Curing or gelling material viscosity detecting method

Curing or gelling material viscosity detecting method

application

Various materials such as epoxy or other composite resins, slow curing adhesives, gelatin or hydrocarbon gels.

Test Equipment

Instrument: Viscometer or rheometer

Spindle: The choice of any standard spindle, or Zui is a one-time spindle and the chamber is easy to clean.

Accessories: Multiple options: small sample adapter, tc - 550 ap programmable bath, ThermoselTM programmable controller

Speed: Various possibilities: 100 to 0.01 RPM

Test Methods

Aiming at this problem, the corresponding curing mode algorithm is proposed. Customers worry that their gel timer does not provide viscosity or flow

Change the data. They can't afford expensive rheometers to monitor the "cure" of materials such as gels or epoxies. The algorithm allows

Data collected over a very large viscosity range.

Brookfield RheocalcTM software is used for instrument control and data acquisition. The software uses the "wizard" in Rheocalc

- Selecting the "Curing Mode" wizard will guide the user through setting up the test.

In the example below, the Brookfield DV3TLV and SC4-27RD disposable spindles and the SC4-13RD disposable spindle sample chamber.

The initial speed is 100 rpm. As the epoxy resin system reacts or cures, the viscosity increases. Every time the measured torque is reached

The 90% range of full scale or "FSR" has a 10x reduction in speed. When the 90% FSR is reached, the program ends up running

The slow speed of Zui - in this case 0.01 RPM. Figure 1 shows the data.

Figure 1: Epoxy curing at 23 ° C Torque to time ratio Each curve represents a different data speed (RPM) segment

Each of the curves in Figure 2 represents the speed of the spindle. The curve to the left of zui is the torque data at 100 rpm, the curve to the right of zui

Is 0.01 RPM. The spindle speed is reduced by an order of magnitude at regular intervals.

Figure 2: Relationship between spindle speed and time for epoxy curing test

As the test temperature increases, the reaction or "cure" process accelerates. Figure 3 shows three different controls for viscosity versus time.

Temperature: 23 ° C, 50 ° C and 60 ° C.

Figure 3: Viscosity of the epoxy resin curing test at three different temperatures over time. Epoxy resin curing monitoring

23°, 40° and 60°C