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Sikaflex®-527 AT

Sikaflex®-527 AT

Isocyanate free sealant with reduced substrate preparation

Sikaflex®-527 AT is a 1-component Silan Terminated Polymer (STP) sealant that cures at exposure to atmospheric humidity. It is made for multipurpose elastic joints for interior and exterior of the vehicle body. Sikaflex®-527 AT adheres well to most materials commonly used in body shop.  

  • Fast curing
  • Excellent working properties
  • Over paintable with water-based paint systems
  • Good adhesion to a wide variety of substrates without primer
  • Ageing and weathering resistant
  • Low odor
  • Non-corrosive
  • Solvent and isocyanate-free
  • Silicone and PVC-free
 
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PRODUCT BENEFITS

  • Fast curing
  • Excellent working properties
  • Over paintable with water-based paint systems
  • Good adhesion to a wide variety of substrates without primer
  • Ageing and weathering resistant
  • Low odor
  • Non-corrosive
  • Solvent and isocyanate-free
  • Silicone and PVC-free
 

Areas of Application

Sikaflex®-527 AT is suitable for sealing, seam sealing, simple bonding as well as for vibration reduction and sound dampening measures in collision repair and vehicle body construction. It adheres well to most the materials commonly used in body shops, e.g. metal primers and paint coatings, metals, painted plastics and plastics. Seek manufacturer’s advice and perform tests on original substrates before using Sikaflex®-527 AT on materials prone to stress cracking. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed ensuring adhesion and material compatibility.  

Product Details

Typical Product Data
Chemical base

Silane Terminated Polymer

Color (CQP001-1)

White, black, light grey

Cure mechanism

Moisture-curing

Density (uncured)

(depending on color)

1.4 kg/l

Non-sag properties

Good

Application temperature

ambient

5 ─ 40 °C

Skin time (CQP019-1)

40 minutes A

Curing speed (CQP049-1)

(see diagram)

Shrinkage (CQP014-1)

3 %

Shore A hardness (CQP023-1 / ISO 7619-1)

40

Tensile strength (CQP036-1 / ISO 527)

1.5 MPa

Elongation at break (CQP036-1 / ISO 527)

400 %

Tear propagation resistance (CQP045-1 / ISO 34)

6 N/mm

Service temperature (CQP513-1)

 

4 hours

1 hour

-50  ─ 80 °C

120 °C

160 °C

Shelf life (CQP016-1)

cartridge

unipack

drum

15 months B

12 months B

9 months B

CQP = Corporate Quality Procedure

A) 23 °C / 50 % r. h.

B) storage below 25 °C
Technical Information

CURE MECHANISM

Sikaflex®-527 AT cures by reaction with atmospheric moisture. At low temperatures the water content of the air is generally lower and the curing reaction proceeds somewhat slower (see diagram 1).

en_PNG_01-diagram-sikaflex-527at

Diagram 1: Curing speed Sikaflex®-527 AT

CHEMICAL RESISTANCE

Sikaflex®-527 AT is generally resistant to fresh water, seawater, diluted acids and diluted caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, glycolic alcohol, concentrated mineral acids and caustic solutions or solvents.

Application

Application Information

Surface preparation

Surfaces must be clean, dry and free from grease, oil, dust and contaminants.

Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond. Suggestions for surface preparation may be found on the current edition of the appropriate Sika® Pre-treatment Chart. Consider that these suggestions are based on experience and have in any case to be verified by tests on original substrates.

 

Application

Sikaflex®-527 AT can be processed between 5 °C and 40 °C but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and sealant is between 15 °C and 25 °C.

Sikaflex®-527 AT can be processed with hand, pneumatic or electric driven piston guns.

Tooling and finishing

Tooling and finishing must be carried out within the skin time of the sealant. It is recommended using Sika® Tooling Agent N. Other finishing agents must be tested for suitability and compatibility prior the use.

Removal

Uncured Sikaflex®-527 AT can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically. Hands and exposed skin have to be washed immediately using Sika® Cleaner-350H cleaning towels or a suitable industrial hand cleaner and water.

Do not use solvents on skin.

Overpainting

Sikaflex®-527 AT can be best painted within the skin formation time. If painting process takes place after the sealant has built a skin, adhesion could be improved by treating the joint surface with Sika®Aktivator-100 or Sika®Aktivator-205 prior to paint process. If the paint requires a baking process (> 80 °C), best performance is achieved by allowing the sealant to fully cure first. All paints have to be tested by carrying preliminary trials under manufacturing conditions.

The elasticity of paints is usually lower than that of sealants. This could lead to cracking of the paint in the joint area.