Patent Publication Number: US-8522980-B2

Title: Glue pellet separator

Description:
BACKGROUND OF INVENTION 
     The present invention relates generally to segregating the components of a heterogeneous mixture of glue pellets and supplying only homogenous glue pellets to a bulk hot melt glue machine. 
     In an automobile assembly plant or a plant where automotive components are manufactured, head impact countermeasure devices are attached by bonding to a headliner substrate using adhesive. At such a plant, however, a dry mixture comprising adhesive pellets of various materials is available for producing various bonded assemblies. For example, a heterogeneous mixture of polyolefin pellets and polyamid pellets or glue pellets of one of those materials can easily be loaded into and supplied incorrectly to a bulk adhesive system that requires pellets of the other material. 
     It is important that one, correct adhesive be used to bond the head impact countermeasure devices to the headliner substrate. If the incorrect adhesive were used to produce this bonded attachment, the bulk system would have to be purged and cleaned out, which may require more than eight hours to complete this corrective operation. Also, use of the wrong adhesive may create a risk that the head impact countermeasure may not remain fully attached to the headliner substrate. A failure of the bonded joint may be undesirable. 
     A need exists in the industry for a reliable, repeatable method or device, suitable for a high volume production environment, that ensures that a homogenous supply of glue pellets of the correct material be provided to a bulk adhesive dispensing machine, whose use is compatible with the material of the pellets being supplied. Preferably the device will segregate the correct glue pellets from foreign glue pellets, which are then available for use in another glue dispensing machine. 
     SUMMARY OF INVENTION 
     A device for supplying glue pellets to a machine includes a screen for segregating pellets according to size, a passageway for carrying into the machine pellets that do not pass through the screen, and a container for containing glue pellets at a higher elevation than an elevation of the screen, and directing away from the machine pellets that pass through the screen. 
     The invention includes a method for supplying glue pellets to a glue machine supporting a separator on the glue machine, using a screen of the separator with a heterogeneous mixture of glue pellets of various sizes to separate glue pellets that can pass through the screen from glue pellets that cannot pass through the screen, if the machine is to be supplied with glue pellets that are larger than a desired size, using the separator to direct pellets that cannot pass through the screen into the glue machine and directing glue pellets that pass through the screen away from the glue machine, and if the machine is to be supplied with glue pellets that are smaller than the desired size, directing pellets that pass through the screen into the glue machine and directing glue pellets that cannot pass through the screen away from the glue machine. 
     The device supplies glue pellets that are compatible with a bulk hot melt glue machine and prevents supplying incompatible glue pellets to the machine. 
     The device is simple to manufacture and minimizes the complexity of the bulk glue system. Its use prevents costly downtime due to loading the wrong adhesive into the system. 
     The device will separate desired glue pellets from undesired glue pellets and supply the glue pellets that are required for a particular machine depending on how the device is mounted to the bulk glue system. No controls or moving parts are required. 
     The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The FIGURE is a perspective view showing separators used to segregate glue pellets according to size and to supply selected pellets to bulk hot melt glue machines and to send rejected pellets to bins. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, there is illustrated in the FIGURE first and second bulk hot melt glue dispensing machines  10 ,  12 , the first machine  10  requiring a supply of polyolefin glue pellets, the second machine  12  requiring a supply of polyamid pellets. 
     A glue pellet separator  14  includes a cylindrical canister or container  16 ; a chute  18 , including a passageway inclined downward from an upper elevation of the container; a grid or screen  20 , located in the container and preferably inclined toward the chute. Preferably narrow strips  22  of elastic, flexible plastic material supported above the entrance of the chute  18  hang downward across the depth and extend along the width of the entrance of the chute, thereby providing a flexible barrier between the chute  18  and airborne glue pellets that otherwise would bypass the separator screen  20 . The strips return elastically to their position and shape following contact with such airborne glue pellets. 
     The grid may be of thin metal wire or plastic forming a mesh having openings about one-quarter inch square. For example, polyamid glue pellets located in container  16  can pass through the screen  20 , whereas polyolefin pellets cannot pass through the screen  20 . When at least two types of adhesive pellets, such as polyolefin pellets and polyamid pellets at room temperature, are combined in a heterogeneous mixture located in container  16 , the pellets can be sorted according to size and shape by separator  14 . 
     When separator  14  is used to supply polyolefin glue pellets to machines  10 , container  16  is located over a bin  24  and the chute  18  communicates with a machine  10 . When the separator  14  is used to supply polyolefin glue pellets to a machine  10 , polyamid pellets in container  16  pass through the screen  20  and fall into bin  24 . But polyolefin glue pellets, which are unable to pass through the screen  20 , slide across the screen  20 , past the barrier strips  22 , down the chute  18  and into machine  10 . 
     When the separator  14  is used to supply polyamid glue pellets to machines  12 , container  16  is located over machine  12  and the chute  18  communicates with a bin  26 . When the separator  14  is used to supply polyamid glue pellets to a machine  12 , polyolefin glue pellets in container  16 , which are unable to pass through the screen  20 , slide across the screen  20 , past the barrier strips, down the chute  18  and into bin  26 . But polyamid pellets in container  16  pass through the screen  20  and fall directly into machine  12 . 
     Glue pellets collected in bins  24 ,  26  can be used to supply a glue machine with which they are compatible. 
     The separator  14  prevents supplying incorrect glue pellets to a hot melt adhesive bulk system. The separator sorts the adhesive based on size, large from small and small from large, depending on how the separator is mounted on the machines  10 ,  12 . 
     While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.