1. Surface cleaning
1) Ensure that the surface of the adherend is dry and clean without rust, oxidation, grease, dust and other pollutants. 3M recommends using IPA / distilled water (50/50) as a universal surface cleaner.
2) For different surface contaminants, 3M's recommended cleaning solvents are as follows:
3) For heavily polluted surfaces, after cleaning with other solvents, use isopropyl alcohol for cleaning.
4) The wipes and wipes used for cleaning must be changed frequently to avoid secondary contamination of the cleaning surface.
2. Surface sanding
1) The following effects can be obtained by grinding the bonding surface:
Remove heavy oil and metal oxide layer;
To a certain extent, improve the adhesion of the adhesive tape to the bonding surface;
Improve the flatness of the bonding surface, thereby facilitating the wetting of the bonding surface by the tape
Improve plastic adhesion
2) Use precision sandpaper for sanding to ensure that there are only small scratches on the surface. 3M Scotch-Brite Pads 7447 is recommended for surface sanding.
3) After grinding, use IPA / distilled water (50/50) to clean the surface.
3． Primer use
Using a primer can effectively improve the initial and final tack of the tape, especially for plastics and some sprayed / low surface energy surfaces.
The primer coating should be thin and uniform.
After the primer is applied, it should be fully dried (> 5 minutes at room temperature) before the adhesive tape can be used.
2: Adhesive tape
First, stick the tape on the surface of the adherend; leave the contact area of the rolling hand on the adhesive surface to leave it empty, and remove it later. Apply pressure from the starting point.
After the attachment is complete, remove the release paper, attach the other adherend to the adhesive surface, and apply pressure (> 100 kPa) to achieve adhesion.
Properly increasing the bonding pressure can improve the wetting of the adhered surface and can effectively eliminate air bubbles.
If precise alignment is required, the release paper can be raised with a "small tail" first, and the release paper can be torn off after positioning.
VHB tape is not suitable for operation at too low temperature, because the initial viscosity of the tape is poor at this time.
Specific construction personnel should pay attention to keep their hands clean and free of oil during operation, otherwise the final bonding strength will be affected.
Keep the operating environment clean and free of dust.
VHB takes about 30 minutes to reach 50% of the maximum bonding strength at room temperature and 72 hours to reach the final strength. If the temperature is low, this time may be longer. To avoid cementation damage, allow sufficient curing time before moving or using to ensure the safety of the joint.