Patent Publication Number: US-2018050366-A1

Title: System and method for preventing overflow of adhesive

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Taiwan Patent Application No. 105126788, filed Aug. 22, 2016, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD 
     The present disclosure relates to production of materials control, and more particularly to a system and method for preventing overflow of adhesive, which is beneficial to production of brightness enhancement films. 
     BACKGROUND 
     A conventional process for production of brightness enhancement films is a continuous roll-to-roll process. The continuous roll-to-roll process comprises embossing and curing a polyethylene terephthalate (PET) film with ultraviolet curable adhesive (UV adhesive), thus producing a brightness enhancement film having microstructures. However, a UV adhesive overflow on the PET film is difficult to prevent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a block diagram of a system for preventing overflow of adhesive. 
         FIG. 2  is a schematic perspective view of a roll-to-roll laminator. 
         FIG. 3  is a schematic top view of a PET film. 
         FIG. 4  is a flow diagram of a method for preventing overflow of adhesive. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the exemplary embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the exemplary embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
     With reference to  FIG. 1 , an exemplary embodiment of a system  1  for preventing overflow of adhesive is applied to a roll-to-roll laminator  2 . With reference to  FIG. 2 , the roll-to-roll laminator  2  includes a gumming device  21 , a center roller  22 , two side rollers  23 , and a guide roller  24 . A PET film  25  is disposed between the center roller  22  and the side rollers  23 . The gumming device  21  can apply UV adhesive to the PET film  25 . A rotational direction of the center roller  22  is opposite to a rotational direction of the side rollers  23 . The center roller  22  and the side rollers  23  are rotated to spread UV adhesive on the PET film  25 . The guide roller  24  can rotate to guide the movements of the PET film  25 . The roll-to-roll laminator  2  further includes a UV lamp (not shown) for curing the UV adhesive on the PET film  25 . 
     With reference to  FIG. 3 , the PET film  25  has two opposite sides  251 , and a surface with two inner limit lines  253  and two outer limit lines  254 . The inner limit lines  253  and the outer limit lines  254  are parallel to the sides  251 . Each outer limit line  254  is disposed between one of the sides  251  and one of the inner limit lines  253 . A predetermined applying zone  252  is defined between the inner limit lines  253 . The inner limit lines  253  and the outer limit lines  254  are used to determine an extent to which the UV adhesive is spread in relation to the applying zone  252 . 
     With reference to  FIG. 1 , the system  1  for preventing overflow of adhesive includes a drive unit  11 , a detection unit  12 , and a processing unit  13 . The drive unit  11  can drive the guide roller  24  to rotate. The detection unit  12  is configured to detect whether the UV adhesive on the PET film  25  flows to the inner limit lines  253  and the outer limit lines  254 . The detection unit  12  generates an auxiliary trigger signal upon detecting that the UV adhesive on the PET film  25  flows to either of the two inner limit lines  253 , and then transmits the auxiliary trigger signal to the processing unit  13 . The processing unit  13  triggers an alarm upon receiving the auxiliary trigger signal from the detection unit  12 . The alarm may be a flash alarm or a buzzer alarm. The detection unit  12  generates a main trigger signal upon detecting that the UV adhesive on the PET film  25  flows to either of the two outer limit lines  254 , and then transmits the main trigger signal to the processing unit  13 . The processing unit  13  controls the drive unit  11  to accelerate a rotational speed of the guide roller  24  upon receiving the main trigger signal from the detection unit  12 , so as to accelerate a moving speed of the PET film  25 . The accelerating movement of the PET film  25  prevents the overflow of the UV adhesive on the PET film  25 . The processing unit  13  also controls the gumming device  21  to reduce an amount of the UV adhesive applied to the PET film  25  upon receiving the main trigger signal from the detection unit  12 . The reduction in the amount of the UV adhesive applied to the PET film  25  prevents the overflow of the UV adhesive on the PET film  25 . 
     In the present exemplary embodiment, the detection unit  12  includes two inner laser light sensors and two outer laser light sensors. One inner laser light sensor and one outer laser light sensor are mounted on one side  251  of the PET film  25 , and the other inner laser light sensor and the other outer laser light sensor are mounted on the other side  251  of the PET film  25 . The two inner laser light sensors are configured to respectively detect whether the UV adhesive on the PET film  25  flows to the two inner limit lines  253 , and the two outer laser light sensor are configured to respectively detect whether the UV adhesive on the PET film  25  flows to the two outer limit lines  254 . Either of the inner laser light sensors can generate the auxiliary trigger signal upon detecting that the UV adhesive on the PET film  25  flows to the inner limit line  253 , and then transmit the auxiliary trigger signal to the processing unit  13 . Either of the outer laser light sensors can generate the main trigger signal upon detecting that the UV adhesive on the PET film  25  flows to the outer limit line  254 , and then transmit the main trigger signal to the processing unit  13 . 
     With reference to  FIG. 4 , an exemplary embodiment of a method for preventing overflow of adhesive is illustrated. 
     In step  401 , the detection unit  12  detects whether the UV adhesive on the PET film  25  flows to the inner limit lines  253 . If yes, step  402  is executed, otherwise the step  401  is executed. 
     In step  402 , the detection unit  12  generates the auxiliary trigger signal, and transmits the auxiliary trigger signal to the processing unit  13 . 
     In step  403 , the processing unit  13  triggers an alarm upon receiving the auxiliary trigger signal from the detection unit  12 . 
     In step  404 , the detection unit  12  detects whether the UV adhesive on the PET film  25  flows to the outer limit lines  254 . If yes, step  405  is executed, otherwise the step  404  is executed. 
     In step  405 , the detection unit  12  generates the main trigger signal, and transmits the main trigger signal to the processing unit  13 . 
     In step  406 , the processing unit  13  controls the drive unit  11  to accelerate the rotational speed of the guide roller  24  upon receiving the main trigger signal from the detection unit  12 , so as to accelerate the moving speed of the PET film  25 . The processing unit  13  also controls the gumming device  21  to reduce the amount of the UV adhesive applied to the PET film  25  upon receiving the main trigger signal from the detection unit  12 . 
     The exemplary embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a system and method for preventing overflow of adhesive. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the exemplary embodiments described above may be modified within the scope of the claims.