Patent Application
20060117980
This invention pertains generally to the manufacture and processing of products made from a moving web or other continuous sheet material, and more particularly, to an apparatus and method for applying markings onto the moving sheet material.
Often it is necessary to provide markings on various web or sheet formed products. Preferably, the markings are applied to the web or sheet products as they are undergoing other processing. For example, roofing materials, such as asphalt shingles, commonly are produced in a process line in which a web of sheet material, made of organic or fiberglass material, is drawn from a supply roll through (1) a coating station in which the web is coated with a hot liquid tar or asphalt, (2) a surfacing station in which granular surfacing material is directed onto the hot liquid coating, (3) a cooling and press roll station in which the granular surface material is pressed into the hot liquid coating and sheet material and coating are cooled by spraying a cooling liquid onto the moving sheet material and (4) cutting and stacking stations in which the cooled sheet material is cut into predetermined-size shingles and stacked.
Roofing products include a variety of different shingles and rolls each of which is designed to be nailed down in a particular location. In order to help the roofers who install the products determine where a particular roofing product should be nailed, roofing material processing lines can include a nail marking system. A typical nail marking system uses one or more marking wheels to apply a rough line that runs the length of the roofing product identifying where the particular roofing product should be nailed. The marking wheels pick-up the marking fluid, which is a mixture of industrial latex paint and water, from a trough to which the marking fluid is pumped. Known water/paint mixtures used as marking fluids have water to paint mix ratios of 70/30 to 40/60.
Roofing material processing lines are now running at faster and faster speeds as compared to in the past with most roofing material lines running at close to 750 ft/min. Unfortunately, at higher speeds, the line produced by the marking wheel in conventional nail marking systems can include skips or become crooked, ragged and/or faint. Because improperly marked roofing products must be scrapped or rejected, failure of the marking system can be expensive and time consuming.
In addition, nail marking systems using applicator wheels are quite messy and relatively labor intensive and expensive to maintain. For example, because of paint build-up, the applicator wheels have to be cleaned and replaced on a regular basis. Moreover, the paint used in the marking fluid is relatively expensive. However, it is difficult to monitor and control paint utilization with wheel and trough marking systems leading to further inefficiencies.
The invention provides an apparatus for applying a marking to an elongated sheet material. The apparatus includes a processing machine through which an elongated length of the sheet material is passed. A marking system is arranged to apply a marking to the elongated length of sheet material passing through the processing machine. The marking system comprises at least one spray gun and a pump for supplying marking fluid to the spray gun. The pump is operable at selectively variable speeds. A controller controls the speed of the pump based upon a speed at which the sheet material is passed through the processing machine.
Referring now more particularly to
The illustrated asphalt shingle processing line 10 basically is of a conventional type. In this case, the processing line 10 includes an unwind stand 11 in which a spool of a continuous web or sheet material 12, such as fiberglass or felt, is drawn from a takeout roll 14 over a splicing table 15 and through an accumulator 16 by means of pull rolls 18. The web 12, as shown in
In accordance with the present invention, for producing a mark on the roofing material, in this case a line that runs the length of the roofing product identifying where the shingles should be nailed, the illustrated shingle processing line 10 includes a marking system 32 in which the application rate of the marking fluid can be controlled on the basis of the speed of the processing line 10. As described in greater detail below, unlike conventional wheel and trough marking systems that produce ragged edged, uneven lines at higher line speeds, the marking system 32 of the present invention is able to provide a clean, distinct line of consistent width across a wide range of processing line speeds. Moreover, the marking system 32 of the present invention can be operated at relatively low paint to water ratios leading to significant cost savings (because of the use of less paint) as compared to conventional wheel and trough marking systems.
To this end, the marking system 32 includes a plurality of spray guns 34 that are supplied with marking fluid via a pump 36, in this case a positive displacement gear pump, as shown in
The illustrated spray guns 34 are supported on a header 38 arranged, in this case, above the moving web 12 of roofing shingles. As will be appreciated by those skilled in the art, the spray guns 34 are arranged on the header 38 so that the marking fluid discharged by each of the spray guns 34 hits the moving web 12 in a desired location so as to produce a continuous marking line along the web identifying where the finished shingles should be nailed. In the embodiment illustrated in
Each spray gun 34, in this case, is a pneumatic spray gun 34 equipped with a solid stream type spray nozzle. The spray nozzles can be selected so as to provide a marking line of the desired width, e.g. 0.125 in. One suitable type of spray nozzle is the 1/4JAU automatic spray gun available from Spraying Systems, the assignee of the present invention. In the illustrated embodiment, each spray gun 34 has lines connecting to a common marking fluid supply line 40 and a common pressurized air line 42 (see
To control the pump 36 as well as monitor other operational parameters of the marking system 10, a controller 44 can be provided. In order to monitor the speed of the processing line 10, the controller 44 can be in communication with one or more line speed sensors associated with the shingle processing line. A shingle processing line typically includes one or more such sensors with which the controller can communicate. For example, the processing line 10 can include a speed sensor 46 arranged to detect the rotational speed of the one of the rollers that can be in communication with the controller 44 as diagrammatically depicted in
The controller 44 can also provide fault or warning signals or other information associated with the operation of the marking system 10. For example, with the system of the present invention, the positive displacement pump 36 acts as a virtual flow meter allowing for much closer monitoring of the paint utilized by the system. In particular, the positive displacement pump 36 monitors the set point or reference flow rate through the spray guns 34 and reports that information to the controller 44. The controller 44 can be adapted to display the flow rate and the line speed so that the shingle processing line operators are able to monitor the amount of marking fluid being consumed by the system. In addition, the controller 44 can compare the reference flow rate as measured by the positive displacement pump 36 to a theoretical or predetermined desired flow rate for the system. In such as case, the controller 44 can be programmed to provide a high or low flow alarm if the measured flow rate exceeds the theoretical or predetermined flow rate for a predetermined period of time.
To further ensure the application of a clear and distinct mark on the roofing materials, the marking system 32 can include flow sensors 48 arranged to monitor the discharge from the spray guns 34. The flow sensors 48 can be used to detect whether the spray guns 34 are actually spraying or whether the discharging spray is wobbling or drooping (due, for example, to a partially clogged spray gun) in such a manner that the marking line is not being applied to the moving web correctly. The flow sensors 48 can communicate with the controller 44 or some other device capable of providing a warning signal when the flow from one or more of the spray guns 34 has stopped, is wobbling or drooping. This warning signal can allow the shingle processing line operators to take appropriate actions to minimize product loss due to plugged nozzles or spray wobble or droop by warning the operators so that they can take appropriate action.
To help clean-out the system when it is shut down, the marking system 32 of the present invention can be configured to execute a quick system flush. The system flush mode can be executed quickly (e.g., 5-7 seconds) by directing one or more bursts of a flushing liquid such as water through the system.
As shown in
Advantageously, the system flush will clean out most of the marking system piping upstream of the spray guns leaving only the spray guns themselves to be cleaned out manually. A flush mode is particularly useful in situations where the line between the pump and the spray guns is relatively long. According to one preferred embodiment, the switch to a system flush mode can be controlled by the controller and automated based on the occurrence of a triggering event associated with operation of the shingle processing line such as an interruption in the movement or breakage of the web.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This patent application claims the benefit of U.S. Provisional Patent Application No. 60/627,218, filed Nov. 12, 2004
| Number | Date | Country | |
|---|---|---|---|
| 60627218 | Nov 2004 | US |
