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Quick Details

  • Other Names: Polyurethane Swelling Waterproof Mastic Sealant
  • Place of Origin: Beijing, China (Mainland)
  • Classification: Other Adhesives
  • Main Raw Material: Polyurethane
  • Usage: Construction, Waterproof Structure
  • Brand Name: Langwei
  • Model Number: LW-S50
  • Type: One Component
  • Product name: Polyurethane Swell Seal Mastic
  • Feature: Swell Meet With Water
  • Color: Black and Grey
  • Specification: 600ml, 310ml
  • Packing: Sausage
  • Application: Waterproof Structure
  • Material: Polyurethane
  • Certificate: ISO9001:2008
  • Price: Competitive
  • Quality: High grade

Packaging & Delivery

Packaging Details 600ML per piece, 20PCS in a carton
Delivery Time 15 days after receiving the deposit

 One Component Polyurethane Sealant Mastic For Waterproof Structure

Product Description


It is one-component, polyurethane, water swelling sealant.


Easy operation

Excellent adhesive to different surface

Good expiation rate to protect fresh concrete during solidifying


Water swelling

Durable water sealing

Various products for different task


Technical Data:









Before solidify

Density, g/cm³       


Solidification, %


Sagging(50±2℃), mm≤


Surface dry time, h≤





After solidify

Elongation, %


Tensile strength, MPa≥


Bonding strength to concrete±, MPa≥



Water expansion (room Temp, distilled water),%



Applied in waterproof structure , cross section of fix water stop or LW preventive injection hose. 


Construction joint

Pipeline and concrete iron in wall or cement board

Surrounding the concrete iron or joint

Inner joint of cable


Preventive injection hose: type LWRI, I and II

Cross section of water stop


Base surface must be sound, clean, dry, no oil or dust,etc.

Clean all practical,demolding agent, bleeding cement,old coating film and other loose animals.

Construction Conditions:       

Base surf. Temp.     Min+5℃ Max.+35℃       

Environment Temp.    Min+5℃ Max.+35℃

Base surf. humidity    Dry and no visible water


 Applied for fixing water stop or placing injection hose.    

Apply the sealant on base surface, if base surface is not flat, nozzle size need to be changed.

Fix water stop and injection hose to the sealant. Concreting 2 hours after sealant solidify .

Applied for sealing of the construction joint

If the triangle nozzle is used, refer to the following instruction:

Building Thickness

Size of the triangular section

Length of the extrusion 600 ml/bar (theory data)


Length of the extrusion 320 ml/bar (theory data)










Actual length of extruded sealant may be shorter because of condition difference.

Apply the sealant flat in the middle of concrete section.

Concrete edge: 10cm (reinforced concrete ) or 15cm (non reinforced concrete)

Concrete height: <50cm------- Solidifying time :2-3 hours

Concrete height: >50cm-------- Solidifying time :2 days

Press the sealant tightly during concreting to avoid cellular holes.     

Clean Tools: 

Clean all the tools and equipment when process finished.


LW swell sealant will expand some hours after water contact. It is not allowed to stay a long time in water (water draining complete in 24 hours) before concreting.

Placing the sealant in movable crack is not allowed.

When water level rise, the sealant expand and sealed the crack.

In drying condition, the sealant shrinks to original size; but will re-expand when touching water.

Suggest to apply the sealant under less than 2 bar pressure  (test pressure is 5 bar) because of sealing width limit.

If the pressure is high than 2 bar, the sealant can be used to fix the injection hose.



Shelf time:

12 months  (sealed packing, Temp. +5℃---+25℃, drying condition)


600 ml/bar (20 branch/box) 320 ml/bar (24 teams/box)


Company Information

As an member of Chemical Grouting Sub-Committee, Chinese Hydraulic Engineering Society, the Director Member of Waterproof Sub-Committee and China Construction Industry Association.LANGWEI Conchem is a fast growing international manufacturer of construction chemicals with plants in Beijing, China. The company is specialized in preventative and remedial waterproofing products. 
Preventative waterproofing products are wildly used during new construction and are usually installed by the general contractor. Examples are bentonite strips, hydrophilic mastics and rubbers, which swell in contact with water and hence block water ingress, injection hoses, which can be injected at a later stage to block water and finally cementitious coatings for basement waterproofing and elastomeric membranes for tanks and roofs.
Remedial waterproofing products are mostly used when major (or minor) water leaks happen at a later stage and are usually applied by specialist applicators. Remedial waterproofing products are also often used during construction of tunnels and other underground constructions to prevent infiltrating water from hindering the normal progress of the works. Examples are injection resins based on polyurethanes (both 1C and 2C) and poly-acrylates. These products are also used for soil and rock stabilization, together with organo-minerals.
LANGWEI Conchem also manufactures a series of products for the protection and repair of reinforced concrete. Examples are cementitious grouts and mortars, epoxy injection resins, carbon fibre laminates and epoxy glues.



Why choose us ?

-The member of Architectural Society of China

-Best quality: LW joint sealant has been applied in the subway and hydraulic power project, 

-have taken excellent application effect.

-Cheapest price: factory price, send inquiry for quotation

-Good after service: guidance for your project, make sure performance well


LW Certifications



Packaging & Shipping




LangWei Conchem is specialized in preventative and remedial waterproofing products, which are mostly used in balcony waterproofing, car part decks, concrete repair and protection, facade waterproofing, flooring systems, injection equipments, packers & accessories, preventative waterproofing, remedial waterproofing, roof waterproofing, sewer rehabilitation, soil injections, tunnel applications and so on.

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