Different temperatures, construction building sealants should pay attention to what?

With the changing temperature, the construction of building sealant will change differently. In order to let everyone use good glue, to introduce you to different environments, building sealant what changes, what needs to be noted?
, extrusion decreases (thickening
as the temperature decreases, the sealant will gradually thicken and the flow will become smaller. For two-component sealants, thickening increases the pressure on the puncher

. For single-component sealants, the pressure of the glue gun extruding sealant increases, and manual operation may find time-and-effort.
solution: if there is no effect on the construction efficiency, low temperature thickening is a normal phenomenon, no improvement measures are required. If the construction efficiency has an impact, indoor construction can consider increasing the use of sealant temperature or the use of some auxiliary heating measures, such as sealant storage in the warm room or air-conditioning room, adhesive workshop installation heating heating, improve the adhesive ambient temperature. If it is outdoor construction, you can choose suitable adhesive tools, such as high thrust manual glue gun or pneumatic glue gun, electric glue gun and so on.
, slow curing
the most direct problem brought to the sealant by the sudden drop in ambient temperature is the slow curing sensation during the application process. Sealant curing process is a chemical reaction process, and ambient temperature has a great influence on its curing speed. For two-component sealants, the higher the temperature, the faster the curing, the lower the temperature, the slower the curing, for the single-component sealant, the higher the temperature, humidity, the faster the curing speed. After autumn, the temperature drops sharply, accompanied by low humidity, and the curing reaction of the sealant is affected.
, when the temperature is below 15 degrees C, the phenomenon of slowing the curing of sealant is more obvious. Especially for single-component sealants, the time to fully cure at low temperatures is much longer.
solution: If the user to work in a low temperature environment, it is recommended to test before use, confirm that the sealant can be normal curing, curing time is acceptable, so as not to affect the curing speed of the duration.
, non-bonding
with the temperature decrease, with slow curing accompanied by, there is sealant and substrate bonding problems. Please note the process of using sealants, which generally defines the construction temperature range. Beyond the minimum temperature requirements of the product, the bonding speed will be significantly slower and the time for full bonding with the substrate will be significantly longer. At the same time, when the temperature is too low, the wetting of the surface of the glue and substrate is reduced, and there may be imperceptible fog or frost on the surface of the substrate, which can affect the bonding between the sealant and the substrate.
solution: When the temperature is lower than the minimum construction temperature of the sealant, the sealant and substrate in the actual construction environment to do bonding test, confirm that the bonding is good before construction. Factory construction can also speed up the curing of sealants by increasing the temperature and humidity of the environment in which the sealants are used, while also requiring appropriate extension of maintenance time.
, the appearance of uneven (weather-resistant sealant drum)
autumn and winter low temperature, often the temperature difference between day and night is also large. In the aluminum screen wall application, weather-resistant sealant easy to appear drum phenomenon, the main reason is that in low-temperature environment, weather-resistant sealant curing speed is slow, its surface curing enough depth will take a long time, in the weather-resistant sealant surface has not cured enough depth, if the width and narrow change of the seam (which is usually due to the panel's hot expansion cold shrink) is larger, the surface of the seam will be affected, uneven phenomenon, we become "drum".
These uneven surface of the glue seam in the final curing, its interior is solid, not hollow, will not affect the long-term sealing performance of weather-resistant sealant, only on the appearance of the smoothness of the glue seam has an impact.
Solution: At low temperatures, especially under extreme application conditions with large temperature differences and low humidity, the drumming phenomenon is difficult to avoid, if there is still a drum phenomenon, we recommend the following one or several ways to carry out construction:
★ choose the right time to glue, can improve the drumming phenomenon (panel after the sun after construction).
note: Do not in the plate surface temperature is low glue construction, glue after a short period of time by the sun exposure, plate by thermal expansion squeeze glue seams, glue seams are easy to produce drums.
Most of China's sun exposure point, 7 to 12 o'clock in the east, 9 to 15 o'clock in the south, 12 to 18 o'clock in the west, the east, west, south three facades can be based on the sun exposure point, reasonable arrangement of construction time; If the next day is cloudy, the day to seize the time of construction, because cloudy day and night temperature difference is small, small deformation of the glue seams, not easy to occur drum phenomenon.
★ use appropriate shade measures, such as dust net and other scaffolding, so that the panel is not directly exposed to the sun exposure, reduce the temperature of the panel, reduce the temperature difference caused by seam deformation.
★ If the above two methods can not solve the drum situation, you can use the method of secondary gel (i.e., first hit a recessed glue seam, until it is cured for 2 to 3 days, elastic, and then a layer of glue on its surface). This method is for the human eye easy to see the drum glue seam, the appearance of the smoothing, such as the human eye is not easy to observe the drum glue seam, can not be repaired. It is not recommended to re-glue the drum glue after sewing it.
temperature drop, to sealant construction inconvenience, through the above-mentioned sharing, hope to bring help to construction personnel, pay attention to the possible impact of the construction environment, pay attention to good construction details, to ensure good construction quality.
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