To understand the full range of construction silicone sealan
Silicone sealant refers to linear polysiloxane as the main raw materials of sealant, silicone sealant is also called, is a kind of silicone rubber. 一、The characteristics of building silicone sealant The polymer chain of silicone sealant
Silicone sealant refers to linear polysiloxane as the main raw materials of sealant, silicone sealant is also called, is a kind of silicone rubber.
一、The characteristics of building silicone sealant
The polymer chain of silicone sealant is mainly composed of silicon oxygen silicon — — key components, and other polymer chain is mainly composed of &mdash organic carbon carbon bond; sealant composition (such as: polyurethane sealant, acrylic sealant, polysulfide sealant etc.), the most notable is the excellent characteristics of high and low temperature resistance and weather resistance.
二、Classification of building silicone sealant
The construction of silicone sealant is mostly used at room temperature vulcanization (RTV) condensation type curing system, which does not require heating curing, curing at room temperature, and the curing process will release some small molecules.
1、According to the classification of the curing system
According to the type of small molecules released during curing, construction silicone sealant can be divided into deacetic type, deketoxime type, dealcohol, de amide type etc..
Deacetic type silicone sealant that is usually the “ &rdquo acid gel;, fast curing, good transparency, but the release of acetic acid during the curing process, with a pungent odor, and the metal coated glass and some corrosive inorganic materials.
Deketoxime type silicone sealant belongs to“Neutral gel”，The use of a wide range, curing the release of butanone oxime, no corrosion of aluminum, coated glass and inorganic materials, but is corrosive to copper, lead, zinc and polycarbonate.
Dealcoholized silicone sealant belongs to“Neutral gel”，The use of a wider range of curing process, the release of small molecular alcohols, no corrosion of any material.
De amide type silicone sealant has very low modulus, mainly used in airports, roads and bridges to a low modulus high displacement caulking sealing occasions.
2、According to group scores
According to the number of products, construction silicone sealant usually can be divided into single and double component two categories. Single component construction is only one component silicone sealant. Single component silicone sealant for building is generally cured by reaction with moisture in the air, the curing process from the surface to the deep gradually, therefore, the deep curing speed is relatively slow, and there is a certain requirement of the construction depth, width, environmental temperature and humidity, relative humidity influence.
Two-component silicone sealant A, B building two components, the need to use the first two components are mixed evenly, and then used to glue glue injection in a certain period of time, mixed over a certain period of time will not use sealant curing. Two component construction silicone sealant must use the two components to mixed construction equipment, hand mixing hand is not uniform, on the other hand will be wrapped into the bubble, affect the use effect. Therefore, compared with the single component, the use of the two component products is more complex, which increases the risk of operation errors. However, two-component silicone sealant for building two components can be mixed evenly curing in the curing process, does not need to react with water in the air, surface and deep and deep curing, curing speed, and curing speed can be adjusted by mixing regulation of A and B components, is not affected by the depth of construction the width and the humidity of the environment. In addition, the use of two-component glue machine can greatly improve labor efficiency.
3、According to function classification
According to the use function of building silicone sealant can be divided into structural silicone sealants and silicone sealant.
Not only has the function of sealing silicone sealant in use, more important is the structure of bond effect, mainly used for structural bonding of glass curtain wall in need of occasions, such as hidden frame hollow glass bonding, glass and aluminum frame glass curtain wall with hidden frame glass curtain wall in the two seal, full glass curtain wall in between the glass plate with the bonding of glass rib.
三、Silicone weatherproof sealant
Silicone weatherproof sealant is used as curtain wall plate sealing silicone sealant, silicone sealant for sealing the doors and windows and other airports, highways, roads and bridges in the performance and the function with silicone weatherproof sealant is basically the same, the performance index can refer to the sealant, adhesive joint structure combined with the actual use.
The main technical indexes of silicone weatherproof sealant, characterization of the construction performance of sagging, extrusion, surface drying time, characterization of the cured sealant is mainly displacement capacity and mass loss rate. The mass loss rate of weather resistant rubber is equivalent to the thermal weight loss of the structural adhesive. The main reason is the change of the performance of weather resistant adhesive after long-term use.
The main role of weather resistance is to seal the joints between the plates, because the plate is often subject to temperature changes, deformation of the main structure, such as the impact of displacement, resulting in the width of the joint will also change. This requires the sealant has good bearing joint displacement, in a long-term bear joint width changes without cracking, this performance is called the displacement ability of sealant, and structural adhesive “ deformation capacity”Different.
四、The construction of silicone sealant for special purposes
In addition to the universal application of building structural silicone sealant and weatherproof sealant, in the actual application process, there are many special occasions must use special construction silicone sealant.
1、Silicone sealant for stone
2、Dry hanging stone elastic sealant
3、Insulating glass sealant
At present, insulating glass processing abroad, second sealing with polysulfide sealant is less and less, and the use of more and more silicone sealant. This is because the polysulfide sealant production on the environment pollution is serious, leading to higher prices of polysulfide sealant good performance, on the other hand, because the silicone sealant has high and low temperature and excellent weathering performance, greatly prolong the service life of the hollow glass. Although the silicone sealant for water vapour transmission rate is higher than that of polysulfide sealant, but studies have shown that the two insulating glass sealant water vapor permeability of hollow glass performance and the service life of the impact is very small. With China's increasing emphasis on environmental protection, silicone sealant will be more widely applied to the hollow glass industry.