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Analysis of the characteristics and advantages and disadvantages of epoxy resin glue How to use it

Jun 04, 2020

Epoxy resin adhesive generally refers to an adhesive made with epoxy resin as the main body. Epoxy resin adhesive generally also includes an epoxy resin curing agent, otherwise the adhesive will not cure.

Epoxy resin is to reprocess or modify its characteristics on the basis of epoxy resin to make its performance parameters meet specific requirements. Generally, epoxy resin glue also needs a curing agent to be used, and it needs to be mixed evenly It can only be fully cured after curing. Generally, epoxy resin glue is called A glue or main agent, and curing agent is called B glue or curing agent (hardener).

1. Epoxy resin is divided into soft glue and hard glue

1. Epoxy Resin: It is a liquid type, two-component, soft, self-drying soft glue. It is colorless, transparent, and elastic. It can restore its original shape by scratching the surface lightly. Suitable for decoration of signs such as polyester, paper and plastic.

2. Epoxy resin hard glue: It is a liquid type, two-component hard glue, colorless and transparent. It is suitable for metal signs and can produce various crystal buttons, crystal bottle caps, crystal wooden combs, crystal crafts, etc. High-end decorations.

Second, the characteristics of epoxy resin

1. Basic characteristics: Two-component glue, which needs to be mixed with AB, has strong versatility and can fill larger gaps

2. Operating environment: room temperature curing, both indoor and outdoor, manual glue mixing or special equipment for AB glue (such as AB glue gun)

3. The applicable temperature is generally -50 to +150 degrees

4. Suitable for general environment, waterproof, oil resistant, strong acid and alkali resistant

5. Place in a cool place to avoid direct sunlight, the shelf life is 12 months

Epoxy resin is to reprocess or modify its characteristics on the basis of epoxy resin to make its performance parameters meet specific requirements. Generally, epoxy resin glue also needs a curing agent to be used, and it needs to be mixed evenly It can only be fully cured after curing. Generally, epoxy resin glue is called A glue or main agent, and curing agent is called B glue or curing agent (hardener).

The main characteristics of epoxy resin before curing are: color, viscosity, specific gravity, proportion, gel time, usable time, curing time, thixotropy (flow stop), hardness, surface tension, etc.

The main characteristics that reflect the characteristics of the epoxy resin after curing are: resistance, voltage resistance, water absorption, compressive strength, tensile (stretch) strength, shear strength, peel strength, impact strength, heat deformation temperature, glass transition Temperature, internal stress, chemical resistance, elongation, shrinkage coefficient, thermal conductivity, electrical conductivity, weather resistance, aging resistance, etc.

Epoxy glue

Third, the advantages of epoxy resin:

(1) Epoxy resins contain a variety of polar groups and highly active epoxy groups, so they are very strong with metals, glass, cement, wood, plastics and other polar materials, especially materials with high surface activity. At the same time, the cohesive strength of the epoxy cured product is also very large, so its bonding strength is very high.

(2) There is basically no low molecular volatiles when the epoxy resin is cured. The volume shrinkage rate of the adhesive layer is small, about 1% to 2%, which is one of the varieties with the smallest curing shrinkage rate among thermosetting resins. After adding filler, it can be reduced to below 0.2%. The linear expansion coefficient of the epoxy cured product is also very small. Therefore, the internal stress is small and has little effect on the bonding strength. In addition, the creep of the epoxy cured product is small, so the dimensional stability of the adhesive layer is good.

(3) There are many types of epoxy resins, curing agents and modifiers, which can be designed through reasonable and ingenious formulations to make the adhesives have the required manufacturability (such as rapid curing, room temperature curing, low temperature curing, water curing, low viscosity , High viscosity, etc.), and have the required performance (such as high temperature resistance, low temperature resistance, high strength, high flexibility, aging resistance, electrical conductivity, magnetic permeability, thermal conductivity, etc.).

(4) It has good compatibility and reactivity with various organic substances (monomers, resins, rubbers) and inorganic substances (such as fillers, etc.), and is easy to modify by copolymerization, crosslinking, blending, filling, etc. Improve the performance of the adhesive layer.

(5) Good corrosion resistance and dielectric properties. It can resist the corrosion of various media such as acid, alkali, salt and solvent. The volume resistivity is 1013~1016Ω·cm, and the dielectric strength is 16-35kV/mm.

(6) The general-purpose epoxy resin, curing agent and additives have many places of production and large output. It is easy to prepare and can be contact-pressed for large-scale application.

4. Disadvantages of epoxy resin adhesive:

(1) When not toughened, the cured product is generally brittle, with poor resistance to peeling, cracking, and impact.

(2) Low adhesion to materials with low polarity (such as polyethylene, polypropylene, fluoroplastics, etc.). Surface activation treatment must be carried out first.

(3) Some raw materials such as reactive diluents and curing agents have different degrees of toxicity and irritation. It should be avoided when designing formulas, and ventilation and protection should be strengthened during construction operations.

V. Scope of epoxy resin adhesive

1. Epoxy resin mortar is suitable for anti-abrasion, anti-cavitation and anti-freeze-thaw protection on the overflow surface of hydraulic structures, and repair after damage;

2. Used for repairing defects and strengthening and strengthening of concrete buildings;

3. Epoxy resin cement is suitable for the treatment of cracks in beams, columns, pile caps, etc. of buildings, honeycomb, holes and exposed bars on the surface of concrete structures;

4. Epoxy resin cement is suitable for anti-wear and repair of engineering parts such as airstrips, highways, bridges, tunnels and workshop mortar floors;

5. It is suitable for the bonding of steel structure and concrete, and the bottom layer is leveled when the steel is bonded and the carbon fiber is reinforced;

6. It is used for the protection and repair of anti-acid and alkali corrosion of concrete or metal components such as chemical industry, petroleum, factory, wharf, sewage treatment tank, acid and alkali resistant ground, FRP anticorrosion and other chemical anti-corrosion industries.

7. Epoxy resin cement is suitable for sealing and anti-corrosion of underground pipelines, hydropower stations, dam foundations and other interfaces and repairing and strengthening leakage plugging.

8. Paving and caulking of granite, marble, acid-resistant ceramic tile (board), anti-corrosion of FRP lining of sewage tank, etc.

Epoxy glue

6. How to use epoxy resin

1. Use dry cotton cloth or sandpaper to remove the dust, grease and rust on the surface, and then wipe with acetone or trichloroethylene to clean the surface.

2. Unscrew the front cover, and use the weight ratio of agent A + agent B as described above to mix it evenly before use (A:B=2:1); in order to ensure the effect of use, it can also be vacuumized use.

3. Note that it must be used up within the operable time, otherwise it will solidify, resulting in waste of material, and the highest strength can be obtained after 24 hours.

4. After glueing. Curing at room temperature for 2 to 6 hours, curing at 40 degrees to 50 degrees for 1 to 3 hours; applying after 24 hours of glue application; better adhesion after ten days. In cold and humid days, it is better to bond at room temperature of 15~25 degrees.

5. Adhesive straight face. When hanging upside down. After applying glue, you must use adhesive paper to help paste. Or use 502 glue to position. Epoxy Resin Formulation Epoxy resin AB glue is a two-component high temperature resistant adhesive based on epoxy resin, which is mainly suitable for the bonding of high temperature resistant metals and ceramics. Its operating temperature is -50 ~ +180 ℃, short-term up to +250 ℃.

Epoxy resin needs more attention when it is used. It has a wide range of use, and the operation is relatively fine. The operation is good, and the effect is obvious.