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There are particles, lumps and chalking phenomenon of B component
Possible reasons
The curing agent in the B component is not used in time after opening the barrel, and contacted the moisture in the air to produce the phenomenon of hydrolysis, forming particles or lumps.
Solution
1. Component B should be sealed and stored, not exposed to air for a long time, and should be stirred evenly before use.
2. If component B is not used up, it must be covered with the original lid and pressed tightly and sealed tightly at the joints between the lid and the barrel with sealant tape, and if there are lumps on the surface when it is used again, it must be cleaned up before it is used.
Separation and delamination of component B
Possible reasons
Component B is mainly composed of curing agent, coupling agent, filler and other physical co-mingling, after a long period of time or transportation bumps, it is easy to segregation, delamination phenomenon.
Solution
Before use, please stir along the same direction, or for the use of the unopened sealed B-component barrel side on the ground, rolling back and forth a few times to make it mix evenly before use, the advantage of rolling is that it will not produce and bring in mechanical impurities.
Glue machine pressure plate pressure does not go down
Possible reasons
1. Mismatch between the drum and the size of the press disk of the gluing machine.
2. The diameter of the seal ring is small or the seal ring is aging and losing elasticity.
Solution
1. Select the barrel that matches with the gluing machine platen or trim the platen size.
2. Replace the sealing ring with a larger diameter or add some liner inside the original sealing ring to increase the diameter of the sealing ring.
Gluing process appears “flower glue”
Possible reasons
1. Glue machine B component pipe blockage.
2. The static mixer has not been cleaned for a long time, resulting in cured sealant blocked part of the path of the mixer, so that A, B components can not be fully mixed.
3. Different manufacturers of different product performance, equipment process parameters are set differently.
Solution
1. Clean the B component pipeline.
2. Clean the static mixer regularly.
3. Adjust the equipment process parameters to the best.
4. If necessary, replace the mixing rod can be solved.
Pull-off time is too long or too short
Possible reasons
1. The pull-off time is too long, probably because of the ambient temperature is low or the proportion of B component is low.
2. Pull off time is too short, may be because the ambient temperature is high or the proportion of B component is too high.
3. Fluctuations in the quality of the sealant itself will also lead to fluctuations in the pull-off time.
Solution
Increasing or decreasing the proportion of component B can speed up or slow down the pull-off time, but it should be adjusted within the range of the recommended mixing ratio, otherwise, it may result in the sealant not being able to achieve the expected performance, or even become brittle, slow deep curing, and reduced strength.
After gluing, the phenomenon of one section curing and one section not curing occurs
Possible reasons
Glueing machine B component pipe clogging, resulting in B component supply more or less caused by the above phenomenon.
Solution
1. Clean the B-component pipe.
2. Adjust the equipment process parameters to the best.
Slow curing speed
Possible reasons
1. low temperature.
2. Low humidity.
3. B component is low.
4. Silicone sealant expired.
Solution
1. Increase the maintenance temperature.
2. Increase the maintenance humidity.
3. Gluing twice or double-sided gluing.
4. Increase the proportion of B component.
5. Replace the sealant and other ways to solve.
Sealant surface curing, the gel surface smooth, black color, internal not curing or curing slow
Possible reasons
The amount of B component is far beyond the range of recommended mixing ratio.
Solution
B component is used within the recommended mixing ratio.
Poor bonding with the substrate
Possible reasons
1. Failure to conduct bonding performance test before construction.
2. Failure to clean in accordance with the method recommended by the bonding performance test results;
3. Not applying primer solution in accordance with the method recommended by the bonding performance test results.
4. The curing time is too short.
5. Low curing temperature.
6. The substrate used in the actual works is not the same as the substrate for which the bonding test was conducted.
7. Difference between batches of base material used in the actual project.
8. There are differences between batches of silicone sealant products.
Solution
1. Before the construction of the actual use of the substrate bonding test to determine whether the need to clean the substrate, and apply primer;
2. Clean the substrate or replace it with a suitable cleaning agent;
3. Applying primer solution or replacing primer solution;
4. Increasing the curing temperature;
5. Extend the maintenance time;
6. When the above measures still can not be solved, the substrate should be special surface treatment or replacement of special sealant.
7. Dense bubbles inside the gel and interface
Possible reasons
1. There is gas into the A, B components of the material tube, through the two-component gluing machine gun head inside the static mixer is dispersed into tiny bubbles, the curing process, bubbles due to the role of surface tension to the interface (the surface of the colloid, the colloid and the interface with the substrate) migrate, and ultimately manifested in the curing of the glue surface and the interface between the glue and the substrate with a dense small bubbles.
2. A component is wrapped into the gas in the process of dispensing.
3. Glue the process of improper operation into the (change the barrel exhaust is not clean or a barrel of material pressure plate pressure to the bottom of the barrel when the time to change the barrel, resulting in air inhalation).A, B components of the internal wrapped in gas bubbles caused by a group of sealant generally occurs in the middle of the process of the use of the sealant; and improper operation of the barrel resulting in air bubbles generally occurs in the group of sealant has just begun to use or about to be used up.
4. There is only one glue machine, structural sealant and hollow sealant back and forth to change, half a barrel is not used up to change the barrel by the air pressure when the pressure plate brought in, and then used again when the glue curing in the glue surface has a dense small bubbles. This situation is often mistakenly thought to be wrapped with gas inside the glue.
Solution
1. Check the glue machine A, B components of the pipeline on the connecting parts and valves whether there is a gas leak, timely replacement.
2. Change a group of rubber.
3. Train the operator to use the equipment correctly and skillfully.
4. Use two gluing machines to separate the structural glue from the hollow glue. If there is only one glue machine, you can only wait until one kind of glue is used up and then change the bucket.
Separate air bubbles inside the gel
Possible reasons
1. Air wrapped in during glue injection.
2. Wet interface or accessory material, moisture invades the glue seam.
3. Improper selection of foam stick.
4. The surface of the foam rod is punctured during the filling process and deflated from the broken hole after being squeezed; some base materials react with the sealant.
Solution
1. The injection of glue should be uniform, continuous and filled with the interface.
2. The interface and accessory materials must be dry.
3. Choose the right size of foam rod and can not use spatulas, screwdrivers and other sharp tools to fill the foam rod.
Remarks: Some base materials, such as concrete, cement, etc., are prone to chemical reaction with sealant, resulting in bubbles, non-bonding, non-curing and other phenomena inside the sealant. Bonding test before construction can avoid such bubbles.
Cured sealant surface crust
Possible reasons
1. Repeatedly trimming the glue joints.
2. Exposure to air for too long after glue application, beyond the sealant trimming time, resulting in trimming the surface of the silicone sealant has begun to cure, the formation of crust.
3. The remaining recycled sealant after trimming the sealant seam is filled into the sealant seam again and used is also prone to surface crusting phenomenon.
Solution
1. Shorten the interval between the gluing operation and the trimming operation, and trim the glue as soon as possible to avoid the crusting phenomenon.
2. Avoid gluing operation in high temperature or dry and windy environment.
Structural sealant seam cracking, water leakage
Possible reasons
1. Unreasonable design of glue joints, such as glue joints are too narrow, resulting in difficulties in applying glue and sealing is not in place.
2. Sealant displacement capacity cannot meet the demand of joint deformation.
3. Excessive deviation of the installation size of the slab.
4. Sealant pre-curing process, the joint deformation is too large.
5. Three-sided bonding, resulting in sealant displacement capacity is limited.
6. The thickness of sizing does not meet the specification requirements, such as sizing is too thin, resulting in the use of the process of breakage or bond damage.
7. Sealant filled with mineral oil is used.
Solution
1. Design the glue joints according to the specification requirements.
2. Select the displacement capacity and design to match the sealant.
3. Strictly in accordance with the operating procedures for construction, to ensure that the thickness of the sealant.
4. Avoid three-sided bonding, etc.
5. Select sealant with low heat loss.
Insulating glass oil flow
Possible reasons
Insulating glass two sealant or neighboring sealant, door and window sealant filled with mineral oil. With the use of time, mineral oil gradually diffuse from the sealant, penetrate into the insulating glass a sealant, so that it dissolves, manifested as butyl rubber overflow, hollow, flow, resulting in insulating glass sealing failure, water leakage, leakage, fogging, rainbow and other phenomena.
Solution
Select sealant products that do not contain mineral oil or conduct compatibility tests with butyl sealant before use.
