US 5,269,436 AGranted

Double-wall tank and method of its manufacture

AssigneeAdisa Entwicklungs AG

InventorWerner Bachmann

Life of this patent

Estimating the term…

Loading patent…

Abstract

To improve the strength, resistance to leaks, and formation of tears and fissures in the inner wall of a double-wall tank, the inner wall is formed, as described in the inventor's earlier U.S. Pat. No. 4,739,895 (U.S. Pat. No. Re. 33,421) by a plurality of foil or sheet elements which are overlapped at the edges, and covered by a plastic, preferably epoxy layer. The sheet elements are preferably aluminum foils of from 0.15 to 0.3 mm, preferably 0.2 mm thickness. The plastic layer is reinforced by a multi-ply, preferably two-ply, glass fiber fabric, which is so woven that the layers or plies of the fabric are interwoven or interlocked. The fabric is embedded in the plastic coating, before it is cured, for example by rolling it into the plastic coating. To assure good fitting of the inner wall against the outer wall, a vacuum is applied in the space formed by the projections or puckers of the sheet elements and the outer wall before the plastic coating has cured, and maintained until it is cured. The sheet or foil elements and the reinforced plastic will then form a laminate of high inherent stability with high bending and tensile strength, so that fissures are effectively avoided and the tank construction will be reliably tight and highly resistant to the formation of bulges and damage, for example due to dropped tools during installation, or inspection.

Claims17

Dependent claims

A double-wall tank having

an outer wall (21) and an inner wall (23),
wherein the inner wall comprises;
a foil element (25) having projections extending from the major surface of the foil element towards the inner surface of the outer wall (21), said foil element having a ridged surface facing the outer wall;
a plastic layer (27) having a reinforcement material embedded therein, whereby the plastic layer and the reinforcement material forms a reinforced plastic layer, said reinforced plastic layer covering the foil element and forming with said foil element a laminated structure (23), and
wherein the reinforced plastic layer has terminal end regions at an uppermost portion thereof and said terminal end regions extend beyond the foil element and are sealingly connected to the inner surface of the outer wall (21) to define a leakage test space (19) between the inner surface of the outer wall (21) and the facing surface of the foil element (25) for testing the double-wall tank for leakage,
and wherein the reinforcement material comprises
at least two layers of woven fabric (29) having strands or threads of high strength material in which said at least two layers are interlocked by at least some of the strands of the fabric of one layer extending into the other layer, over and around at least some of the strands of the fabric of the other layer and extending back into said one layer again, over and around at least some of the strands of the fabric of said one layer.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/928,967Filed 11 Aug 1992
Granted: 14 Dec 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B29C 63/26
Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor: lining or sheathing of internal surfaces
B29C 63/0021
Characterised by the choice of the material: with coherent impregnated reinforcing layers
B65D 90/042
Rigid liners fixed to the container: fixed pointwise or linewise
B29K 2105/08
Containing reinforcements, fillers or inserts: of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns