Xinhe Gel Industry

      Determine the minimum width of the glue seam is calculated as follows. In general, the elastic caulking sealant width can not be less than 6mm, is not greater than 30mm, too difficult to glue seam adhesive surface finishing. Sizing thickness can not be less than 6mm, and generally half the width (eg: 12mm wide take 6mm deep), however, usually do not need glue thickness greater than 10mm (25mm wide, such as glue seam thickness sizing take 10mm deep, is enough to meet the requirements) . Sizing sealant width control the maximum displacement capacity of the sealant can provide, but will not produce sealant fracture. The wider the seam, the greater the required displacement capacity. Therefore, we must calculate the total displacement of the seam and then to determine the optimal sizing of the seam width. Heat generated by the displacement change easy to calculate; but it shall be calculated in the other forms of displacement deformation, requires two calculations calculate the minimum seam dimensions. First calculate the possible displacement of the deformation, and then derive the joint width.

      Joint displacement calculation

      Calculation of deformation of the substrate may have the following formula:

      M = (MT-T) × S × L

      Wherein: M represents a substrate deformation mm.

      MT represents the base may reach a maximum temperature ℃, including temperature rise caused by the radiation and temperature changes increased. As the temperature 40 ℃, black aluminum surface temperature may reach 80 ℃ or more. T represents the substrate surface may reach a minimum temperature ℃, including the temperature change caused by the wind. S represents the thermal expansion coefficient of the substrate, extruded material typical coefficient table. L represents the length of the substrate m.

Joint displacement has two daily cycle and the temperature difference between summer and winter cycle, day and night temperature changes produce changes in circulation generated.

       Sealants can claim after years of displacement can still meet these cyclic changes without losing its elasticity, and requires the ability to meet these displacement, as required to meet the possible maximum and minimum displacement, calculate the required sealant actual joint dimensions.

       Joint width

       After calculating the possible displacement of the deformation of the substrate, it can calculate the minimum joint size is calculated as follows:

       W = (100 × M) / S

       Wherein: W represents the minimum joint width mm.

       M represents the maximum possible displacement of the seam.

       S represents allow sealant displacement deformation, expressed as a percentage, provided by the product specification.

       According to a variant can be expected to calculate the maximum range of the substrate possible displacement seams, if the substrate expansion joints will be smaller, glue joints will be compressed; if the base shrink, glue joints will become large. Displacement deformation around the joints may tend to be different, such as at the bottom of the bottom will not be moved mechanically fixed vertical plates, then it will result in thermal deformation of the substrate to produce deformation in the direction. The substrates for in the bottom by the support, so that all the Y-axis directions are deformation will have an impact in the horizontal direction. Although the X-axis direction displacement deformation 50-50, but the deformation displacement between the substrate A and B up to ##, fixed between B and the wall, only 50% of the horizontal movement, it will be with the wall deformation displacement in a horizontal direction. When each module is not the same need to consider the imposition size patchwork they will produce different displacement deformation; such as different sides of patchwork material, such as glass and aluminum curtain wall, you need to calculate their effect on the displacement of the deformation joints produced; each different deformation results in displacement of the entire joint deformation. Displacement deformation there may be other reasons, increases floor will form a suspension tilting plate when mounting a fixed or mobile device in a building or structure. Porous materials such as concrete and masonry with different moisture due to swelling and shrinking. All these changes affect the deformation of the seam should be considered. Under normal circumstances should also consider the different construction time would produce a certain bias. Construction of thermal expansion of the substrate during the summer, joints become smaller, the sealant was extended working life; in the winter glue seam widens plastic working life will be shortened. Only the above formula to calculate the minimum glue seam width, using the sealant and the substrate will also affect the performance of the actual joint width. We require a width of not less than 6mm. There is also a maximum joint width. Expandable sealant, glue and curing time of the sealant has a limit. For silicone rubber, the biggest joint width 40 ~ 50mm.

Weather sealed

       Typically, the depth of the glue seam is half the width. If the depth is too large, joint deformation increases, the surface prone to displacement when sealant irregularities, leading to excessive pressure deformation caused by adhesion failure. If the glue seam depth is too small, too few glue, or the light of the stress concentration caused by the formation of bubbles cracking, and even lead to adhesion failure. Solvent-based sealant (such as butyl rubber) is also due to plasticizer loss caused by shrinkage cracking, therefore, weathering plastic depth of not more than 12mm, width of not less than 6mm.