Process for Preparing Sorptive Substrates, and Integrated Processing System

• US 20150330007A1
• Filed: 01/19/2015
• Published: 11/19/2015
• Est. Priority Date: 08/01/2011
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Blaiss, H. Dennis, Sene, Laurent H., Hall, Gregory T., Whittington, Randy H.
• Granted Patent: US 9,884,351 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A47L 13/17 containing cleaning agents A47L13/19 takes precedence ; chemical compositions C11D17/049
• CPC Class Codes: B08B 1/143 Wipes
• CPC Class Codes: B08B 1/20 Cleaning of moving articles, e.g. of moving webs or of objects on a conveyor
• CPC Class Codes: B08B 3/12 by sonic or ultrasonic vibrations washing or rinsing machines for crockery or tableware using sonic or ultrasonic waves A47L15/13; of natural teeth, of prostheses using ultrasonic techniques similar to those used for natural teeth A61C17/20; application of ultrasonic vibrations to chemical, physical or physico-chemical processes in general B01J19/10
• CPC Class Codes: B08B 5/023 Cleaning travelling work
• CPC Class Codes: B08B 7/028 Using ultrasounds
• CPC Class Codes: D06B 13/00 Treatment of textile materials with liquids, gases or vapours with aid of vibration
• CPC Class Codes: D06B 21/00 Successive treatments of textile materials by liquids, gases or vapours successive treatments in which the characteristics of a single treatment are of interest only, or in which all treatments have characteristics provided for in a single main group, see the relevant groups for the single treatment

Abstract

A process for treating a substrate comprised of sorptive material is provided herein. The sorptive material may be an absorbent synthetic material such as polyester. The material is designed to be used for cleaning surfaces in an ultraclean environment. The process first comprises unwinding a roll of sorptive material as a substrate into a cleaning system. The cleaning system utilizes several sections. These include a pre-washing section, an acoustic energy washing section, and a drying section. Preferably, the process of moving the substrate through the cleaning system is continuous. The acoustic energy washing section employs one or more acoustic energy generators. In one aspect, the process also includes cutting the substrate into sections to form wipers after moving the substrate through the drying section. Thereafter, the wipers are placed into a bag and the bag is sealed.

Claims

1. A process for treating a sorptive material, comprising:

unwinding a roll of sorptive material as a substrate into a cleaning system, the roll being between about 4 inches (10.16 cm) and 18 inches (45.72 cm) in width;

moving the substrate through an acoustic energy washing section in the cleaning system, wherein each of a front side and a back side of the substrate are directly exposed to energy pulses from acoustic energy generators within a tank of a washing solution, with at least one of the acoustic energy generators in the washing section being a tubular resonator that operates at a frequency of between about 20 and 80 kHz, thereby producing a cleaned sorptive material for use in wiping surfaces in a cleanroom environment; and

further moving the substrate through a drying section in the cleaning system, wherein HEPA-filtered and heated air is applied to product a cleaned and dried sorptive material; and

wherein the cleaned and dried sorptive material uniformly has less than 150 contaminant fibers per square meter that are greater than 100 μ

m in length.

2. The process of claim 1, wherein the sorptive material comprises a synthetic material.

3. The process of claim 2, wherein the sorptive material comprises primarily polyester.

5. The process of claim 1, wherein the sorptive material is an absorbent material.

6. The process of claim 2, wherein the absorbent material has an absorbency of between about 300 mL/m² to 650 mL/m².

7. The process of claim 2, further comprising:

moving the substrate through a pre-washing section in the cleaning system, wherein a prepping fluid is sprayed onto the sorptive material before moving the substrate through the acoustic energy washing section.

8. The process of claim 7, wherein:

the prepping fluid in the pre-washing section (i) is a liquid that comprises primarily deionized water, (ii) is a gaseous fluid comprising carbon dioxide, steam, ozone, or mixtures thereof, or (iii) combinations thereof;

the substrate moves through a series of rollers above a fluid container in the pre-washing section; and

the prepping fluid is sprayed onto both the front and back sides of the substrate.

9. The process of claim 8, wherein moving the substrate through the pre-washing section, the acoustic energy washing section, and the drying section is continuous.

10. The process of claim 9, further comprising:

after moving the substrate through the drying section, cutting the substrate into sections to form individual wipers;

placing the wipers into a bag; and

sealing the bag.

11. The process of claim 10, wherein the steps of cutting the substrate into sections and placing wipers into a bag are substantially performed without a human hand touching the sorptive material.

12. The process of claim 11, wherein the step of cutting a length of the substrate is performed by using a laser cutter, a sonic knife, or a sonic horn.

13. The process of claim 10, wherein each wiper only has between about (i) 30,000 and 70,000 contaminant fibers per square meter that are between about 5.0 and 100 μ

m in length, (ii) 0.5.×

10⁶ and 5.0×

10⁶ contaminant fibers per square meter that are between about 0.5 and 5.0 μ

m in length, or (iii) both.

14. The process of claim 10, wherein each wiper has less than about 0.06 ppm potassium, less than about 0.05 ppm chloride, less than about 0.05 ppm magnesium, less than about 0.20 ppm calcium, and less than about 0.30 ppm sodium.

15. The process of claim 7, wherein:

the acoustic energy washing section comprises a first acoustic energy washer having the tank as a first tank through which the substrate is moved during cleaning, with the first tank holding a volume of deionized water and surfactant;

the first acoustic energy washer has a first set of rollers for guiding the substrate around a first transducer such that the front side of the substrate is directly exposed to ultrasonic energy from the first transducer;

the first acoustic energy washer also has a second set of rollers for guiding the substrate around a second transducer such that the back side of the substrate is also directly exposed to ultrasonic energy from the second transducer; and

the first tank further holds the tubular resonator as either the first or the second transducer.

16. The process of claim 15, wherein:

the acoustic energy washing section further comprises a second acoustic energy washer, the second acoustic energy washer comprising a second tank holding a volume of deionized water and surfactant, through which the substrate is also moved during cleaning;

the substrate passes across two or more rollers submerged within the second tank; and

at least one of the acoustic energy generators in the washing section also comprises a megasonic transducer within the second tank that operates at a frequency of between about 900 kHz and 2.0 MHz.

17. The process of claim 7, wherein the acoustic energy washing section comprises:

an ultrasonic energy washing station having the at least one tubular resonator, operating at a frequency of between about 20 kHz and 50 kHz;

a tank in the ultrasonic energy washing station for holding a volume of deionized water and surfactant while the substrate is moved through the ultrasonic energy washing station, wherein the substrate moves into the tank while passing through the ultrasonic energy washing station;

a megasonic energy washing station having at least one acoustic transducer operating at a frequency of between about 900 kHz and 2.0 MHz; and

a separate tank in the megasonic energy washing station for holding a volume of deionized water and surfactant while the substrate is moved through the ultrasonic energy washing station, wherein the substrate moves into the separate tank while passing through the ultrasonic energy washing station.

18. The process of claim 3, further comprising:

before moving the substrate through the drying section, moving the substrate through a rinsing section, wherein the substrate is rinsed with an aqueous solution comprising primarily deionized water.

19. The process of claim 7, further comprising:

placing a roll of sorptive material onto a shaft; and

wherein unwinding the roll of sorptive material comprises unwinding the roll from the shaft in order to introduce the substrate to the pre-washing section.

20. The process of claim 19, wherein:

the roll of sorptive material is wound around a core before being placed onto the shaft;

the roll of sorptive material has a length of at least 25 feet (3.31 meters) before being placed onto the shaft; and

unwinding the roll of sorptive material comprises rotating the shaft.

4. (canceled)

21-33. -33. (canceled)

34. A method of cleaning a surface, comprising:

receiving a package of wipers, with each wiper uniformly having less than 150 contaminant fibers per square meter that are greater than 100 μ

m in length, and the wipers having been packaged in a processing system comprising;

an acoustic energy washing section configured to expose at least one of the front side and the back side of the substrate to energy pulses from one or more acoustic energy generators within a tank of a washing solution,

a rinsing section after the acoustic energy washing section, wherein the substrate is rinsed with an aqueous solution comprising primarily deionized water;

a drying section configured to apply warmed and HEPA-filtered air to the cleaned sorptive material,

a cutting section configured to continuously cut the substrate into individual wipers after the substrate has passed through the drying section, and to place the wipers into a stack, and

a packaging section configured to continuously receive each stack of wipers, and place them into a bag substantially without need of human hands;

opening the package of wipers;

removing one of the wipers; and

using the removed wiper to wipe a surface in a cleanroom environment.