Single Part Structural Silicon Sealant (MF-899)



MF-899 Is Extensively Applied For All Kinds Of Sealing Where Anti-Aging Is Most Concern

MF-899 is a one component, neutral cured, high elasticity and high modulus silicone sealant. The sealant has excellent adhesion strength with outstanding weatherproofing ability.

This neutral cured single part MF-899 sealant has excellent adhesion strength with outstanding anti-UV and anti-aging



  • High elasticity and high modulus.
  • Neutral cured, no corrosion to the surface.
  • Excellent resistance to air aging.
  • Movement capability: ±12.5%
  • Excellent adhesion to most building materials, particularly to glass and aluminum. No priming paint is required.
  • No pollution to environment.


MF-899 is mainly applied for structural assembly of hidden-frame curtain walls and total glazing. It could also be used for waterproofing and weatherproofing sealing for automobiles and ships, etc.


  • Testing should be carried out for compatibility and adhesive property of project materials before application.
  • In case of contact with eyes, rinse immediately with plenty of water.
  • Avoid long-term contacting with skins.
  • Avoid contaminating food, medicine or cosmetics, etc.


Surface Cleaning

Surfaces where silicon shall be applied must be cleaned, dried and free of grease. Masking tape should be used to avoid contamination and they shall be removed after sealing.

Cleaning Skill

Used with neat cloth with lint-free, or cleaned, white and lint-free cotton cloths.

Used with solvents such as allotropic-propanol, butanone or dimethyl benzene, etc.

Apply “two-cloth” cleaning.

  • Use a white clean lint-free cloth dipped in the solvents to wipe the areas to be attached.
  • Use the second one to wipe off the remained cleaning solvents on surface before volatilization.
  • The surface is often injected within an hour after wash in case of twice contamination. The surface (washed already), with which sealant is not applied in time, should be cleaned again before application.
  • Solvents should be poured out from the container while dipping solvents, but the cloth should not be put in the container to soak in case of contamination. The cloth should be changed in time.
  • No burning in the area using solvents. Keep good ventilation.

Sealant injection

The silicon is injected manually or by pneumatic injecting gun at above 10℃ along one direction. The joints-filling should be fully filled with sealant. Masking tapes should be used to avoid contamination and they shall be removed after sealing.


Apply the sealant according to < The Application Standard of Silicone Structural Sealant >. It is inapplicable under following circumstances.

  • Any building materials with exudation of grease, plasticizer or solvent, etc
  • Vulcanized or semi-vulcanized rubber.
  • Those areas where other sealants are applied.
  • The joint which undertake structural intensity, suffering excessive rub or physical destroy.
  • Those regions where are closed and are cut off the air.
  • Frosted or humid surface.


  • Cartridge package:300 ml / pc(25 pcs / carton)
  • Sausage package:592 ml / pc(12 pcs / carton or 20 pcs / carton)


MF-899 is non-dangerous and it could be delivered by different transportation methods such as truck, train, boat and plane, etc.


The shelf-life shall be 12 months stored in shady, dry and ventilated environment below 27℃.


The information does not include all the safety notices one should know. For safely using, carefully reading of < The Application Standard of the Structural Silicone Sealant > and the introductory sheets are necessary. Applying on Cr-plated surface should be done carefully. Consultations with specialists are required in case of necessary. Sufficient secure tests should be carried out. For details, please refer to JGJ102 standard.


Items Description Specifications
1 Colour Black, white, brown and grey, etc
2 Sag Placed Vertically (mm) ≤ 1
Placed Flatly No Distortion
3 Extrusion Property (s) ≤ 5
4 Tack-free Time (hrs) ≤ 2
5 Shore Hardness 30 - 60
6 Tensile Strength (MPa) Standard Conditions ≥ 0.8
90℃ ≥ 0.6
-30℃ ≥ 0.8
After Water Soak ≥ 0.8
After Water-UV Soak ≥ 0.8
Damaged Areas (%) ≤ 5
7 Cured Time (T=25℃, RH=50%) (days) 7 - 14
8 Weatherproofing Property (℃) -60 - 120
9 Resistance to Ultraviolet Ozone Continuous irradiation under water-ultraviolet for 2500 hrs, no change
Meet ASTM C920 and GB16776 standards