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.
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| 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:
- good heat resistance
- high resistance against usual commercial cleaning processes
- high resistance against organic solvents
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:- high strike-through and strike-back reliability
- good bond strength
- specially for "open" substrates
Schematic view of Double-dot Process:
Competence
We are happy to advise you further. Contact our experienced technicians.
ROWAK AG