The challenge of fabric pattern matching

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Fabrics that feature a pattern or visual motif contain inherent variability, both within a roll and between rolls. Slight distortions in pattern repeat and in deviation from true square relative to warp and weft threads must be accommodated for during the layout and cutting process to preserve the visual continuity of the fabric design on the finished product that is a hallmark of quality furniture.

Manufacturers face operational challenges in marker making and cutting when the selected fabric features a repeat pattern or visual motif. The design on each cut piece must match precisely when stitched to its adjoining partner pieces and from part to part within a style to avoid any visual disruption of the misaligned plaid, stripe or other pattern.

A complicating factor is the inherent variability of patterned fabrics, both within a given roll and from one roll to the next. Slight distortions in pattern repeat and in deviation from true square relative to warp and weft threads must be accommodated for during the layout and cutting process, to preserve the visual continuity of the fabric design on the finished product.

Many manufacturers still rely on hand manipulation. of pattern pieces to match patterns across cut parts, drastically limiting the number of cut parts per hour produced. This low technology environment can be labor intensive, typically requiring at least two workers. One worker is stationed at the cutting table, responsible for feeding the fabric onto the surface in preparation for cutting and for removing the pieces afterwards. The second worker stands on an elevated platform operating a projector that casts the outlined image of the nested layout plan onto the fabric below. The cutting area is usually surrounded by tarps to block ambient light, with illumination provided by the projector. The operator adjusts the marker to accommodate the inherent distortions of the fabric pattern. In some cases where the material pattern grossly differs from the nested job, the marker is returned to the CAD system for re-nesting.

SHORTCOMINGS OF THE CURRENT SYSTEM

This method of manual layout adjustment to accommodate pattern variances has several shortcomings:

  • Time consuming
  • Prone to inaccuracy
  • Wastes raw materials — A batch of pieces that is cut incorrectly must be scrapped and re-cut;
  • Relies on skilled labor —
  • Subject to equipment breakdowns —
  • Creates unpleasant work environment —

Some production facilities avoid this time- and labor intensive manual accommodation in the cutting room by allowing for extra fabric in the layout plan, intentionally cutting oversize pieces to ensure sufficient fabric for pattern matching. This method pushes adjustments down the line to the sewing stage. The downfall of this workaround is built-in waste of expensive upholstery fabric, which can cost hundreds of dollars a yard.

INCREMENTAL TECHNOLOGY ADVANCEMENT

Incremental technology advancement has been introduced to this process by some manufacturers, which adds greater automation to the process by creating a digital representation of the fabric pattern that is integrated with the cutting software. This method uses a high-resolution digital camera to take multiple images, which are tiled in a series to reproduce the fabric pattern. The software then automatically compensates these images for distortion in pattern layout and cutting.

This method eliminates the need for a skilled worker to visually re-assess the layout plan with each cut batch, but tiling the still images has proven to be time consuming and inaccurate, resulting in gaps or overlapping areas. As a result, there are still some major shortcomings to these systems.

THE GERBER AUTOMATCH SYSTEM FOR Z1 CUTTER SYSTEMS

A new pattern matching technology for the cutting room solves the problem associated with tiling of still images and brings a higher level of automation, speed and accuracy to the process. The AutoMatch™ System from Gerber Technology employs advanced vision technology to capture a fluid image of the fabric patterns that accurately and automatically adjusts for material distortions and pattern repeat variances.

Using AutoMatch, when a patterned fabric is selected and laid on the cutting table for initial use, the camera Ncaptures a fluid image of its entire width in a single pass. This image, or digital swatch, is captured in a training process where the system learns image points of interest and repeat values and is stored in a configuration file unique to that fabric pattern.

After the first production scan is completed and the batch is cut, additional cut bites can proceed continuously. The scan occurs during material advance and the cut file is created while the previous bite is being cut, adding no additional time to the process.