Release time：2023-11-22 popularity：0 source：admin
First, silicone structural adhesive
As the only connection and load transfer "member" between the curtain wall glass and the backed aluminum alloy frame, it must have quite high tensile and shear strength, resistance to repeated tensile, compression and peel bond strength. It should also have a high elastic modulus, and can still maintain the basic shape of its rubber layer under high positive and negative stresses to prevent the glass from breaking due to excessive deformation.
Second, silicone weather-resistant sealant is used for the glass curtain wall of the hidden frame glass or other materials joint caulking a kind of glue, in addition to resist the invasion of wind and rain, but also must adapt to the curtain wall glass plate due to climate change caused by thermal expansion and contraction, so that the joint width change can still be firmly bonded, generally allowed to expand the width of the joint should reach ±25%.
Third, the structural sealant for insulating glass is the hidden frame glass curtain wall adhesive.
Generally used for framed aluminum alloy glass curtain wall insulating glass, polysulfide glue is used to seal the outside of the insulating glass, and the insulating glass is embedded around the aluminum alloy frame, generally no condensation for five years. However, the bonding strength of polysulfide glue is low and it is not resistant to ultraviolet radiation from the sunlight through the glass. In the hidden frame curtain wall, there is no aluminum alloy frame to block the light, and the weight and load of the outer glass of the insulating glass must be passed to the inner glass with insulating glass glue. Therefore, the role of insulating glass silicone structural adhesive is not replaced by polysulfide adhesive, otherwise under the action of negative wind pressure, the outside glass has the danger of falling, so it must not be used to replace insulating glass silicone structural sealant with general glue.
Fourth, silicone structural sealant is divided into single-component, two-component, acid curing adhesive and neutral curing adhesive.
Single component silicone sealant can be directly coated between aluminum and glass bonding, it depends on the absorption of moisture in the air and hydrolysis, condensation reaction from the surface to the inside and curing, the glue room is required to be clean, the temperature is not less than 23℃, the relative humidity is not less than 40%, otherwise it will affect the curing, so that the strength of the adhesive layer is reduced.
The single component silicone adhesive is acidic and neutral. The acidic adhesive releases acetic acid when curing, which corrodes the film layer of the coated glass produced by vacuum magnetron sputtering for the curtain wall of the hidden frame. Therefore, neutral silicone structural adhesive should be used.
The two-component silicone structural adhesive must be added to the base adhesive before use, and the adhesive is fully mixed between the coating aluminum and glass in the glue machine for bonding and curing, and the two-component adhesive is neutral.
Silicone structural sealant has one outstanding feature. That is, there is a compatibility problem between the adhesive and the bonded aluminum, glass, and foam strips, and it is necessary to do a compatibility test, which can not be done in China for the time being. If the compatibility test results show that the structural adhesive is incompatible with one of the three materials, even in the bonding process, the various strength indicators at that time meet the requirements. After half a year or a little longer, the silicone structural adhesive will begin to change color and deteriorate into a liquid state, thereby losing its bonding ability, and the glass will fall down, causing serious consequences. Therefore, in order to ensure the long-term bonding ability of silicone structural adhesives, compatibility tests must be done.