How long does synthetic resin take to cure?
The curing of synthetic resins is a chemical process and depends on several factors.
The information in the technical data sheets and product descriptions is important; you can find this directly on the product page.
Temperature plays a decisive role. There are resins that cure independently at room temperature (20° to 25°C) and resins that cure through the application of heat (annealing). First, the viscosity increases evenly until the gel point is reached and the resin transitions to a solid state. At higher temperatures, the viscosity of the resin decreases (becomes thinner), the processing time is shortened, and curing is faster. At low temperatures, the viscosity increases (becomes more viscous), curing is delayed, and it becomes more difficult to wet the fibers during lamination, for example. At low temperatures, the curing process can take several days.
The correct mixing ratio is extremely important, especially with epoxy resins. If it is not adhered to precisely, unmixed components will remain and the properties (e.g., strength) will change. The mixing ratio must therefore be strictly adhered to and can only be achieved by weighing the components accurately. To achieve a homogeneous mixture, it is also necessary to stir slowly but thoroughly during mixing. It is important to scrape the mixture from the edge of the mixing cup and transfer it to a second mixing cup.
In addition, cross-linking can be increased during curing by means of heat treatment (tempering). Tempering refers to the targeted heating of the material over a longer period of time (from a few minutes to several hours). The component is heated evenly to just below its melting temperature. This increases the mobility of the molecules and optimizes the structure. Structural defects are compensated for and any gases (air bubbles) are expelled. Performance characteristics such as strength, chemical resistance, and heat resistance are improved.
Two examples:
Our Epox4307 epoxy resin + Hardener313 is a universal system for coatings, adhesives, and fillers, and is also ideal for impregnating glass, aramid, and carbon fibers. With a mixing ratio of 100 parts resin to 50 parts hardener and a processing temperature of 20°C, the processing time is approx. 40 minutes and the curing time approx. 24–36 hours. The resin reaches its final strength after approx. 7 days at 20°C. To improve the properties, you can temper the resin for 1 hour at room temperature, then 5 hours at 50°C and then 5 hours at 70°C.
Our Epox R2 + Hardener H2 middle up to 5 cm is a system that is particularly suitable as a casting resin for especially thick-layer casting applications with high transparency. It adheres very well to almost all materials (GRP plastic, wood, glass, stone, porcelain). The system offers good mechanical properties with a long pot life. With a mixing ratio of 100 parts resin / 40 parts hardener and a processing temperature of 23°C, the processing time is >7 hours and the curing time at 20°C is approx. 24 - 48 hours. The resin reaches its final strength after approx. 7 days at 20°C.
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The information contained in this manual is based on careful research. It is provided for informational purposes only and does not release the user from the responsibility of conducting their own tests for the intended purposes and checking for any infringement of third-party property rights. The information is non-binding and does not constitute a guarantee of properties within the meaning of any laws. No liability is accepted for the accuracy and completeness of the information.
