Road Construction Materials


BORNIT® Joint Flex

  • Quick Facts
  • Detailed Information
  • Downloads
  • Hits

Quick Facts

BORNIT® Joint Flex (Nahtflex®)
Solvent-free, thixotropic (high viscosity) and to -5°C frostresistant bituminous compound for making flexible and permanent seams when installing asphalt mix in tapes - highly flexible and crack-bridging. Can be applied by hand with a trowel or by machine with the specially developed  working machine BORNIT® Flexomat AIR. Depending on the machine used to work the compound, layer thicknesses of up  4 mm can be easily applied.
Protect against strong frost!
Color: black

4 017228 002903
4 017228 003399
12 liter
25 liter
44 buckets
18 buckets
approx. 0.3 l/lfm for4 cm layer thickness
BORNIT® Joint Flex - 25 liters

Detailed Information

Product description
BORNIT® Joint Flex is a solvent-free, thixotropic (viscous) bitumen mass that is freeze-resistant down to -5°C. Thanks to the high-quality plastic modification, the product is highly flexible and can bridge cracks. This product is used to achieve a high-quality, elastic binder accumulation in the hot mix asphalt (HMA) joint area, which contributes to permanent and durable joint connections between asphalt lanes according to ZTV Asphalt- StB 07. BORNIT® Joint Flex is ready to process and is applied mechanically using the specially developed processing machine BORNIT® Flexomat Air. This enables to applicate material layers of up to 5 mm thickness. BORNIT® Joint Flex has a high strain-at-break value of 370% (MPA Dresden test certificate is available).

Areas of Application 
BORNIT® Joint Flex is used for the production of flexible and permanent seams between hot mix asphalt lanes (both “hot on cold” and “hot on hot”) as well as asphalt lane connections on building materials with irregular surfaces (kerbstones, milled edges, mounting parts made of concrete etc.).The main areas of application are the mechanical pre-treatment of the vertical cold joint of longitudinal and transverse joints in HMA surfaces. The product can also be used for bonding and making seam joints and connections flexible when carrying out asphalt repairs.It’s also possible to use the material for cut asphalt edges but it is recommended to use BORNIT® Joint Tape (Fugenband) in this case.

•  reduces future cracksealing, provides a better connection
•  stable at the upper surface of the vertical joint up to a layer thickness of 5 mm
•  processing and storage down to –5°C possible
•  highly flexible, resilient and can bridge cracks
•  can be cool and mechanically applied in a cost-effective and time-saving manner
•  solvent-free, environmentally-friendly and almost odourless

Technical data
Type Plastic-modified bitumen emulsion
Base Rubber latex, bitumen emulsion
Solvent None
Colour Black
Density approx. 0.98 g/cm³
Consistency viscous, thixotropic
Application paint brush, spatula, BORNIT® Flexomat 3.1 with joint modul or edge modul
Processing temperature not below - 5°C
Storage not below - 5°C
Storage life 12 months if kept closed in original packaging
Cleaning With water if fresh or with BORNIT® Bitumen Cleaner if hardened
Materials harmful to health in terms of the German substances regulation (Arbeitsstoffverordnung) none
Hazard class according to VbF and ADR none

The vertical and straight edges of the joint should be free of dirt, dust, oil and unbonded material. The product also adheres to slightly moist (but not wet) subgrades. BORNIT® Joint Flex is applied immediately before the next asphalt lane will paved.

BORNIT® Joint Flex is designed for the mechanical processing of long, even joint edges with the specially developed processing machine BORNIT® Flexomat AIR.
The thickness of the application at the joint edge can vary depending on the application speed (feed) and the valve position at the machine. Including all of the bywork, this machine can easily achieve an application rate of approximately 700 m per hour. Please request the technical documents for this handy machine separately.

BORNIT® Joint Flex can also be applied using other suitable machines or manually using a paintbrush or spatula on small sections. During application, the joint edge or connection area must be completely coated evenly with a material thickness of approximately 4-5 mm. Particular attention must be paid to careful application in the area of the upper joint edge.
The hot mix asphalt can be paved immediately after the application of BORNIT® Joint Flex and it is important that this is done on the same working day. By normally rolling of the asphalt joint area the material will spread out in the asphalt cavities and is immediately drying out through the heat of  the asphalt. Processing is possible down to -5°C, providing the subgrade is free from ice.
Buckets that have already been opened must always be closed.

approx. 0.30 litres / each running meter by an asphalt layer thickness of 4 cm - corresponds to about 50g/lfm per cm asphalt layer thickness, consumption ZTV Asphalt StB 07th

Can be stored for 12 months in the original closed buckets. Can be stored down to -5°C.

Only empty containers may be recycled. Residual product according to GCU ASN: 080410 (adhesives and sealants containing wastes other than those mentioned in 080409) to be disposed of.

25 l - bucket...................18 buckets per pallet


Stock Note


Necessary information – particularly for the use and the use of our products – please refer our brochures. We are at your personal disposal.