Abstract:
A label removal system for removing a label with a stock portion and an adhesive from a product includes a stripper, an applicator, a remover, and a transportation system. The stripper sprays a first liquid at the label to strip at least a portion of the stock portion of the label off of the product. The applicator applies a chemical substance on at least a portion of the adhesive and any remaining portion of the label on the product. The remover removes at least a portion of the adhesive and any remaining portion of the label on the product. The transportation system moves the product sequentially from the stripper to the applicator and then to the remover. A method for removing a label with a stock portion and an adhesive from a product includes a number of steps. First, at least a portion of the stock portion of the label off is stripped off of the product by spraying a first liquid at the label. Next, a chemical substance is applied on at least a portion of the adhesive and any remain stock portion of the label. Finally, at least a portion of the adhesive and any remaining portion of the label is removed from the product after the application of the solvent.

Description:
This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/105,331 filed on Oct. 23, 1998 which is herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to recycling systems and, more particularly, to a system and method for removing a label affixed to a product with an adhesive. 
     BACKGROUND OF THE INVENTION 
     Although recycling and reuse of products in a variety of different industries is becoming more commonplace, there are still a substantial number of products which could be recycled and reused, but are not. For example, in the electronics industry electronic chips are often transported by affixing the electronic chips onto carrier tape and then winding up the chip-laden carrier tape onto polystyrene reels. Prior to transporting these reels, pressure-sensitive labels are affixed to each of the reels which identify their content, origin, and destination. Once the reels have reached their destination, the carrier tape with the chips on each reel is unwound and the reels are typically discarded even though their useful life is not spent. If the labels on the reels could be removed, then they could be reused several more times. 
     Unfortunately, a cost-effective way to remove the pressure-sensitive labels from certain products, such as these reels, without warping or otherwise damaging the products has not been found. As a result, these products are not recycled and reused and instead are often disposed of in landfills after a single use. This contributes to the growing volume of solid waste in landfills. Additionally, this requires new products to continually be manufactured which adds to the overall cost of products. 
     Attempts have been made to develop a system and/or method for removing labels from certain products, such as reels, but these attempts have been unsuccessful for a variety of different reasons. For example, one attempt has involved manually removing labels from the reels. Unfortunately, in addition to being an expensive, slow, and labor-intensive process, this technique has not been particularly effective in removing the labels including the adhesive from a substantial number of reels. Other attempts have involved the use of a variety of different chemicals to remove the labels, including the adhesive, from products. Unfortunately, the chemicals were either ineffective in removing all of the stock of the label and/or all of the adhesive residue, warped or otherwise damaged the reels, were too expensive to use and/or could not be disposed of economically. Accordingly, a cost-effective method for removing a label affixed to certain products, such as a reel, with an adhesive has not been found. 
     Although the example discussed above relates to the removal of labels from reels used in the electronics industry, the same problems are faced in the removal of labels from products in a variety of different industries which could be reused. 
     SUMMARY OF THE INVENTION 
     A label removal system for removing a label with a stock portion and an adhesive from a product in accordance with one embodiment of the present invention includes a stripper, an applicator, a remover, and a transportation system. The stripper sprays a first liquid at the label to strip at least a portion of the stock portion of the label off of the product. The applicator applies a chemical substance on at least a portion of the adhesive and any remaining portion of the label on the product. The remover removes at least a portion of the adhesive and any remaining portion of the label on the product. The transportation system moves the product sequentially from the stripper to the applicator and then to the remover. 
     A label removal system in accordance with another embodiment of the present invention includes a stripper, an applicator, a scrubber, a washer, and a transportation system. The stripper sprays a first liquid at the label to strip at least a portion of the stock portion of the label off of the product. The applicator applies a chemical substance on at least a portion of the adhesive and any remaining portion of the label on the product. The scrubber scrubs at least a portion of the adhesive and the remaining portion of the label on the product. The washer removes most or all of the residual stock portion, the adhesive, and the chemical substance from the product. The transportation system moves the product sequentially from the stripper, to the applicator, to the scrubber and then to the washer. 
     A method for removing a label with a stock portion and an adhesive from a product in accordance with yet another embodiment of the present invention includes a number of steps. First, at least a portion of the stock portion of the label is stripped off of the product by spraying a first liquid at the label. Next, a chemical substance is applied on at least a portion of the adhesive. Finally, at least a portion of the adhesive and any remaining portion of the label is removed from the product after the application of the chemical substance. 
     Another method for removing a label with a stock portion and an adhesive from a product in accordance with yet another embodiment of the present invention also includes a number of steps. First, a first liquid is sprayed at the label to strip off at least a portion of the stock portion of the label. Next the product is at least partially dried and then a chemical substance is applied on at least a portion of the adhesive and any remaining portion of the label. Once the chemical substance is applied, at least a portion of the adhesive and any remaining portion of the label is scrubbed off of the product. Finally, at least the portion of the product where the label was located is washed. 
     One of the unique aspects of the invention is that the present invention recognized the benefit of combining the best characteristics of several cleaning technologies in a cost-effective integrated system. More specifically, the present invention recognizes that labels can be removed in a cost effective manner by first stripping off at least a portion of the stock portion of the label by spraying a liquid, such as water, and then applying a less corrosive, toxic, and/or expensive chemical substance to the remaining adhesive and stock portion and scrubbing the remaining portion of the label away. As discussed in greater detail earlier, previous methods focused on single cleaning technologies which were ineffective, resulted in damage to the product, were not cost effective, and/or relied upon the use of chemicals which were difficult to handle and/or dispose of. The present invention also recognized the benefit of drying the product after stripping away at least a portion of the stock to optimize the contact between the chemical substance and the adhesive. 
     Another unique aspect of the present invention is that it will now permit the reuse of a much larger number of products. As a result, fewer products will be disposed of after a single use which should help to further reduce the volume of solid waste being disposed of in landfills. Additionally, the present invention should also reduce the need for the manufacture of as many new products as before, because now many of these products will be able to be reused. As a result, more natural resources will be saved and the overall costs of products should go down. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is block diagram illustrating a label removal system in accordance with one embodiment of the present invention; 
     FIG. 2A is a cross-sectional view of a transportation system used in the embodiment of the label removal system shown in FIG. 1; 
     FIG. 2B is a top view of a portion of the transportation system shown in FIGS. 1 and 2A; and 
     FIG. 3 is a flowchart illustrating a method for removing a label with a stock portion and an adhesive from a product in accordance with another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     A label removal system  10  in accordance with one embodiment of the present invention is illustrated in FIG.  1 . This embodiment of the label removal system  10  includes a transportation system  12 , a loading/unloading station  14 , a stripping station  16 , a drying system  18 , an application station  20 , a removal station  22 , and a washing station  24 . The present invention provides a number of advantages including providing a method and system for removing a label affixed to a product  26  which combines the best characteristics of a few different cleaning technologies in a cost-effective integrated system. Additionally, with the present invention the volume of solid waste disposed of in landfills should be reduced because more products will now be able to be reused. 
     Referring to FIGS. 1,  2 A, and  2 B, in this particular embodiment the transportation system  12  includes an endless conveyor system  28 , although other types of transportation systems can be used. Since the parts and operation of conveyor systems  28  are well known to those of ordinary skill in the art, they will not be discussed in detail here. The conveyor system  28  includes a motor  30 , a drive shaft  32 , connecting gears and components, a conveyor control system  34 , and a conveyor belt  36  with a plurality of flat top chain links  38  along with some plates  40  and pins  42 , which are all connected together by fastening devices  44 , such as screws, to detachably secure the product  26  to the conveyor belt  36  for processing. 
     Referring more specifically to FIGS. 2A and 2B, in this particular example, one pin  42 ( 1 ) passes through the center hole  46  in a product  26  and another pin  42 ( 2 ) passes through another hole  48  in the product  26  and the product  26  rests on the plates  40  secured by each pin  42 . As a result, the products  26  are secured to the conveyor system  28  so that the product  26  will not move, rotate or fall off, but the product  26  can still be easily loaded and unloaded. In this particular example, when the product  26  is positioned on the pins  42  and the plates  40 , the product  26  is positioned so that the label to be removed faces away from the plates  40  and the conveyor belt  36 . Although pins  42  and plates  40  are shown in this example to detachably secure the product  26  to the conveyor system  28 , other types of connecting assemblies and mechanisms to secure the product  26  to the conveyor system  28  can also be used. 
     The transportation system  12  may also include optional drip pans below the conveyor belt  36  to catch fluids dripping off of the product  26  during processing. Preferably, the drip pans are constructed of a material, such as stainless steel or plastic, which is resistant to corrosion. 
     In this particular embodiment, the endless conveyor system  28  has a length of one hundred-twenty feet and has a nominal line speed of up to fourteen feet per minute so that twelve half reels (products  26 ) having a diameter of up thirteen inches can be processed per minute, although the length, size, and speed of the conveyor system  28  can vary as necessary for the particular application. The transportation system  12  may also include an extended portion  50  for the conveyor system  28  between the application station  20  and the removal station  22  which permits any chemical substance applied to the adhesive and/or any of the remaining stock portion of the label to soak in, although other techniques for providing soak time may also be used. For example, the transportation system  12  may simply be stopped for a period of time or the product  26  may be removed from the transportation system  12  for a period of time and then the product  26  may be placed back on the transportation system  12  after the period of time has expired. Preferably to remove the adhesive and/or any of the remaining stock portion of the label from products  26 , such as polystyrene reels, the extended portion of the conveyor system  28  is designed to permit the chemical substance to soak in for between about fifteen seconds and fifteen minutes, and more preferably about five minutes. This provides adequate time for the chemical substance to work on and react with adhesive and/or any of the remaining stock portion of the label. 
     Referring back to FIG. 1, in this particular embodiment the loading/unloading station  14  is located adjacent to the transportation system  12  and between the stripping station  16  and the washing station  24 . In this particular embodiment, the product  26  is loaded onto and is unloaded from the transportation system  12  manually at the loading/unloading station  14 , although the loading and unloading process could be automated using a variety of different types of components, machines, and/or assemblies well known to those of ordinary skill in the art. Additionally in this particular embodiment, the product  26  is inspected manually at the loading/unloading station  14  prior to passing through the label removal system  10  to determine if a label or other item needs to be removed from the product  26  and if the product  26  is saleable or can still be reused, although again this inspection process could be automated using a variety of different types of components, machines, and/or assemblies well known to those of ordinary skill in the art. Product  26  which can not be reused is recycled when possible. Further in this particular embodiment, the product  26  is inspected manually at the loading/unloading station  14  after passing through the label removal system  10  to determine if the label or other item has been removed, although again this inspection could be automated using a variety of different types of components, machines, and/or assemblies well known to those of ordinary skill in the art. 
     Although not shown, the label removal system  10  may also include an optional electrostatic discharge coating station. As discussed above, in the loading/unloading station  14  the product  26  is inspected to determine if the product  26  is saleable and clean. If the product  26  is saleable and clean, the transportation system  12  may include a separate track for the conveyor system  26  in the loading/unloading station  14  which leads to and transports the product  26  to the electrostatic discharge coating station where an electrostatic discharge coating is applied to the product  26 . 
     The stripping or spraying station  16  is also located adjacent to the transportation system  12  and between the loading/unloading station  14  and the application station  20 . The stripping station  16  is designed to remove at least a portion of, and preferably all of, stock portion of the label. Typically, the label is comprised of a stock portion upon which information is printed and which is secured to a product  26 , such as a polystyrene reel, by an adhesive. The stock portion is usually paper stock, although the stock portion can be comprised of other materials, such as a plastic or a metal. Since the parts and operation of stripping or spraying stations  16  are well known to those of ordinary skill in the art, they will not be discussed in detail here. 
     In this particular embodiment, the stripping station  16  includes a plurality of rotary nozzles which deliver a pulsed flow and which are connected by pipes to a pump, a heating system, and a source of liquid, such as water, although stripping stations with other types and/or variations of components and liquids can also be used. Preferably, to remove the stock portion of labels affixed to products, such as polystyrene reels, the stripping system  16  includes four rotary nozzles which each deliver a flow rate of about three gallons per minute (gpm) at pressures ranging between about 500 psig and 5,000 psig and preferably at about 2,500 psig. The stripping system in this particular example also includes a twenty-five horsepower (hp) pump, a heating system which heats the water to a temperature between about eighty degrees Fahrenheit and two-hundred degrees Fahrenheit, and preferably to about one-hundred-sixty degrees Fahrenheit, and pipes which connect the nozzles to the pump, heating system, and the source of liquid, although the number of nozzles, the flow rate, the flow pressure, the liquid temperature, and the horsepower rating of the pump can vary as needed for the particular application. An optional screen spread over a steel grate can be positioned below the nozzles to catch portions of the label as the label is stripped from the product  26 . 
     One of the advantages of the present invention is the discovery that heated water sprayed at high pressure is an effective and inexpensive way to strip at least a portion of the stock portion of the label off of a product  26  and, in particular, off of a polystyrene reel. By removing at least a portion of the stock portion of the label with water, the present invention is able to use less corrosive, toxic, and/or expensive chemical substances along with a scrubbing station to remove the adhesive and any remaining stock portion. The combination of the different removal procedures discussed in this application provides a cost effective and relatively safe method and system for removing labels. Another advantage of the present invention is that the liquid used to strip the stock portion of the label can be captured, filtered, and reused. As a result, the method and system help to conserve water. 
     A portion of the drying system  18  is located adjacent the transportation system  12  and following the stripping station  16 . Since the parts and operation of drying systems  18  are well known to those of ordinary skill in the art, they will not be discussed in detail here. In this particular embodiment, the drying system  18  includes a compressed gas supply  52 , such as a source of compressed air, which is connected by pipes  54  to an air knife  18 ( 1 ), although other types of drying systems with other types of components can also be used. The air knife  18 ( 1 ) is positioned to direct a gas, such as air, from the compressed gas supply  52  at the product  26  to at least partially dry off the product. Another advantage of the present invention is that the product  26  is dried prior to applying the chemical substance at the application station  20  which promotes optimal contact between the applied chemical substance and the adhesive on the product  26 . 
     The application station  20  is also located adjacent to the transportation system  12  and between the first portion of the drying system  18  and the removal station  22 . Since the parts and operation of application stations  20  are well known to those of ordinary skill in the art, they will not be discussed in detail here. In this particular embodiment, the application station  20  includes a sprayer connected to a supply of chemical substance by pipes, although application stations with other types and/or variations of components can also be used. The sprayer is positioned to spray chemical substance on to the adhesive and any remaining stock portion of the label. Although a sprayer is discussed in this example, other systems for applying chemical substances, such as rolling the chemical substance on or dipping the product  26  in the chemical substance can be used. In this particular embodiment, a chemical substance, such as, such as Tarksol, d-Limonene (Chemical Abstract Series No. 5989-27-5), or isoparaffinic hydrocarbon (Chemical Abstract Series No. 64742-48-9), is used and has been found to be particularly effective in helping to remove adhesive and any remaining portion of the stock portion of labels on products  26 , such as polystyrene reels, although the particular chemical substance or chemical substances used can vary based upon the particular application. Some of the chemical substances discussed above are insoluble which aids in their recovery after use as discussed below. 
     The removal station  22  is located adjacent to the transportation system  12  and between the washing station  24  and the application station  20 . Since the parts and operation of removal stations  22  are well known to those of ordinary skill in the art, they will not be discussed in detail here. In this particular embodiment, the removal station  22  includes a plurality of rotating brushes and a motor, although other types of removal stations with other types of components can also be used. The brushes, in this example, are positioned to scrub at least the portion of the product  26  where the adhesive and any remaining portion of the stock portion of label is located. In this particular embodiment, the brushes are either cleaned periodically to remove accumulated adhesive and stock or are replaced periodically. 
     The washing station  24  is located adjacent to the transportation system  12  and between the removal station  22  and the second portion of the drying system  18 . Since the parts and operation of washing stations  24  are also well known to those of ordinary skill in the art, they will not be discussed in detail here. In this particular embodiment, the washing station  24  includes a plurality of sprayers connected by pipes to a pump and a source of liquid, such as water, although washing stations  24  with other types and/or variations of components can also be used. Preferably, to remove any remaining residue of adhesive and/or any remaining portion of the stock portion of the label, particularly on a polystyrene reel, a two horsepower pump is used to deliver liquid at fifteen gpm at one-hundred-forty degrees Fahrenheit, although the horsepower rating of the pump, the flow rate, and the liquid temperature can vary as needed for the particular application. Another optional screen spread over a steel grate can be positioned below the washing station  24  and the conveyor system  28  to catch portions of the adhesive and any stock portion of the label washed off of the product  26 . Another advantage of the present invention is the ability to reuse the washing liquid and the ability to separate and recover at least a portion of the used chemical substance located in the washing liquid. 
     Another portion of the drying system  18  is located adjacent the transportation system  12  and following the washing station  24 . Again, since the parts and operation of drying systems  18  are well known to those of ordinary skill in the art, they will not be discussed in detail here. In this particular embodiment, another air knife  18 ( 2 ) is connected by pipes  54  to the compressed gas supply  52  discussed earlier, although this air knife  18 ( 2 ) could be connected to its own compressed gas supply and drying systems with other types and/or variations of air knives or of components could also be used. The air knife  18 ( 2 ) is positioned to direct a fluid, such as air, from the compressed gas supply  52  at the product  26  to at least partially dry off the product  26  in preparation for unloading, inspection, pack out, and shipping. 
     The operation of the label removal system  10  will be explained with reference to FIGS. 1-3. Although in this particular example, label removal system  10  and method will be described with reference to the removal of a label from a reel, the system and process will be the same for other types of products  26 . First, in step  56  the product  26  is inspected prior to passing through the label removal system  10  and in step  58  a determination is made on whether the product  26  is saleable or reuseable. If the product  26  is not saleable, then the No branch is taken from step  58  and the product  26  is packaged for shipping in step  60  and then in step  62  is transported to a grinding or other type of scrap recycling center. Alternatively, if the product  26  not saleable, then the product  26  may simply be disposed of. Again, in this particular embodiment the inspection process as described above and below is conducted manually, however these steps could be automated if desired. 
     If in step  58  a determination is made that the product  26  is saleable, then the Yes branch is taken and in step  64  the product is inspected to determine if a label or other item needs to be removed from the product  26 . If the product  26  does not need a label removed and thus is clean, then the Yes branch is taken and in step  66  the product is packaged for shipping and in step  68  the product is ready for distribution to the customer and is considered to be finished goods inventory (“FGI”). 
     If the product  26  does need a label removed, then the No branch is taken and in step  70  the product  26  is loaded onto the conveyor system  28 . In this particular embodiment, the product  26  is a reel which is detachably secured to the conveyor belt  36  using the pins  42  which pass through holes  46  and  48  in the reel. The transportation system  12  transports the product  26  through the various stations shown in FIG.  1  and described in detail earlier. In this particular embodiment, the transportation system transports the product at about fourteen feet per minute, although the rate at which the product  26  is transported through the label removal system  10  will vary based upon the particular application. 
     Next, in step  72  the product  26  is transported to the stripping station  16  where at least a portion of the stock portion of the label is removed. Again, preferably, to remove labels affixed to products, such as polystyrene reels, water is heated by a heat source to a temperature of about one-hundred-sixty degrees Fahrenheit and is sprayed at the reels using four rotary nozzles which each deliver a flow rate of about three gallons per minute (gpm) at 2,500 psig and a twenty-five horsepower (hp) pump, although the particular temperature, pressure, and flow rate of the liquid being sprayed will vary based upon the particular application. Again, one of the advantages of the present invention is the combination of different cleaning technologies to remove the labels in a cost effective manner and without damaging the product  26 . 
     As discussed earlier, an optional screen spread over a steel grate is located below the stripping station  16  and catches portions of the label as the label is stripped from the product  26 . The stock portion of the labels is collected and disposed of and the liquid, in this example water, is cleaned and recirculated for reuse in the stripping station  16 . 
     Next, in step  74  the transportation system  12  moves the product  26  to the first portion of the drying system  18  where the product  26  is dried with an air knife  18 ( 1 ). As discussed earlier, another advantage of the present invention is that the product  26  is dried prior to applying the chemical substance to promote optimal contact between remaining adhesive residue and the chemical substance. 
     Once the product  26  is dried it is transported by the transportation system  12  to the application station  20  where in step  76  the chemical substance is applied to the product  26 . In this particular embodiment, approximately 10 milliliters or less of a chemical substance, including, for example, a terpene alcohol based solvent such as environmentally safe Tarksol®, made by Tarksol, Inc., d-Limonene (Chemical Abstract Series No. 5989-27-5), or isoparaffinic hydrocarbon (Chemical Abstract Series No. 64742-48-9), is sprayed onto the product  26 , although the quantity of the chemical substance applied as well as the type of chemical substance can vary based upon the particular application. Although in this particular embodiment, the chemical substance is applied by spraying, other methods of application, such as rolling the chemical substance on or dipping the product  26  into the chemical substance, can also be used. Next, in step  78  the chemical substance is allowed to soak into the adhesive residue and any remaining stock portion of the label for a period of time. In this particular embodiment, the chemical substance is allowed to soak for approximately five minutes. Additionally, in this particular embodiment, the soak time is provided while the product  26  travels along the extended portion  50  of the transportation system  12  (between the application station  20  and the removal station  22 ), although other techniques for providing soak time may also be used, such as simply stopping the transportation system for a period of time or removing the product  26  from the transportation system  12  for a period of time and then placing the product  26  back on the transportation system  12  after the period of time has expired. 
     Next, in step  80  the product  26  is transported by the transportation system  12  to the removal or scrubbing station  22  where the adhesive and any remaining stock portion of the label is removed. In this particular embodiment, the removal station  22  uses rotary brushes to scrub the adhesive and any remaining stock portion of the label off of the product  26 , although other types of removal systems  22  could also be used. 
     Next, in step  82  the product  26  is transported by the transportation system  12  to the washing station  24  where the product  26  is washed. In this particular embodiment, the product  26  is washed with a liquid, such as water at room temperature, which is sprayed on the product  26  at low pressure, although other types of washing systems could be used using other techniques for washing. In this particular embodiment, the liquid which rinses off of the product  26  is collected and the liquid is reused in the washing station  24  after being filtered or cleaned. Additionally, certain chemical substances may be recovered from the liquid in the washing station  24  and subsequently reused in the application station  20 . 
     Once the product  26  is washed, then in step  84 , the product  26  is transported by the transportation system  12  to the second portion of the drying system  18  where the product is dried again. In this particular embodiment, the product  26  is dried with an air knife  18 ( 1 ), although other types of drying systems could be used, and passed to the loading/unloading station  14 . 
     Next, in step  86 , the product is transported by the transportation system  12  to the loading/unloading station  14  where the product  26  is unloaded. Once the product  26  is unloaded, then the product  26  is subject to the process described above beginning again with step  56 . A product  26  may require more than one pass through the removal system  10  to remove the label. Accordingly, as described above, the present invention combines the best characteristics of a few different cleaning technologies to provide a cost-effective integrated system for removing labels from products  26 . 
     Having thus described the basic concept of the invention, it will be rather apparent to those skilled in the art that the foregoing detailed disclosure is intended to be presented by way of example only, and is not limiting. Various alterations, improvements, and modifications will occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested hereby, and are within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims and equivalents thereto.