OFFER / PRODUCTS / Glass VSG (laminated)
Laminated safety glass is composed of two layers of glass laminated with PVB (Polyvinyl Butiral). Depending on the glass sheet thickness and number of PVB interlayers the glass safety class range from class of P1A to P4A. In case of breakage of laminated safety glass the risk of injury is reduced because the broken pieces and splinters are held together by the film.
Standard laminated glass is available as transparent and opaque matt, while the typical nominal thickness of 8.38 mm (VSG 44.1 ), 9.52 mm (VSG 44.4 - class P4A ), 12.76 mm ( 66.2 ), etc. The description in brackets is the symbolic notation of the type of glass, for example 44.1 means that the laminated glass consists of two sheets of glass 4mm thick and a one (1) layer of PVB. The single layer PVB film is 0.38 mm thick. The table below shows the strength parameters of the different classes of safety glazing exposed to free fall of a steel ball with a mass of 4.11 kg onto the surface of glass mounted in a frame.
Quite often safety glass are wrongly called or refered to as anti-burglary, which is not in accordance with their real purpose. Class of safety glazing shall have the following markings P1A, P2A, P3A, P4A according to PN-EN 356. The letter A was intentionally specified for an explanation of the difference between the ordinary safety glass and and anti-burglary glass. Burglar-proof windows shall have the following markings: P6B, P7B and P8B. Of course, the difference is not due to a different recording, but the method of testing of laminated glass during certification. As has already been mentioned, the test of safety glazing depends on checking the strength of the glass subjected to impact of a test steel ball. Burglary-proof glass marked as B are tested in a different way, a description of the issues can be found in the section OFFER / Products / Glass burglar.
A special case is the glass P4A, which may be referred to as "glass with increased resistance against burglary. The application of such glass prevents from breaking in, but keep in mind that is not a serious obstacle for a skilled burglar.
Equally important is the proper installation of safety glazing. It is required to assembly laminated glass in the frame supporting edges all around. Different mounting solution is incorrect. Any wholes should not be drilled in anti-burglary glass because they weaken it. The table below shows some information on the laminated glass offered.
The use of safety flat gass is limited to fillings for example, "cold" aluminum or PVC structures often seen in the hallways and stairwells of public buildings. Very often this type of glass is used for the production of insulating glass units.