Glue knowledge

Typical problems and treatment methods of glass glue


1. What is the reason for the yellowing of neutral transparent adhesive?

Answer: neutral transparent glue yellowing is the glue itself has defects, mainly caused by the crosslinking agent and viscose agent in the neutral glue, the reason is that these two raw materials with "amine group", amine group is very easy to cause yellowing, many imported famous brand glass glue is therefore yellowing phenomenon. In addition, if the neutral transparent adhesive and acid glass adhesive are used at the same time, it may cause the neutral adhesive to turn yellow after curing; It may also be caused by the long storage time of the glue or the reaction between the glue and the substrate.

2. Why does neutral porcelain white glue turn pink? After some glue is solidified, a week turns back to porcelain white again?

Answer: alcohol-based neutral glue may have this phenomenon, which is caused by the production of raw materials titanium chromium compound. Titanium chrome compound itself is red, and the glue of porcelain white color is titanium dioxide in the glue in the role of color. But glue is organic matter, and organic chemical reaction is overwhelmingly reversible reaction, there are side reactions. Temperature is exactly the key to causing these reactions. When the temperature is high, there is a forward reaction that changes the color, but when the temperature cools down and stabilizes, the reaction goes back to the original shape. Production technology and formula grasp well, should be able to avoid this phenomenon.

3, some domestic transparent glue, five days after playing out porcelain white color? Neutral green glue after the construction of porcelain white color, why?

Answer: this also should be the quality problem of glue, belong to the problem of raw material selection and verification. Because some domestic glue add plasticizer, volatile; And some glue with more reinforcing filler, when the plasticizer volatilizes, the rubber strip is stretched due to shrinkage, packing color (neutral glue all the filler itself is white). All kinds of color glue is to add pigment to make it into a variety of color, if there are problems in the choice of pigment, glue color will change after construction; Or the color glue is too thin during construction, and the inherent small amount of shrinkage in the curing process will make the color of the glue light. In this case, it is recommended to maintain a certain thickness (more than 3mm) when sizing.

4, why the mirror on the back of the glass glue, after a period of time, the mirror appeared spots or traces of glue?

A: Mirrors on the market usually have three different back coatings: mercury, sterling silver and copper. Common mirror sizing after a period of time, the mirror appears speckled, this situation should be the user used acid glass glue, and acid glass glue usually reacts with the above material, causing the mirror to see speckled. Therefore, we emphasize that neutral adhesive should be selected, and neutral adhesive is divided into alcohol and ketoxime type two. If the copper mirror uses ketoxime-type neutral adhesive, the ketoxime will have slight corrosion on the copper material. After construction for a period of time, the mirror can see the traces of corrosion at the sizing place behind the mirror. If the alcohol neutral adhesive is used, this phenomenon will not occur. The above is due to the diversity of the substrate caused by improper material selection. Therefore, it is recommended that users do a compatibility test before using the glue to see whether the glue is soluble with the material. Select appropriate glass glue products to avoid unnecessary losses.

5, some glass glue when the size of the grain of salt, and some of the particles will automatically resolve after curing, why?

Answer: this is the problem of selecting the raw material formula of glue. Because some glue contains some crosslinking agent, there is crystallization phenomenon in the low temperature environment, crosslinking agent in the glue bottle condensation, hit out after will see the size of salt powder particles, but it will slowly melt, so the solidified particles will automatically resolve. This situation has little effect on the quality of the glue. This situation is mainly affected by low temperature.

6, some domestic glue on the glass, 7 days still not dry glue, what is the reason?

A: This happens most often in cold weather. First, glue is too thick, dry glue is slow. Two, the construction environment impact, bad weather. Three, the glue expired or have a problem. Four, the glue is soft, feel dry.

7, some domestic glass glue in sizing bubble sound, what is the reason?

Answer: there may be three reasons: first, the technology of packing is not up to standard, and air is mixed into the plastic bottle; Two, a small number of black manufacturers deliberately do not press the bottom cover of the bottle, the bottle has air, but give a person with enough glue feeling; Three, some domestic rubber because it is not a hundred percent silicone rubber, which will increase the filling material and glass plastic packaging bottle PE soft adhesive slight chemical reaction, so that the bottle has the phenomenon of swelling, the air retained in the space into the glue slurry to produce a gap, in sizing will play bubble sound. The effective method to overcome this phenomenon is: change to hard bottle packaging, pay attention to the product storage environment (30℃ below the shade).

8. Why do some neutral glue appear many bubbles after curing in the combination of concrete and metal window frames in summer, and some do not? Is it a quality problem? Why hasn't this happened before?

Answer: many brands of neutral glue have had similar phenomenon, after careful testing and repeated experiments confirmed that it is not a quality problem of glue. Because the neutral adhesive has alcohols and ketoxime type two, and alcohols glue in the curing process of methanol will release gas (methanol at 50℃ left and right began to volatilize), especially in direct sunlight or high temperature reaction is more intense. In addition, concrete and metal window frames are difficult to breathe. In addition, the summer temperature and humidity are high, and the curing will be faster. The gas released by the glue can only run out of the adhesive layer that has never been completely cured, and bubbles of different sizes will appear on the cured adhesive strip. And ketoxime type neutral adhesive in the curing process will not release gas, will not produce bubbles. But the disadvantage of ketoxime type neutral adhesive is that once the technology and formula are not handled well, the cold in the curing process in winter will have the opportunity to appear shrinkage cracking phenomenon. The technology is good, and the formula will not have this phenomenon. Of course, the ketoxime type of neutral adhesive is slightly more expensive than alcohol.

In the past, there was no similar phenomenon because in the past, the building construction unit in this place with very little silicone glue, generally often use propylene waterproof sealing material, so the phenomenon of silicone neutral glue foaming is not very common; In recent years, silicone sealant has been widely used, which greatly improves the quality of the project, but because of the lack of understanding of the material characteristics, the improper selection of sealant foaming phenomenon.

To solve such problems, the following points should be noted: first, the most prudent approach is to do local use test to observe whether it meets the use needs (two or three days after the general sizing can see the reaction); Two, distinguish the use of time and substrate type, choose the appropriate neutral adhesive use: summer choose ketoxime type, winter choose alcohol type; Three, keep the construction surface clean and dry; Four, summer sizing should avoid high temperature period (above 35℃) and direct sunlight, generally in the evening is more appropriate; Five, similar projects can be known to the manufacturer's technical personnel tracking.

9. How to do the compatibility test?

Answer: speak from strict sense, the compatibility test between making adhesive and building base material should admit to the country building material test department is carried out, but because of well-known reason, the cycle that sends check to get a result in these departments is longer, cost is high. Has the necessary engineering of course must be enough the national authoritative testing institutions inspection report to determine whether or not to use some building materials products, and general engineering base material can be provided to the glass glue manufacturer do compatibility test, structural adhesive, 45 days neutral glue, acid gel 35 days or so can be concluded that the test result. The simplest and quickest way is that the user can try the glass glue on a small amount of substrate, to observe the surface effect after complete curing and try its peel strength by hand, in order to simply determine whether the adhesive force and tension of the glass glue product meet the use needs.

10, acid glue used in cement why is it easy to fall off?

Answer: This is actually one of the most basic problems in the application of glass glue. Acid glue in the curing of acetic acid, will react with cement, marble, granite and other alkaline materials on the surface, forming a chalky substance, resulting in shedding.

11. What is the reason for the wrinkling of the surface of the neutral adhesive after curing?

Answer: there are several reasons generally: (1) the expansion coefficient of the substrate is larger; (2) There is displacement or vibration; (three) some domestic glue itself is too thin, the filling material in the glue is less and more plasticizer (white oil), the plasticizer (white oil) in the curing process has a certain degree of volatilization makes the volume of the glue smaller, so the glue will shrink and wrinkle; (4) If the sizing is too thin after curing, it is easy to shrink and wrinkle, and the thickness of the thickening sizing can reduce the occurrence of this phenomenon (it is recommended that the sizing is more than 2mm).

12. What is the reason for oil seepage?

Answer: Generally appear the glue of seepage oil phenomenon is not good quality glue, because it is not a hundred percent silicone glass glue, it increases the petroleum plasticizer in which, and the plasticizer itself is a kind of oily substance, with swelling, destroy the balance between the plasticizer and other components, oil will ooze out. In this case, it is best to choose good quality 100% silicone glass glue.

13, what is the cause of the phenomenon of neutral glue ptosis?

Answer: mainly the thixotropy of glue is not good, droop is not qualified, feeling glue is too thin.

14, acid glue in what circumstances can not be used normally?

A: All materials that exude grease, plasticizer or solvent; A place with no ventilation; Frosted or wet surfaces; Assembly of metal and coated glass; Contact with marble, granite, concrete and other alkaline materials and so on are not suitable for use. Acid silicone glass adhesive will corrodes or fail to bond copper, brass (and other copper containing alloys), magnesium, zinc, electroplated metals (and other zinc containing alloys), and it is recommended not to use acid silicone glass adhesive on brick and stone materials and iron carbide matrix. In the methyl isobutenate (PLEXIGLAS), polycarbonate, polypropylene, polyethylene and TEFLON (TEFLON, ptfe) materials to use this product will not get good bonding effect and good compatibility. Move more than 25% of the joint width of the connection is not suitable for the use of acid glass glue, in the structure of glass is also best not to use ordinary acid glass glue, in addition, there is abrasion and will produce substantial disadvantages should not use acid glass glue. In addition, the temperature is too high or too low, humidity is too large or too small will affect the drying glue speed.

15, why the same grade of glue, mixed color glue will be more granular than transparent glue?

Answer: This phenomenon generally occurs in the domestic glue, because the mixed color glue than transparent glue to add more pigment, more than a process is more than a granular possibility, mixing if not uniform, there will be granular.

16. What is the reason for the powder on the surface of the neutral glue after it is dry?

Answer: There are several general situations: (1), the rubber strip has the phenomenon of powder is the raw material selection of the glue itself has defects; (2) Uneven mixing of raw materials; (three), may be due to the influence of the construction environment, more dust is easy to adsorb on the surface of the glue and this situation occurs.

What is the reason why the glass glue in the bathroom or kitchen becomes yellow, moldy and black?

Answer: bathroom, kitchen and other places are often damp, dark, glass glue will be moldy and yellow, black, so including bath, bathtub, shower in the bathroom mirror and visible objects such as pipe sealing, bonding, caulking should choose neuter mouldproof glue, because mouldproof glue added mould inhibitor, antiseptic, inhibit the growth of bacteria.

18, there have been soft particles, hard blocks, black spots of glass glue is what reason?

Answer: These three kinds of situations appear separately also have, appear together also have, all because of in the production or the processing in the process of packaging is improper, have solidified glass glue block or sundry mix and cause. Soft particles, hard block is due to the surface dry fast part of the surface crust and mixed with glue caused; It may also be caused by scraping glue on the bottom and face of the bucket when it is divided into different containers. Black spots are caused by unclean raw materials.

19, why some imported high-grade silicone acid glue and part of the aluminum plastic plate, stainless steel, aluminum alloy bonding effect is not good, but the domestic glue is very firm?

Answer: because the structure system of both is different. High grade silicone acid gel generally is hundred silicone glass glue, its material quality, lack of invasive, and part of the intermiscibility of aluminum-plastic plate, stainless steel, aluminum alloy is bad, and the curing speed is faster, and aluminum-plastic plate, stainless steel, aluminum alloy surface is very smooth, glue hasn't fully penetrate into the surface of the aluminum, stainless steel, aluminum alloy has been finished curing, So it doesn't stick. The curing speed of domestic glue is slightly slower, the penetration time is longer, and the addition of plasticizer and other materials, so that its properties are softer, so the domestic acid glue and the above materials are easy to dissolve, so the stick is stronger. So the better the glue may be mixed with some aluminum plastic plates, stainless steel, aluminum alloy is not necessarily good, but the domestic glue will be better. These are caused by the diversity of the substrate material. Therefore, we repeatedly stress that users should test themselves before using the material to see whether it meets the needs of use.

20, why the same bottle of glue or the same batch of glue will appear thin thick different phenomenon?

Answer: This phenomenon is often in the poor quality of the glue, because the glue slurry mixing is not uniform, the glue contains filler, filler will see a vacancy will drill down, so there will be a thin thick phenomenon. This phenomenon can be avoided if the production technology and formula are well mastered. The same bottle of glue appear thin thick often may be due to glue and bottle reaction, or glue has expired.

The acid glue is played on the stainless steel door, and after a few minutes, sometimes the surface will bubble. Why is there this phenomenon?

Answer: the compatibility of acid glue and stainless steel is not good, and it is generally not recommended to use acid glue on stainless steel. The reason for foaming is mainly the quality of stainless steel, some stainless steel manufacturers in order to reduce the cost, so that stainless steel more impurities, and the PH value of acid glue is low, acid is strong, acid substances will react with this stainless steel, so the release of bubbles.

22. Why is the effect of neutral adhesive bonding some aluminum plastic plates and plastic steel doors and Windows not good or sticky?

Answer: This phenomenon generally occurs in alcohol-type neutral adhesive, because the materials on aluminum plastic plates and plastic steel doors and Windows are not soluble with alcohol-type silicone adhesive, which affects the bonding quality. In this case, it is recommended that users choose ketoxime-type neutral adhesive, which will greatly reduce the occurrence of this situation; If users choose alcohol-based neutral glue, should first wipe the surface of the substrate with acetone or xylene, the substrate surface is completely dry after sizing; After scrubbing the substrate should be applied within one hour. Therefore, we repeatedly emphasize that due to the diversity of the base material, the user should test the compatibility between the glass glue and the base material according to their own needs before using to observe whether it meets the use needs.

23. What is the reason why the two ends of the silicone rubber of flexible packaging dry glue and the length of the dry glue increases with the increase of time?

Answer: flexible packaging glue two dry glue is mainly in the summer. It is hot in summer, and the aluminum foil layer of the packaging film breaks under the action of external force and internal pressure for a long time, resulting in the water and air in the air into the sealant through the packaging film, and the sealant will react with water and air to lead to the curing of the sealant. If the nail is not strong, it may also cause moisture through the nail seal is not strict place into the sealant, resulting in dry glue at both ends. 【 the 】