To prevent misalignment, it is necessary to comprehensively control the four links of production, transportation, installation and use and maintenance.
I. Production stage: This is the foundation, ensuring that the quality of the glass itself is up to standard
Select high-quality raw glass sheets: Use high-quality raw glass sheets with high flatness and uniform thickness to reduce the possibility of uneven stress from the source.
Precise lamination process: During lamination (bonding two or more pieces of glass with an intermediate layer such as PVB/SGP), it is essential to ensure that the edges of each layer of glass are aligned. Modern production lines adopt automatic edge alignment equipment, which can effectively ensure accuracy.
Standardized autoclave process
Control of temperature, pressure and time: It must be strictly carried out in accordance with the process requirements of the intermediate layer material (such as PVB film). If the heating is uneven or the pressure is insufficient, it will lead to inadequate flow of the film, insufficient adhesion, and it is prone to misalignment due to stress during use.
Stable placement: When entering the autoclave, the glass should be placed horizontally and the support should be flat to prevent the glass sheets from sliding due to uneven force under high temperature and high pressure.
Ii. Transportation and Storage: Avoid causing "internal damage" before installation
Proper packaging: Glass should be stored and transported upright, and each piece of glass should be separated by soft materials (such as foam strips, rubber pads). The packaging box should be strong to prevent shaking and collision during transportation.
Proper handling: Avoid violent jolts and sudden braking. When handling, professional tools such as suction cups should be used. It is strictly forbidden to lift the edge of the glass directly by hand to avoid uneven force causing shear deformation of the internal film.
Proper storage
It should be stored upright in a dry and well-ventilated indoor area, and the recommended inclination Angle from the ground is 85 to 90 degrees.
The bottom must use elastic pads, which should be on the same vertical line to ensure that the weight of the glass is evenly distributed.
It is strictly prohibited to place the glass flat or against the wall at an Angle. This will cause the glass's own weight to continuously creep the film, posing a hidden danger of misalignment in the future.
Iii. Installation Stage: This is the most crucial step
Improper installation is the most common cause of misalignment of laminated glass.
Well-designed installation slots
Sufficient gap: The depth and width of the slot must be precisely calculated based on the thickness and size of the glass, leaving sufficient expansion allowance (usually the depth is 2/3 of the glass thickness and the width is 4-6mm). If the gap is too small, when the glass expands due to heat, it will directly squeeze the frame, and the huge stress will force the glass sheets to shift.
Uniform support: The installation frame must be flat, vertical and horizontal to ensure uniform force distribution on all four sides of the glass.
Use qualified support pads
This is the core measure to prevent misalignment. The spacers must have sufficient hardness and elasticity (commonly hard PVC or rubber).
Correct placement of spacers: Spacers should be placed at the load-bearing parts where the glass weight is vertically downward (usually at the bottom two points), and their positions should ensure that the spacing between the support points of the glass frame does not exceed 300mm. Key point: All the spacers must be on the same plane to ensure that the glass does not generate torsional stress.
Avoid hard contact: The function of the spacers is to isolate the direct contact between the glass and the metal frame, provide elastic support, and absorb the displacement caused by vibration and thermal expansion and contraction.
Use appropriate sealing materials
Neutral silicone structural sealant must be used. Acidic sealant will corrode the intermediate layer film and the frame.
The sealant should have good adhesion and elasticity, capable of adapting to the displacement between the glass and the frame, rather than being rigidly fixed.
Before applying the adhesive, the groove and the glass surface must be thoroughly cleaned to ensure there is no oil, dust or moisture, so as to guarantee the bonding effect.
Avoid forced installation
It is strictly forbidden to strike the edge of the glass with hard objects to position it. If installation is difficult, check the size of the slot, the position of the spacer or whether the frame is deformed instead of forcibly "stuffing" the glass in.
Iv. Usage and Maintenance Procedures
Avoid long-term uneven force application: Do not hang heavy objects on large glass for a long time, or let furniture or equipment hold against a certain point of the glass for a long time.
Cleaning precautions: When cleaning, avoid using sharp metal scrapers to prevent scratches on the edges of the glass or accidental impacts.
Regular inspection: For large or important glass curtain walls, guardrails, etc., regular checks should be conducted to see if there are any misalignment, cracking, delamination or other phenomena to prevent potential problems before they occur.
