CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Serial No. 61/459,718, filed December 17, 2010, titled "Flash boot de-icer," the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to de-icers that are used for inhibiting ice accumulation on aircraft structures. Particular structures that experience atmospheric ice accumulation are the wings, tail, and engine intake, although other aircraft structures are considered within the scope of this invention.

BACKGROUND

Ice accumulation on aircraft structures is recognized as a serious hazard, both in flight and when the aircraft is parked on the ground. There are two types of solutions— one is to provide anti-icing equipment, which prevents the ice from forming (and is turned on before the aircraft enters icy conditions), and second solution is to provide de-icing equipment, which is designed to remove ice after is has accumulated on the aircraft. Embodiments of this invention will be described with respect to de-icing equipment, but it should be understood that it is possible to use embodiments described herein with anti-icing equipment as well.

Various de-icing devices have been developed and are in current use today. A number of different de-icer options exist. Generally, a de-icing boot is an ice protection system that is installed on one or more aircraft surfaces to permit a mechanical de-icing. These boots are generally installed on the leading edges of wings because these are the areas on the aircraft that are the most likely to accumulate ice, which can severely affect the aircraft's performance in icy conditions. However, de-icing boots may be positioned on other structures of the aircraft, and the embodiments described herein may be used on any aircraft surface.

For example, one type of de-icer is a pneumatic de-icer boot that is used to safely remove ice accumulation on the external surfaces of the aircraft wing, tail, and engine intake. This type of de-icer is designed with expandable layers of rubber or fabric, and as atmospheric icing occurs and ice builds up, a pneumatic system inflates the boot with compressed air. This expansion in size cracks any ice that has accumulated, and the cracked ice is then blown away by the airflow current over the wing. Other de-icing systems include, but are not limited to, electrothermal heating systems and bleed air systems. Electrothermal heating usually include a heating element that uses electrical power to generate heat to cause the ice to melt or to prevent its formation. Other electrically-powered systems are known. Bleed air systems use hot air from the engine exhaust manifolds, which is routed to the leading edge of the wings, and/or horizontal and vertical tail stabilizers.

Current de-icer boots are bonded to the aircraft with cement as Bostik 2402, which is a long and difficult process. As example of this method is shown in Figure 2. It requires preparation of the cement (usually a mixture with at least two components to be mixed), and then application of a primer. The cement application process requires several coats with a waiting time in between coats. That layer is then wiped with solvent, and the de-icer boot is bonded to the surface with a tackifying substance, using a rolling process. The downtime of the aircraft during the installation may cost up to thousands of dollars.

Other installation methods use an adhesive, such as or 1300L from 3M. However, installation of a de-icer with 1300L adhesive involves applying the adhesive to the aircraft structure as well as to a bonding surface of the de-icer. This can lead to user error in determining the correct amount of adhesive to use, as well as determining whether the adhesive dry time has been sufficient before the boot is applied. The adhesive dry time also adds to aircraft downtime. A further improvement upon the adhesive and cement process has been described by U.S. Patent No. 6,250,587, which relates to a technology called the FASTboot™ de-icer from BF Goodrich. Examples of the steps of this system are shown in Figures 3-5. This system uses a PSA (pressure sensitive adhesive) technology that requires a primer to be applied over a solvent. First, the surface is cleaned with a cleaning solvent. Once the de-icer has been measured and the leading edge of the wing has been marked, a coating of primer is then applied to the area that will receive the boot. After the primer has dried, the release backing of the boot is removed and it is applied to the wing, typically using a roller. Edge sealer or edge filler is then applied. There is a working time of about sixty minutes, otherwise, the primer will need to be reapplied. In short, there are two adhesive steps required for the installation of this system— the first is priming the surface with primer, and the second is rolling the de-icer boot into place. Additionally, the installer needs to maintain the primer on site, as well as have access to brushes or rollers for application of the primer.

Although these prior applications are acceptable, it is desirable to provide further improved adhesives for securing de-icer boots to an aircraft surface with safety and efficiency. It is also desirable to provide a de-icer boot application system that uses fewer steps and that has less dry and working time involved.

BRIEF SUMMARY

Embodiments of the invention described herein thus provide improved adhesives and methods for securing de-icer boots to an aircraft surface with safety and efficiency, without the use of a primer. In one embodiment, there is provided a device for de-icing an aircraft structure, comprising a de-icing boot and a pressure-sensitive adhesive pre-applied to the de-icing boot, the pressure sensitive adhesive comprising a high-tack adhesive that can adhere the de-icing boot to the aircraft structure without use of a primer. In a further embodiment, there is provided a method of applying a de-icing boot to an aircraft structure, comprising (a) providing a de-icing boot having a pressure sensitive adhesive pre-applied to a lower surface thereof; (b) preparing the aircraft structure to receive the de-icing boot; (c) removing a backing covering the pressure sensitive adhesive from the de-icing boot; and (d) applying the de-icing boot directly to the aircraft structure without first applying a primer to the structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top plan view of one embodiment of a de-icer boot application system according to embodiments of the invention.

FIG. 2 shows a prior art cement de-icer boot application.

FIG. 3 shows a prior art primer/adhesive de-icer boot application. FIG. 4 shows a first step of the prior art system of FIG. 3.

FIG. 5 shows a second step of the prior art system of FIG. 3.

FIG. 6 shows more detail of the improved embodiments provided herein.

FIG. 7 shows the single step of the system of FIG. 6. FIG. 8 shows a schematic of the application of a pressure sensitive adhesive to a de-icer boot.

DETAILED DESCRIPTION

Embodiments of the present invention provide a pressure sensitive adhesive system that eliminates some of the above-described problems. There is provided a de- icer system that can be installed without cements or primers.

In the embodiments shown in FIGS. 1 and 6, the de-icer system 10 includes a de-icer boot 12 that has a pressure sensitive adhesive applied thereto. The de-icer boot has a lower surface 14 that may be formed of polychloroprene or any other appropriate material that forms the de-icer boot 12. In one specific embodiment, the polychloroprene may be combined with other materials to improve adhesive performance. For example, the polychloroprene may be mixed with a rubber component. The rubber component may be a natural rubber. Any combination percentage is possible and within the scope of this invention, potential ranges including but not limited to about 75% polychloroprene/25% natural rubber; about 85% polychloroprene/ 15% natural rubber; about 65% polychloroprene/35% natural rubber; or about 60% polychloroprene/40% natural rubber. Generally, more polychloroprene is used than rubber, but that is not a requirement. This mixture helps the adhesive applied to the de-icer boot to obtain an excellent adherence to the boot.

The lower surface 14 is a portion of the de-icer boot that is in contact with a pressure sensitive adhesive (PSA) 16 that is directly pre-applied to the surface 14. The pressure sensitive adhesive 16 used in connection with this application allows the de-icer boot 12 to be installed directly to the aircraft surface, without the need for primer or any other adhesive-assisting material. The system is provided with the PSA pre-applied, so the user does not have to obtain, mix, or apply adhesive. In a specific embodiment, the PSA used is a high performance, transfer tape made of modified adhesive based on acrylate. It should be designed or acceptable for use for heavy duty applications on smooth or textured surfaces, and on flat or curved surface. It should have good tack and be able to withstand and maintain its effectiveness in extreme temperature changes and other extreme conditions, such as ice, sleet, snow, high velocity wind, and rain. Desired service temperatures range from about -40°C to about +70°C, and possibly even up to +120°C or +150°C. The PSA used should also exhibit good tack and immediate adhesion on aluminum and composite materials. In a particular embodiment, the PSA has a coating weight of about 350 g/m ² .

In a further particular embodiment, the PSA is provided as a transfer tape in a roll, that can be applied directly to the de-icer boot during manufacturing, so that the boot is provided with the adhesive pre-applied. In a further particular embodiment, the PSA has a tape thickness of less than about 0.64 mm, and in an even more particular embodiment, a thickness of about 0.35 mm (generally excluding the liner).

One specific example of a PSA that is suitable for use in embodiments of this invention is ProLINK 350 LE, manufactured and sold my Biolink Tape Solutions. Other potential adhesives are manufactured and sold by Biolink, as well as 3M or Tesa Company. It is preferable that the PSA selected for use with the de-icer boot embodiments described herein be useable with the application of a first primer layer. The PSA should have good and immediate tack to the aircraft surface.

In order to apply the PSA to the lower surface 14 of the boot 12, the boot is first manufactured according to standard process (but there may be a mixture of the polychloroprene and natural rubber described above), providing one side as having a grained surface. The de-icer boot is positioned with the grained side upward and cleaned, e.g., with isopropyl alcohol or any appropriate cleaning solvent or solution. After the solvent has evaporated, the PSA is applied to lower grained surface of the boot. A protective backing on the back of the PSA layer remains in place and a steam roller may be used to ensure securement of the PSA to the boot. An example of this process is shown in Figure 8. If desired, the protective backing may be replaced with a branded protective backing to evidence the de-icer boot supplier, rather than the adhesive supplier. The de-icer system 10 described eliminates the time consuming and environmental impact during de-icer boot installation due to leading edge priming. Instead of using a potentially long dry time primer on the leading edge surface of the aircraft in order to install the de-icer, the flash boot allows installation of the de-icer without the extra labor required to apply a primer. The installation of system 10 includes first buffing and otherwise cleaning the aircraft surface to which the de-icer boot is to be applied. The de-icer boot is then applied by simply removing the backing and rolling it onto the leading edge. The use of a high-tack adhesive eliminates the need for a primer required to bond the de-icer boot to the aircraft surface.

Implementation of the de-icer system described will reduce installation time (because no primer or cement coating is needed), will reduce hazardous waste due to its pre-applied adhesive, and will reduce the amount of solvent used during the bonding operation, rendering it a more environmentally-friendly solution. There are low solvent quantities in the PSA used, and there is no tackifying operation required. This improvement also allows a shorter replacement time versus a "standard" bonding installation method.

Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the invention and the following claims.