Do you know the phenomenon of "drumming"?

The seams between the curtain wall plates are usually filled with silicone weather -resistant sealing gels to play a role in waterproof and beautiful. However, in the construction sealing, the situation of the seam density sealing "drums" "often encounters aesthetics, which affects the aesthetics. These two phenomena are similar and different. Different treatment measures should be used.

1. The characteristics, reasons and improvement measures of the phenomenon of "drumming"

A. Characteristic

① The phenomenon of "drums" mainly appears in the aluminum -sheet curtain wall and a small number of large sections of glass curtain walls, manifested in the seam densely sealed glue, partially bulging, partially bulging, or twisted glue surface (fold) state, and part of the roll up is solid.

② The phenomenon of "drums" mostly appears in spring (3/4/ May) with large temperature differences and autumn (September 10/November), and the time of different regions will be different.

③ The larger the sector, the narrower the gel sewing, the more serious the drums are;

④ Generally, the yang surface is more serious than the shade.

⑤ Flat seams are more serious than right -angle seams.

B. Reason

① The phenomenon of "drumming" is mainly caused by environmental factors, and the quality of non -sealing glue. In the Spring and Autumn Period, the average temperature is low (the northern humidity is also low), the sealing glue is slow, and the temperature difference is large. The curtain wall plate is swollen and contracted with the temperature and the seams are displaced. In the middle, a bulge or fold.

② Because the thermal expansion coefficient of aluminum plate is much larger than stone and glass, the phenomenon of "drums" mostly appears in the aluminum board curtain wall seam.

Material                     Thermal expansion coefficient mm/(mm · ℃) × 10-6

Aluminum plate        23.8

Glass                          8

Stone                         5

③ Calculation formula according to the linear expansion of the object: displacement generated by thermal expansion and contraction = aluminum plate length × aluminum thermal expansion coefficient × temperature difference. It can be seen that the larger the sector, the larger the temperature difference, the greater the deformation generated by the seams, and the more serious the phenomenon of "drumming".

④ When the depth of the sewing is not enough, the foam stick after the glue bounces the collagen.

⑤ If you encounter heavy winds after gum, the seams will also cause deformation and cause colloid distortion.

C. Improvements

① Construction in a season with large temperature differences, choose fast -drying type (the temperature is above 25 ° C, not recommended to choose, the surface is too fast to scratch gum), or the use of thickened products can be used to improve the drums to a certain extent.

② Select construction of consecutive clouds, and shading measures should be taken when the conditions permit.

③ Small the gel time in different parts. After the temperature rises in the afternoon, the construction of the yang seams is relatively small. At this time, the seams are relatively small; after the temperature drops in the morning or afternoon, the shade seam gap is constructed.

④ Select the foam stick with the appropriate size according to the width of the gap to avoid loosening.

⑤ Adopting the "two -way glue" method, the first latch is applied to about 5mm first. After the dense sealing is completely solidified, the second latch of the construct will be built to flatten the surface. It should be noted that the second latch must wipe the surface of the glue clean.

The above are improved measures for "drums". In the seasons with large temperature differences, the drum problem cannot be completely solved. Although the phenomenon of "drumming" affects the beauty, it will not crack and leak. It can be performed on the spot to confirm whether the bondability is qualified.

In addition, because the surface temperature difference between the aluminum plate in some areas is large, it can reach more than 60 ° C, and the seam displacement should be large. Pay attention to the selection of the appropriate level of sealing to avoid cracking due to insufficient sealing displacement capacity.