Crosslinker

Crosslinker for aminoterminated Copolyamides

ROWAK AG offers with its tradename ROWAFLEX® X 600 a emulsifier containing crosslinker that reacts particularly with aminoterminated Copolyamides. ROWALIT® 200-63 is an aminoterminated Copolyamide and has appropriate amingroups that can be well converted duroplastic.

Crosslinking reaction



When processing complex paste systems with aminoterminated copolyamides a choice of important processing guidelines must be considered. Especially the "open time" is important when applying the paste to the substrate. The "open time" defines a time period betwen coating of the adhesive paste and fusing of the laminate / composite / lining.

The crosslinker ROWAFLEX® X 600 in combination with the aminoterminated, crosslinkable copolyamide ROWALIT® 200-63 defines also the "open time" at the paste preparation and following coating process. After the paste formulation has been prepared it should be processed / coated within 2 hours.

Recipe recommendation

In practice, the crosslinkable paste is been formulated like a normal paste recipe. Although the earlier mentioned paramaters must be considered.

After paste preparation, the crosslinkable paste must be used within 2 hours.

Crosslinkable Paste Formulation (Standard)

Sequence 
Product Qty (kg)
Purpose
 1.  Water  55.0-60.0  Matrix
 2.  ROWAFLEX® X 600  3.00  Emulsifier/Crosslinker
 3.  ROWALIT® 200-63  30.00  Aminoterminated COPA
 4.  ROWAFLEX® TH 3
 0.30-0.50
(max. 0.80)
 Thickener
 5.  ROWAFLEX® X 100 8.0-10.0 Stabilizer

After the coating has been finished, the coated substrate must be laminated with 2 hours.

     
     
  Stork – CT 4 Pastehead    Meyer - Flow-through-press

Influence of crosslinkable process speed and temperature setting of the used dryer in the coating process:



 
As shown in the above time/temperature chart, the open time is reduced the higher the dryer temperature is. In practice, this means that lamination must be executed within 2 hours. Otherwise the bond strength decreases severely. A direct lamination process does not impact bond strenght and provides favourable results.

Direct lamination process ( Paste-Drying-IR-Lamination )



    Paste Unit                Circulation air dryer        IR     Lamination Unit

Discontinous lamination of crosslinkable paste systems

If no direct lamination is possible, the coated substrate must be laminated/ fused within 2 hours:
 
The results of aminoterminated copolyamides used in crosslinkable paste formulation are outstanding when processed with appropriate parameter settings.


Automotive: Example rear shelves
At this application the special properties as high adhesion and cohesion is exploited. It garantees a high heat resistance and excellent bond strenght against usual commercially used needle felts.

Properties after crosslinking

Due to the interference of aminoterminated copolyamide (ROWALIT® 200-63) with the appropriate crosslinker component (ROWAFLEX® X 600), composites with special properties can be produced.

Primarily:

Application for double-dot technology

A further application for crosslinkable pastes is for the double-dot technology that is used in the apparel industry. The crosslinkable paste is used for the base dot. In combination with acid-based copolyamides favourable fastnesses are achieved in terms of:


Schematic view of Double-dot Process:

Competence

We are happy to advise you further. Contact our experienced technicians.

ROWAK AG