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Unsaturated Resin Gel Time Measurement Method

Jun 12, 2020

Unsaturated resin blending paper cup test is the simplest and most effective method for measuring resin gel time. At the same ambient temperature, adding different proportions of curing dose to 100g of unsaturated resin, the actual resin gel time observed is valuable . This is very necessary when replacing new resins, adding fillers, or making large vacuum components, to avoid some potential risks.

Vacuum resin diversion process Generally speaking, the factors that affect the gel speed of unsaturated resin are mainly temperature and curing amount, and the addition of accelerators and other additives. You can refer to the following and test the gel time of unsaturated resin in paper cup according to your actual situation.

First, if it is a combination of pure resin and glass fiber, other inert fillers are not added. You can use the addition of 1.5% curing agent MEKP as a benchmark to compare the gel time and select the most suitable gel time. According to experience, the final addition amount of curing agent should not be less than 1% or more than 2.5%, too low will cause the composite material products to become soft or insufficient strength, too high will cause problems such as brittle parts and reduced toughness.

If adjusting the curing dose does not meet the actual gel time requirements, then you need to increase the ambient temperature, add dimethylaniline and other additives or special initiators to accelerate the curing speed of the unsaturated resin. When it is at an extreme temperature, such as below 5 ℃, it is not recommended to continue the operation or try to increase the curing dose to increase the curing speed of the resin, and the result is often not ideal.

Second, if the resin needs to be mixed with fillers, such as adding talc, aluminum hydroxide, etc. Then the actual required accelerator and curing dose are determined according to the amount of filler, and sometimes even increased to 5% or more, which is also common. Of course, the curing temperature is always the most critical factor that affects the resin gel speed.

The final point of the resin paper cup gel test is that the resin gel time tested in the paper cup will not be exactly the same as the actual application, because even at the same ambient temperature, the temperature of the surface of the mold or base surface of different materials will be slightly different. At the same time, the resin casting body will accumulate heat more easily, so the actual gel speed of the resin in the paper cup will be faster. In short, the gel time test of unsaturated resin in paper cups is still effective and has practical guidance value.