Glass Expert Discusses Glass Ovenware

A glass expert in California compares Pyrex glass ware from two eras. The original glass ovenware was developed by Corning Glass Works. They introduced annealed borosilicate glass that had a lower thermal expansion coefficient than the more common soda lime glass. The lower expansion coefficient reduced the level of thermal shock and allowed this glass to be used for ovenware. For a long period Pyrex was synomonous with borosilicate glass. Later the decision was made to make glass ovenware from heat strengthened soda lime glass and to continue to call it pyrex. This is the present approach to this type of cookware. Above, the upper right image is an edge stress measurement performed on an older piece of glass cookware. This measurement shows that this glass is annealed. This is an older piece of traditional pyrex cookware. On the lower right is the same measurement performed on a recently purchased piece of pyrex cookware. The presence and number of the color bands indicates that this ovenware is made from heat strengthened glass.

Safety Expert Examines a Personal Injury from Bungee Cord

Safety Expert analyzes the cause of injury to a wake board user from a bungee cord on the wakeboard rack. The rack is a piece of sports equipment, and it is designed to hold two boards in place with two 19" long bungee cords; each has a 1" plastic ball on one end. The cord is stretched to a length of 40" in order to get the ball over the racks,and the cord is fit into a slot. The ball holds the board in place. During the mounting of the wakeboards, the user is looking under the rack to perform the slotting operation; this puts his face in the 'line of fire" if the user accidentally lost hold of the ball as he is stretching the cord. This is exactly what happened, and the user lost an eye. According to the safety expert, this design is even more dangerous because boaters hands may be wet or coated with sun tan oils etc. Tests on the cord indicated that the ball velocity is greater than 100 mph. The photo on the upper left is the users view. The two balls are in their appropriate slots. Upper right is looking at the rack with two mounted wakeboards. This rack model has been discontinued.

Beer Bottle Impact Failure Analysis

Glass failure expert analyzed a failed beer bottle to determine if there was a product defect. It was stated that the bottle exploded when it was put into a cooler filled with ice. The failure analysis revealed that the bottle had been hit with a sharp object. The photograph on the left is the bottle after re-assembly. The photograph in the center is a closeup of the failure origin from the outside of the bottle, The photo on the right is the failure origin from the inside of the bottle. The hertzian cone from the impact is readily visible. It is obvious that this bottle broke after it was hit on the side. Thus there are no product liability issues or manufacturing defects associated with this failure.