Honeycomb core sandwich panels

Abstract

In accordance with one embodiment of the present disclosure, a method for manufacturing a honeycomb core sandwich panel includes placing a thermoset facesheet in contact with a thermoplastic honeycomb core without using a separate adhesive and attaching the thermoset facesheet to the thermoplastic honeycomb core by using a curing profile comprising a temperature that is lower than a gel point temperature of the thermoset facesheet and higher than a softening point temperature of the thermoplastic honeycomb core.

1 .- 40 . (canceled) 
     
     
         41 . An apparatus, comprising:
 a thermoset facesheet; and   a thermoplastic core, wherein the thermoplastic core has a deformation zone;   wherein the thermoset facesheet is attached to the thermoplastic core using a curing profile and wherein the curing profile comprises curing the thermoset facesheet and the thermoplastic core at a same time and at a same temperature.   
     
     
         42 . The apparatus of  claim 41 , wherein the thermoset facesheet comprises an epoxy resin. 
     
     
         43 . The apparatus of  claim 41 , wherein the thermoplastic core comprises polyetherimide (PEI). 
     
     
         44 . The apparatus of  claim 41 , wherein the thermoset facesheet is attached to the thermoplastic core without using a separate adhesive disposed between the thermoset facesheet and the thermoplastic core. 
     
     
         45 . The apparatus of  claim 41 , wherein the thermoplastic core comprises a plurality of cells, each cell comprising a curved cell wall in a substantially circular tube shape. 
     
     
         46 . The apparatus of  claim 45 , wherein each cell has a diameter that, when measured at a midplane of each cell, does not vary more than 10 percent within each cell. 
     
     
         47 . The apparatus of  claim 45 , wherein the plurality of cells have a longitudinal axis that is perpendicular to a plane of the thermoset facesheet. 
     
     
         48 . The apparatus of  claim 41  wherein the curing occurs at a pressure less than an ambient pressure for a certain period of time and in a vacuum-capable oven. 
     
     
         49 . The apparatus of  claim 41 , further comprising a second thermoset facesheet attached to the thermoplastic core on an opposite side of the thermoplastic core from the thermoset facesheet. 
     
     
         50 . The apparatus of  claim 49 , wherein the second thermoset facesheet is attached to the thermoplastic core using a curing profile and wherein the curing profile comprises curing the second thermoset facesheet and the thermoplastic core at a same time and at a same temperature. 
     
     
         51 . The apparatus of  claim 41 , wherein a first cell in the thermoplastic core has a different size than a second cell in the thermoplastic core. 
     
     
         52 . The apparatus of  claim 45 , further comprising a space interposed between at least some of the plurality of cells, wherein each space comprises a same material as the curved cell wall of the at least some of the plurality of cells. 
     
     
         53 . The apparatus of  claim 45 , further comprising a space interposed between at least some of the plurality of cells, wherein each space comprises a different material as the curved cell wall of the at least some of the plurality of cells. 
     
     
         54 . The apparatus of  claim 45 , wherein each of the plurality of cells comprise a void. 
     
     
         55 . An apparatus, comprising:
 a thermoset facesheet; and   a thermoplastic core, wherein the thermoplastic core comprises a plurality of cells, the cells comprising:
 cell walls; and 
 a void; 
   wherein the thermoset facesheet is attached to the thermoplastic core using a curing profile; wherein the curing profile comprises curing the thermoset facesheet and the thermoplastic core at a same time and at a same temperature; and wherein a thickness of the cell walls measured at an interface of the thermoset face sheet and the thermoplastic core is greater than at a midplane of the cells.   
     
     
         56 . The apparatus of  claim 55 , wherein the thermoset facesheet is attached to the thermoplastic core without using a separate adhesive disposed between the thermoset facesheet and the thermoplastic core. 
     
     
         57 . The apparatus of  claim 55 , wherein the curing occurs at a pressure less than an ambient pressure for a certain period of time and in a vacuum-capable oven. 
     
     
         58 . The apparatus of  claim 55 , further comprising a second thermoset facesheet attached to the thermoplastic core on an opposite side of the thermoplastic core from the thermoset facesheet. 
     
     
         59 . The apparatus of  claim 58 , wherein the second thermoset facesheet is attached to the thermoplastic core using a curing profile and wherein the curing profile comprises curing the second thermoset facesheet and the thermoplastic core at a same time and at a same temperature. 
     
     
         60 . An apparatus, comprising:
 a first thermoset facesheet;   a second thermoset facesheet; and   a thermoplastic core, wherein the thermoplastic core comprises as plurality of cells, the cells comprising:
 cell walls; 
 a void; 
 a longitudinal axis perpendicular to a midplane of the first thermoset facesheet; and 
   wherein the first thermoset facesheet is attached to the thermoplastic core using a curing profile and without using a separate adhesive disposed between the first thermoset facesheet and the thermoplastic core;   wherein the second thermoset facesheet is attached to the thermoplastic core using the curing profile and without using a separate adhesive disposed between the second thermoset facesheet and the thermoplastic core;   wherein the curing profile comprises curing the first thermoset facesheet, the second thermoset facesheet, and the thermoplastic core at a same time and at a same temperature; and   wherein a thickness of the cell walls measured at an interface of first thermoset facesheet or the second thermoset facesheet and the thermoplastic core is greater than at the midplane of the cells.