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Supex PU 25 Polyurethane Sealant


PU sealant, Supex PU 25

Supex PU 25 PU sealant ( Shore A hardness 40 ) price is competitive considering its superior European technology. It is an organic material used for sealing and bonding. Its properties like resilience, flexibility, bond strength, UV resistance, hardness etc can be modified as per application requirements.


Used in joints between prefabricated building elements, in joints of rainwater collection pipes on roofs and in rain gutters, insulating joints between precast concrete blocks and sealing of joints of aluminum pipes in HVAC (ventilation) sector.


Especially used in automotive industry, in the manufacture of vehicles, in the sealing of metal structures such as containers and trucks, in the manufacture and installation of air conditioning in HVAC systems, in order to reduce vibration and provide sealing in metal sheet joints.

shipping container repair
roof repair

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Supex PU 25, pu sealant developed for India, is a high-quality multipurpose non-sag one-part Polyurethane sealant that cures on exposure to atmospheric moisture to form a durable elastomer. Supex PU 25 has been especially developed for Indian subtropical conditions. Most suitable in high temperature & extreme humid conditions. Usage mostly in Bonding & sealing for Bus Body, Rail Coaches, expansion joint sealing and other automotive / construction applications.

Technical Data

  •   Chemical Base:                                                                   Polyurethane
  •   Curing Mechanism:                                                       Atmospheric Moisture
  •  Specific gravity                                                                 1,45 ± 0,03 g/cm3
  • Tack free time:                                                                     30-60 min.
  •  Cure Rate                                                            2 mm/24 hour
  •  Hardness (ASTM D 53505):                 40±5 Shore A
  •  Elongation at Break(DIN 53504)        ≥ 400%
  •   Modulus 100 % (DIN 53504)               >0.4 Mpa 
  •   Tensile Strength:                                            1.1  N/mm

Characteristics of Supex PU 25

  • Reacts with moisture to cure
  • Characteristics: High gap filling , High Bonding strength , Flexibility , Chemical Resistance , Paintable
  • Bonds well to a wide variety of substrates
  • Overpaintable and has non sag consistency
  • Suitable for making permanent elastic seals of high adhesive strength
  • Vibration and sound dampening properties
  • Excellent resistance to many chemicals
  • Developed specifically for automotive and bus industry, bodywork & container applications
  • Good resistance to ageing & weathering – thus, suitable for indoor and outdoor applications
  • Sandable & over-paintable with many water, solvent based paints

Uses of Polyurethane sealant Supex PU 25

  • Sealing & Bonding in automotive industry
  •  General coach-building, caravans & motor-homes assembly as well as repairing
  •  Bus Body & truck industries
  •  Thermal & acoustic insulation technology in refrigeration, air-conditioning
  •  Suitable substrate materials include timber, metals, particularly aluminium, sheet steel, metal primers, paint coatings, ceramic materials as well as plastics
  •  Joint sealing for construction applications, Eg: expansion joints

How to use Polyurethane sealant

  • Before application, make sure that the surface is free from dust and grease. This will otherwise inhibit the process of application of the sealant.
  • We recommend that you conduct a preliminary compatibility test before proceeding to use the sealant for its desired purpose.
  • Apply the sealant evenly. If required, use masking tape to mark the areas of application. Before it cures, make sure to remove the tape.
  • The ratio of the joint width to the depth ratio should be 2:1.
  • Further, it is recommended to use a backup material if you feel like joint adjustment is required.
  • You may use backer rods and bond breakers to facilitate the adhesion. It should adhere only to two surfaces of the joint.
  • Take care to follow the standard industrial application procedures. Clean the fun after use before giving the sealant time to cure.

What are the advantages of using PU sealant ?

Polyurethane sealants offer many advantages, primarily versatility. PU sealants can be formulated into different kinds of products for a variety of applications, especially in large infrastructure construction projects. They can be used in various joints, such as expansion and deformation joints in the construction of buildings, tunnels, bridges, roads, and subways, as well as building projects for airports, railway stations, and power station projects.

PU sealants can also be designed for smaller application projects such as basement waterproofing, window and door installations, and swimming pool sealing. Sealants of different kinds have separate application areas and can be specified correctly based on project requirements and demands.

PU sealant price is low vs MS polymers yet offers strong bonding to wood, metal, and plastic, along with great flexibility (particularly at low temperature), recovery properties, and tear resistance. They rapidly develop strength before complete cure, helping to reduce downtime during application. PU sealants are also resistant in tough environments, both in terms of exposure to temperature extremes and in their resistance to chemicals. They are easily formulated into a variety of colours and can be overpainted after application. 

Typical Automotive applications  with PU sealantpolyurethane sealant uses
  • Roof sealing, roof bottom sealing for mica bonding
  • Roof gap sealing
  • Side panel 
  • Floor bonding with plywood
  • Dash board bonding
  • Plywood bonding in Driver’s cabin
  • Rear FRP & FRP bumper, front FRP 
  • Battery box sealing
  • FRP staircase sealing 
  • Skirt panel bonding
  • Gaps between window frames
  • Plywood to steel structure 
  • ABS to frame 

PU 25 is used in Elevator, Escalator  metal to metal bonding applications, Eg:  panel stiffner bonding

Typical Construction applications with PU sealant 25pu sealant price
  • Expansion joint, concrete joint sealing, precast structure joint sealing 
  • Gap sealing 
  • sealing wall cracks 
  • Sealing transition joints  
  • Sealing gaps between window frame and wall, door frame and wall gap filling 

Metal to Metal Bonding & Sealing 

PU sealant Supex PU 25,  is a one-component, high-modulus polyurethane sealant that cures on exposure to atmospheric humidity. It possesses excellent adhesion to sheet iron, aluminum, stainless steel, lead, copper, ceramic, glass, wood and various plastic materials. 

  • Body construction of cars, containers, caravans etc.
  • Sealing and bonding of ventilation ducts, gutters and spouts etc.
  • Sealing of sheet metal seams
  • For vibration reduction in all type of sheet metal assembly works
  • Sealing against water, air, gas and dust.

Polyurethane sealant for repairing Wall cracks, dampness  

External wall cracks are a common  phenomenon which leads to rainwater seeping in through walls.  Solution: Open the wall crack and make v groove , clean the groove, apply PU 25 , wait for curing and finish with paint

PU Sealant at best price in India

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Brand Name
Product Name
Supex PU 25 Polyurethane Sealant
Weight 15 kg
Dimensions 42 × 20 × 24 cm