Consolidated Glass Corporation

Tempered Glass - Break Test Quality Procedure for Consolidated Glass Corporation

In order to insure that we maintain the highest quality assurance for our tempered safety glass, the following procedures are to be followed.

  1. Test glass is to be cut and available at the furnace at all times in a size of 24 x 42. This glass is to be in the thicknesses of 1/8, 5/32, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, clear glass and 1/8, 5/32, 3/16, pattern glass.
  2. Test glass, of the appropriate thickness, is to be run prior to any production run being started and every ½ hour during the run, until the run is complete.
  3. All glass will be tested in accordance with ANSI Z97 and the ASTM 1048 standard.
  4. Test glass is to be broken in a test frame using a prick punch. The position of the impact is to be 21” up on the 42” edge and in 1 ½” from the same edge as shown below.
Location of prick punch test point
  1. All test results will be measured by both particle count and by weight. 
  2. All test results will be entered and stored for a period of no less the 10 years in the company’s computer system by the tempering furnace operator.
  3. All results will be registered by operator, date, time, pattern or clear glass, thickness, particle count and weight.
  4. To check that the test piece is within code by weight, the 10 largest pieces are to be selected, placed on the scale and their combined weight is compared to the chart provided to the furnace operator.
  5. To check that the test piece is within code by particle count, a 2”x2” (50mmx50mm) mask template is placed on the broken test piece in the area of the coarsest fracture, excluding the area within 3” (75mm) of the point of impact and a border of 1” (25mm) around the edge of the test piece.
  6. The operator will count the number of crack free particles within the mask. All particles wholly contained within the mask shall be counted as one particle and all particles that are partially within and partially outside the mask shall be counted as one half particle. Particles that are touching the frame are to be counted as one half. Compare this count to the minimum particle count chart.
  7. If either the weight or the particle count for the test has failed, then a isolation of the glass that has been tempered from the time of the previous passed test will be done.
  8. This glass will then be destroyed or tempered over again.