How much do you know about silicone adhesives?
The English name of silicone adhesive is SILICONE, which is a part of the silicone product. It is mainly divided into deacetic acid type, dealcohol type, deaminated type, and deoxime type. Glass glue is the common name of silicone adhesive, because users buy silicone sealants mainly for glass bonding and sealing, so it is called glass glue. Chemical components include polydimethylsiloxane and silicon dioxide polymers can be called silicone. Silicone adhesive is a kind of ointment-like material that will solidify into a tough rubber-like solid material once it comes into contact with moisture in the air.
1. Classification of silicone adhesive
Single component and two-component.
The curing of single-component silicone adhesive depends on the change of physical properties caused by contact with moisture in the air;
Two-component refers to the silicone adhesive divided into two groups, A and B. Any one group alone cannot form curing, but the two groups of adhesives will cure once mixed.
Single-component silicone glass adhesive is common in the market. Single-component silicone glass glue is divided into two types according to its properties: acid glue and neutral glue. Acid glass glue is mainly used for general bonding between glass and other building materials. Neutral glue overcomes the characteristics of acid glue corroding metal materials and reacting with alkaline materials, so it has a wider range of applications and its market price is slightly higher than that of acid glue. A relatively special type of glass glue on the market is silicone structural sealant. Because it is directly used for metal and glass structures or non-structural bonding assembly of glass curtain walls, its quality requirements and product grades are the highest among glass glues, and its market price is also the highest.
1. It is primarily used for metal and glass structures or non-structural bonding assembly of glass curtain walls.
2. It can directly connect glass to the surface of metal components to form a single assembly component, meeting the design requirements of fully hidden or semi-hidden frame curtain walls.
3. Structural bonding and sealing of insulating glass.
2. Use of silicone glue
1. Use: Single-component silicone glass glue can be used immediately. It is easy to use a glue gun to spray it out of the glue bottle, and its surface can be trimmed with a spatula or wood chips.
2. Adhesion time: The curing process of silicone glue develops from the surface to the inside. The surface drying time and curing time of silicone glue with different characteristics are not the same (for detailed description of curing time, please refer to the “Technical Parameters” in the fourth chapter), so if you want to repair the surface, you must do it before the glass glue dries (acid glue, neutral transparent glue should generally be within 5-10 minutes, and neutral variegated glue should generally be within 30 minutes). If you use color separation paper to cover a certain place, after applying the glue, it must be removed before the outer skin is formed.
3. Curing time: The curing time of glass glue increases with the increase of bonding thickness. For example, 12mm thick acid glass glue may take 3-4 days to solidify, but within about 24 hours, the outer layer of 3mm has been cured. When bonding glass, metal or most wood, it has a peel strength of 20 pounds per inch after 72 hours at room temperature. If the place where the glass glue is used is partially or completely closed, then the curing time is determined by the tightness of the seal. In an absolutely closed place, it may remain uncured forever. If the temperature is increased, the glass glue will soften. The gap between metal and metal bonding surfaces should not exceed 25mm. In various bonding occasions, including closed situations, the bonding effect should be fully checked before the equipment after bonding is used. During the curing process of acidic glass glue, a smell will be generated due to the volatilization of acetic acid. This smell will disappear during the curing process and there will be no odor after curing.
4. Bonding:
A. Clean the metal and plastic surfaces completely, remove oil stains, and then, except for plastics, rinse the entire surface with acetone first. The rubber surface should be polished with sandpaper and then wiped with acetone. Please follow the precautions for using acetone when using this solvent.
B. Apply the glass glue evenly on the surface of the prepared object. If two surfaces are to be bonded together, one side can be placed first, and then the other side can be squeezed with enough force to squeeze out the air, but be careful not to squeeze out the glass glue.
C. Place the bonded device at room temperature and wait for the glass glue to solidify.
5. Sealing: When silicone glass glue is used for sealing, follow the above steps and squeeze the glass glue into the joint surface or gap to make the glass glue fully contact with the surface.
6. Cleaning: Before the glass glue is solidified, it can be wiped off with a cloth strip or paper towel. After solidification, it must be scraped off with a scraper or scrubbed with solvents such as xylene and acetone.
