Polyester Resin

How do you make a Polyester Resin?

Polyester resins get produced through a process called polycondensation which is a chemical reaction of polybasic acids and polyhydric alcohols. These resins are typically found in a liquid state and hardened with the addition of a catalyst.

Due to its strength and flexibility, polyester resin is considered a general-purpose resin and seen across the construction, transport and marine industries. It is available as a saturated, or unsaturated resin, the most significant difference being that saturated is a synthetic resin and only contains the benzene ring.

Unsaturated Polyester Resin

Unsaturated polyester resins are the most common polyester resins and are easily identifiable by the double bond in its carbon chain. This resin offers a higher heat resistance, higher tensile and compression strength and higher resistance to chemical corrosion than their saturated resin counterparts. Best used for manual lamination, spray lamination and injection mouldings. They are also available as a low styrene product.

Saturated Polyester Resin

Saturated Polyester resins have no double or triple bonds and use excess polyol (glycol) in the reaction process.  It is more widely known for its use as a coating material and also often seen in the production of printing inks. Note that saturated polyester resins offer fantastic weather resistance, excellent resistance to dirt and are highly cost-effective for non-critical requirements.

Polyester Resin by Chemistry

Polyester resins can also be broken down by their chemistry. We stock our warehouses with a variety of orthophthalic, isophthalic and dicyclopentadiene – better known as DCPD resins.

Orthophthalic resins are inexpensive and offer a good base for any general moulding purposes. They have good wet-out and do not require any specialist heat or pressure to cure to a tack-free finish.

The next step up would be an isophthalic resin which is better suited for more corrosive situations and are perfect for industries that require a better resistance to water, heat and chemicals. With better mechanical properties isophthalic resins have a higher molecular weight and often are less viscous than their orthophthalic counterparts.

DCPD resins are polyester resins that are best for use when a high surface finish is required. They offer a lower shrinkage in comparison to orthophthalic and isophthalic resins. However, this attribute does not necessarily indicate that it is a better resin choice. DCPD resins provide similar properties to orthophthalic resins but with a lower styrene content. It is common for these to be mixed with other polyester resins to increase its positive aspects.

Polyester Resin for General Moulding

Our resins from key suppliers: AOC, Ciech, Gazechim and Polynt offer excellent mechanical properties suitable for a wide range of general moulders. We supply a range of specialist polyester resins that also provide increased resistance to chemicals, temperature, weather, water, UV radiation as well as offering excellent mechanical and thermal parameters which give very high strength and durability of finished products

We use these in our water and environmental products that are available from tricel.eu

“Excellent service with a wide range of products, reps that know the job and can advise when needed, it’s nice to know if you have an issue, they are there to support my business which is key to its growth. All products advised have been excellent I am now more efficient and maximising my profit. Thank you to Craig for your continued help on new projects you have helped my business grow you have gone above and beyond to help.”

Polyester Resin for the Construction and Sanitary Industry

Composites in the construction industry are expected to reach sales of over $10 billion by the end of 2019. Considered one of the most significant sectors for composite products, our range of polyester resins create some of the pipes, liners, bathrooms, doors, window, swimming pools and roofs you see across the UK and Ireland every day.

Built for strength, versatility, as well as being able to create aesthetically pleasing products.  When teamed with our gel coats and topcoats, these items can offer unrivalled heat and chemical resistance with relatively low maintenance.

“From advice on proper storage of moulds to recommending the right tools for the job in flow matt cutters for the RTM laminator, Tricel has been there every step of the way and will continue to be.”

Polyester Resin for the Marine Industry

Unsaturated Polyester Resins are used with great success in a range of marine products from surfboards to yachts to industrial fishing boats, offering great flexibility while being light and robust. Our polyester resin offers excellent thixotropic properties with excellent water repellency and a high strength to weight ratio.

In the marine sector, resins need to be UV resistant, Lloyds approved (so not to be harmful to aquatic life) as well as have excellent resistance to chemicals and temperature variants. All our resins offer this plus a fantastic surface finish.

Polyester Resin for the Automotive Industry

The Automotive industry is better known for its advanced composites epoxy and carbon reinforcements, but there are some uses for polyester resins in the growing automotive sector. When it comes to polyester resins used with fibreglass reinforcements offers superb durability, toughness and chemical resistance over a broad range of temperatures.

Unlike advanced composites, our polyester resins when combined with our reinforcements do not require an autoclave, meaning parts can be repaired, recreated and reproduced faster than their advanced composites – critical in high-volume applications.

“We noticed that on comparing our previous complete parts, our newer parts using Tricel’s Polycor Gel Coat and different production methods offered a reduction of around 10% incomplete parts being rejected or requiring additional attention from laminators due to air pockets or de-laminations.”