Tempered glass and bent laminated glass is security glass of most main of form, it was widely of should for building doors and Windows curtain wall, and sightseeing corridor, and guardrail, and various car with doors and Windows, field, since burst problem is tempered security glass and bent sandwich security glass application by faced of a tricky problem, author following for tempered glass and bent laminated glass of burst problem, around how take effective of process processing for simple of described.
1 glass of bursting in the following reasons
Glass edge and surface quality, product design defect, quality, glass tempering process during the installation of and the expansion coefficient of glass ink effects, nickel sulfide in glass caused by caused by glass from explosions and other related factors.
1.1 glass edge and surface quality
Poor quality of glass edge fried, blasting, deep scratches on glass surface is an important factor causing tempered glass breakage. Glass side Department of fried mouth main performance for side Department appeared longitudinal RIP, glass side Department fried mouth produced of reasons main has two a aspects, while is glass side Department by forces collision by produced of fried mouth, on the is due to glass of side Department mill side quality poor, mill side more light, glass in for tempered Shi, glass of front-end (that released end) from released to up arc has larger of temperature loss, stress relative concentrated, easy caused glass side Department of micro-crack and fried mouth; burst side main performance for glass side Department of both inside and outside surface appeared shells-like defect.
In order to prevent the glass edge and quality of tempered glass resulting from explosion, the most effective way is a good milling quality, milling depth over thickness of glass one-third, explosive side of the edge, sandpaper, shell-shaped defect transition smooth. In addition, the glass during processing, handling, installation of the glass edges must be properly protected. Again, avoid glass surfaces and other hard object collision, friction, causing deep scratches.
1.2 product design flaws
Tempered glass products design exists defects is caused glass since explosion crack of hidden, products design exists of defects main refers to of is some open hole, and open hole and dug angle of glass, open hole or opening design too near glass of side Department, or two a hole and two a opening apart of distance too near, glass dug angle or opening part of corner too sharp, to caused glass of stress too concentrated, very easy caused tempered products late using process in the of burst.
To prevent due to products design of improper caused of tempered glass of burst, in on glass Shang open hole, and open hole, and dug angle part for design Shi, for thickness in 12mm following of glass can accept of hole side from for 1.5x glass thickness; for thickness in 12mm above of glass can accept of hole side from for 2x glass thickness; due to glass angle Department of stress more concentrated, hole of side Department from glass angle Department of distance not should is less than glass thickness of 6 times times; addition, to guarantee tempered glass has more stable of performance and strength, Practice in design glass, try to relax the hole spacing and hole margins, corner transition is very smooth, on this point, tempered glass product design staff must be in clear control.
1.3 tempered process quality
Rational tempering process will not result in tempered glass products since the late explosion, later due to improper tempering process glass burst factors are: too high level of tempered glass, glass dimensions meet or exceed load capacity of the furnace.
1.3.1 glass tempering degree too high will increase later in the process of using self-
Evaluation of tempered glass tempered glass is mainly from the broken fragments of glass were observed. After breaking glass, fragments of fine instructions glass surfaces excessive stresses, surface tempered glass are prone to burst of excessive stress, so under the premise of national standards for tempered glass, try to avoid excessive compressive stress on the surface of the glass.
In order to avoid high degree of tempered glass, in control of the tempering process, mainly for the heating temperature of the glass and steel wind pressure control. Glass heating temperature, cooling the air pressure is too big, glass internal tensile stress and compressive stress of surface layer of glass is too large, thereby increasing the risk of glass since the explosion. So in the actual production, must according to the glass thickness, color, worked out a set of correct process parameters for their equipment, and tempering time adjustment of the process parameters of strict control.
1.3.2 glass specifications meet or exceed the tempering furnace capacity
According to the author's many years of production experience, if the glass size is too large, almost reaches or exceeds the tempering furnace capacity, glass production, itself likely to be significantly higher than that of normal glass. Reason lies mainly in the following aspects: the bigger overall uneven heating may cause the glass to glass, different areas of the glass surface temperature difference, tempered due to temperature stress does not have glass in the wind during cold hardening, uneven distribution of hair does not cause stress.
In order to solve after its tempered glass specifications stress caused by uneven distribution of burst, for the production of large-size glass on the one hand, try to choose a large size furnace; the other hand almost tempering furnace production capacity of large-size glass, glass tempering process control is difficult on parts of a uniform heating, hair dryer and quenching uniformity. So, in process control aspects also to around this two points to for control: first is uniform heating of control, observation furnace within all regional of temperature displayed, will furnace within all regional of temperature regulation consistent, and opened furnace within of heating balance, appropriate reduced heating temperature and extended heating of time, Shang a furnace glass released Hou don't eager to into Xia a furnace, best Middle empty a furnace, stay temperature for recovery; second is uniform quenching hair dryer of control, check hair dryer hole whether completely permeability, Especially windshield corner they normally use less the windshield area, in addition, the upper and lower grille air pressure adjustment, whether watch windshield and glass, glass tempering air cooling, possible increase in tempered glass blowing of the swinging distance, and extend the steel hair dryer hair dryer and cooling time.