The glass glue hits the glass, but the glue hasn't dried for 7 days. What is the reason?
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- Time of issue:2018-12-28 00:00
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(Summary description)
The glass glue hits the glass, but the glue hasn't dried for 7 days. What is the reason?
(Summary description)
- Categories:Technology sharing
- Author:
- Origin:
- Time of issue:2018-12-28 00:00
- Views:
Typical problems and treatment methods of glass glue
1. What is the reason why the neutral transparent glue turns yellow?
Answer: The yellowing of the neutral transparent glue is caused by the defect of the glue itself, which is mainly caused by the crosslinking agent and the tackifier in the neutral glue. It is easy to cause yellowing, and many imported brand-name glass glues also turn yellow due to this. In addition, if the neutral transparent glue is used together with the acid glass glue, it may cause the neutral glue to turn yellow after curing; it may also be affected by the long storage time of the glue or the glue reacts with the substrate.
2. Why does the neutral porcelain white glue turn pink? Some glues turn back to porcelain white one week after curing?
Answer: Alcohol-based neutral glue may have this phenomenon, which is caused by the production of raw material titanium chromium compound. The titanium chromium compound itself is red, and the porcelain white color of the glue is the color of the titanium dioxide in the glue. But glue is organic, and most of the organic chemical reactions are reversible reactions, and there are side reactions. Temperature happens to be the key to causing these reactions. When the temperature is high, a positive reaction will cause the color to change, but after the temperature drops and stabilizes, the reaction proceeds in the reverse direction and restores to its original appearance. If the production technology and formula are well mastered, this phenomenon should be avoided.
3. Some domestic transparent glues will become porcelain-white color after five days of printing? The neutral green glue turns porcelain white color after construction, why?
Answer: This should also be a quality problem of the glue, which is a problem of raw material selection and verification. Because some domestic rubbers are added with plasticizers, which are easy to volatile; while some rubbers have more reinforcing fillers, when the plasticizers evaporate, the strips are stretched due to shrinkage, and the filler color appears (all the fillers of neutral rubbers) Itself is white). Various colored glues are added with pigments to make them into various colors. If there is a problem with the choice of pigments, the color of the glue will change after construction; or the color glue is too thin during construction, and the glue is inherently small in the curing process. The shrinkage will make the color of the glue lighter. In this case, it is recommended to maintain a certain thickness (above 3mm) when sizing.
4. Why is the glass glue applied on the back of the mirror, and after a period of time, mottling or glue marks appear on the mirror surface?
Answer: Mirrors on the market usually have three different back coatings: mercury, sterling silver and copper. Freckles appear on the mirror surface of common mirrors after applying glue for a period of time. In this case, the user has used acid glass glue, and acid glass glue usually reacts with the above materials, causing the mirror surface to see mottling. Therefore, we emphasize that neutral glue should be used, and neutral glue is divided into two types: alcohol type and ketoxime type. If the copper base mirror uses ketoxime neutral glue, the ketoxime will slightly corrode the copper material. After a period of construction, you can see the traces of corrosion on the back sizing part of the mirror. If you switch to alcohol type neutral glue This phenomenon will not occur. All of the above are improper selection of materials due to the diversity of substrates. Therefore, it is recommended that users do a compatibility test before using the glue to see if the glue is compatible with the material. Use appropriate glass glue products to avoid unnecessary losses.
5. Some glass glue has a granular shape of salt size when it is shot out, and some granular shapes will be automatically resolved after curing. Why?
Answer: This is a matter of choosing the raw material formula of the glue. Because the cross-linking agent contained in some glues will crystallize in a low temperature environment, the cross-linking agent will condense in the rubber bottle. After being punched out, you will see the granular shape of salt powder, but it slowly It will melt, so the granular shape will automatically decompose after solidification. This situation has little effect on the quality of the glue. This situation is mainly due to the relatively large impact of low temperature.
6. Some domestic glues have not dried on the glass for 7 days. What is the reason?
Answer: This situation mostly occurs in cold weather. 1. The glue is too thick and the glue is slow. 2. The construction environment is affected, and the weather is bad. 3. The glue is out of date or there is a problem. Fourth, the glue is too soft and does not feel dry.
7. What are the reasons for the bubbling sound of some domestic glass glues when sizing?
Answer: There may be three reasons: 1. The technique was not enough during the dispensing process, and air was mixed in the plastic bottle; 2. A few black-hearted manufacturers deliberately did not press the bottom cap of the bottle, leaving air in the bottle but giving people enough glue to fill the bottle. Feeling; 3. Because some domestic glues are not 100% silicone glue, the added filler will react slightly with the PE soft glue of the glass plastic packaging bottle, which will cause the plastic bottle to swell and increase, and it will remain in the space. The air infiltrates the mortar to create voids, and bubbles will be heard when sizing. An effective way to overcome this phenomenon is to change to hard bottle packaging and pay attention to the product storage environment (in a cool place below 30°C).
8. Why do some neutral glues appear in the joints of concrete and metal window frames in the summer when they solidify, but some will not? Is it a quality issue? Why hasn't a similar phenomenon appeared before?
Answer: Many brands of neutral glue have similar phenomena, and it is confirmed by careful inspection and repeated experiments that it is not a quality problem of the glue. Because the neutral glue has two kinds of alcohol type and ketoxime type, and the methanol contained in the alcohol type glue will release gas during the curing process (methanol starts to volatilize at about 50 ℃), especially when it is exposed to direct sunlight or high temperature, the reaction is more intense . In addition, concrete and metal window frames are difficult to breathe. In addition, the temperature and humidity are higher in summer, and the curing will be faster. The gas released by the glue can only escape from the uncured adhesive layer and on the cured adhesive strip. Bubbles of varying sizes will appear. The ketoxime neutral glue will not release gas during the curing process, and will not produce bubbles. However, the disadvantage of the ketoxime neutral glue is that once the technology and formula are not handled well, there will be a chance of shrinkage and cracking in the winter during the curing process when it is cold. If the technology is good, the formula will not have this phenomenon. Of course, the price of the ketoxime type neutral rubber is slightly more expensive than that of the alcohol type.
Similar phenomena did not occur in the past because in the past, construction units used very few silicone glues in such places, and they generally used acrylic waterproof sealing materials. Therefore, the phenomenon of foaming of silicone neutral glue is not very common; in recent years In recent years, silicone sealants have been widely used, which greatly improved the quality of the project. However, due to the lack of understanding of the material properties, improper selection of materials caused the sealant to bubble.
To solve such problems, the following points should be paid attention to: 1. The most prudent way is to do a partial use test first to observe whether it meets the needs of use (generally, the reaction can be seen two or three days after sizing); 2. To distinguish the use time And the type of substrate, choose the appropriate neutral glue to use: choose ketoxime type in summer and alcohol type in winter; 3. Keep the construction surface clean and dry; 4. Avoid high temperature periods (above 35°C) when sizing in summer. Direct sunlight is generally appropriate in the evening; 5. Similar projects can be tracked by the manufacturer’s technicians.
9. How to do compatibility test?
Answer: Strictly speaking, the compatibility test between the adhesive and the building base material should be carried out in the building material testing department recognized by the state. However, due to well-known reasons, the period for the results of the inspection in these departments is longer. costly. Of course, if there is such a necessary project, the inspection qualification report of a national authoritative inspection agency must be sufficient to determine whether to use a certain building material product, and a general project can provide the base material to the glass glue manufacturer for compatibility testing. The test results can be obtained in about 45 days for structural glue and 35 days for neutral glue and acid glue. The simplest and quickest way is that the user can test the glass glue on a small amount of substrates. After it is completely cured, observe the surface effect and test its peel strength by hand, so as to simply determine whether the glass glue product's adhesion, tension, etc. Meet the needs of use.
10. Why does the acid glue fall off easily when used on cement?
Answer: This is actually one of the most basic problems in the application of glass glue. Acid glue produces acetic acid when it is solidified, which will react with the surface of alkaline materials such as cement, marble, granite, etc. to form a chalky substance, which causes it to fall off.