Dishwasher detergent viscosity

Use

To be used in the dishwasher to facilitate the cleaning of the dishes.

METHOD 1

Test equipment

Instrument: DV3T

Theometer spring Torque: HB

Pin: HB-3

Speed: 5, 10, 50, 90, 130, 170, 210 and 250 rpm

Temperature: Ambient temperature (70 ° -72 ° F)

Test method

We used a Brookfield DV3THB rheometer with Rheocalc ™ software for automated instrument control and data acquisition. We performed our test at room temperature (70-72 ° F) in a 600 ml beaker. We used an HB-3 pin submerged to its immersion mark. Three tests were performed to ensure repeatability. Each test was performed in a new portion of the sample. Representative data of the analyzes are shown in Figure 1 which shows that the viscosity of the dishwasher detergent decreased as the shear rate increased. This behavior is known as "shear thinning". The results over the shear rate range were all on a scale between 10 and 100 % of the couple from the full range. Note that the three curves overlap, which shows excellent repeatability.

Figure 1: Dishwasher detergent at 70 ° -72 ° C

Viscosity versus rotational speed

METHOD 2

Test equipment

Instrument: DV3T / DVNext

Rheometer spring Torque: HA

Spindle: SC4-27 Spindle with 13RPY Sample chamber

Accessories: Small sample adapter, TC-550AP

Programmable refrigerated wash speed: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210 and 220 rpm min

Temperature: 25 ° C

Test method

The Small Sample Adapter can be used with various Brookfield viscometers or rheometers. In our example, we used a Brookfield DV3THA rheometer with Rheocalc ™ software for automated instrument control and data acquisition. Our test temperature of 25 ° C was maintained by connecting the small sample adapter water jacket to a Brookfield TC-550AP programmable refrigerated bath.

Three different samples were tested to ensure repeatability. A syringe was used to measure 10.4 ml of the sample and dispense it into the chamber. The Small Sample Adapter can be an extremely valuable accessory, especially if you want to use samples much smaller than those required to perform Method 1. Representative data from the analyzes are shown in Figure 2.

Figure 2 shows that the viscosity of the dishwasher detergent has decreased. as the shear rate increases. This behavior is known as "shear thinning". The results over the shear rate range were all on a scale between 10 and 100 % of couple. The results were reproducible.

Figure 2: Dishwasher detergent at 25 ° C

Viscosity vs. shear rate

METHOD 3

Test equipment

Instrument: DV3T / DVNext rheometer

Spring Torque: RV

Spindle: V-73 vane spindle, submerged to the primary immersion mark

Speed: 1rpm

Temperature: Ambient temperature (70 ° -72 ° F)

Test method

We used the Brookfield DV3TRV rheometer, along with EZ-Yield ™ software for automated instrument control and data acquisition. The elasticity tests determine the stress that must be applied to make a material flow. The corresponding apparent strain is the strain at which the sample structure breaks down and begins to flow. The sample was taken from its bottle into a 250 ml beaker, where it was tested. The axis of the pallet has been submerged to its primary immersion mark. The Vane spindle was immersed in a new part of the sample for each test. Figure 3 shows the stress (Pa) versus the apparent stress (rad) of the dishwasher detergent at 1 rpm. The stiffness or firmness of the material is reflected in the slope or stiffness of the stress-strain curve. The yield strength is the maximum stress (approximately 37 Pa) at each pass. The results were reproducible.

Figure 3: Dishwasher detergent at 70 ° -72 ° C

Shear stress with respect to the apparent stress