Apparatus
Cold water bath
Hot water bath
Basket
Tongs
Tungsten carbide scribe
50 grit emery paper
Timer
Ruler
Clause 4.1 Annealing (CPSD-HL-09404-MTHD) 退火
Test Method A: tungsten carbide scratch test
1.Score around the inside knuckle of the sample using the tungsten carbide scribe (apply just enough force so that the glass surface is penetrated)
2. Score an “X” across the sample’s entire inside bottom surface
3. Fill the sample with tap water up to the rim of the sample or approximately 1 in from the inside bottom surface whichever is the minimum, water temperature: 18-25ºC
4.Leave the sample filled with tap water for 15min to 18min
5.After the time duration, pour out the water and examine the sample for any fractures, record the finding and note the time when failure occurs
Test Method B: 50 grit emery paper test
1.
With a 50 grit emery paper abrade the entire inner surface of the sample
2.
Apply enough pressure with the emery paper to penetrate the glass surface, ensure all sharp corners、dimples、indentations on the inside surface of the sample are abraded
3.
Fill the sample with tap water to a sufficient height to allow for a complete immersion of the abraded section
4.
Leave the sample filled with tap water for 15 min to 18min
5.
After the time duration, pour out the water and examine the sample for any fractures, record the finding and note the time when failure occurs