METHOD OF MAKING ACOUSTIC HOLES USING UV CURING MASKING MATERIAL
A method of forming acoustic holes in a composite sound-insulating material includes creating a image of at least a portion of an array of holes and transferring the image to an ultraviolet (UV) radiation transparent medium. The method continues with positioning the medium in contact with a UV-curable mask and exposing the medium-covered mask to UV radiation to cure the UV-exposed areas. The method further includes removing the uncured mask material to create an abrading mask that includes a plurality of holes in a desired pattern. The method also includes positioning the abrading mask in contact with the sound-insulating material and directing a stream of abrasive matter at the abrading mask to create perforations in the sound-insulating material that correspond to the pattern of holes in the abrading mask.
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1. Field of the Invention
Embodiments of the present invention relate to the creation of acoustic holes in a sound insulating material. More particularly, embodiments of the present invention relate to a method of creating acoustic holes in a sound insulating material using an ultraviolet radiation curing mask.
2. Description of the Related Art
Aircraft engines include sound insulating material to reduce the amount of noise that they produce. The sound insulating material may include a plurality of acoustic holes to enhance its sound insulating ability. Such acoustic holes are typically produced by applying pressure to a polymeric pin mat that is in contact with the sound insulating material. Unfortunately, there are drawbacks to this procedure. Pin mats may be difficult to utilize on sound insulating surfaces that possess varying contours. It is also possible that one or more pins on the mat may break and not create the appropriate perforations, thereby diminishing the sound insulating ability. Correction of this problem may require manual creation of the acoustic holes, often by hand drilling. Furthermore, pin mats are generally fabricated using metal dies, which produce a fixed pattern of pins. Modification of the pin hole pattern requires modification of the metal die, which may be costly and time-consuming.
SUMMARY OF THE INVENTIONEmbodiments of the present invention solve the above-mentioned problems and provide a distinct advance in the art of creating acoustic holes in a sound insulating material. More particularly, embodiments of the invention provide a method of creating acoustic holes in a sound insulating material using an ultraviolet radiation curing mask that is easily created and modified. In addition, the mask is flexible to match varying contours and includes no protruding parts that can detach or break.
The method of forming acoustic holes in a composite sound-insulating material includes creating a positive image of at least a portion of a desired array of holes and transferring the image to an ultraviolet (UV) radiation transparent medium. The method continues with positioning the medium in contact with a UV-curable mask and exposing the medium-covered mask to UV radiation to cure the UV-exposed areas. The method further includes removing the uncured mask material to create an abrading mask that includes a plurality of holes in a desired pattern. The method also includes positioning the abrading mask in contact with the sound-insulating material and directing a stream of abrasive matter at the abrading mask to create perforations in the sound-insulating material that correspond to the pattern of holes in the abrading mask.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.
A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:
The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSThe following detailed description of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
The steps of the method of making acoustic holes using ultraviolet (UV) curing masking material are outlined in
The image 14 may include a positive representation of the array 12, as shown in
The image 14 may be created using computer software, such as computer-aided drafting or design (CAD) programs, word-processing or desktop publishing programs, spreadsheet programs, data presentation preparation programs, photographic or video editing programs, combinations thereof, and the like. The image 14 may also be created by using manual drafting techniques either alone or in combination with computer software techniques.
The image 14 may be transferred to a UV-transparent medium 16 as listed in step 102. Opaque material corresponding to the image 14 is applied to the medium 16 and filters UV radiation from transmitting through the medium 16. The transfer may be performed by printers, plotters, copiers, graphic reproduction machines, combinations thereof, and the like. It is also possible that the image 10 may be formed directly on the UV-transparent medium 16. Manual drafting techniques using permanent, opaque ink on the medium 16 may be utilized or manual placement of patterned opaque stickers or masking tape onto the medium 16 may also be employed.
The UV-transparent medium 16 is positioned in contact with a UV-curable material 18 as listed in step 103 and shown in
The UV-curable material 18 may include monomers, oligomers, or prepolymers as are known in the art. Photosensitive resins may also be included. The thickness of the UV-curable material may be between approximately 0.002 inches and 0.010 inches.
The UV-transparent medium 16 and the UV-curable material 18 are both exposed to a UV-wavelength radiation source 20 as listed in step 104 and shown in
In certain embodiments, if the desired array of acoustic holes 12 is a regular, repeated pattern, then it is possible to use a smaller UV-transparent medium 16 than the UV-curable material 18, such that the medium 16 is repeatedly exposed in different locations across the material 18. The UV-transparent medium 16 is aligned to one location on the UV-curable material 18 and exposed to UV radiation while the rest of the material 18 is covered (or masked) with UV-opaque material to prevent unwanted UV exposure. The UV-transparent medium 16 is aligned with another location on the UV-curable material 18 and exposed to UV radiation while the rest of the material 18 is covered. This process continues until all areas of the UV-curable material 18 have been exposed to UV radiation.
The uncured material is removed from the UV-curable material 18, leaving behind the cured material which forms an abrading mask 22 as listed in step 105 and shown in
The abrading mask 22 is positioned in contact with the surface of the target material 10 as listed in step 106 and shown in
The abrading mask 22 and the target material 10 are exposed to a stream of abrasive material 30 from an abrasive material source 32 as listed in step 107 and shown in
In certain embodiments, the desired array of acoustic holes 12 includes a pattern that is repeated. Thus, the abrading mask 22 may be smaller in size than the size of the array of acoustic holes 12 and may include just the pattern of holes that is to be repeated. Typically, the mask 22 includes more than one copy of the pattern to minimize the stepping and repeating process. The abrading mask 22 is aligned and temporarily affixed to one area of the target material 10. The rest of the surface of the target material is covered with a protective coating to prevent undesired abrasion or damage. The stream of abrasive material 30 is directed at the mask 22 and the target material 10 and is scanned across all of the holes 28 in the abrading mask 22 to create perforations in the target material 10. The mask 22 is moved to the next location where it is aligned and temporarily affixed to the target surface 10. The abrasive material stream 30 is scanned across all holes 28 in the abrading mask 22. This process is repeated until all necessary areas of the target material 10 have been exposed to the abrasive stream 30 and the desired array of acoustic holes 12 has been created.
Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
Claims
1. A method for creating acoustic holes in a target material, the method comprising the steps of:
- a) exposing an ultraviolet radiation transparent medium that includes an image of at least a portion of an array of acoustic holes and an ultraviolet sensitive mask with a thickness between approximately 0.002 inches and approximately 0.004 inches to ultraviolet radiation;
- b) removing uncured material from the ultraviolet sensitive mask such that cured material forms an abrading mask;
- c) positioning the abrading mask in contact with the target material; and
- d) directing a stream of abrasive material with a stream pressure between approximately 50 pounds per square inch and approximately 69 pounds per square inch at the abrading mask to create acoustic holes in the target material.
2. The method of claim 1, further including the step of creating the image of at least a portion of the array of holes.
3. The method of claim 2, further including the step of transferring the image to the ultraviolet radiation transparent medium.
4. The method of claim 3, further including the step of positioning the ultraviolet radiation transparent medium in contact with the ultraviolet sensitive mask.
5. The method of claim 1, wherein the target material includes a sound-insulating material for an aircraft engine.
6. The method of claim 1, wherein the abrasive material includes silicon carbide (SiC) particles.
7. The method of claim 1, wherein the abrasive material includes alumina (Al2O3) particles.
8. The method of claim 1, wherein removing uncured material from the ultraviolet sensitive mask includes using a high-pressure liquid rinse.
9. (canceled)
10. A method for creating acoustic holes in a sound-insulating material for an aircraft engine, the method comprising the steps of:
- a) creating a positive opaque image of at least a portion of an array of acoustic holes;
- b) transferring the image to an ultraviolet radiation transparent medium;
- c) positioning the ultraviolet radiation transparent medium in contact with an ultraviolet curable mask with a thickness between approximately 0.002 inches and approximately 0.004 inches;
- d) exposing the ultraviolet radiation transparent medium and the ultraviolet curable mask to ultraviolet radiation to cure exposed areas of the mask;
- e) removing uncured material from the ultraviolet curable mask using a high-pressure water rinse such that the cured material forms an abrading mask;
- f) positioning the abrading mask in contact with the sound-insulating material; and
- g) directing a stream of abrasive material with a stream pressure between approximately 50 pounds per square inch and approximately 69 pounds per square inch at the abrading mask to create acoustic holes in the sound-insulating material.
11. The method of claim 10, wherein the abrasive material includes silicon carbide (SiC) particles.
12. The method of claim 10, wherein the abrasive material includes alumina (Al2O3) particles.
13. A method for creating acoustic holes in a sound-insulating material for an aircraft engine, the method comprising the steps of:
- a) creating a positive opaque image of a portion of an array of acoustic holes;
- b) transferring the image to an ultraviolet radiation transparent medium;
- c) positioning the ultraviolet radiation transparent medium in contact with an ultraviolet curable mask with a thickness between approximately 0.002 inches and approximately 0.004 inches;
- d) exposing the ultraviolet radiation transparent medium and the ultraviolet curable mask to ultraviolet radiation to cure exposed areas of the mask;
- e) removing uncured material from the ultraviolet curable mask using a high-pressure water rinse such that the cured material forms an abrading mask;
- f) positioning the abrading mask in contact with a first location of the sound-insulating material;
- g) directing a stream of abrasive material with a stream pressure between approximately 50 pounds per square inch and approximately 69 pounds per square inch at the abrading mask to create acoustic holes;
- h) positioning the abrading mask in contact with a second location of the sound-insulating material and directing a stream of abrasive material at the abrading mask to create acoustic holes; and
- i) repeating step h) until acoustic holes have been created at all desired locations of the sound-insulating material.
Type: Application
Filed: Dec 20, 2007
Publication Date: Jun 25, 2009
Applicant: Spirit AeroSystems, Inc. (Wichita, KS)
Inventors: Amitabh Vyas (Wichita, KS), Peter H. Wu (Wichita, KS)
Application Number: 11/961,272
International Classification: B24B 1/00 (20060101);