Polyurethane Sealant

Other products

عددی

Polyurethane Adhesive, commonly abbreviated as PU or sometimes PUR, is a single-component adhesive composed of specialized polymers that include organic chains and urethane or carbamate groups. This adhesive activates by absorbing moisture from the environment and does not require air to cure. Once cured, it remains elastic, making it ideal for sealing and waterproofing in areas exposed to vibration and movement. In Iran, polyurethane adhesive is known by various names such as polyurethane mastic, polyurethane glue, and sausage-type adhesive.

Sharing:

Lazio Polyurethane Sealant is used in construction and automotive applications for fast sealing of moisture, metal roofs, tanks, silos, and flexible joints. Key Features This sealant adheres well to various materials such as cement, brick, ceramic, glass, glazed surfaces, acrylic coatings, and metals. It is highly regarded in waterproofing projects including water tanks, sewage systems, treatment plants, and swimming pools. It is also used for sealing expansion joints in concrete. In dry building facades like fiber cement boards, it is ideal for sealing joints and corners.

Applications of Polyurethane Adhesive

Filling expansion joints
Waterproofing facade joints and other structural gaps
Sealing water pipes and channels
Waterproofing drinking water tanks and treatment facilities
Installing automotive glass
Sealing in automotive manufacturing

Application Guidelines

Surface must be dry and free of dust and grease.
Avoid water contact with the applied surface for 24 hours.
Recommended application temperature: +5°C to +40°C.
Requires a specialized sausage gun for use.

Safety Precautions

Avoid inhalation and contact with eyes.
Keep out of reach of children.

Physical Properties of Polyurethane Sealant

Physical State: Uniform semi-liquid paste, injectable
Color: Typically gray, white, black, or custom colors (depending on brand)
Density: Approximately 1.2 to 1.4 g/cm³
Skin Formation Time: 30 minutes to 1 hour (depending on ambient temperature and humidity)
Full Cure Time: 3 to 7 days depending on depth
Application Temperature: +5°C to +40°C
Service Temperature After Curing: Resistant from approx. -30°C to +80°C
Paintability: Yes (after full curing)
Flexibility: High, with deformation capacity of 25–50% without cracking
Adhesion: Strong adhesion to concrete, metal, wood, stone, tile, brick, and certain plastics

Chemical Properties of Polyurethane Sealant

Base Composition: One-component or two-component polyurethane
Formulation: Based on isocyanate and polyol reaction
Solvent-Free: Modern formulas are typically free of aromatic solvents or toxic substances

Chemical Resistance

Resistant to: Water, moisture, light oils, gasoline, detergents, atmospheric gases
Semi-resistant to: Weak acids and bases
Not resistant to: Strong organic solvents like acetone, toluene

UV Resistance

Available in UV-resistant grades with additives to prevent yellowing

Corrosion-Free

Non-reactive with sensitive metals such as aluminum or galvanized steel

Non-toxic After Curing

Generally safe after full curing, with no harmful gases or vapors released

Steps for Applying Polyurethane Sealant

1. Surface Preparation: The substrate must be completely dry, clean, and free from dust, oil, grease, rust, or any adhesive residue. For better adhesion, a polyurethane primer may be required on porous surfaces (such as concrete).

2. Backer Rod Placement (if needed): If the joint depth is significant, use foam or backer rod to set the proper depth and reduce sealant consumption.

3. Cartridge Nozzle Cutting: Cut the nozzle to the desired size according to the joint width. Insert the sealant cartridge into a caulking gun (silicone or metal type).

4. Sealant Injection: Inject the sealant evenly and continuously into the joint. For vertical surfaces, apply from bottom to top; for horizontal surfaces, apply in one direction.

5. Tooling and Finishing: Immediately after injection, smooth the joint surface using a spatula, a soap-water-moistened finger, or a specialized tooling tool. This step must be completed before skin formation begins.

6. Curing and Drying: Polyurethane sealant typically surface-dries within 24 hours. Full curing may take up to 7 days depending on temperature and joint depth. Avoid direct water contact or mechanical pressure during this period.