The use and requirements of structural adhesive

Structural glue should be applied in a specially designed glue injection room, which is required to be clean, dust-free, fireless, and ventilated. The indoor temperature should be controlled at 23 ± 5 ℃, and the relative temperature should be controlled at 70% ± 5%. Glue injection operators must receive specialized business training and pass practical operation assessments before they can operate with certificates. It is strictly prohibited to use expired silicone structural adhesive, and it is strictly prohibited to use silicone structural adhesive that has not undergone compatibility testing, butterfly testing, and other related inspections, and all inspection parameters are qualified.
2.2 Cleaning of the injection site. Strictly follow the requirements of standard specifications, design drawings, and process procedures, and use auxiliary materials such as cleaning agents, cleaning cloths, and protective tapes. For the cleaning of the substrate at the injection site, a mixed solvent of 50% isopropanol and 50% water is usually used for non oily pollutants; For oily pollutants, xylene solvents are usually used. The cleaning cloth should be a clean, soft, non shedding white or natural cotton cloth. Do not dip the cloth into the container containing the cleaning agent to avoid contaminating the entire solvent. When cleaning, use the "double wiping" process for cleaning. After cleaning, the cleaned parts must not come into contact with hands or other sources of contamination, otherwise they must be cleaned again. The cleaned substrate must be glued within 15-30 minutes, otherwise a second cleaning is required.
2.3. Mixing of structural adhesive. The two-component silicone structural adhesive should be mixed using a dedicated two-component silicone glue machine. When mixing, the glue machine should be cleaned according to the instructions of the glue machine, the glue nozzle should be adjusted, and then the two-component sealant should be fully mixed according to the specified mixing ratio. To control the mixing of structural adhesive, butterfly samples and cup break samples should be left during each mixing process, and the mixing of structural adhesive should be checked in a timely manner, with on duty records kept. The butterfly test is to verify whether the structural adhesive is fully mixed, and only when the color of the structural adhesive is uniform and fully mixed can the adhesive be injected. The butterfly sample number should be recorded throughout the entire mixing process.
The rubber cup test is used to check the mixing ratio of two-component silicone structural adhesive base and curing agent.
2.4. Injection of structural adhesive. The injection of structural adhesive must be done mechanically, and the injection should be carried out in order to remove the air in the injection gap; The nozzle of the glue injection gun should be inserted to an appropriate depth, so that the glue is continuously, evenly, and fully injected into the glue injection gap, and no bubbles are allowed to appear; Adjust the pressure at the joint to ensure sufficient silicone structural adhesive is present. During the adhesive injection process, it is important to observe the color changes of silicone structural adhesive to determine the changes in the mixing ratio of the structural adhesive. Once the mixing ratio of the structural adhesive changes, the machine should be immediately shut down for maintenance, and the adhesive in the changed area should be cut off and replaced with qualified structural adhesive. After gluing, use a scraper to flatten it, scrape off excess structural glue, and trim its exposed surface to make it flat and smooth, with no bubbles in the seams. The injection of glue should be recorded in a timely manner. The finished glass components after injection molding should be sampled for adhesive peeling test to inspect the bonding firmness and curing degree.