Not applicable to this application.
1. Field of the Invention
This invention relates to filling systems for plastic valve bags and other types of containers typically used for filling flowable materials such as concrete products, pet foods, foodstuffs and other bulk products. It may also be used for other types of products that may not be considered flowable such as any number of hard and soft goods like briquettes, medical devices, and so on. More specifically, this invention relates to filling these plastic bags and containers in a unique method that provides a dust-control filling environment and may speed up the filling process.
2. Description of the Related Art
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
Presently there are many types of heavy duty bags and containers and several methods in which they are filled. These bags and methods include paper and plastic valve bags filled on nozzles, stitched bags, top load and seal, bags that are top filled and glued closed, and an assortment of rigid containers that may accept a fill nozzle type of system. Generally speaking, these bags are put up in larger sizes to handle loads from a few pounds up to as many as 100 pounds. Various forms of bags and containers may be substantially more.
Most bags used with cement and concrete products and other heavy flowable contents are paper valve bags like those commonly seen palletized in home improvement centers throughout the U.S. and contain products sold to consumers for use in home garden and yard applications, such as 60# mortar and concrete mix and 94# cement and concrete mix. The chief reason paper valve bags are used for these applications is primarily due to per unit cost and productivity factors. Paper valve bags cost more than standard, top-loading plastic bags but the paper valve bags are faster to fill thus they substantially improve productivity and output. There has been some limited use of plastic valve bags made from a woven polypropylene—especially in Europe—with similar productivity. In the U.S. and other countries where paper is still relatively inexpensive, the polypropylene valve bags cost 20% to 30% more than paper. Another form of plastic valve bag is that cited in my pending patent application US20040184680, which costs less than both the paper and polypropylene valve bags and have many advantages over the two. Various forms of containers may include commonly used cardboard cartons, rigid plastic containers and even forms of bottles, buckets and so on.
One significant problem associated with the filling of flowable contents with the aforementioned bag and container types and the aforementioned systems is the amount of dust that is generated during the filling process. In any top loading system fugitive dust tends to drift upwards, then float away and settle nearby. The most commonly used valve bag filling system used today is that of placing a valve bag on a nozzle whereas the valve is in a horizontal disposition as illustrated in U.S. Pat. No. 4,589,454, which uses a conventional valve bag such as that of U.S. Pat. No. 4,759,641. When a valve bag is filled according to this methodology, fugitive dust escapes from the bag and filling system in three ways. First, during the fill process, it escapes from vent holes in the bags. Since current filling methods use injected air or are air assisted, they require bags to have vent holes in order to allow the injected air to escape. The injected air (which may also be referred to as trapped air in the case of a gravity feed system) contains the fugitive dust. This dust is emitted directly into the environment where the bag filling operator works. Second, once the bag has been filled to the designated weight, the bag is ejected from the nozzle and a “puff of fugitive dust” is emitted from the nozzle. Obviously this puff of dust drifts outward, and again, into the environment where the operator works. Third, after the bag is filled and ejected from the nozzle, the valves on prior art paper and plastic bags tends to remain partially open and during its drop to the conveyor belt system below and transportation away from the fill station additional fugitive dust is emitted. The exception to this rule is the valve bag of the US '680 application that provides a relatively leak proof seal once the bag has been filled with its contents.
In addition, fugitive dust leaks out of prior art paper and polypropylene valve bags and stitched bags after they are filled. During the palletizing process and through subsequent handling, dust continues to escape from the leaky valves, vent holes, and through the porous paper material. All told, bag packing facilities using existing bag filling technologies are notoriously dusty environments. This stray dust is also a problem for distributors and retailers, as may be seen at any home improvement center selling concrete products.
Perhaps what is of most concern with the fugitive dust associated with materials such as concrete is its toxicity. The dust associated with concrete products contains lime and federal law requires companies to print warning labels on bags. Other toxins in other forms of flowable filling applications may include herbicides, fungicides, carbon black, drug-related chemicals and so on. Due to this inherent danger, most bag packaging facilities (and state or federal laws), require employees operating the filling systems to wear dust-control masks to help screen out the fine particles. Presently this relatively dusty filling environment is considered the best available technology otherwise it would probably be illegal to subject employees to such a large volume of potentially harmful toxins.
The only system that partially addresses the serious issues previously described is that of U.S. Pat. No. 4,471,820, Lepisto, and its related issued patents. It discloses a means of using blasts of high and low pressure air and subsequently a vacuum to remove dribblings that may be suspended in a valve sleeve. However, it does not prevent the overall loss of fugitive dust through vent holes or leaky valves during or after the fill process. Furthermore the system of the '820 patent negatively affects productivity as additional time is required to clear the nozzle with the blast of high pressure air then a second blast of low pressure air to suspend the dust particulate (suspended dribblings) and subsequently, the employment of a vacuum in order to remove the suspended dribblings. Another problem with this rather elaborate system would be the cost to replace the fill nozzle. Since they commonly wear out rather quickly, in a matter of weeks even, the expense to replace the sophisticated fill nozzles would be virtually cost-prohibitive, thus allowing cheaper competition to thrive.
When filling rigid containers similar dust control problems are generated. Whether the rigid container is a 55-gallon drum, a cardboard carton or some form of plastic container, the emission of dust can be a troubling problem. This type of problem is evident in medical clean room operations and any number of chemical plant operations.
A filling system that can reduce or eliminate the fugitive dust during the filling process would be desirable. Furthermore, if the system also had a means to control the air and its fugitive dust after it was filled, it too would be highly desirable. Ideally, the system would not have a negative effect on productivity. Such a system may also eliminate the need for vent holes in bags and allow the use of the more desirable valve bag as described in the US '680 application. It would also allow for the use of rigid containers that would be constructed with similar air tight qualities.
The dust control problems associated with prior art are substantially reduced and may be eliminated with the present invention. The solution to dust control is through containment. The filling system of the present invention accomplishes that by using a method to mount a valve bag onto a fill nozzle that has a second internal chamber suitable to neutralize any air that may be injected during the fill process. It may also be accomplished by inserting the nozzle into a bag or container. Thus, once a bag is mounted or a nozzle is inserted into a container, the neutralized air with its inherent dust content may be extracted and disposed of as desired. The result of such a system may eliminate the requirement for vent holes and may also eliminate the “puff of dust” that is emitted from the nozzle after filling.
In the present invention, we accomplish these objectives by using a fill nozzle that allows a valve bag or other form of aperture to firmly affix itself. The fill nozzle also uses a narrowed tip to allow for easier mounting of a bag valve or insertion of the nozzle. Last it may incorporate an air control system that in combination with the other attributes to be revealed, creates not only a dust free filling environment, but uses both negative and positive air to control the resident air and its inherent fugitive dust, and direct it elsewhere for future use.
The objectives of the present invention include: 1) a method of preventing fugitive dust from escaping into the work environment during the bag or container filling process; 2) a method of handling resident air that contains potential fugitive dust that is inherent to filling a bag or container with flowable contents; 3) a method of capturing the fugitive dust contained in the resident air; 4) a method of storing the fugitive dust for later use and applications; 5) a method of using air control to maintain a valve bag in position while being filled on a nozzle; 6) a method of releasing the valve bag after it has been filled; 7) a nozzle that helps prevents fugitive air from escaping; 8) a nozzle and system that provides for escape and/or control of resident air and fugitive dust; 9) a nozzle with replaceable inner feed tubes; 10) a nozzle with replaceable outer sleeves; 11) a method of controlling the displacement of air that may otherwise be captured inside a bag or container; 12) a method to recapture the dust contained in the “puff of dust” emitted during the fill process, and; 13) a method of utilizing positive and negative air in the bag or container filling process.
Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.
Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
In
In
In
In
In
In the cross-sectional view in
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above descriptions then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.
I hereby claim benefit under Title 35, United States Code, Section 119(e) of U.S. provisional patent application Ser. No. 60/720,329 filed Sep. 22, 2005. The 60/720,329 application is currently pending. The 60/720,329 application is hereby incorporated by reference into this application.
Number | Date | Country | |
---|---|---|---|
60720329 | Sep 2005 | US |