Tempering is a heat treatment process to increase the strength the float annealed glasses. There are two main purpose to apply tempering;
1- Increasing the strenth the float glass more than 4-5 times than float annealed(non tempered) glasses.
2- When tempering is applied, in case of broken of tempered glasses, the broken parts is being small and non sharp. This feature make the tempered glass non hazardous on contrary non tempered glasses.
You can see the differences of broken glass parts belong to tempered and non tempered glasses as figured below.
Tempered glasses are mostly used in different industries due to the purposes mentioned above. Architectural, automative, industrial refrigeration, white goods, furniture, electronics industries commonly use tempered glasses their applications.
The mechanisim of the tempered glass;
1- Float annealed glass is heated up to 700 °C with different heating rates by changing of thickness, types of glass and types of tempering furnace.
2- After reaching the target temperature, the glass is quenched faster. Quenching should done as fast as possible.
3- The reason of the fast cooling(quenching) is keeping the tension forces without escaping in the glass.
4- This kept tension forces make the glass strenth.
1 mm thickness clear float glass should be heated 41 seconds in according to empirical calculations. In the view of such information, 10 mm clear glasses should be heated 410 seconds. Heating time is depend on glass thickness, glass type(tinted, solar low-e, thermal low-e…etc) and the mechanism of the heating type of tempering furnace(full or semi convectional, convansional...etc)
General tempering standart is EN-12150 should be followed by glass processors to obtain exact tempering glass. Some testing methods help to check the tempered glasses are suitable for EN-12150 or not.
Above mentioned tempering type is full tempering by heat treatment. Also there are two different tempering types excluding this one.
1- Chemical tempering: applying on extra thin(0-1 mm) glasses that used in electronic industries. For example; smart phone glasses.
2- Semi tempering: mostly like as full tempering by heat treatment with one differences.The air pressure and air consumption is half of full tempering. This means to obtain half of strenth in contrast with full tempering.
2-19 mm thickness glass are producer by float lines. Each type and thickness can be tempered with suitable parameters. Tempered glasses can be used in different glass applications and process after tempering like glazing, laminating…etc.
Refriglass can serve wide range tempered glass types to the customers. Please get in touch with us in case of tempered glass demands. Our experienced sales team will help you.