, wearing, corrosion, peeling, or damage from environmental and chemical degradation. Polyester resin is fragile and significant for immediate fixes and uses that have low stress. 

Cost differences

Epoxy resins cost more than polyester resins. This is because of their high formulation and strength requirements. Polyester resins are famous for their applications like jewellery making, craft making, etc, due to their low cost and great quality. 

Moisture resistance

The epoxies have excellent moisture resistance; some formulations can be perfect even underwater. However, the polyester resin offers less resistance to moisture and remains water permeable with chances to develop fractures easily.

Cure Time

Though the cure times are different for both polyester and epoxy resin, polyester resin has a quick cure time. However, you can raise or reduce the temperature to manipulate and alter the cure time for both products. You can even formulate some epoxy cures in increased temperatures.

Odour

When you compare it with Epoxy, Polyester is less pleasant to use. Though it accommodates a faster setup, Polyester resin stinks so much that it burns your nostrils. While you apply both epoxy and polyester resins, it is great if you use appropriate ventilation.

Durability

Epoxy products incorporate higher shelf life than polyester resins. If they are not mixed, this fascinating material can reside in the garage for many years without losing its potency. However, the polyester resin gets very fragile with time.

Also Read: How to Select the Ideal Chemical Supplier in India 

Polyester resin vs Epoxy resin: Application  Differences

Epoxy and polyester resins offer great surface protection and structural support, with the benefit of a reinforcement material. In most cases, resin goes through a ‘matrix phase’, while the matting goes through the ‘reinforcement phase’.

 

Applications in Common

Both resins are ideal for big projects such as space vehicles, Fibreglass roofing, spray layup for car and truck bodies, mechanical layup for turbines, spray and contact moulding, vacuum bag and autoclave moulding, etc. 

 

Applications without reinforcement

You can use the Polyester resins as additives in the paints. However, epoxies have a vast range of applications – bund wall linings, storage tank linings, resin floor coating application process, epoxy coatings, and protective linings. The high chemical resistance characteristics of epoxy resins make them strong and last longer.

 

Applications with reinforcement

The epoxy-specific reinforcement can help industries to use it in flooring surfaces to enhance mechanical strength. Polyester reinforcement applies to the CSM ie. Chopped Strand Mat, Woven glass cloth, glass fibre, etc.

Also Read: Chemicals Used in Daily Life

The Parting Shot

Polyester and Epoxy resins are both unique in their characteristics and hold various favorable properties  for industrial applications. Let us take a glance at the core applications of both these resins:

Specific Applications of Polyester Resin include construction industry processes, lamination, plane and ship parts, fishing rods, filler auto repairs, coatings, bottles, and decorative accessories. 

Specific Applications of Epoxy Resin include epoxy floors, laminates, epoxy adhesive, linings, epoxy coatings, and propellers.

Want to get in touch with a trusted Chemical supplier for all your resin and other chemical needs? Bansal Trading Company is one of the best Chemical suppliers in India who can serve your purposes in time with the quality you can count on. Let’s talk to know more or to solve any clarifications.