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Thermoplastics vs Thermosets

Have you ever wondered why you can melt and re-shape some plastics a myriad of times, while melting other plastics will instead result in burning? Well, the cause of this is the way that the polymers within the material react when cured.


Thermoplastics are composed of long polymer chains with loose entanglements that occur during the curing process. The randomly assorted molecular structure makes thermoplastics springy, flexible, and generally easy to color. This arrangement at the molecular level also results in a material that is fairly easily worked on (e.g. glued, sanded, etc.) and can be recycled multiple times allowing for a better cradle-to-cradle lifecycle than thermoset plastics. The inclusion of additives to a thermoplastic may result in property changes that prevent the plastic from being recyclable, so ensure you know what additive, if any, are in your plastics. Thermoplastics can be easily re-shaped by simple using a heat gun that can reach the glass transition point of the thermoplastic you wish to modify. Thermoplastics are great for injection molding & vacuum molding – while they also offer strength while being relatively lightweight. Examples: ABS, PVC, HDPE, Polystyrene (PS), Acrylic, Polycarbonate (PC)

You probably won’t be surprised to hear that Thermoset plastics aren’t able to be heated and re-shaped after initial curing. That’s because during this curing process, crosslinks are formed at a molecular level between polymers creating a strong and rigid network. Thermosets typically consist of a two-part mixture that harden during the curing process to form a finished part. Thermoset plastics have high strength and high thermal stability because their structure is crosslinked - but this feature also leads to the risk that a thermoset plastic can break without warning, can be very difficult to repair, and cannot currently be recycled.

Examples: Polyurethane, Epoxy Resins, Fibreglass,

Omachron Plastics Inc. has developed new molding techniques that use 75% less energy than traditional processes - while our molding process can take up to 100% recycled material and convert them into finished goods. Many thermoplastics can be recycled and/or re-manufactured into finished goods from anywhere between 3 to 30 times.


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