Method and apparatus for making particle-embedded webs

• US 6,569,494 B1
• Filed: 05/09/2000
• Issued: 05/27/2003
• Est. Priority Date: 05/09/2000
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Livingstone, David E., Connell, Glen, Divigalpitiya, Ranjith, Chambers, David C., Noe, Susan C., Monteagudo, Agatona D., Sandhu, Tejmeen K.
• Primary Examiner(s): Parker, Fred J.
• Application Number:
  US09/567,316
• Time in Patent Office: 1,113 Days
• Field of Search: 427/482, 427/475, 427/485-86, 427/120, 427/202, 427/204, 427/205, 994/94, 222/190, 222/630, 222/522, 222/333, 222/343, 222/342, 222/372, 222/386, 222/410, 222/565
• US Class Current: 427/180
• CPC Class Codes: B05B 5/057 Arrangements for discharging liquids or other fluent material without using a gun or nozzle
• CPC Class Codes: B05B 5/14 specially adapted for coating continuously moving elongated bodies, e.g. wires, strips, pipes
• CPC Class Codes: B05C 19/04 the particulate material being projected, poured or allowed to flow onto the surface of the work B05C19/02 takes precedence; involving spraying or electrostatic projection B05B B05C19/005 takes precedence

Abstract

A method for dispensing particles onto a surface. The steps of the process include holding the particles in a hopper having a dispensing opening covered by a screen which has uniformly sized openings that are sufficiently large to allow the largest particles to pass through, yet sufficiently small to hold the particles back when the dispenser is not operating; rotating, outside the hopper, a cylindrical brush covered with regularly spaced bristles and positioned such that the bristles protrude through openings in the screen and draw particles through the screen to dispense them onto the surface; and varying the dispensing rate of the particles by at least one of (a) varying the rotation speed of the brush, (b) adjusting the distance from the screen to the central longitudinal axis of the brush, (c) adjusting the screen opening size, (d) adjusting the brush-to-screen pressure, or (e) adjusting the tension of the screen.

A method of making a web with embedded particles. This method includes the following sequential steps: making the web receptive to the particles; eliminating static charge present on the web; dispensing the particles onto the web; dispersing the particles to minimize particle clumping in the web; and embedding the dispensed particles in the web.

Claims

1. A method of dispensing particles onto a surface such that the particles are at least partially embedded in the surface comprising:

holding particles in a hopper having a dispensing opening covered by a screen having openings that are uniformly sized and spaced and are sufficiently large to let the largest particles pass through while being dispensed yet sufficiently small to hold the particles back when the dispenser is not operating;

rotating, outside of the hopper, a cylindrical brush covered with regularly spaced bristles that are adjacent the dispensing opening to protrude the bristles through openings of the screen and draw particles through the screen to dispense them onto the surface; and

varying the dispense rate of the particles comprising at least one of (a) varying the rotation speed of the brush, (b) adjusting the distance from the screen to the central longitudinal axis of the brush (c) adjusting the screen opening size;

(d) adjusting the brush-to-screen pressure; and

(e) adjusting the tension of the screen.

2. The method of claim 1 further comprising removing excess particles from the brush.