Patent Application
20200196825
The present inventions relate generally to cleaning devices and methods, and more particularly to such devices and methods used in cleaning “clean rooms”, semiconductor fabrication plants, pharmaceutical manufacturing facilities, and other cleaning applications and environments where extreme cleanliness is maintained.
The requirements for maintaining cleanliness in semiconductor fabrication clean rooms, pharmaceutical manufacturing clean rooms and similar facilities are stringent. In semiconductor fabrication clean rooms, surfaces frequently must be wiped with an exceptionally clean wiper and cleaning solution in order to prevent contamination. The contamination which is to be controlled often is called “micro-contamination” because it consists of small physical contaminants, such as particulate matter of a size between that of bacteria and viruses, and chemical contaminants in very low concentrations, typically measured in parts per million or parts per billion.
The contaminants usually are of three types; viable and non-viable particles, ions and non-volatile residues. These contaminants are deposited in the clean room and on products and surfaces to be cleaned by a host of sources including raw materials, previous processing steps, manufacturing equipment, and humans in the clean room. The wipers must be very clean to minimize the introduction of additional contaminants. Loose particles 100 micrometers and smaller in size are an anathema to obtaining high production yields and reliable semiconductor devices. Therefore, cleaning applicators and cleaning materials used in such clean rooms should emit as small a number of particles as possible. Similarly, contaminants interfere with the exacting processes of pharmaceutical and semiconductor manufacturing, and their quantities are to be minimized.
In the past, such requirements have been met by the provision of specially fabricated cloths designed to release very few loose particles, while maintaining structural integrity when wetted with cleaning solution and being used to wipe the surfaces to be cleaned. Typically, such wipers have been packaged in sealed containers such as flexible plastic bags, which can be opened, a wiper withdrawn and the bag resealed. Then, the cleaning solution, kept in a separate container, is applied to the wiper and the wiper is used.
Substantial quantities of chemical solvents used as cleaning fluids must be stored and applied to the wipers. This can result in accidents or working conditions deleterious to the health of the workers. Also, when workers apply cleaning fluids from separate containers to dry wiper cloths, the amount of cleaning fluid used often is either too little or too much, which can result in ineffective cleaning, or oversaturation and waste.
In response to these issues, pre-saturated wipers have been developed and commercialized. The wipers are pre-wetted with varying amounts of cleaning solutions, and packaged in a re-sealable plastic bag until needed. Then, the bag is opened, the wiper or wipers withdrawn, and the bag is re-closed. This is repeated until the bag is empty. Unfortunately, bags of pre-saturated wipers often may be stored for prolonged periods, such as months or even years before use. During that time, the cleaning liquid and the wiper material are in intimate contact with one another. It is believed that this often leads to a degradation of the fibers of the wiper material such that the quantity of contaminants released by the wiper when used is substantially higher than when the wipers are first packaged. It is believed that the bonds holding the particles to the fibers are loosened, and the releasable ions and extractables are increased by prolonged contact between the cleaning solutions and the wipers.
In addition, where adhesives are used to fasten various parts of plastic packaging together, such as in the re-closable seal of some wiper packages, the adhesive may deteriorate due to prolonged contact with the cleaning liquid.
Another issue of cleaning pharmaceutical manufacturing and other medical facilities with pre-saturated wipers lies in maintaining the effectiveness of the biocide. More specifically, the effectiveness of the biocide may deteriorate due to prolonged contact with the wiper material.
In order to overcome the various shortcomings of pre-saturated wipers, others have attempted to include both the unsaturated wipers and cleaning fluid in a single system, but with the wipers and cleaning fluid kept separate until immediately before use. One such system is set forth in U.S. Pat. No. 6,602,381 issued to Paley et al., the disclosure of which is hereby incorporated by reference in its entirety.
Challenges with these “point-of-use saturation” systems include leakage, bulky designs that are expensive to manufacture and ship, and difficulty in saturating the wipers with cleaning fluid prior to use. In particular, premature rupturing of the cleaning fluid compartment during shipping and handling is a serious problem, with known systems exhibiting a 40% failure rate when tested according to ASTM Test Protocol D5276-98 (2009) for Drop Test of Loaded Containers by Free Fall.
One way to protect against rupture during shipping is to employ bubble wrap or other special packaging to provide cushioning. Another way to protect against rupture during shipping is to minimize the quantity of packs in a shipped case in order to reduce weight and thus lessen the pressure on the contents when jostled during shipping. Unfortunately, cushioned packaging and/or shipping smaller quantities adds to shipping and materials expenses.
Another way to protect against rupture during shipping is to employ durable cleaning fluid packaging. Unfortunately, however, this durability likewise makes it difficult for the user to rupture the package in use. If the cleaning fluid packaging isn't effectively ruptured, then the wipers may not be properly saturated.
Thus, there remains a need for a new and improved cleaning kit system including a pouch divided into a first liquid-tight container that receives one or more applicators and a second liquid-tight container for the cleaning fluid liquid, the second liquid-tight container adapted to reduce accidental rupture during shipping and handling while, at the same time, being adapted to be easily ruptured by the application of pressure by a user to the second container.
The present inventions are directed to a cleaning kit including a pouch divided into a first liquid-tight container and a second liquid-tight container, with the second liquid-tight container adapted to be ruptured by the application of pressure by a user to the second container. The second container includes a baffle extending at least partially across the second container adapted to reduce accidental rupture caused by handling during shipping; and a frangible seal along at least a portion of the boundary between the first container and the second container, wherein the frangible seal is broken by the application of pressure by the user to the second container in one embodiment of greater than about 30 inches of water when tested according to ASTM Test F1140-07 (2007). A cleaning liquid may be in the second container and there may be at least one absorbent applicator in the first container and adjacent to the second container whereby the release of cleaning liquid from the second container is applied to the applicators in the first container.
The baffle may be selected from the group consisting of a partial weld line, a plurality of spaced apart dashed weld lines, weld lines scattered and/or at angles to each other, a plurality of spaced apart weld dots, knurled seams, a plurality of intersecting weld lines, a plurality of spaced weld lines, one or more curved weld lines, and combinations thereof. Also, the welds may be formed by joining together opposite faces of the pouch by heat sealing, RF welding, ultrasonic welding, adhesives, and combinations thereof.
The baffle may be discontinuous in use. For example, in one embodiment the baffle partially extends across a portion of the second container. In another embodiment, the baffle extends fully across the second container and is adapted to be ruptured by the application of pressure by a user to the second container.
In one embodiment, the pouch is formed by sealing opposing edges of sheets of material. The pouch may include a frangible seal along at least a portion of the boundary between the first container and the second container. Also, the pouch may be a fold pouch and at least a portion of the boundary between said first container and said second container is a frangible seal.
Other pouch configurations within the scope of this invention include two pieces of film sealed on four sides; tubular film sealed on two sides; or one piece of folded film sealed on three sides. At least a portion of one of the seals between the two containers or a separated chambers within one of the containers on any of these configurations would be frangible.
In one embodiment, the baffle is adapted to provide an effective volume after filling with a liquid of between about 30% and about 80% and the strength of the frangible seal is between about 30 inches of water and about 80 inches of water when tested according to ASTM test F1140-07 (2007).
In another embodiment, the baffle is adapted to provide an effective volume after filling with a liquid of between about 40% and about 70% and the strength of the frangible seal is between about 40 inches of water and about 70 inches of water when tested according to ASTM test F1140-07 (2007).
In another embodiment, the baffle is adapted to provide an effective volume after filling with a liquid of between about 30% and about 65% and the strength of the frangible seal is between about 45 inches of water and about 65 inches of water when tested according to ASTM test F1140-07 (2007).
In still another embodiment, the baffle is adapted to provide an effective volume after filling with a liquid of about 60% and the strength of the frangible seal is about 55 inches of water when tested according to ASTM test F1140-07 (2007).
The applicator may be selected from the group consisting of wipers, mops, swabs, gloves, mitts, pads and combinations thereof. In one embodiment, the applicator is a wiper for use in clean rooms requiring the use of wipers producing very small quantities of contaminants in use. The applicator may include a plurality of the wipers forming a stack. Also, the applicator may be made from materials selected from the group consisting of knitted fabrics, woven fabrics, non-woven fabrics, foams, meshes, sponges and combinations thereof.
In one embodiment, the first liquid-tight container is a pouch having an access opening. The pouch may be a fold pouch formed from a single sheet of material having the edges joined together to form sides and the opening. The pouch may also be a 3-side sealed pouch formed from two sheets of material having the edges joined together to form sides and the opening.
In one embodiment, the opening of the first liquid-tight container is sealable across the opening. The opening may be re-sealable after opening the first container during use. In one embodiment, the opening is a re-sealable peel and re-seal pouch. In another embodiment, the opening may further include a flap normally covering the opening and a pressure sensitive adhesive adapted to re-seal the first container after opening. In another embodiment, the opening includes a re-sealable slider zipper adapted to re-seal the first container after opening. In still another embodiment, the opening includes a re-sealable pressure zipper adapted to re-seal the first container after opening. Slider and pressure zippers are preferably located on a seam, versus on the top surface.
The pouch may be formed from a plastic film. In one embodiment, the plastic film is a single layer plastic film. In another embodiment, the plastic film is a multilayer, composite plastic film. The plastic film may be a thermoplastic film.
Accordingly, one aspect of the present inventions is to provide a cleaning kit, the kit including (a) a pouch divided into a first liquid-tight container and a second liquid-tight container, the second container having a baffle extending at least partially across the second container adapted to reduce accidental rupture caused by handling during shipping; and (b) a cleaning liquid in the second container, wherein the second container is adapted to be openable thereby releasing the liquid from the second container into the first container.
Another aspect of the present inventions is to provide an improved liquid container, the container including (a) a pouch divided into a first liquid-tight container and a second liquid-tight container, the second container adapted to be ruptured by the application of pressure by a user to the second container; (b) a baffle extending at least partially across the second container adapted to reduce accidental rupture caused by handling during shipping; and (c) a frangible seal along at least a portion of the boundary between the first container and the second container, wherein the frangible seal is broken by the application of pressure by a user to the second container greater than about 30 inches of water when tested according to ASTM Test F1140-07 (2007).
Still another aspect of the present inventions is to provide a cleaning kit, the kit including (a) a pouch divided into a first liquid-tight container and a second liquid-tight container, the second liquid-tight container adapted to be ruptured by the application of pressure by a user to the second container, the second container including (i) a baffle extending at least partially across the second container adapted to reduce accidental rupture caused by handling during shipping and (ii) a frangible seal along at least a portion of the boundary between the first container and the second container, wherein the frangible seal is broken by the application of pressure by the user to the second container greater than about 30 inches of water when tested according to ASTM Test F1140-07 (2007); (c) a cleaning liquid in the second container, wherein the second container is adapted to be openable to release the cleaning liquid from the second container into the first container; and (d) at least one absorbent applicator in the first container and adjacent to the second container whereby the release of cleaning liquid from the second container is applied to the applicator in the first container.
These and other aspects of the present inventions will become apparent to those skilled in the art after a reading of the following description of embodiments when considered with the drawings.
In the following description, like reference characters designate like or corresponding parts throughout the several views. Also in the following description, it is to be understood that such terms as “forward,” “rearward,” “left,” “right,” “upwardly,” “downwardly,” and the like are words of convenience and are not to be construed as limiting terms.
Referring now to the drawings in general and
The second liquid-tight container 30 portion of the pouch 10 is preferably a four-sided pouch having a frangible seam 32 and one folded edge 34, although other configurations are within the scope of this invention. As used herein, “frangible seam”, “frangible seal” and the like shall refer to a seam that purposefully comes apart when a pre-determined amount of pressure is applied, rather than deforming elastically and retaining its cohesion as a single object. When force is applied to second container 30, for example through a user exerting pressure on second container 30, frangible seam 32 is compromised and cleaning liquid is evacuated from second container through broken frangible seam. It should be understood that it is not necessary that all frangible seams in their entirety, be compromised. Rather, a portion of one seam compromised may be adequate to allow evacuation of cleaning liquid from second container.
The second container 30 portion of the pouch 10 is preferably formed of a piece of plastic film that is frangibly sealed adjacent to the first container 20 portion of the pouch 10. This film is preferably a liquid impermeable thermoplastic. Examples of suitable films include polyester, polypropylene, polyethylene, polyamide, TTFE, or laminates or coforms thereof.
Second container 30 envelops a volume of cleaning fluid liquid 37 within, as shown in
Second container 30 contains at least one baffle 35, but two baffles, or a plurality of baffles, as shown in
It is desirable that the baffle is “discontinuous in use”. As use herein, “discontinuous in use” shall mean that the baffle doesn't significantly impede the movement of flow within the second container when the frangible seam of the second container is compromised. Said another way, if in use a user applies pressure to the second container so the baffles and frangible seams “give way”, the baffles that have “given way” can't significantly prevent the cleaning fluid liquid from draining out of the second container through broken frangible seam. Likewise if baffles are designed to remain intact during rupturing of frangible seam(s), the baffles can't be oriented in a manner that would prevent evacuation of virtually all of the cleaning fluid liquid from the second container when the frangible seams have given way. A discontinuous baffle can extend only partially across a portion of the second container, or extend fully across the second container.
As shown in
The first container 20 portion of the pouch 10 is preferably constructed of a liquid impermeable plastic film such as laminated PET/LLDPE film, or PET, PA, PP, CoPET variations, that is preferably sealed on peripheral edges with standard (non-frangible) seam 33 and frangibly sealed adjacent to the second container 30 portion of the pouch 10. Preferably, the plastic film is a thermoplastic. The plastic film may be a multilayer composite plastic film. In one embodiment, first container 20 is formed from a piece of plastic film having its outer edges joined together and including an access opening. Alternatively, first container 20 can be formed of two sheets of material having joined edges. First container 20 preferably includes access opening 22 (
Opening 22 is preferably closed using seal 23. Seal 23 can be a variety of configurations including re-sealable “peel and seal” flaps, pressure sensitive adhesives, slider zippers, and combinations thereof. Opening 22 can preferably be opened and reclosed using seal 23 multiple times. Second container 30 is frangibly sealed adjacent to first container 20.
The effective volume of cleaning liquid within the second container is a crucial aspect of the present inventions. If the effective volume is too low, then it is difficult for the user to rupture the second container for use. Too low volumes will also result in more time required to achieve uniform saturation and may limit the number of wipers in the pack for a desired saturation level. If the effective volume is too high, then the second container is likely to rupture before desired, for example during shipping. As used herein “effective volume” shall refer to the maximum volume of fluid in a baffled container versus the maximum volume of fluid in that container without a baffle, expressed as a percentage. By way of example, if a 1 liter container with baffles has a maximum volume of 0.7 liters, the effective volume would be 70%. This is calculated as follows:
(VBaffle/VUnbaffled)×100=Effective Volume
Likewise, the strength of frangible seam 32 is an aspect of the present inventions. If the frangible seam is too strong then it is difficult for the user to rupture the second container for use, but if it is too weak then the second container is likely to prematurely rupture.
Extensive experimentation was necessary to achieve both ease of use and shipping and handling durability. “Ease of use” pertains to how easy it is for a user, for example a cleaning technician in a clean room, to rupture the second container for purposes of allowing cleaning fluid liquid to come in contact with cleaning applicator. “Shipping durability” refers to how resilient the second container is during the shipping and handling process, as defined by ASTM Test Protocol D5276-98 (2009) for Drop Test of Loaded Containers by Free Fall. Ease of use and shipping durability are inherently contradictory qualities,
It is desirable that the second container of the present inventions has an effective volume of approximately 30%-80%, and a frangible seam strength of approximately 30-80 inches of water. It is more desirable that the second container of the present inventions has an effective volume of approximately 40%-70%, and a frangible seam strength of approximately 40-70 inches of water. It is even more desirable that the second container of the present inventions has an effective volume of approximately 45%-65%, and a frangible seam strength of approximately 45-65 inches of water. It is most desirable that the second container of the present inventions has an effective volume of approximately 60%, and a frangible seam strength of approximately 55 inches of water. As used herein, frangible seal strength is determined by ASTM Protocol F1140-07 (2007).
As demonstrated in the following prophetic tables, the percent of pouch volume capacity is also an important factor in performance. In these tables a rating of 1 is unacceptable; 2 is a 10% failure rate; 3 is a 1% failure rate; 4 is a <0.023% failure rate; and 5 is excellent performance. As used herein “percent of pouch volume capacity” shall refer to the percent capacity that a pouch is filled. For example, if a baffled or unbaffled pouch has a maximum capacity of 1 liter, but is filled with 0.8 liters, the percent of pouch volume capacity would be 80%. This is calculated as followed:
(VActual/VCapacity)×100=Percent of Pouch Volume Capacity
Referring now back to
Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. By way of example, baffles could be structures other than welds, for example physical barriers such as flaps, objects, gussets, folds, and combinations thereof. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims. It should also be understood that “approximately” and other similar terms are +/−10% unless otherwise stated or contrary to common sense. All ranges set forth should be understood to include stated endpoints as well as all increments there between. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.
