Abstract:
A hot melt adhesive system includes a melting unit configured to liquefy a bulk form of hot melt adhesive and deliver the liquefied hot melt adhesive to an application location. The melting unit includes a controller for establishing and/or verifying at least one system condition, such as temperatures associated with system operation. A machine reading unit is coupled with the controller and is capable of receiving information from a machine readable element and communicating the information to the controller for use in establishing and/or verifying the system condition. A method of operating the system includes scanning information on at least one system condition into the controller from a machine readable element, and using the scanned information during operation of the melting unit.

Description:
CROSS REFERENCES 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/765,312 filed Apr. 22, 2010 (pending), which claims the benefit of U.S. patent application Ser. No. 10/699,404, filed Oct. 31, 2003 (abandoned), the disclosures of which are hereby incorporated by reference herein in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention pertains to dispensing systems for dispensing flowable material, and more particularly to hot melt adhesive dispensing systems. 
       BACKGROUND 
       [0003]    Thermoplastic adhesives, otherwise known as “hot melt” adhesives have been widely used in industry for adhering many types of products. Hot melt adhesive dispensing systems generally include a dispenser coupled with one or more dispensing guns, heated hoses fluidly connected to the guns, and a melting unit for melting and supplying heated liquid adhesive to the guns through the heated hoses. The melting units of conventional hot melt adhesive systems typically include a tank, a heater, a pump, a pump manifold, and a controller. The heater is generally located in a base of the tank for melting and heating adhesive material received into the tank in solid or semi-solid form. The pump manifold has an inlet connected to the tank and has multiple outlet ports adapted for connection to the heated hoses. 
         [0004]    After the adhesive material is melted and heated in the tank, a pump operatively coupled to the tank and the pump manifold pumps liquid adhesive from the tank, through the pump manifold and heated hoses to the dispensing guns. Typically, the guns are connected to their own manifold. The controller controls the power supplied to the tank heater and heated hoses to maintain the liquid adhesive at an appropriate viscosity and temperature, depending on the application. The controller is also used to control many other operations of the system. 
         [0005]    Before an adhesive dispensing operation can begin, the operator must ensure that the system parameters are set to values that are appropriate for the particular adhesive being used, as well as for the application needs. As some examples, system conditions such as adhesive application temperature, set back temperature, and over-temperature conditions should be set in the controller. If the system parameters are incorrectly set, various problems can arise such as overheating and charring of the adhesive, or underheating of the adhesive which could result in operational problems and adhesive bonding problems. Various other conditions may need to be set to establish a proper dispensing cycle. For example, there will be a delay time between when the system is turned on and the time that actual dispensing can take place. 
         [0006]    A need therefore exists for a hot melt adhesive dispensing system having the ability to better ensure that system parameters are properly set in the controller. It would also be desirable to enable an operator to more easily and positively establish system conditions appropriate to the adhesive being processed, and efficiently utilize information related to system operation. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention generally relates to a hot melt adhesive system including a melting unit and a controller coupled to a suitable machine reading unit which can receive information from a machine readable element and communicate that information to the controller. The melting unit is configured to liquefy a bulk form of hot melt adhesive and deliver the liquefied hot melt adhesive to an application location. The controller establishes or verifies at least one system condition and the information received from the machine reading unit is used by the controller to verify or establish the system condition. 
         [0008]    As examples, the machine reading unit may take the form of a bar code reader or magnetic strip reader, however any other machine readable element and appropriate device for reading the element may be used. The system condition or conditions which are established based on the information received by the machine reading unit can, for example, include the application temperature of the hot melt adhesive, an over-temperature condition of the hot melt adhesive, a set-back temperature of the adhesive, or other conditions, such as warnings or parameters associated with a system flushing operation. 
         [0009]    The invention further provides a method of operating a hot melt adhesive system having a controller operating a melting unit. The method includes scanning information on at least one system condition into the controller from a machine readable element, and using the scanned information during operation of the melting unit. Using the scanned information can further comprise setting appropriate temperature conditions, warning conditions, system flushing parameters. Other uses involve collecting information such as adhesive identification information or information indicating the amount of adhesive processed by the melting unit. Any information of the type used in carrying out this invention may also be logged into a database for various diagnostic or analytical purposes. Preferably, the information is located directly on the container in which the bulk hot melt adhesive typically is packaged. This may involve, for example, a bar code or other machine readable element affixed to or forming part of the container. A conventional bar code scanner, magnetic strip scanner, or other device may be used which is appropriate for the machine readable element. 
         [0010]    Various advantages are realized from this invention, including the ability to quickly and positively download any necessary system parameters associated with a particular system operational procedure or type of adhesive. The parameters for each type of adhesive may be contained on the machine readable element associated with the bulk container of the adhesive which is then scanned or read in just prior to system operation as opposed to relying on the operator to input such information manually. Various system warnings may alert personnel if the type of adhesive is changed during a manufacturing operation, or if the settings are different than those recommended by the adhesive manufacturer. By scanning or reading adhesive information, such as lot numbers, into the controller, a defective lot of adhesive may be more easily identified. If each bulk container is scanned or read, then the amount of adhesive used in a given time period may be determined and tracked. Any or all information can be logged into a database for purposes such as verifying that all adhesive types are being applied under the proper conditions. The invention further contemplates hot melt adhesive containers of bulk adhesive material having such machine readable elements affixed thereto in any suitable manner allowing information to be input upon delivery of the container to an operator. 
         [0011]    These and other features, advantages and objectives of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the details of the preferred embodiments. 
           [0013]      FIG. 1  is a schematic drawing of a hot melt adhesive system, including a melting unit, controller and bar code scanner configured according to one illustrative embodiment of the present invention; and 
           [0014]      FIG. 2  is a schematic drawing similar to  FIG. 1 , but illustrating an alternative scanner and machine readable element of magnetic form. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    The inventive principles will be described below in connection with a specific description of a hot melt adhesive system  10 , however, it should be understood that the invention is applicable to many other types of systems and is not limited to the details described below. The various components described below may be modified, eliminated, added to, and generally assembled in many different manners. 
         [0016]    Referring to  FIG. 1 , a hot melt adhesive system  10  includes a pair of adhesive guns  12 ,  14 , a dispensing unit  16  for supplying adhesive  18  to the guns  12 ,  14 , and heated hoses  20  connecting the dispensing unit  16  to the guns  12 ,  14 . Cord sets  21  are used to heat and control the temperature of hoses  20  in a known manner. The dispensing unit  16  includes a tank  22  for receiving and melting hot melt adhesive  18 , a manifold  24  in fluid communication with the tank  22 , a pump  26  constructed according to the principles of the present invention and coupled to the manifold  24 , and a controller  28 . The tank  22  comprises side walls  30  and base  32  which includes a tank heater  34  for melting and heating the adhesive material  18  in the tank  22 . A tank outlet  36  proximate the base  32  is coupled to a passage  38  which connects to an inlet  40  of the manifold  24 . 
         [0017]    The manifold  24  is located adjacent the tank  22  and includes a manifold heater  42  that is separate from the tank heater  34  and which may be independently controlled by the controller  28 . Pump  26  is coupled to the manifold  24  and pumps liquid adhesive  18  from the tank  22 , through a filter (not shown) removably disposed within the pump  26 , and into the manifold  24 . The manifold  24  splits the adhesive  18  into separate flows  46  and directs the flows  46  to a plurality of outlet ports  48 . The plurality of outlet ports  48  are configured to be coupled to the heated hoses  20  whereby the liquid adhesive  18  is supplied to the guns  12 ,  14 . 
         [0018]    The guns  12 ,  14  may be mounted to a frame  50  and include one or more adhesive dispensing modules  52  which apply the adhesive  18  to a desired product (not shown). Modules  52  may be coupled to their own manifolds  54  for supplying adhesive, actuating air and process air thereto. The hot melt adhesive system  10  illustrates two gun manifolds  54  each supplied by a single hose  20 , however, a second hose  20  is shown on each side of system  10  and may supply additional gun manifolds (not shown) located respectively behind manifolds  54 . Other hot melt systems may have a single gun, or may have other guns and the guns and other components of the system may take on many different configurations, according to the particular adhesive dispensing requirements without departing from the scope of the present invention. 
         [0019]    Still referring to  FIG. 1 , in accordance with one embodiment of this invention, a bar code reader or scanner  62  is coupled to the controller  28  and is operable to read a conventional bar code label  64  which may, for example, be affixed to a bulk container  66  of hot melt adhesive. The scanner or reader  62  may be hand held as shown, or may be fixed in place such that the container  66  may be brought within sufficient proximity to enable reading of the bar code  64   a.  The bar code reader  62  is capable of receiving information from the bar code  64   a  and communicating that information to the controller  28  for use in establishing and/or verifying various system parameters or conditions. Typically these conditions, such as adhesive application temperature, over temperature, setback temperature, as well as other setup conditions are inputted into the controller  28  through various methods. For example, they may be entered manually through a control pad, as is conventional, or they may be entered via a remote computer or other electronic device via any number of ways including, but not limited to, the Internet, an intranet, infrared devices, other wireless devices, memory cards, etc. Other conditions may also be set based on information contained on the label  64  or other machine readable element. For example, various dispensing cycle parameters may be set or verified relative to cycle times, on/off or dispensing time delays, etc. This includes various system warnings, adhesive information, and other data collection which may be used for diagnostic or analytical purposes. The information obtained from the label  64  or machine readable element is electrically transmitted to the control  28  via a cable  68  which may comprise a conventional programmable logic controller (PLC) or other microprocessor based control system configured to communicate with the bar code reader  62 . Element  64  could instead be an embedded electronic chip which is readable via a portable wand or other reading device, or which is read upon coming into proximity with such a reader which is part of system  10 , such as within controller  28 . 
         [0020]    As illustrated in  FIG. 2 , one of many alternative types of machine readable elements and scanners may comprise a suitable card  70  having a magnetic strip  70   a  and a scanner or reader  72  configured to receive the information from the magnetic strip  70   a.  The machine readable element, in this case being a card with a magnetic strip  70 , may be separable and/or independent of the container  66  of hot melt adhesive. For example, an operator may be supplied with a card  70  detachable from the hot melt adhesive container  66 , or the card  70  may be chosen by the operator from a set of cards at the system workstation based on the set of parameters desired, for example, related to a particular type of adhesive. The card  70  may transmit information to the control  28  in manners such as those described above with respect to  FIG. 1 . All other components shown in  FIG. 2  have like reference numerals and thus have been described in connection with  FIG. 1  as well. The present invention, and its various aspects, may be implemented using many other types of machine readable elements including, but not limited to, other elements which rely on any wireless communication technology, such as radio frequency (RF) technology (such as RFID tags or transponders), WiFi technology and magnetic devices of various types. 
         [0021]    It will be appreciated that the present invention may be used in many different manners to improve the operation of a hot melt adhesive dispensing system. By scanning (i.e., transmitting) the machine readable element on the container of adhesive, such as a drum or other type of container, the particular operational parameters corresponding to that adhesive may be automatically downloaded into the system controller  28 . This minimizes the possibility of error in the system operational parameters. In addition, process conditions can be verified with the operator before operation of the system. For example, if a container is scanned and is providing different information from the previously scanned container, the control system can prompt the operator to confirm that the change in adhesive is desired. This ensures that an incorrect adhesive is not inadvertently used in the middle of a manufacturing operation potentially resulting in system downtime and product scrap. In addition, the system controller can track whether settings different from those recommended by an adhesive manufacturer are being used during operation of the system  10  to assist with diagnosing maintenance or other problems with the system  10 . During a system flushing operation, scanning a machine readable element with system flushing information can adjust the controller settings appropriate to the system flush procedure. After the system flush, rescanning the adhesive container label or other machine readable element associated with the particular hot melt adhesive, will return the controller  28  to the hot melt adhesive application settings. Finally, the controller  28  can also receive information appropriate to tracking the amount and type of adhesive being used in system  10 . This can aid in determining whether a particular lot or batch of adhesive was defective and track use of the system  10  for purposes of scheduling appropriate maintenance. Logging of application data can provide confirmation and certification that the adhesive is being applied under the appropriate settings. 
         [0022]    While the present invention has been illustrated by the description of various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants&#39; general inventive concept.