The experimental operation methods of sponge

A, density

1. Measuring the length, width and height of sponge specimen

2. The average values of length, width and height are taken three times, and the unit is taken to 0.01.

3. Measuring unit of weight to 0.01 g

4. Weight divided by volume equals density

B. Hardness <Handwashing/Fujian Sponge Test Method p>

1. Place the sponge specimen under the circular pressure plate of the hardness tester.

2. The beginning is pressed down to 75-5% of the thickness at a speed of 10 mm/min.

3. Agile eliminates tightening, then press down 25% of thickness and hold for 20 seconds.

4. After 20 seconds, read the load to 0/kg unit, which is hardness.

C. Tensile Strength

The sponge specimens were placed in the fixture of universal testing machine and pulled down at a speed of 500 mm/min. The tensile strength was calculated by measuring the weight of the sponge specimens during fracture.

D. tear strength

Pull the specimen fixture down at a speed of 500 mm/min, measure the heavy load when it breaks, and calculate the tear strength.

E. Elongation

1. Draw a straight line at 2 centimeters on the left and right sides of the center point.

2. Fix the sponge specimen to the upper and lower fixture of universal testing machine and pull it down to fracture at 500 mm/min speed.

3. Measure the long distance of the marking line to calculate the elongation

F. Compression residue skew

1. Correct thickness measurement of the central part of the specimen

2. Fixed after compressing 50% thickness with compression plate

3. Setting temperature 70-1C

4. Place in thermostat for 22 hours

5. 22 hours later, after 30 minutes recovery at room temperature, the thickness was measured and the residual distortion of compression was calculated.

G, Number of Cells

Sponge specimens are painted with oil brushes in a thin layer of color. The microscope is adjusted to 10 times the objective lens to catch the eye.

Measuring the number of bubbles by adjusting the mirror to three times