Fly-cutting system and method, and related tooling and articles

Abstract

Methods of fly-cutting a workpiece are disclosed, and in methods in which the position of a fly-cutting head or its associated cutting element is known as a function of time. Also disclosed are methods of forming features, such as grooves or groove segments, in a workpiece such as a cylindrical roll. The features may be provided according to one or more disclosed patterns. Articles made using tools machined in the manner described are also provided, such as polymeric film or sheeting that exhibit certain beneficial properties.

1 . A method for use in machining a workpiece, comprising the steps of:
 (a) providing a fly-cutting head adapted for carrying a cutting element to machine the workpiece, and for rotation about a central axis; and   (b) determining the position of the fly-cutting head with respect to the central axis as a function of time.   
   
   
       2 . The method of  claim 1 , further comprising the step of:
 (c) transmitting a position signal that includes information related to the position of the fly-cutting head as a function of time.   
   
   
       3 . The method of  claim 2 , wherein the method further comprises the step of:
 (d) providing a controller for receiving the position signal.   
   
   
       4 . The method of  claim 3 , wherein step (b) comprises using a rotary encoder to determine the position of the fly-cutting head as a function of time. 
   
   
       5 . The method of  claim 2 , wherein the method further comprises the step of:
 (d) using information obtained from the transmitted position signal to create a command signal.   
   
   
       6 . The method of  claim 5 , wherein the method further comprises the step of:
 (e) transmitting the command signal to a motor that drives the fly-cutting head.   
   
   
       7 . The method of  claim 6 , wherein the command signal causes a change in the speed of the fly-cutting head. 
   
   
       8 . The method of  claim 5 , wherein the method further comprises the step of:
 (e) transmitting the command signal to a motor that drives a spindle adapted to hold a workpiece.   
   
   
       9 . The method of  claim 8 , wherein the command signal causes a change in the speed of the spindle. 
   
   
       10 . The method of  claim 2 , wherein the method further comprises the step of:
 (d) transmitting the command signal to an actuator that changes the position or the orientation of a cutting element, or both, with respect to the fly-cutting head.   
   
   
       11 . The method of  claim 2 , wherein the method further comprises the step of:
 (d) changing the position or the orientation, or both, of a cutting element based on the position signal.   
   
   
       12 . The method of  claim 11 , wherein step (d) comprises providing an actuator associated with the fly-cutting head, wherein the actuator adapted to change the position or orientation of the cutting element, or both. 
   
   
       13 . The method of  claim 1 , wherein the method further comprises providing at least one cutting element for carriage by the fly-cutting head. 
   
   
       14 . A method for use in machining a workpiece, comprising the steps of:
 (a) providing a fly-cutting head adapted for carrying a cutting element, and for rotation about a central axis;   (b) providing a spindle adapted for carrying the workpiece, and for rotation about a central axis;   (c) determining the position of the fly-cutting head with respect to the fly-cutter central axis as a function of time; and   (d) determining the position of the spindle with respect to the central axis of the spindle as a function of time.   
   
   
       15 . The method of  claim 14 , wherein at least one of steps (c) and (d) comprises using a rotary encoder to determine position as a function of time. 
   
   
       16 . The method of  claim 14 , further comprising the steps of:
 (e) transmitting a position signal that includes information related to the position of the fly-cutting head as a function of time; and   (f) transmitting a position signal that includes information related to the position of the spindle as a function of time.   
   
   
       17 . The method of  claim 16 , wherein the method further comprises the step of:
 (g) providing a control system for receiving the position signals related to the fly-cutting head and the spindle.   
   
   
       18 . The method of  claim 17 , wherein the method further comprises the step of:
 (h) using information obtained from the transmitted position signals to create at least one command signal.   
   
   
       19 . The method of  claim 18 , wherein the method further comprises the step of:
 (i) transmitting the command signal to a motor that drives the fly-cutting head.   
   
   
       20 . The method of  claim 19 , wherein the command signal causes a change in the speed of the fly-cutting head. 
   
   
       21 . The method of  claim 18 , wherein the method further comprises the step of:
 (i) transmitting the command signal to a motor that drives the spindle.   
   
   
       22 . The method of  claim 21 , wherein the command signal causes a change in the speed of the spindle. 
   
   
       23 . A method of forming features in a surface of a cylindrical workpiece using a fly-cutting head, comprising the steps of:
 (a) providing a fly-cutting head having a cutting element;   (b) providing the cylindrical workpiece;   (c) using the fly-cutting head to form an initial feature in the surface of the workpiece while the workpiece is rotated around a central axis of rotation, the initial feature having a major axis extending generally parallel to the axis of rotation for less than the length of the workpiece;   (d) rotating the workpiece around the central axis of rotation; and   (e) using the fly-cutting head to form a subsequent feature in the surface of the workpiece, the subsequent feature having a major axis extending generally parallel to the axis of rotation, wherein the subsequent feature is in predetermined location relative to the initial feature.   
   
   
       24 . The method of  claim 23 , wherein the subsequent feature is aligned with and adjoins the initial feature such that the two features approximate a single continuous feature. 
   
   
       25 . The method of  claim 23 , wherein the method further comprises, after forming the initial feature and before forming the subsequent feature, the step of forming additional features in the surface of the workpiece and around the perimeter of the workpiece, wherein at least some of the additional features have a major axis extending generally parallel to the axis of rotation. 
   
   
       26 . The method of  claim 23 , further comprising the steps of:
 (f) applying a viscous polymeric material to the workpiece such that the material substantially conforms to the surface of the workpiece; and   (g) removing the material from the workpiece.   
   
   
       27 . A method of forming adjacent longitudinally-extending features or grooves in a cylindrical workpiece, comprising the steps of:
 (a) forming, beginning near a first end of the workpiece, an initial portion of each feature or groove; and   (b) forming subsequent portions of each feature or groove during successive revolutions of the workpiece, the subsequent portions being substantially aligned with the initial portion of each feature or groove, the subsequent portions being formed progressively closer to a second end of the workpiece.   
   
   
       28 . The method of  claim 27 , wherein the initial portions of the features or grooves formed near the first end of the workpiece are relatively sharper than the subsequent portions of the features or grooves formed closer to the second end of the workpiece. 
   
   
       29 . A method of forming features in a surface of a cylindrical workpiece using a fly-cutting head, comprising the steps of:
 (a) providing a fly-cutting head having a cutting element;   (b) providing the cylindrical workpiece;   (c) using the fly-cutting head to form an initial feature in the surface of the workpiece while the workpiece is rotated around a central axis of rotation, the initial feature having a major axis extending at an angle with respect to the axis of rotation;   (d) rotating the workpiece around the central axis of rotation; and   (e) using the fly-cutting head to form a subsequent feature in the surface of the workpiece, the subsequent feature having a major axis extending at an angle with respect to the axis of rotation, wherein the subsequent feature is in predetermined location relative to the initial feature.   
   
   
       30 . The method of  claim 29 , wherein the subsequent feature is aligned with and adjoins the initial feature such that the two features approximate a single continuous feature. 
   
   
       31 . The method of  claim 29 , wherein the method further comprises, after forming the initial feature and before forming the subsequent feature, the step of forming additional features in the surface of the workpiece and around the perimeter of the workpiece, wherein at least some of the additional features have a major axis extending at an angle with respect to the axis of rotation. 
   
   
       32 . The method of  claim 29 , further comprising the steps of:
 (f) applying a viscous polymeric material to the workpiece such that the material substantially conforms to the surface of the workpiece; and   (g) removing the material from the workpiece.   
   
   
       33 . A method of forming adjacent features or grooves in a cylindrical workpiece, comprising the steps of:
 (a) forming, beginning near a first end of the workpiece, an initial portion of each feature or groove at an angle relative to a central axis of rotation of the workpiece; and   (b) forming subsequent portions of each feature or groove during successive revolutions of the workpiece, the subsequent portions being substantially aligned with the initial portion of each feature or groove, the subsequent portions being formed progressively closer to a second end of the workpiece.   
   
   
       34 . The method of  claim 33 , wherein the initial portions of the features or grooves formed near the first end of the workpiece are relatively sharper than the subsequent portions of the features or grooves formed closer to the second end of the workpiece. 
   
   
       35 . A tool made using the method of one of  claims 1 ,  2 ,  5 ,  8 ,  14 ,  16 ,  23 ,  27 ,  28 ,  29 , or  33 . 
   
   
       36 . A polymeric article made with the microreplication tool of  claim 35 . 
   
   
       37 . A cylindrical tool comprising a plurality of groove segments individually formed around the perimeter of the tool, the groove segments being aligned with other groove segments to form generally uniform longitudinally-extending grooves in the tool. 
   
   
       38 . A cylindrical tool having features or grooves extending from a first end toward a second end, wherein portions of the features or grooves nearest the first end are all relatively sharper than the corresponding portions of the features or grooves near the second end. 
   
   
       39 . A cylindrical tool having grooves extending from a first end toward a second end, wherein the tool is characterized by the absence of a virtual seam along which a sharp groove is adjacent to a less sharp or dull groove. 
   
   
       40 . The cylindrical tool according to either  claim 38  or  claim 39 , wherein the features or grooves extend at an angle relative to a central axis of rotation of the tool. 
   
   
       41 . A cylindrical tool having groove segments formed therein, wherein the groove segments have a beginning and an end, and the groove segments are arranged according to an integer brick pattern, wherein the integer is greater than one. 
   
   
       42 . The cylindrical tool of  claim 41 , wherein the integer is greater than two. 
   
   
       43 . A cylindrical tool having groove segments formed therein, wherein the groove segments have a beginning and an end, and successive groove segments are offset with respect to previous groove segments by a helix angle. 
   
   
       44 . A cylindrical tool comprising a plurality of groove segments, wherein the groove segments are individually formed in positions relative to each other, and wherein the groove depth distribution of successive adjacent grooves, measured along a line that is parallel to any helix angle associated with the groove segments, is multi-modal. 
   
   
       45 . The tool of  claim 44 , wherein the major axis of the groove segments is parallel to the longitudinal axis of the tool. 
   
   
       46 . The tool of  claim 44 , wherein the major axis of the groove segments is angled relative to a central axis of rotation of the tool. 
   
   
       47 . The tool of  claim 44 , wherein the grooves comprise an arcuate bottom with a radius of curvature generally coinciding with the central axis of the tool. 
   
   
       48 . A polymeric article formed using the tool of  claim 37  through  41  or  43  through  46 . 
   
   
       49 . The polymeric article of  claim 48 , in combination with a display.