Forming a perforate membrane by laser drilling and a subsequent electro-polishing step
First Claim
1. A method of forming a perforate membrane for use in a liquid transport device, by applying laser energy selectively to a first surface of the membrane in the form of a pulsed, focused beam to form a plurality of nozzles each having a throat portion opening of a selected diameter at one end through the opposite surface of the perforate membrane and a smoothly curved outwardly diverging portion extending from the other end of the throat portion to the first surface of the perforate membrane, and further comprising the steps of:
- thereafter electro-polishing the first surface of the membrane and the surface of the diverging portion of the nozzles to remove surface imperfections, and controlling the electro-polishing so as to remove material from the surface of the diverging portion of the nozzles to a depth within the membrane less than the length of the throat portion so that the diameter of the throat portion is unchanged by the electro-polishing step.
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Accused Products
Abstract
A method of forming a perforate membrane (1) is disclosed for use in a liquid transport device. The membrane has at least plural nozzles (10) formed therethrough. Each of those nozzles has a throat portion (12) opening at opposite end through opposite surface (2′) of the perforate membrane and a smoothly curved outwardly diverging portion (11) extending from the first end of the throat portion to the first surface (2) of the perforate membrane. Laser energy is applied selectively to the first surface (2) of the membrane in the form of a pulsed, focused beam to form the nozzles (10) and thereafter the first surface (2) of the membrane and the surface of the diverging portion (11) of the nozzles (10) are electro-polished to remove surface imperfections. The electro-polishing is controlled so as to remove material from the surface of the diverging portion (11) of the nozzles to a depth less than the length of the throat portion (12).
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Citations
18 Claims
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1. A method of forming a perforate membrane for use in a liquid transport device, by applying laser energy selectively to a first surface of the membrane in the form of a pulsed, focused beam to form a plurality of nozzles each having a throat portion opening of a selected diameter at one end through the opposite surface of the perforate membrane and a smoothly curved outwardly diverging portion extending from the other end of the throat portion to the first surface of the perforate membrane, and further comprising the steps of:
thereafter electro-polishing the first surface of the membrane and the surface of the diverging portion of the nozzles to remove surface imperfections, and controlling the electro-polishing so as to remove material from the surface of the diverging portion of the nozzles to a depth within the membrane less than the length of the throat portion so that the diameter of the throat portion is unchanged by the electro-polishing step. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A perforate membrane for use in a liquid transport device, the perforate membrane comprising:
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a first surface and an opposite surface; a plurality of pulsed, focused laser energy formed nozzles, each nozzle having a throat portion of a selected diameter and being open at one end through the opposite surface and having a smoothly curved outwardly diverging portion extending from the other end of the throat portion to the first surface of the perforate membrane; and wherein the first surface of the membrane and the surface of the diverging portion of the nozzles having been electro-polished to a depth of less than the length of the throat portion so that the diameter of the throat portion is unchanged by the electro-polishing. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification