Adhesion of acrylic sheet is a key process in acrylic products processing. How to display the clear and transparent characteristics of acrylic, reflect the value of acrylic crafts, maximize the grade and taste of acrylic crafts, bonding technology plays a decisive role.
Adhesion of acrylic board is mainly affected by two aspects, one is the applicability of the adhesive itself, the other is the bonding skills.
At present, there are many adhesives on the domestic and foreign markets, there are mainly two types, one is a two-component, such as universal adhesive, epoxy resin, and the other is a single component, such as CCl3 (chloroform). Generally speaking, two-component adhesives are bonded by curing reaction, and one-component adhesives are the final volatilization of a solvent to achieve bonding.
The characteristics of two-component adhesives are good bonding effect, no bubbles, no whitening and high strength after bonding. The disadvantage is that the operation is complex, difficult, curing time is slow, and it is difficult to meet the requirements of mass production. The general one-component adhesives are characterized by high speed and can meet the technological requirements of mass production. The disadvantage is that the adhesives are easy to produce bubbles, whitening and poor weatherability, which directly affects the external beauty and product quality of acrylic products. Therefore, in the processing of acrylic products, how to select appropriate adhesives to improve the grade and grade of acrylic products? Secondly, it is a big problem that must be solved first in the bonding process. In addition, the bonding skills are also very important. Here are some common bonding processes, a brief analysis of their practical experience.
1. Docking: Place two acrylic plates to be butted on the operating platform horizontally, close them, and glue a tape at the bottom, leaving a gap not more than 0.3 mm wide for the application of adhesive. Use syringe to inject the adhesive evenly and slowly from one side into the crevice until it is fully filled. Remove the tape after curing completely.
2. Vertical bonding: Vertical bonding is the most widely used bonding technology, which is widely used in the production of acrylic products. First, the surface to be bonded should be wiped clean. It is better to use die to achieve bonding, so that the bonding material does not shake, which is conducive to improving the quality of bonding. Acrylic bonding with thickness of 3 mm can be padded with fine wires, which can be bonded by capillary action. The wires can be extracted before the bonding agent solidifies, or can be bonded with adhesive tape and then coated with adhesive.
3. Inclined surface bonding: The bonded inclined surface must use 90o angle and so on to prevent the displacement of the bonded surface. The application of adhesives should be uniform and slow. The backing die can not be removed until it is completely cured.
4. Surface bonding: Planar bonding is a special bonding method. First of all, the adhesive surface will be wiped clean, and placed horizontally, with a proper amount of adhesive on it. One side of the other acrylic plate is slanted to contact the acrylic plate coated with adhesive, then evenly and slowly lowered, and the bubbles are driven out from one side to complete the bonding. Acrylic adhesives can erode the surface of Acrylic board and leave traces that are difficult to eliminate. Therefore, sticking adhesive tape can be used to protect the unbonded parts. Oil, dust or stomata can prevent the uniform coating of the adhesives and leave bubbles. Excessive use of a small amount of adhesives will bring air into the adhesive when it receives shrinkage. Direct blowing will whiten the edges of the bonding surface due to the volatilization of the bonding agent. Indoor humidity, temperature and so on have a direct impact on the adhesion of acrylic board.
