Apparatus and method for measuring roll sidewall quality

Abstract

An apparatus for measuring a sidewall characteristic of a wound roll includes a housing, a platform mounted in the housing having a surface adapted to receive the wound roll, a distance measuring sensor supported in the housing for movement along a predetermined line of measurement extending across at least a portion of the sidewall of the wound roll for measuring the sidewall characteristic, and a processor for processing the sidewall characteristic and generating at least one quality metric representative of the quality of the roll.

1 . An apparatus for measuring a sidewall characteristic of a wound roll, said wound roll comprising a strip of material wound about an axis, thereby forming a wound roll having concentric windings parallel to the axis with an upstanding sidewall with edges extending radially from the axis, said apparatus comprising: 
 a housing;    a platform mounted in the housing having a surface adapted to receive the wound roll;    a distance measuring sensor supported in the housing for movement along a predetermined line of measurement extending across at least a portion of a sidewall of the wound roll for measuring the sidewall characteristic; and    a processor for processing the sidewall characteristic and generating at least one quality metric representative of the quality of the roll.    
   
   
       2 . The apparatus as claimed in  claim 1  wherein the sidewall characteristic measured by the distance measuring sensor comprises distance data taken along the line of measurement, said distance data corresponding to the distance of the upstanding edges of the lap windings from the platform surface.  
   
   
       3 . The apparatus as claimed in  claim 2  wherein the wound roll comprises a strip of material wound about a core and has a width determined from the surface of the platform to one or more of the upstanding sidewall edges or protruding core and the quality metric comprises a profile of the width dimension as seen from the sidewall of the wound roll.  
   
   
       4 . The apparatus as claimed in  claim 3  wherein the processor generates a maximum roll width quality metric based on the profile of the width dimension of the sidewall.  
   
   
       5 . The apparatus as claimed in  claim 4  wherein the maximum roll width quality metric is determined by comparing the profile to a maximum width and failing the roll if any part of the profile or core exceeds the maximum width by a predetermined amount.  
   
   
       6 . The apparatus as claimed in  claim 1  wherein the processor generates a quality metric that correlates roll quality with the visual appearance of the sidewall.  
   
   
       7 . The apparatus as claimed in  claim 6  wherein the distance measuring sensor returns data points along the line of measurement and the visual appearance of the sidewall is determined by the calculation of the relative presence of shadow areas comprising data points that would be shadowed if the sidewall were to be illuminated by light of low incident angle.  
   
   
       8 . The apparatus as claimed in  claim 7  wherein the processor includes means for accumulating shadowed data points and determining length of said shadow areas.  
   
   
       9 . The apparatus as claimed in  claim 8  wherein the processor generates a shadow quality metric by determining the ratio of ((total number of data points−the number of data points comprising shadow areas greater than a predetermined length)/(total number of data points)).  
   
   
       10 . The apparatus as claimed in  claim 1  including a monitor attached to said housing.  
   
   
       11 . The apparatus as claimed in  claim 1  further including one or more positioning members arranged on the platform for confining the wound roll to a specified location on the surface of the platform.  
   
   
       12 . The apparatus as claimed in  claim 11  wherein the positioning members are arranged in a v-shape and a sensor is arranged at the vertex of the v-shape to check the positioning of the roll on the platform.  
   
   
       13 . The apparatus as claimed in  claim 1  including a door that substantially closes over the housing when the distance measuring sensor is taking a measurement.  
   
   
       14 . The apparatus as claimed in  claim 1  wherein the distance measuring sensor is a triangulation sensor using a laser light source, and the light source emits in the infra-red wavelength range so as not to expose light-sensitive roll materials.  
   
   
       15 . A method for measuring sidewall quality of a wound roll, said wound roll comprising a strip of material wound about an axis, thereby having concentric windings parallel to the axis with an upstanding sidewall with edges extending radially from the axis, said method comprising the steps of: 
 positioning the wound roll on a planar surface with the axis perpendicular to the planar surface and with one edge of the sidewall exposed in an upstanding position;    positioning a distance measuring sensor above the sidewall for movement along a predetermined line of measurement extending across at least a portion of the sidewall of the wound roll;    moving the distance measuring sensor along the line of measurement and generating a plurality of data points; and    processing the data points to generate at least one quality metric representative of the quality of the roll.    
   
   
       16 . The method as claimed in  claim 15  wherein the data points measured by the distance measuring sensor comprise distance data taken along the line of measurement, said distance data corresponding to the distance of the upstanding edges of the lap windings from the platform surface.  
   
   
       17 . The method as claimed in  claim 16  wherein the wound roll comprises a strip of material wound about a core and has a width determined from the planar surface to one or more of the upstanding sidewall edges or protruding core and the quality metric is derived from a profile of the width dimension as seen from the sidewall of the wound roll.  
   
   
       18 . The method as claimed in  claim 17  wherein the quality metric comprises a maximum roll width quality metric based on the profile of the width dimension of the sidewall.  
   
   
       19 . The method as claimed in  claim 15  wherein the quality metric correlates roll quality with the visual appearance of the sidewall.  
   
   
       20 . The method as claimed in  claim 19  further comprising the step of determining shadowed data points by the presence of shadow areas comprising data points that are shadowed if the sidewall were to be illuminated by light of low incident angle.  
   
   
       21 . The method as claimed in  claim 20  further comprising the step of accumulating shadowed data points and determining a length of said shadow areas.  
   
   
       22 . The method as claimed in  claim 21  wherein the quality metric is a shadow quality metric that is obtained by determining the ratio of ((total number of data points−the number of data points comprising shadow areas greater than a predetermined length)/(total number of data points))  
   
   
       23 . The method as claimed in  claim 15  further including the steps of locating a calibration fixture with one or more defined calibration steps on the planar surface and calibrating the distance measuring sensor relative to the defined calibration steps.  
   
   
       24 . A method for measuring sidewall quality of a wound roll using a sidewall position measuring sensor, said wound roll comprising a strip of material wound about an axis, thereby having concentric windings parallel to the axis with an upstanding sidewall with edges extending radially from the axis, said method comprising the steps of: 
 calibrating the position measuring sensor relative to a calibrating fixture placed on a planar surface;    inspecting and preparing the wound roll for a sidewall measurement;    positioning the wound roll on a planar surface against one or more roll placement stops with the axis perpendicular to the planar surface and with one edge of the sidewall exposed in an upstanding position;    enter data pertaining to the measurement, including a nominal width of the wound roll;    moving the distance measuring sensor above the sidewall along a predetermined line of measurement extending across at least a portion of the sidewall of the wound roll, thereby generating a plurality of data points describing the height of the sidewall edges above the planar surface;    generating a data file comprising the data points taken during the measurement; and    processing the data file to generate at least one quality metric representative of the quality of the roll.    
   
   
       25 . The method as claimed in  claim 24  wherein the quality metric is derived from a sidewall profile of the wound roll.  
   
   
       26 . The method as claimed in  claim 24  wherein the quality metric is maximum roll width acceptability of the sidewall width of the wound roll relative to the nominal width.  
   
   
       27 . The method as claimed in  claim 24  wherein each data point is evaluated as to whether it represents a sidewall edge that is shadowed in the presence of low angle grazing light and as to whether such shadowed data points accumulate to form adjacently positioned shadow areas, and wherein the quality metric is a shadow quality metric that is obtained by determining the ratio of ((total number of data points−the number of data points comprising shadow areas greater than a predetermined length)/(total number of data points)).