Körapur® 128 S is an elastic one-component adhesive and sealant used for bonding in the manufacturing of containers, vehicles, vehicle bodywork, air conditioning and heating equipment, metalwork, and other applications. It exhibits good adhesion to primed and painted metals, aluminum and steel, wood, and duroplastics. It also offers good resistance to humidity and weathering.

Chemical FamilyPolyurethanes (PU)

Product Type1K (1 component) Adhesive, 1K (1 component) Sealant, Reactive Adhesive, Reactive Sealant

Application AreaAir Conditioning , Appliances, Containers, HVAC Applications, Heating Equipment, Metal Parts, Vehicles

Compatible Substrates & SurfacesAluminum, Metal, Painted Surfaces, Steel, Wood

FeaturesExcellent Elasticity, Excellent Humidity Resistance, Excellent Substrate Adhesion, Good Adhesion, Good Substrate Wetting, Good Weather Stability, High Elongation, High Flowability, Paintable, Self-Leveling, Temperature Resistance

Technical Data Sheet

Enhanced TDS

Identification & Functionality

Chemical Family

Features & Benefits

Product Benefits
  • Good adhesion to primed and painted metals, aluminium and steel, wood and duroplastics
  • Good resistance to humidity and weathering
  • Overpaintable after curing
  • Resistant to temperatures from -40°C to +90°C (up to +120°C for short intervals)
  • Self-levelling
  • Can be used with booster Köracur 110 S

Applications & Uses

Compatible Substrates & Surfaces
Cure Method

Processing temperature: 40°F to 95°F


  • The surfaces to be bonded must be clean, dry and free from dust and grease. For cleaning we recommend Körasolv PU. In the case of powder coated substrates, Körasolv WL should be used.
  • To increase bond strength of non-porous substrates such as glass, glass-fibre reinforced plastics, aluminium, stainless steel, etc. we recommend the use of Körabond HG 81. For porous substrates such as wood, Körabond HG 74 E is recommended.
  • For certain plastics such as ABS or PVC we recommend the use of Körabond HG 77. Due to the diversity of substrates, preliminary tests are re commended.
  • Körapur 128 S can be overpainted after skin formation. Adhesion and compatibility must be tested by prelimiary trails. Please consider that the brittleness of the paint film may limit the elastic movement of the sealant and may lead to cracking of the paint. Thus, the curing reaction proceeds slower under the paint film.
  • Avoid direct contact with isocyanate reactive substances, especially alcohol such as spirit, dilutions and cleaning com-pounds until the adhesive has attained full cure. This will prevent the adhesive from curing properly. By direct or indirect contact with some other organic products preliminary tests are recommended.


  • The thickness of the layer depends on the expected mechan-ical movement.
  • Join the materials to be bonded within the skin formation time. Due to the low initial tack, we recommend mechanical fixing in some applications until a complete cure is obtained.
  • The curing is dependent on temperature, humidity and the dimensions of the joint.
  • By using the special hardener Köracur 110 S the product cures independent of humidity.


Körasolv PU: Clean tools immediately after use. Once cured, material can only be removed mechanically.


Physical Form
Technical Data
ValueUnitsTest Method / Conditions
Densityapprox. 1.2g/cm³DIN EN ISO 1183-1
Skin Formation Time30.0minDIN 50014
Curing ((first day)3.0mmDIN 50014
Change in Volumemax. 1%DIN 52 451
Hardness40.0ISO 868/DIN 53 505, Shore A
Elongation at Tear500.0%ISO 527 / DIN 53 504
Tensile Strength1.5ISO 527 / DIN 53 504
Tear Propagation Strength5.0N/mmISO 34 / DIN 53 515
Building Material ClassB2DIN 4102 part 1 + part 4

Packaging & Availability

Regional Availability
  • Asia Pacific (Excluding Russia)
  • Australia
  • Canada
  • China
  • Europe (Excluding Russia)
  • Japan
  • Korea
  • Malaysia
  • North America
  • Philippines
  • USA

Storage & Handling

Shelf Life
12 Months (Cartridges and sachets), 9 Months (Drums)
Storage Condition
  • Do not store at temperatures above +25°C.
  • Precautions: When processing Körapur 128 S avoid direct contact with the uncured material. Safety gloves are recommended.