Method of and apparatus for producing labels

Abstract

A method of producing a succession of self-adhesive labels carried on a length of release backing material, the method comprising the steps of: (a) providing a laminar material which includes a release backing material as a lower layer and an upper layer comprised of a web of self-adhesive backed material or a layer of pressure-sensitive adhesive; (b) depositing a succession of pre-printed labels onto the upper layer of the laminar material and adhering the pre-printed labels thereto, the laminar material being conveyed past a label applying station; and (c) cutting through the upper layer of the laminar material as far as the release backing material thereby to form the required self-adhesive labels; wherein the rate of deposition of the pre-printed labels onto the upper layer is controlled by detecting the position of pre-printed labels which have been deposited onto the laminar material, comparing the detected position with a desired position of the pre-printed labels and changing the said rate of deposition in response to that comparison. The present invention also provides an apparatus for use with the method.

What I claim is:  
     
         1 . A method of producing a succession of self-adhesive labels carried on a length of release backing material, the method comprising the steps of: 
 (a) providing a laminar material which includes a release backing material as a lower layer and an upper layer comprised of a web of self-adhesive backed material or a layer of pressure-sensitive adhesive;    (b) depositing a succession of pre-printed labels onto the upper layer of the laminar material and adhering the pre-printed labels thereto, the laminar material being conveyed past a label applying station; and    (c) cutting through the upper layer of the laminar material as far as the release backing material thereby to form the required self-adhesive labels; wherein the rate of deposition of the pre-printed labels onto the upper layer is controlled by detecting the position of pre-printed labels, comparing the detected position with a desired position of the pre-printed labels and changing the said rate of deposition in response to that comparison.    
     
     
         2 . A method according to    claim 1    wherein the pre-printed labels are detected before they have been deposited onto the laminar materials.  
     
     
         3 . A method according to    claim 1    wherein the pre-printed labels are detected after they have been deposited onto the laminar material.  
     
     
         4 . A method according to    claim 1    wherein the desired position of each pre-printed label is related to the position of a respective one of a succession of particular locations on the laminar material.  
     
     
         5 . A method according to    claim 4    wherein the succession of particular locations on the laminar material are detected, and wherein when the position of a pre-printed label is detected a label detection signal is produced, and when one of the particular locations on the laminar material is next detected, a laminar material detection signal is produced, the two detection signals are processed to yield an error signal which is related to the distance with the detected pre-printed label leads or lags the desired position and the error signal is employed to retard or advance the rate of deposition of the pre-printed labels.  
     
     
         6 . A method according to    claim 5    wherein the label detection signal is employed to initiate the count of a series of pulses which represent distance travelled by the laminar material, the laminar material detection signal is employed to stop that count, and the counted number of pulses is compared to a particular number of pulses to yield a difference signal which comprises the error signal.  
     
     
         7 . A method according to    claim 1    wherein the cutting is carried out by a die-cutting roller which is continuously driven, and the rotational position of the die-cutting roller is periodically advanced or retarded by means of a servo motor, the servo motor being controlled in response to a die error signal which is produced by comparing the actual rotational position of the die-cutting roller with a desired position.  
     
     
         8 . An apparatus for producing a succession of self-adhesive labels carried on a length of release backing material, the apparatus comprising means for depositing at a label applying station a succession of pre-printed labels onto the upper surface of a laminar material, which includes a lower layer of a release backing material and an upper layer comprised of a web of self-adhesive backed material or a layer of pressure-sensitive adhesive, the pre-printed labels being adhered to the laminar material, means for conveying the laminar material past the label applying station, a cutting device for cutting through the upper layer of the laminar material as far as the release backing material thereby to form the required self-adhesive labels, means for detecting the position of pre-printed labels, means for comparing the detected position with a desired position of the pre-printed labels, means for controlling the said depositing means in response to the means for comparing thereby to change the rate of deposition of the pre-printed labels onto the upper layer.  
     
     
         9 . An apparatus according to    claim 8    wherein the detecting means is located upstream of the label applying station and the detecting means is arranged to detect the position of pre-printed labels before they have been deposited on the laminar material.  
     
     
         10 . An apparatus according to    claim 8    wherein the detecting means is located downstream of the label applying station and the detecting means is arranged to detect the position of pre-printed labels after they have been deposited onto the laminar material.  
     
     
         11 . An apparatus according to    claim 8    further comprising a second detecting means for detecting a succession of particular locations on the laminar material, the desired position of each pre-printed label being related to the position of a respective one of the succession of particular locations.  
     
     
         12 . An apparatus according to    claim 11    wherein the first detecting means is arranged to produce a label detection signal when the position of a pre-printed label is detected, and when the second detecting means next detects one of the particular locations on the laminar material, a laminar material detection signal is produced, the apparatus further comprising means for processing the said two signals to yield an error signal which is related to the distance which the detected pre-printed label leads or lags the desired position and a control means which employs the error signal to retard or advance the rate of deposition of the pre-printed labels by the depositing means.  
     
     
         13 . An apparatus according to    claim 12    wherein the processing means comprises means for counting a series of pulses which represent distance travelled by the laminar material, the label detection signal and the laminar material detection signals being employed to initiate and to stop the count, respectively, and means for comparing the counted number of pulses with a particular number of pulses to yield a difference signal which comprises the error signal.  
     
     
         14 . An apparatus according to    claim 8    wherein the cutting device is a die-cutting roller which is continuously driven, the apparatus further comprising a servo motor which is operable periodically to advance or retard the rotational position of the die-cutting roller and means for comparing the actual rotational position of the die-cutting roller with a desired position to produce a die error signal which is employed to control the servo motor.