Sealants are mostly synthetic adhesives, whose main body is polymer, and their properties can be divided into three categories: bulk properties, process properties and use properties (product properties). The nature of use (product performance) is self-evident, mainly refers to the comprehensive performance of the sealant during the formation of the cementation process to the formation of the cemented joint, and this performance depends on the functional requirements of the building joint for the sealant. Regardless of the building envelope or building interior decoration; whether it is window structure or other forms of enclosure and decoration structure, they can be regarded as unit composition, then each unit will have a seam, which is extremely large. Most require construction sealant to seal and fill. Reasonable design of building joints, understanding of building sealants, reasonable selection of materials and correct construction of building seals are the indispensable whole process to ensure the successful sealing of building joints. Here are some common problems encountered in the actual use of sealants, and provide you with corresponding solutions.

　　(1) Acid Gum

　　1. The acid glue bottle will grow taller after being stored for a period of time. Deformation may even cause oil on the bottle body. Why?

　　There are two reasons for this problem, namely, it is related to both glue and glue bottle.

　　First, the cause of glue. Except for a few high-grade glues, other acid glues on the market now have a certain amount of filler added to different degrees to reduce costs. The lower the grade of the glue, the more fillers are added. It will react with the plastic bottle, which will cause the plastic bottle to grow tall, deform and have oil on the bottle; for example, high-grade glue may cause the plastic bottle to react after 6 months, and relatively low-grade glue may react after 6 months.

　　Second, the reason for the plastic bottle. The quality of the plastic bottle itself is also the reason for the growth. The raw materials used in the bottle body are also good or bad. If the raw materials used are good, the plastic bottle will change slowly. For example, a good-quality plastic bottle can be stored for 7-8 months without response when loaded with high-grade plastic; on the contrary, if a poor-quality plastic bottle is used, even a good-quality plastic bottle may be deformed in 2-3 months.

　　2. Why do I find that the glue is thick or dry when looking at the bottom cover of the plastic bottle?

　　This is mainly produced during the packaging process. Because it takes a certain amount of time from installing the glue to pressing the cover, although the time is short, it also makes the glue and air contact. If the sealant solidifies a lot from the bottom, the bottom cap and bottle are not tightly sealed, which is a quality control problem of the packaging material.

　　3. The flow of acid glue may be cut off or there are small bubbles during the extrusion process, why?

　　This situation is mainly caused by the following two reasons.

　　One is caused by too low storage temperature: if acid glue (especially low-grade glue) is stored at a lower temperature, a lot of bubbles will be formed. The reason may be that after low-temperature storage, the liquid raw material has more bubbles due to the change in the volume of the cold shrinkage. Therefore, it is recommended that the storage temperature be not lower than 0°C.

　　The second is the formation during the canning process: in normal canning, there will often be a small amount of small bubbles at the end of the glue. Impact: If there are more bubbles or cut-off (large bubbles), it is caused by improper operation, which must be improved and should be avoided as much as possible. However, this situation also has the probability of occurrence. If this phenomenon occurs rarely or occasionally, it should be regarded as an accident. Large bubbles should be avoided during operation.

　　4. Why does the surface of the acid glue get wrinkled after curing?

　　This is mainly caused by the glue layer being too thin when sizing on the surface of the two substrates. Due to the difference in thermal expansion and contraction rates of different materials, there is a large temperature difference, and the incompletely cured glue will deform and wrinkle.

　　Solution: Coat the adhesive layer thickly. The thickness of the adhesive layer is generally about 1mm during general construction. It is recommended to increase the thickness to (1.5-2)mm.

　　5. Why do some acid glues discolor the aluminum after curing?

　　Acetic acid is released when the acid glue is cured, which is corrosive to metal materials. The reason why it can be used on aluminum is because the surface of the aluminum is plated with an oxide film or coating, which is protected by a layer of coating. Therefore, in general, discoloration of aluminum is not a problem of glue, but the construction operation and the quality of the aluminum itself are more involved here. The quality of aluminum material mainly refers to the unqualified coating layer of the coated aluminum material, such as poor adhesion, too thin film, etc., will affect its discoloration after sizing; improper construction can also cause discoloration. If the aluminum material is placed in a poorly ventilated environment after sizing, the acetic acid released by the curing of the glass glue cannot be dispersed in time, and the local concentration is too high, and the aluminum material will be corroded for a long time to change its color.

　　6. The adhesive strip will turn white or yellow after curing, why?

　　Yellowing: In more cases, the yellowing of the rubber strip is caused by the influence of other materials in contact with the glass glue. The most common occurrence is to hit the glass glue on some black rubber strips (the seal between the glass and the aluminum material). ), due to the poor quality of some glue strips, they will turn yellow when contacted with glass glue, even imported glue. Under normal circumstances, the rubber strip discolors the glass glue. The analysis may be due to the material used in the rubber strip, specifically the filler reacts with the acid glue to change the color of the transparent glue; it is also not ruled out that the rubber strip is added with precipitated or volatile substances to pollute the glass. Adhesive strips. Whitening: The whitening of glass glue is mainly caused by too much filler in the sealant; if occasionally whitening occurs, it often appears in some projects where the glue layer is too thin, so it is recommended to add glass glue when sizing The thickness (1.5-3mm) to avoid similar situations.

　　7. Why does the glass glue appear on the paper when there are some sticky papers and some non-sticky papers?

　　Glass glue is not used to stick paper, so neither sticky paper nor non-sticky paper will affect the actual use; but sticky non-sticky paper is related to some characteristics of paper and glass glue. First of all, the material and texture of the paper have a great influence on the sticky paper. If the paper fiber is relatively loose, the glass glue will easily wet the paper and stick the paper; secondly, the glass glue will also have an effect. The preliminary analysis has a certain relationship with the curing speed.

　　8. Why does the cured hyaluronic acid glue strip turn white after stretching?

　　Because solid fillers are added to many acid glues to increase the strength, the solid fillers appear white after stretching, so they look whitish; this situation mostly occurs in domestic glues. Due to cost constraints, the solid fillers used are different from imported glues. A certain difference, but it has no effect on the performance and actual use of the glass glue.

　　9. Why is the deep curing of glass glue slow?

　　Deep curing has a lot to do with the use environment. Generally speaking, glass glue cures slowly in an environment with low temperature and high humidity; in addition, it cures slowly in a poorly ventilated environment; there are different grades of glass glue to cure The speed difference is large, especially for domestic glue. The curing speed of low-grade glue is obviously different than that of high-grade glue. This difference is especially obvious when the ambient temperature is low. Therefore, it is recommended that domestic low-grade glue should not be near the specified lower limit temperature (5℃). use.

　　10. Why does the glass glue shrink after curing?

　　All sealants will shrink after curing, but the shrinkage rate of high-grade glue and low-grade glue is very different. For example, the high-grade rubber only shrinks by 5% after curing, and the low-grade rubber may shrink by 30% or more. This is because the low-grade rubber adds fillers, and the fillers will slowly volatilize in the air, so the more fillers, the greater the shrinkage rate. Big.

　　11. There is a small amount of oil separation at the bottle mouth?

　　This is a normal phenomenon of long-term storage, generally stored for more than 3 months, but the probability of this situation is not very high in practice, because the glass glue oil separation occurs only after a long period of standing, and the support Glue sales are often in motion, such as transportation, loading and unloading, and sorting warehouses, which is equivalent to constant mixing, so there will be no delamination for more time. The reason for the occurrence of a small amount of oil separation is: the product is composed of liquid raw materials and solid raw materials. Because of their different specific gravity, they will sink when they are left for a long time. However, because this process is very slow, it does not affect the use. And product performance, this phenomenon also exists in imported glue.

　　12. Vat gum is more sour than imported sour gum?

　　The difference here is mainly the low-grade rubber, because the basic materials of the domestic low-grade rubber are limited by the cost, resulting in a short storage period. In order to improve the storage period, it is necessary to add a variety of additives, the taste is great, but the main release is acetic acid, which is harmless to humans.

　　13. Why does some glass glue surface dry too fast and there is no time for dressing?