Polyurethane Adhesive is a high-performance bonding material, widely used in bonding materials such as metal, plastic, wood and rubber. The following points should be noted during use to ensure the bonding effect and safety:
1. Surface treatment
Before bonding, the surface of the objects to be bonded must be thoroughly cleaned to remove impurities such as oil stains, dust, rust or mold release agents. For non-polar materials (such as polyethylene and polypropylene), it is recommended to carry out grinding or chemical treatment (such as flame treatment, halo treatment) to increase surface energy and enhance bonding strength.
2. Environmental control
Polyurethane adhesives are sensitive to temperature and humidity. The construction environment should be maintained at 15 to 30 degrees Celsius, with a relative humidity of less than 70%. Excessively low temperatures may lead to incomplete curing, while excessively high humidity may cause bubbles or reduce the bonding strength. Some two-component products need to be mixed strictly in proportion to avoid performance being affected by incorrect proportioning.
3. Operational safety
Ventilation and protection: During the curing process, trace amounts of volatile substances such as isocyanate may be released. Operations should be carried out in a well-ventilated area. If necessary, wear a gas mask.
Skin contact: Uncured adhesives may irritate the skin. Protective equipment such as gloves and goggles should be worn during operation. In case of accidental contact, wash immediately with soapy water.
Fire prevention measures: Some solvent-based products contain flammable components. Keep away from fire sources and smoking is strictly prohibited.
4. Solidify management
The initial curing time is usually 30 minutes to several hours, but complete curing takes 24 to 72 hours. Avoid moving or applying loads during the curing period.
Heating can accelerate curing (such as baking at 60 to 80 degrees Celsius), but it is necessary to avoid local overheating that may cause the adhesive layer to age.
5. Storage conditions
Unopened products should be stored in a cool and dry place (recommended temperature range: 5 to 25℃), away from direct sunlight. Single-component products need to be sealed and moisture-proof. Two-component products should be used up within the applicable period after mixing (usually 1 to 2 hours).
6. Special Precautions
When bonding elastic materials, the flexibility matching of the adhesive layer needs to be taken into consideration.
Long-term exposure to ultraviolet rays may cause the adhesive layer to yellow or its performance to decline. For outdoor use, it is recommended to choose weather-resistant products.
Waste adhesives should be disposed of in accordance with the chemical waste treatment standards and are strictly prohibited from being dumped at will.
The correct use of polyurethane adhesives can fully leverage their advantages of impact resistance and high peel strength, but it is necessary to strictly follow the process requirements to ensure a balance between safety and performance.
