Bonding Composite Fabrics using Pressure Sensitive Adhesive (PSA):
1. Determine the width of the seam:
For many applications that use lightweight composites a 12 mm (0.5 inch) PSA seam width may be adequate. All seams should be tested to verify they have the
appropriate properties for the intended end-use application.
2. Before applying PSA, ensure surface is clean and dry.
You can clean the surface with a solvent such as acetone or rubbing alcohol. Residual dirt, oil, or moisture will negatively affect the performance of the bond.
3. Initial Bond:
Peel the paper backer from the PSA and apply the adhesive transfer tape to the first laminate area to be seamed/bonded. Using a roller or thick felt block, apply firm pressure to ensure 100% contact. The PSA tape should be inside the edge of the fabric or dirt/debris will stick to the adhesive. Remove all air bubbles.
4. Final Bond:
Remove release liner. Apply the second laminate to the exposed PSA. Care should be taken to apply the second laminate with equal tension and no creases/wrinkles. Use a rubber roller or felt block and apply firm pressure to ensure complete contact. Allow completed article/part to cure at room temperature for 1-2 days for increased seam strength. Initial peel strength may be lower but will increase over time.
5. It is not required, but adding heat can accelerate the seam bonding time.
If this option is chosen, the recommended cure parameters is 116°C (240°F) for 30 seconds up to 10 minutes depending on the article/seam design. Pressure is also recommend (e.g. heat press). Pressure should be as great as possible. Do not exceed cure temperatures of 130°C (265°F). Depending on end use conditions and the intended performance of the seam, lower cure temperature or time may be sufficient.
NOTE:The seam will gain strength over the next several days as the adhesive ages.
6. Optional stitch:
If necessary, stitching may be added to the seam to improve the peel strength. Be aware that stitching may reduce the strength of the seam because of the perforations. The stitch may also reduce the water-tightness of the laminate; a liquid adhesive such as Seam Grip® may be applied over the stitch to cure this. A straight stitch is recommended, 6-8 stitches per inch, 16 or 18- gauge needle, Nylon 69 thread. Stitch no closer than 1/4-inch from the edge of the laminate.
The PSA has limited tack on woven fabrics and may come off when peeling away the release paper. A mix of stitching and PSA tape will give better seam integrity and performance.
8. Reinforced seam
CT2E.08/PSA is a typical reinforced seam. Remove release liner from PSA and apply pressure using a rubber roller or felt block. Adding heat is not required as this is a room temperature adhesive system but heat can accelerate the bonding time requirement.