4.2 Instruments
4.2.1 Electronic Balance: The accuracy is 0.1 g
4.2.2 Bra bender viscometer: viscograph-E or viscograph-PT100
4.2.3 Conical flask: 500 ml, with glass plug.
4.3 Reagent
The distilled water or deionizer water: conductivity < 4 us/cm.
4.4 Operation
4.4.1 Weighting
Based on the starch slurry concentration 6% or 8%, weighting the right amount of
Sample (precision is 0.1g),add the right amount of water, make the starch slurry is
460g.
4.4.2 Prepare for rotational viscometer and Starch Emulsion
a) Start Bra bender viscometer (4.2.2), open the cooling water.
b) Set the test parameter for viscometer: Stirring speed 75r/min, measuring rang 700
cmg, viscosity of units Bu(or mPa s)
c) The test program: In order to 1.5 C/min heating rate increase temperature from
35 C to 95C, and keep the temperature at 95 C for 30 min. Then in order to 1.5C/min cooling rate reduce temperature to 50 C , holding 30 min
4.4.3 Place the sample
Fully shaking conical flask, decant the slurry into the Bra bender viscometer s
Carrier sample tube, then the carrier sample tube put in the Bra bender viscometer.
4.4.4 measure
Start the test on the basis of the operation of Bra bender viscometer.
4.5 Result
After the test, instrument will draw graph, and related evaluation index from graph: the samples into pasting temperature, peak viscosity and retro gradation value,
Falling value, etc. At the same time on the viscosity curve can also be directly read different viscosity value of the temperature
5 Lab Report