WO2007136666A2

WO2007136666A2 - Method for camouflaging objects

Info

Publication number: WO2007136666A2
Application number: PCT/US2007/011758
Authority: WO
Inventors: Allan Craig Marshall; William Henderson
Original assignee: Omnova Solutions Inc.
Priority date: 2006-05-16
Filing date: 2007-05-16
Publication date: 2007-11-29
Also published as: WO2007136666A3

Abstract

A camouflage covering in the form of a thermoformable film that includes a plurality of camouflage components for concealment can be bonded to an object by contacting the film with the object and applying heat and/or pressure to the covering.

Description

METHOD FOR CAMOUFLAGING OBJECTS

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. provisional application no.

60/800,647, filed 16 May 2007, the entire disclosure of which is incorporated herein by reference.

BACKGROUND INFORMATION

[0002] The present invention relates to a camouflaged object and to a method for forming the same. In a particular but not exclusive aspect, it relates to a method for forming an object protected against detection from military sensing methods. [0003] Camouflage patterns commonly are painted onto structures for concealment during military operations. However, painting requires time to create the camouflage pattern and to apply multiple colors. Furthermore, incorporating into paint(s) additional components to provide protection against detection by a variety of spectral types of radiation is difficult.

[0004] Various coverings capable of providing camouflage are known. Such coverings include nets for throwing over objects to be hidden, magnetic plates for attaching to objects such as vehicles, and sheets which can be adhered, either temporarily or permanently, to objects. Temporary coverings of these types can be inconvenient in situations requiring rapid application of camouflage to objects, for example when troops or equipment are moving or being set up in a new location; for instance, temporary coverings such as nets can take time to put in place. [0005] Accordingly, having permanent camouflage for situations in which troops or equipment are required to move swiftly generally is preferable. Such permanent camouflage should be tailored for the environment in which the troops and equipment are or are to be located. For example, a vehicle in a city environment (generally grey in color) typically requires different camouflage than a vehicle in a desert environment (generally yellow-brown in color) or one in a vegetated environment (generally green in color). [0006] The aforementioned types of temporary camouflage coverings also can be ill-suited for long-term use because they can be damaged by exposure to extreme climatic conditions such as heat or rain and/or by extensive handling. Some also might be unable to remain attached to the objects they are intended to cover in hostile conditions such as storms, high wind and/or enemy attack.

[0007] Providing durable camouflaging of objects requiring protection remains desirable.

SUMMARY

[0008] According to a first aspect is provided a method for bonding to an object a camouflage covering that includes a plurality of components for concealing the covering and object, even in a military environment. The method includes placing a camouflage covering in the form of a thermoformable film against the object and applying heat and/or pressure to the covering to cause it to bond to the object. [0009] According to a second aspect is provided a camouflaged object that includes an object having a camouflage covering bonded thereto. The camouflage covering includes a plurality of components for concealing the covering and object, even in a military environment, and is formed from a thermoformable film. The covering can be bonded to the object by the application of at least one of heat and pressure.

[0010] According to a third aspect is provided a camouflage covering for bonding to an object. The camouflage includes a plurality of components for concealing the covering and object, even in a military environment, and is in the form of a thermoformable film that is capable of being placed against and bonded to an object to be camouflaged by the application of at least one of heat and pressure. [0011 ] The plurality of camouflage components can include one or more components intended to modify the spectral characteristics of the covering so as to conceal it and an object which it covers. The spectral characteristics can be in one or more of the visible, near IR, thermal IR, UV, and radio spectral regions. [0012] The. camouflage covering can include a layer of adhesive or, prior to placing the covering against the object to be protected, a layer of adhesive can be applied to one or both of the covering and the object. The adhesive can include a polyurethane, which may be a thermoplastic and/or which may be provided from a reactive two-component system.

[0013] The camouflage covering can be stretched over the object before and/or during the application process. The application process can be carried out in a device such as a membrane press.

[0014] The camouflage covering can be made from materials that include at least one of acrylics; polyolefins such as polypropylene, low density polyethylene (LDPE), PTFE, etc.; polyesters such as polyethylene terephthalate (PET) or poly- butylene terephthalate (PBT); co-polyesters; a nylon such as nylon 6, nylon 66, etc.; butyl rubber; aramid (e.g., Kevlar™) fibers; and poly(vinyl halide)s such as PVF and PVC. One or more of these materials can be in the base material (film) of the camouflage covering.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the invention are set forth in the following description and shown in the drawings, although the invention is particularly and distinctly set forth in the claims. In the accompanying drawings,

FIG. 1 is a side view, not to scale, of an embodiment of a thermoformable film according to the present invention, and FIG. 1 A is a magnified side view, not to scale, of a portion of the thermoformable film from FIG. 1; and

FIG. 2 is a side view of a membrane press useful for applying a covering to an object to be camouflaged.

Similar numbers refer to similar parts hereinthroughout.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0016] A polymeric thermoformable film is indicated generally by numeral 10 in

FIGa. 1 and 1A. In FIG. 1 , film 10 is rolled around core 15 for ease of storage and transportation. Lengths of film 10 can be extracted from the roll when they are to be applied to an object to be camouflaged.

[0017] Film 10 has a number of features which make it suitable for use as a camouflage covering; each of the features is intended to enable film 10 to avoid detection by one or more observation methods commonly used in military settings. Certain of these features are explained in detail below.

[0018] Film 10 is formed from one or more polymeric material selected to have certain physical qualities such as durability, flexibility and reasonable resistance to environmental conditions. Suitable materials for the base material of the film include acrylics; polyolefins such as polypropylene, LDPE₁ PTFE, etc.; polyesters such as PET or PBT; co-polyesters; a nylon such as nylon 6, nylon 66, etc.; butyl rubber; aramid (e.g., Kevlar™) fibers; and polyvinyl halide)s such as PVF and PVC. Due to a tendency to absorb chemical agents, PVC generally is considered an unsuitable material for use in military applications. However, if covered with a nuclear- biological-chemical (NBC) barrier coating, it can conveniently be used in embodiments of the present invention. Barrier coatings preferably are chosen to conform to U.S specifications MIL-C-64159, MIL-C-46168D or MIL-C-53039A which govern chemical agent resistant coating (CARC) requirements. [0019] Various additives can be incorporated in film 10 to enhance its camouflage properties. Pigments 30 can be incorporated to modify the visible and IR reflectance characteristics of film 10, and various other pigments and dyes may be added to modify the spectral characteristics of film 10 at other wavelengths such as radio and ultraviolet.

[0020] A pattern can be printed on the upper surface 40 of film 10 to enhance its visual camouflage characteristics. This type of pattern typically includes a variety of colors. When applied by digital printing, a pattern with an essentially infinite repeat length can be provided, unlike conventional printing techniques where the repeat length is defined by the diameter of the rollers used in the printing process. [0021] A coating can be applied to upper film surface 40 to improve its physical durability; a further coating can be included to enhance resistance of film 10 to chemical and biological materials. Alternatively, a single combined coating may be applied to enhance both the physical durability and chemical and biological resistance. Physical durability can be enhanced with, e.g., a crosslinked fluoropolymer (e.g., a fluoroacrylate). Suitable materials for imparting resistance to chemical and biological materials include any of a variety of fluόrinated polymers such as, by way of non-limiting example, fluorinated polyesters, fluorinated polyurethanes, fluorinated polyacrylates, fluorinated epoxies, fluorinated polyimides, fluorinated polyamides, fluorinated poly[(alk)acrylamide]s, PVDF, PVF, PTFE₁ FVE, per- and hydro- fluoropolyethers, perfluoro(alkyl)alkoxy resins, and various copolymers. [0022J Particulate materials 20 can be incorporated in film 10 to further enhance its physical durability and/or chemical and biological resistance. Suitable particulates include nano-dispersed metal oxides (e.g. aluminum oxide, zinc oxide, cerium oxide or titanium dioxide), silicates and clays. Nano-clays (clay particles with thicknesses up to ~10 nm and widths of from ~50 to ~600 nm) in particular can increase the barrier properties of film 10; examples include surface-modified montmorillonite (e.g., Cloisite™ nanoparticles from Southern Clay Products, Inc., and Nanomer™ additives from Nanocor Inc.).

[0023J Upper surface 40 of film 10 can be embossed to reduce glint, glare, gloss, etc., by scattering incident radiation in multiple directions. This can be done solely or in conjunction with application of an anti-reflective coating or film layer. [0024] Film 10 also can be provided with an anti-slip surface to permit personnel to climb onto objects. Such a surface characteristic can be achieved by a variety of techniques including one or more of including particles (made of any of a variety of ceramics, metals and/or metal oxides), including rubbery materials (in the film or as a coating), providing indentations or protrusions in upper surface 40 (using techniques such as embossing), etc.

[0025] Phase change and/or aerogel materials also can be included. These could enable a camouflaged object to absorb and/or release heat. They would be of particular use in areas of elevated temperatures such as, e.g., areas surrounding an engine of a vehicle.

[0026] Camouflage films of the type described in US 2005/0118402 A1 , incorporated herein by reference, are envisioned as being useful in certain embodiments. Such films can provide protection against detection by one, two or more of visible observation, near-IR observation (typically about 650-1400 nm wavelength), far IR observation (typically about 3-5 μm and about 8-14 μm), and radar (typically around 94 GHz, or 2-18 GHz). Radar protection can be achieved by providing a surface which reflects radar or by providing a material which absorbs appropriate wavelengths. Other components can be incorporated to protect against other types of detection.

[0027] The described camouflage techniques and components, as well as potentially others, can be used in any desired combination to achieve a film having camouflage capabilities suited to a particular application.

[0028] A method for applying film 10 is illustrated in reference to FIG. 2. In this embodiment, a military vehicle body part 60 is to be covered using a length of camouflage film 10 from FIG. 1. Body part 60 can be provided from a variety of materials including, e.g., ceramics suitable for use as an armor panel.

[0029] The preformed body part is placed on a support member (lower platen)

100 of a membrane press 80, with a layer of film 10 positioned over it. Film 10 can be held together with a membrane 50 in position above part 60 by means of frame

70.

[0030] An adhesive layer 90 can be applied to the upper surface of part 60 before it is placed in membrane press 80. Preferred adhesives include those made from or includes a polyurethane because these tend to have a high resistance to chemicals and abrasions, have better environmental performance .(e.g., more . tolerant of climate extremes) and are less prone to softening, which leads to a loss of adhesion, than. other adhesives.

[0031] A thermally activated adhesive layer can be pre-applied to the inner surface (i.e., the lower surface as shown in FIGs. 1 and 2) of film 10. Another option is to include an adhesive sheet between part 60 and film 10. Suitable adhesives for pre-applying or for applying in sheet form include polyurethanes, nylons, polyesters, polyolefins and vinyl. Thermoplastic polyurethane is particularly suitable for forming an intermediate adhesive sheet.

[0032] A preferred method for applying adhesive is spraying. Suitable adhesives for spraying include two-component reactive polyurethanes.

[0033] Use of an adhesive is not essential; any suitable means for attaching the camouflage film to the body part may be used. In some embodiments, a chemical bonding between the component materials of the film and the object alone may be used for achieving adhesion of the film to the object. [0034] Once film 10, adhesive 90 (if used) and part 60 have Been arranged in membrane press 80, the upper portion (platen) 110 of press 80 is lowered toward support member 100 and pressure is applied at an elevated temperature. In general, useful methods of attaching or adhering the film to an object to be protected typically involve placing or stretching a film 10 over the object and applying heat or pressure so as to cause the film to adhere to the outer surface of the object, optionally with an adhesive therebetween.

[0035] One particular process involves use of a membrane press such as is described in U.S. Pat. No. 5,580,415, to which the interested reader is directed for a thorough description. Nevertheless, for the convenience of the reader, a general description follows. Typically, a membrane press employs vacuums, first to-pull film 10 upwardly away from part 60 and toward membrane 50 and a heating element and then to remove air from the gap between film 10 and part 60, thereby bringing them into intimate contact while film 10 is at an elevated temperature. [0036] If an adhesive is employed, it may be applied to the film during formation of the camouflage covering, i.e., so that the adhesive forms part of the covering incorporating membrane 50 and film 10 that is lowered toward support member 100 by press 80. This may be achieved by, e.g., pre-applying adhesive to film 10 or by incorporating an adhesive sheet into a covering with the film and membrane in a single step. Alternatively, the adhesive may be applied in a separate step subsequent to the formation of the covering incorporating membrane 50 and film 10. For example, lowering upper platen 110 toward support member 100 can result in the formation of a covering incorporating membrane 50 and film 10, with the adhesive being sprayed onto the resulting covering or with the adhesive being a separate sheet that is incorporated subsequently into the covering as it is lowered toward support member 100.

[0037] Once film 10 has been bonded to part 60, excess film can be trimmed to provide a finished camouflaged product having a durable finish and signature management capabilities for avoiding observation, even in a military environment. [0038] Optionally, one or more further sheets can be used in the lamination process of FIG. 2 to further modify the properties of the end product. For example, a durable textured film or paper might be placed above the camoufla^'ge film. This can be achieved by mounting the textured sheet in frame 70 between film 10 and membrane 50. The texture of the sheet (or a mirror image thereof) is transferred to film 10, which has the effect of achieving a low gloss on the resulting outer surface of the camouflaged body part. If necessary, bonding between film 10 and any additional layer(s) can be enhanced through use of an adhesive. [0039] Each of the described individual features is disclosed in isolation; any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the knowledge of the ordinarily skilled artisan, irrespective of whether such features or combinations of features solve any problems disclosed herein, are to be deemed as disclosed.

[0040] Based on the foregoing description, various modifications within the scope of the invention will be apparent to the ordinarily skilled artisan.

Claims

CLAIMSThat which is claimed is:

1. A method for camouflaging an object, comprising: a) bringing into contact with at least one surface of said object a covering that provides camouflage against at least one sensing method in addition to visual detection, said covering comprising a thermoformable film; b) applying at least one of heat and pressure to cause said covering to bond to said object.

2. The method of claim 1 wherein said covering comprises one or more components capable of modifying the spectral characteristics of said covering in at least one of the visible, near infrared, thermal infrared, ultraviolet, and radio spectral regions.

3. The method of any of claims 1 to 2 wherein said covering further comprises an adhesive.

4. The method of any of claims 1 to 2 further comprising applying a layer of adhesive between said covering and said object before they are contacted.

5. The method of any of claims 3 to 4 wherein adhesive comprises a polyurethane.

6. The method of claim 5 wherein said polyurethane is thermoplastic.

7. The method of any of claims 4 to 6 wherein said adhesive is provided from a reactive two-component system.

8. The method of any of claims 1 to 7 wherein said covering is stretched over said object before, during, or both of before and during said application of at least one of heat and pressure.

9. The method of any of claims 1 to 8 wherein the application of at least one of heat and pressure occurs in a membrane press.

10. The method of any of claim 9 wherein a textured sheet is disposed between said covering and a platen of said membrane press so that, upon application of at least one of heat and pressure, said sheet imparts a textured surface to said covering.

11. The method of any of claims 1 to 10 wherein said covering has been digitally printed with a camouflaging pattern, wherein said pattern is designed to make visual detection of said covering more difficult in at least one environment in which said object is intended for use.

12. The method of any of claims 1 to 11 wherein said covering further comprises one or more types of particulate materials.

13. The method of any of claims 1 to 12 wherein said covering further comprises a phase change material.

14. The method of any of claims 1 to 13 wherein said object constitutes a body panel of a vehicle.