METHOD OF MAKING POROUS LAMINATE

• US 3,767,499 A
• Filed: 09/09/1971
• Issued: 10/23/1973
• Est. Priority Date: 09/09/1971
• Status: Expired due to Term

• Current Assignee: Rohr Industries, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Muriel L. Koss
• Inventors: Koss, Muriel L.
• Primary Examiner(s): Powell, William A.
• Application Number:
  US05/179,088
• Time in Patent Office: 775 Days
• Field of Search: 161/55,57-60,68,140,143,112,113,156,157 156/180,181,296,433,441 181/33R,33G,33GA
• US Class Current: 156/181
• CPC Class Codes: B29C 70/00 Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
• CPC Class Codes: B29K 2309/08 Glass
• CPC Class Codes: B32B 2307/102 Insulating
• CPC Class Codes: B32B 3/30 characterised by a layer formed with recesses or projections, e.g. hollows, grooves, protuberances, ribs apertured layer B32B3/266; layer with cavities or internal voids B32B3/26
• CPC Class Codes: B32B 5/12 characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: Y10T 428/24074 Strand or strand-portions
• CPC Class Codes: Y10T 428/24149 Honeycomb-like
• CPC Class Codes: Y10T 428/24298 Noncircular aperture [e.g., slit, diamond, rectangular, etc.]
• CPC Class Codes: Y10T 428/24306 Diamond or hexagonal

Abstract

An apertured laminate which may be used as a face sheet of a honeycomb core sound suppression panel for a jet aircraft engine is formed from a plurality in excess of two superposed layers of thin, ribbon-like bands of selected widths, the bands of each layer being parallel and spaced apart by gaps of selected widths. The bands of each layer are disposed at different, selected angles to those in each of the other layers, and the gaps in successive layers are arranged to intersect and register at selected common points to define apertures of selected size, shape and distribution in the resultant laminate.

Claims

1. The method of making an apertured laminate for use as the facing sheet for a sound absorptive panel having a backing sheet, a resonant chamber, and a facing sheet, said facing sheet having apertures therein of selected size, shape and distribution, which method comprises:

arranging a first plurality of bands of selected material and of selected widths in parallel, side-byside relation, thereby comprising a first layer of said bands, superimposing upon the bands of said first layer a second plurality of bands of selected material and of selected widths, also in parallel, side-by-side relation, thereby comprising a second layer of such bands, superimposing upon the bands of said second layer a third plurality of bands of selected material and of selected widths, also in parallel, side-by-side relation, thereby comprising a third layer of such bands, laterally adjacent bands of each of said layers spaced apart by selected widths to form gaps therebetween, the bands of each of said layers being disposed at a selected anglE to the bands of each of the other layers, and so arranged that selected gaps in all of the layers intersect at common, selected points in the resulting laminate formed by the superpositioning of such layers of bands, thereby to form at each such selected point, an opening of selected size, shape and distribution in the laminate, and impregnating the laminate with a binder to band all of said bands together into an integral, apertured laminate.

2. The method defined in claim 1 wherein the widths of the bands, and the spacing between laterally adjacent bands in the same layer are varied to thereby predeterminedly vary the size and shape of the apertures and their location in the laminate.

3. The method defined in claim 1 wherein selected ones of the bands are of varied strength, thereby varying the strength of the completed laminate in the direction of such varied bands.

4. The method defined in claim 1 wherein edges of bands defining the sides of all of the gaps intersecting at a common point to provide an aperture in the laminate, define the sides of such aperture.