Mistakes in the purchase and use of the Best SILICONE STRUCTURAL SEALANT material

1) The higher the SILICONE STRUCTURAL SEALANT material price, the better?

The positioning of the Best SILICONE STRUCTURAL SEALANT material price is mainly determined by its use, which can be basically divided into structural adhesive, weather resistant adhesive and neutral adhesive. The Best SILICONE STRUCTURAL SEALANT material price is also basically in this order. Structural adhesives generally have high requirements for strength and toughness; The weather resistant adhesive has high requirements for high and low temperature resistance, ultraviolet resistance, corrosion resistance, etc; The neutral adhesive is mainly based on the requirements of glossiness and elasticity. Therefore, if the weather resistant adhesive is tested according to the standard, it is likely to be unqualified. (Note: the state stipulates that other types of the Best SILICONE STRUCTURAL SEALANT material other than structural sealant can not be used in structural assembly). Therefore, it is very important for us to select the appropriate type of the Best SILICONE STRUCTURAL SEALANT material according to practical needs when selecting the Best SILICONE STRUCTURAL SEALANT products.

2) How to cure the Best SILICONE STRUCTURAL SEALANT material?

Many consumers do not know the curing method of the Best SILICONE STRUCTURAL SEALANT products. The Best SILICONE STRUCTURAL SEALANT material is basically divided into single-component and two-component according to the curing mode;

The single component connects the basic polymer into a three-dimensional framework by absorbing water in the air and reacting with a crosslinking agent. Since it is necessary to absorb water for curing, it is a process from the surface to the inside, from shallow to deep, and the deeper it goes, the harder it is to absorb water, and the longer the curing time will be. It is recommended that the sizing depth should not exceed 5cm

The two-component is a mixture of two components, which can be cured in depth without relying on other substances.

3) What are the environmental requirements for the Best SILICONE STRUCTURAL SEALANT material?

Due to the curing method of the Best SILICONE STRUCTURAL SEALANT material, the following use restrictions shall be observed during use:

·It should not be used on the surface of building materials that exude grease, plasticizer or other solvents;

·It should not be used on frosted or wet surfaces, airtight or long-term immersion occasions;

·It should not be used on the painted surface, which may cause sealing failure due to cracking or peeling of the paint film;

·It should not be used on the surface that will directly contact with food or where it is prone to mechanical wear;

·It is not suitable for construction at noon or when the surface temperature of building materials is lower than 4 ℃ or higher than 40 ℃;

·Non structural adhesive shall not be used for structural assembly;

Each adhesive has its own relative use restrictions, such as:

Acid glue: it corrodes copper, brass and other metals, and is not suitable for all kinds of stone materials and iron carbide matrix materials;

Dealcohol glue: it is not suitable for construction at noon or in direct sunlight, nor for fluorocarbon materials;

Loss of glue: it has slight corrosion to copper, brass, silver and other metals, and is not suitable for the mirror industry.

4) The faster the curing speed of the Best SILICONE STRUCTURAL SEALANT material, the better?

In pursuit of construction period or construction speed, many constructors blindly ask the Best SILICONE STRUCTURAL SEALANT manufacturers to accelerate curing, which is actually very wrong. It is a complex process that the crosslinker reacts with the base polymer to form a network structure of Si-O-Si framework. If the reaction time is too short, the skeleton structure may be too small, resulting in low strength and brittle after curing; At the same time, the colloid can not completely infiltrate the substrate, resulting in reduced adhesive strength with the substrate; It is also possible that the curing speed is too fast, and the small molecule gas generated during the curing process can not volatilize from the uncured colloid in time and accumulate, thus generating bubbles, making the surface of the sizing uneven and affecting the appearance; (this kind of situation is more common in outdoor construction in summer). If we insist on fast requirements, the quality of the project will inevitably be affected. Of course, too slow curing speed will also lead to problems such as polluting stones. Therefore, it is recommended that the surface drying time should be about 20-50min at normal temperature.

5) Can the strength of the Best SILICONE STRUCTURAL SEALANT material reach the best within 1-2 days after curing?

We often see that many consumers and even construction companies will pull the adhesive that has just been cured completely to test its performance, and some will compare it with the adhesive that has been cured for several days; In fact, it is also very unscientific. We already know that the crosslinking of the Best SILICONE STRUCTURAL SEALANT material into a skeleton structure is a complex and long process. Therefore, the Best SILICONE STRUCTURAL SEALANT material can only reach 60% strength in 24h after curing, and 75% - 80% strength in 72h. It takes 7-14 days for acid glue to reach the best strength, and longer for neutral glue.

6) Why is acid glue easy to fall off when used on cement and stone?

Acid glue curing is to produce acetic acid, which will react with the surface of alkaline materials such as cement and stone to form a chalky substance and cause it to fall off.

7) What is the reason for the surface wrinkling after the neutral adhesive is cured?

The expansion coefficient of the substrate is large, and there is displacement or vibration; The adhesive is applied too thinly; The catalyst has too much activity, strong shrinkage and too much plasticizer.

8) What is the reason why neutral transparent glue turns yellow?

Amine groups in crosslinkers and plasticizers, which are very easy to cause yellowing; If the neutral glue and acid glue are used at the same time, it may cause the neutral glue to turn yellow; It may also be caused by the long storage time of the glue.

9) Why do some high-grade SILICONE STRUCTURAL SEALANT material and some aluminum-plastic plates, stainless steel, aluminum alloy and other bonding effects not good, but low-grade adhesives stick more firmly?

Because the structural systems of the two are different, the high-grade adhesive is generally 100% silicone adhesive. Its own material is too hard and lacks permeability. It has poor compatibility with general aluminum-plastic plates, stainless steel and aluminum alloys. In addition, its curing speed is relatively fast. The surface of aluminum-plastic plates and other materials is flat and smooth, and the colloid has solidified before it completely penetrates into the surface of the substrate, so the bonding is not firm. The low-grade adhesive has a slow curing speed and a long penetration time. In addition, plasticizers and other materials are added to make it soft, so the low-grade adhesive is easy to be compatible with the substrate and has good adhesion. Therefore, we repeatedly stress that customers should conduct self-test before use to observe whether the materials meet the use requirements.

10) Is it harder to bond aluminum in winter than in summer?

In summer, the aluminum surface is relatively dry due to heat absorption, so that the Best SILICONE STRUCTURAL SEALANT material can quickly infiltrate the substrate after sizing to achieve better bonding effect. However, in winter, due to the difference between the specific heat of aluminum and air, when the temperature changes (especially when the aluminum is moved from the place with low temperature to the place with high temperature), or due to hand touch, dust and other reasons, it is extremely easy to form a film layer on the surface of aluminum that is difficult to be detected by naked eyes. Because of the existence of this film layer, a layer of membrane appears between the Best SILICONE STRUCTURAL SEALANT material and the substrate. The Best SILICONE STRUCTURAL SEALANT material can not infiltrate the surface of the substrate, which greatly reduces the adhesion of the Best SILICONE STRUCTURAL SEALANT material, and even leads to bonding failure.

It is recommended that the Best SILICONE STRUCTURAL SEALANT manufacturers leave the base material in the drying room for a certain time (e.g. 24h) before construction in winter. At this time, the temperature of the base material is close to the indoor temperature, and the temperature of the contact surface between the Best SILICONE STRUCTURAL SEALANT material and the base material after sizing is also high, which is conducive to the reaction between the coupling agent in the sealant and the groups on the base material and increases the bonding strength of the sealant.