Burlington Industries, Inc.

Michael I Glenn

Bobby L McConnell

Joseph P Holder

Louis A Graham

Richard Sutera

John L Dressler

Timothy H Archer

Bruce W Halliday

Randy Bowman

Disclosed is a clean air hood for disposition above the print head of a fluid jet printing apparatus having an orifice plate on one side of the print head for forming a plurality of droplet streams. The droplet streams flow past charge and deflection electrode means as well as a fluid catcher whereby uncharged droplets are deposited on a substrate. The clean air hood includes an interior baffle for directing clean air through the hood for issuance through a pair of laterally spaced slots along opposite sides of the hood whereby the air curtains formed thereby straddle the print head. In operation, the air curtains flow along opposite sides of the print head and opposite sides of the droplet streams ot maintain a clean air region about the electrode means and dampen any tendency of particulate matter carried by the substrate from migrating into the region of the electrodes. The print bar is rotated 180.degree. to locate the orifice plate in opposition to the opening through the lower end of the hood whereby the orifice plate may be changed in a clean air region.

Clean air hood for fluid jet printing

A fluid jet applicator is disclosed which senses orifice plate fluid pressure and the fabric substrate speed and electronically controls the flow of fluid by modulating fluid pressure in accordance with the speed and characteristics of the fabric substrate. In this fashion, a highly uniform solid shade is applied across the width of the fabric. The uniformity of the applied solid shade is limited only by the uniformity of the orifices in the applicator orifice plate. Additionally, by operating at higher fluid pressures than electrostatic fluid jet applicators, the present invention is significantly more productive than such electrostatic applicators.

Ultra uniform fluid application apparatus

The electrostatic fluid jet applicator of the present invention achieves patterning effects with an applicator designed to provide a uniform solid application of liquid onto substrates. The applicator requires no digital memory device to store extensive image data defining patterns to be printed and includes a single ganged charging electrode which is utilized to simultaneously charge (or not charge) droplets emanating from a linear array of orifices. The applicator generates patterning effects primarily by controlling the application of charging voltage to the single electrode and by controlling the print time.

Patterning effects with fluid jet applicator

An electrode for use in a fluid-jet marking apparatus includes a flexible and tensionable electrode member mounted in confronting, substantially parallel alignment to a linear array of fluid droplet streams. The mounting of the flexible and tensionable electrode member is accomplished by a pair of mounting arms in spaced-apart relationship, one of the arms being pivotal while the other arm is immovable. The one pivotal arm is thus displaced relative to the other immovable arm so as to responsively tension the electrode member therebetween. In order to increase the vibrational frequency of the flexible and tensionable electrode member and/or to substantially decrease the vibrational amplitude thereof, at least one intermediate arm having a terminal end in operative contact with the electrode member is provided. The contact of the terminal end of the intermediate arm occurs at least one location along the electrode member between the pair of spaced-apart mounting arm members and thus essentially shortens the 'free length' of the electrode member so that vibrational frequency of the electrode member is substantially increased thereby responsively substantially decreasing the vibrational amplitude of the electrode member towards and away from the droplet streams. In such a manner, the electrode member can be closely positioned laterally of the droplet streams. An alternative embodiment of the electrode structure employs an additional flexible and tensionable ground electrode ('ground shield') preferably composed of a flexible ribbon of electrically conductive material disposed directly beneath the deflection electrode and in a substantially opposed confronting relationship to the droplet catching structure.

Tensionable ground electrode for fluid-jet marking apparatus

Uniform application of a controlled relatively small liquid volume per unit area to a moving fabric substrate is obtained even though application is made using a liquid jet electrostatic applicator which employs random drop formation processes. Repetitive print times during which randomly formed droplets are passed onto the substrate along a linear orifice array are controlled so as to have a minimum duration sufficiently large as to average out expected random variation in droplet formation processes occurring along the orifice array. At the same time, the center-to-center spacing of each printed pixel (during which randomly formed droplets are intercepted so as not to fall onto the substrate) is controlled so as to maintain a desired relatively small controlled liquid volume per unit area within the fabric substrate section to be printed. In one exemplary embodiment, the print times are maintained in excess of approximately 200 microseconds and/or so as to insure that the expected standard deviation of liquid volume printed onto the substrate during each print time is less than approximately 0.2.

Growing community of inventors

Burlington, NC, United States of America

Michael I Glenn