Patent ES-8602485-A3 (ES)
Title: Laminate of metal and thread layers
IPC: B32B15/20
Filed: 1985-02-14
Abstract: EP--56288 A A laminate comprises alternate metal layers and thread contg. adhesive layers. In the unloaded state of the laminate, the metal layers are under compression and the threads are under tension. Pref. the compressive stress in the metal layers is between 0 and 300 N/sq.mm. and the layers are thinner than 1 mm. Pref. the threads are of a material having a modulus of elasticity in the range 10000 to 15000 N/sq.mm. The adhesive may be a metal adhesive or a thermosetting resin adhesive e.g. an epoxy. The laminate may be made by, prior to curing the adhesive, applying tension to the thread layers, the built in stress in the thread layers after curing being effective to put the metal layers under compression. In an alternative method, after curing of the adhesive, the whole laminate is put under tension to elongate the threads and the metal layers and then relaxed to allow the thread layers to pull the metal layers into compression. - A lightweight, very strong laminate of particular use in spacecraft or aircraft applications. EPAB- EP--56288 B A laminate comprises alternate metal layers and thread contg. adhesive layers. In the unloaded state of the laminate, the metal layers are under compression and the threads are under tension. Pref. the compressive stress in the metal layers is between 0 and 300 N/sq.mm. and the layers are thinner than 1 mm. Pref. the threads are of a material having a modulus of elasticity in the range 10000 to 15000 N/sq.mm. The adhesive may be a metal adhesive or a thermosetting resin adhesive e.g. an epoxy. The laminate may be made by, prior to curing the adhesive, applying tension to the thread layers, the built in stress in the thread layers after curing being effective to put the metal layers under compression. In an alternative method, after curing of the adhesive, the whole laminate is put under tension to elongate the threads and the metal layers and then relaxed to allow the thread layers to pull the metal layers into compression. - A lightweight, very strong laminate of particular use in spacecraft or aircraft applications. (28pp) - EP--56288 B A laminate, particularly for use as a component of an aircraft, comprising at least two metal sheets of an aluminium alloy, between which there are provided fibres based on aromatic polyamides and having a high modulus of elasticity, the metal sheets and the fibres being bonded together by means of an adhesive and the metal sheets each having a thickness which is smaller than 1mm, said laminate being characterised in that: (A) the aromatic polyamide fibers consist of polyparaphenylene terephthalamide (PPDT) yarns (B) said aromatic polyamide yarns are made of endless filaments and the yarns are so contained in the completed laminate that they lie in practically straight lines in the adhesive (C) said aromatic polyamide filaments are of a material whose modulus of elasticity is in the range of higher than 5 x 10 power 4 to not higher than 25 x 10 power 4 N/mm2 (D) said aromatic polyamide filaments are present in said adhesive in an amount of 20 to 80% by weight calculated on the total weight of adhesive and filaments (E) each of said metal sheets is of an aluminium alloy having a tensile strength higher than 350 N/mm2 (F) each of said metal sheets has a thickness in the range of 0.1 to 0.7 mm (G) the thickness of each of the metal sheets is greater than the thickness of the individual yarn-adhesive layers (H) in the unloaded state of the laminate in its entirety there is a compressive stress in each metal sheet and a tensile stress in each layer with yarns, said compressive stress in the metal sheets having a value up to 300 N/mm2 (I) said adhesive substantially consists of a thermohardening material. (18pp) USAB- US4489123 A Fibre-reinforced pre-stressed laminate for use in aircraft components comprises sheets of Al alloy bonded together by adhesive layers in which aromatic polyamide fibres are disposed. - The fibres are of poly-paraphenylene terephthalamide yarns made from endless filaments having a modulus of elasticity of 5 x 10 power 4 to 25 x 10 power 4 N/mm2. The yarns lie parallel. The compressive strength of the laminate is up to 300 N/mm2 in each of the sheets.