Brookfield’s new catalog shows the Gel Timer Instrument used for gelling or curing materials in the thermoset industry. Manufacturers of gel coats, resins, and potting compounds supply these materials to companies that produce plastic shower stalls and bath tubs, wind turbine blades, boat hulls, etc. The raw material must flow into a mold, fill all the nooks and crannies, and then harden into the final object. The “gel time” is the important parameter that tells the user how much working time is available before the material cures and will no longer flow.

 

Our Gel Timer Instrument is the DV2TRV Viscometer equipped with a special magnetic coupling and glass rod (similar to a spindle). An important advancement in design over our competitors is the magnetic coupling. The glass rod snugly fits into the compression fit magnetic coupling which attaches to the viscometer with standard threaded coupling or EZ-Lock connection. The rod is immersed into the sample to a depth that positions the end of the rod 1⁄2-inch from the bottom of the sample container.

 

HS-23Y Adjustable Stop on the lab stand rod helps the user establish the immersion mark. Test method for determining gel time uses Brookfield’s time-to-torque algorithm with glass rod rotating at 1 rpm. When the test reaches the customer-defined torque value, the rod stops rotating and gel time is recorded. The instrument is raised and the magnetic coupling separates into two parts, leaving the rod immersed in the material with the lower half of the magnetic coupling still attached. The rod is pulled out of the material, the compression fit coupling is loosened and removed, and the rod, if still serviceable, is cleaned for the next test. The glass rods are reusable, so test technicians should salvage when possible.

 

The test sample continues to cure after the glass rod is removed. Sample temperature increases during this time. Manufacturers of thermoset materials place a temperature probe into fresh material near center of the sample and monitor temperature until a peak value is recorded. This is referred to as “peak exotherm”. Brookfield will offer this measurement feature in a future gel timer instrument coming later this year. The Gel Timer market has been dominated by Sunshine Technologies in the Americas and by Techne in Europe. Techne’s method is different; a rod with a disc on the bottom

moves up and down in the test sample until gel time is reached. Sunshine is no longer manufacturing or supporting gel timer instruments. Major manufacturers of thermoset materials have worked with Brookfield to make DV2T the replacement instrument for QC use. R&D labs have decided that DV3T with graphing display may be a better choice.

 

Brookfield instruments offer the following advantages:

1. DV2T Viscometer is widely used by companies in the thermoset industry

2. Brookfield’s special magnetic coupling for the glass rod offers significant advancement in ease of use for the gel time application

3. Brookfield guarantees proven quality and reliability in its instruments that is superior to all competitors

4. We will introduce further improvements during this year: DV2T Gel Timer Instrument with 2-digit spindle code for glass rod – 45, audible eep at end of gel time test, and measurement for peak exotherm temperature

5. DV3T Gel Timer Instrument will also be offered with these same features