How to Bond to Kevlar
- 1). Analyze the specific application of Kevlar and its material bonding partner. There are typically two classes of bonding to Kevlar: Kevlar-to-Kevlar and Kevlar-to-non-nylons. There are also several sub-categories: fabric-to-fabric, fabric-to-solid and solid-to-solid.
- 2). For Kevlar-to-Kevlar/solid-to-solid applications, light surface abrasion with non-metallic abrasion materials to ~1 mm will suffice. (Note: machine abrasion is not recommended.) Hand clean the surface with rags damp with resorcinol, calcium chloride or ethanol solvent prior to abrasion.
- 3). Apply two thin coats of polymer adhesive -- polyurethane or modified epoxy -- with unidirectional paintbrush strokes. Compress at 2 psi and cure thermally at 150 degrees Fahrenheit for 8 hours.
- 4). All other Kevlar-to-Kevlar bonds require only direct application of modified epoxy, cyano-acrylate or modified phenolic adhesive and similar thermal curing. Fabric contact holding to either fabric or solid is required but varies widely with the Kevlar material.
- 5). All Kevlar-to-non-nylon materials require material-specific techniques, but generally abrasion is required only when one of the bonded materials is solid. Bonding to glass, metal or stone requires a polyamide adhesive and light application but high compression -- in the range of 10 psi -- and low thermal curing at 125 degrees Fahrenheit for 24 hours.
- 6). All Kevlar bonding operations must be performed in an atmospherically controlled environment. Kevlar-to-Kevlar bonding requires only a relative humidity of 55, whereas all Kevlar-to-non-nylon materials requires a RH factor of 8.
- 7). Kevlar-to-non-nylon bonds should pass stress tests in the range of 250 to 1000 psi (1.7 to 6.9 MPa). Post-bonding testing is advised but varies widely by specific application.
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