Abstract: A solventless node adhesive for use in bonding honeycomb layers together. The node adhesive includes thermoset resin and thermoplastic particles dispersed in the adhesive. The node adhesive is applied to the honeycomb node lines while the thermoplastic particles remain dispersed in the adhesive. The amount of thermoplastic particles in the node adhesive is selected to keep the viscosity of the adhesive between 30 and 150 poise at room temperature. The node adhesive may be applied to the honeycomb nodes using conventional application procedures. The thermoplastic particles are dissolved during heat curing of the thermoset resin to form a thermoplastic toughened node adhesive.

Abstract: Resins which are a combination of phenolic and polyamide polymers are used as dipping resins to coat composite honeycomb structures. The phenolic/polyamide dipping resins increase the heat formability of composite honeycomb structures. The dip resin forms a coating on the honeycomb which includes from 30 to 95 weight percent phenolic resin and 5 to 30 weight percent polyamide resin. The dip resin is especially useful for coating composite honeycomb cores made from graphite or glass fibers impregnated with flexible phenolic resins.

Abstract: A solution of phenolic and polyamide polymers is used as a dipping resin to coat composite honeycomb structures. The phenolic/polyamide dipping resin increases the heat formability and strength of composite honeycomb structures. The coating formed by the resin includes from 30 to 95 weight percent phenolic resin and 5 to 30 weight percent polyamide resin.