An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

There is described a process of measuring print-to-print register of a multicolour print (A-D) provided in an effective printed area (EPA) of the surface of printed material, which multicolour print (A-D) is formed on the printed material by means of one or more printing presses and includes at least a first pattern (A) and a second pattern (B) distinguishable from the first pattern (A), the effective printed area (EPA) being provided with a matrix arrangement of individual imprints (P) which are each provided with the multicolour print (A-D) and are repeated over the surface of the effective printed area (EPA) along a pattern of rows and columns. Measurement of an actual print-to-print register between the first and second patterns (A, B), as reflected on the printed material, is derived from processing and finding a correspondence between (i) at least one sample image (SI.sub.A, SI.sub.B) of the printed material covering at least a portion of the first and second patterns (A, B), and (ii) at least one corresponding reference image (RI.sub.A, RI.sub.B) generated using prepress design data of the first and second patterns (A, B). Furthermore, the process is repeated for multiple ones of the individual imprints (P) so as to derive a set of multiple measurements of the actual print-to-print register between the first and second patterns (A, B) at various imprint locations over the effective printed area (EPA), which set of multiple measurements is mapped into a corresponding print-to-print register map (M.sub.B-A, M.sub.C-A, M.sub.D-A, . . . ) that is representative of print-to-print register deviations at the various imprint locations. Also described is a measuring device for carrying out this process and a process of measuring and correcting print-to-print register of a multicolour print.

A can inspection device includes a rotation device rotating cans, an imaging device taking images of rotating cans, and an image processor processing taken images. The imaging device includes a first camera taking an image of an entire can and a second camera taking an image of an opening-side end portion of the can. The image processor includes an image inspection means for inspecting whether printing is performed properly as compared with a master image by using the image taken by the first camera, a density measurement means for measuring densities in designated positions for respective colors by using the image taken by the first camera, and a printing misalignment value measurement means for measuring misalignment values with respect to set positions of printing misalignment inspection marks printed on the opening-side end portion of the can for respective colors by using the image taken by the second camera.

A can inspection device includes a rotation device rotating cans, an imaging device taking images of rotating cans, and an image processor processing taken images. The imaging device includes a first camera taking an image of an entire can and a second camera taking an image of an opening-side end portion of the can. The image processor includes an image inspection means for inspecting whether printing is performed properly as compared with a master image by using the image taken by the first camera, a density measurement means for measuring densities in designated positions for respective colors by using the image taken by the first camera, and a printing misalignment value measurement means for measuring misalignment values with respect to set positions of printing misalignment inspection marks printed on the opening-side end portion of the can for respective colors by using the image taken by the second camera.

In some examples, a processing machine for processing a substrate includes at least one shaping unit. The at least one shaping unit includes at least one forme cylinder and at least one impression cylinder. A processing point for processing a substrate is arranged between the at least one forme cylinder and the at least one impression cylinder. The processing machine includes a control unit for correcting a processing length of the substrate, and which controls a speed of at least one of the at least one forme cylinder or the at least one impression cylinder. The at least one forme cylinder and the at least one impression cylinder have a speed ratio with respect to one another that is changeable at the processing point as a function of the processing length of the substrate, and the speed ratio differs at least once within a full cylinder revolution.

In some examples, a processing machine for processing a substrate includes at least one shaping unit and/or at least one application unit. The at least one application unit and/or the at least one shaping unit in each case includes at least one forme cylinder and at least one impression cylinder. The at least one forme cylinder of the application unit includes at least one application forme including at least one application surface and/or the at least one shaping unit includes at least one shaping tool including at least one working surface. The application surface and/or the working surface are arranged to cover at least a portion of the outer cylindrical surface of the at least one forme cylinder. A speed of the at least one forme cylinder and a speed of the at least one impression cylinder have a speed ratio with respect to one another.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

There is described a process of measuring print-to-print register of a multicolour print (A-D) provided in an effective printed area (EPA) of the surface of printed material, which multicolour print (A-D) is formed on the printed material by means of one or more printing presses and includes at least a first pattern (A) and a second pattern (B) distinguishable from the first pattern (A), the effective printed area (EPA) being provided with a matrix arrangement of individual imprints (P) which are each provided with the multicolour print (A-D) and are repeated over the surface of the effective printed area (EPA) along a pattern of rows and columns. Measurement of an actual print-to-print register between the first and second patterns (A, B), as reflected on the printed material, is derived from processing and finding a correspondence between (i) at least one sample image (SI.sub.A, SI.sub.B) of the printed material covering at least a portion of the first and second patterns (A, B), and (ii) at least one corresponding reference image (RI.sub.A, RI.sub.B) generated using prepress design data of the first and second patterns (A, B). Furthermore, the process is repeated for multiple ones of the individual imprints (P) so as to derive a set of multiple measurements of the actual print-to-print register between the first and second patterns (A, B) at various imprint locations over the effective printed area (EPA), which set of multiple measurements is mapped into a corresponding print-to-print register map (M.sub.B-A, M.sub.C-A, M.sub.D-A, . . . ) that is representative of print-to-print register deviations at the various imprint locations. Also described is a measuring device for carrying out this process and a process of measuring and correcting print-to-print register of a multicolour print.