Problems and Solutions in the Use of Butyl Sealant

Butyl sealant is the first sealant for insulating glass, which directly determines the quality and service life of insulating glass. Today, Truemei will give you a popularization of the problems that often occur in the process of applying sealant and the corresponding measures to solve them.

Butyl sealant coated on the aluminum spacer has rough edges and is not neat.

Reason

There may be impurities at the exit of the two glue nozzles or the mouth of the glue nozzle is not smooth.

Solution

Check whether there are impurities at the exit of the two rubber nozzles or whether the rubber nozzle is smooth.

There is a gap between the butyl sealant and the second sealant after closing.

Reason

The second sealant was not applied in the correct way.

Solution

When applying the second sealant, it should be applied with proper force and in one direction to prevent air from wrapping into the adhesive and reducing the sealing performance of the insulating glass.

Extrusion after heating is not smooth, easy to break the glue (broken line)

Reason

The key to the use of butyl sealant in extrusion, temperature control in the extrusion process is critical, whether the temperature control is appropriate, directly affects the butyl sealant in the entire process of the rheological state, affecting the product’s intrinsic quality of the beautiful, should pay special attention to the temperature. The temperature is too high will cause the sealant melt too much, no strength or even no molding at all (flow phenomenon); temperature is too low, the flow of the rubber is poor, the machine extrusion glue, affecting the construction progress, which is the main reason for the extrusion is not smooth. Another reason may be butyl sealant in the manufacture of air bubbles mixed in the extrusion process resulting in broken glue.

Solution

Temperature selection is generally appropriate to the extrusion temperature provided by the manufacturer, extruder temperature, generally set the barrel between 110-140 ℃, the head between 112-142 ℃. In order to produce a certain pressure on the host, so that the melt is uniformly extruded, so the head temperature is required to be higher than the barrel temperature, the temperature has a certain hysteresis, the adjustment should be noted that the heating and cooling should be carried out gradually, before the start of the application of the glue, it should be properly ventilated in order to reduce the internal air bubbles and voids, to prevent bubbles during the extrusion caused by the broken glue.

Related Reading: Use of Butyl Sealant

Extrusion temperature is suitable, but the aluminum spacer and butyl sealant adhesive poor adhesion

Reason

1. The aluminum spacer or conveyor belt is not clean with oil and dust.
2. The belt transfer is too fast for the aluminum spacer to be coated with adhesive.
3. The aluminum spacer frame is skewed, the glue is not easy to pass through the nozzle or glue position is not correct.
4. Poor initial adhesion of the sealant itself.

Solution

1. Clean and calibrate the aluminum spacer and conveyor belt, and adjust the speed of the conveyor belt.
2. Adjust the gap between the two nozzles proportionally.
3. The aluminum spacer should be placed vertically when applying glue, in order to prevent the aluminum spacer from not sticking to the glue phenomenon caused by the glue nozzle not easy to pass or incorrect position of applying glue.
4. Butyl sealant is both elastic and viscous elastomer, through the appropriate temperature and pressure extrusion adsorption on the clean aluminum, molten butyl rubber to the surface of the adhesive diffusion, gradually wet the surface of the sealant and deep into the surface of the microporous, which is a physical process, the butyl rubber and the sealant (aluminum) in the process of the surface of the line contact, only after the compression of the sealant can be carried out with the sealant between the face of the contact. Only after pressing can there be face-to-face contact between the butyl sealant and the bonded material. Therefore, the right working pressure and temperature are conducive to this process. It is important to note that the adhesion of the sealant to the aluminum strip takes some time (3-5 min) to achieve optimum adhesion.