Face-to-Face Loom Pile Fabric Shadow Effect Weaving

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Solution Overview

Problem

Current carpet weaving methods on face-to-face looms cannot create bi-dimensional patterns with pile yarns of different slanting directions along the weft direction, limiting the creation of freely designed shadow effect zones, as they require modifications to the backing fabric structure and are not effective in producing significant slanting effects with certain warp yarns.

Innovation Solution

A method for simultaneously weaving two pile fabrics with shadow cut pile zones on a face-to-face weaving machine, where upper and lower backing fabrics are woven with filling and binding warp yarns, and weft yarns are inserted in successive cycles, allowing patterning pile yarns to change direction between series of insertion cycles, resulting in more noticeable slanting effects and adjustable pile tuft orientations along both warp and weft directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a standard carpet weaving loom with cam machine or dobby is used, then the backing fabric structure can be modified to change pile leg orientation, but it is not possible to create bi-dimensional patterns with pile yarns of different slanting directions along the weft direction

Engineering Contradiction:
Improvepile leg orientation controlVSAvoidbacking fabric structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention uses a Jacquard machine to dynamically control the binding warp yarns, allowing each pile yarn to be individually addressed and switched between different binding states. This dynamic control enables bi-dimensional patterning where pile slanting directions can vary both along the warp and weft directions, overcoming the limitation of static cam machine or dobby systems that could only change orientation across the whole width.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention segments the control of binding warp yarns by introducing a second binding warp yarn that works in conjunction with the first. Each binding warp yarn can be independently controlled by the Jacquard machine to create different binding patterns (first binding pattern vs. second binding pattern). This segmentation allows individual pile yarns to be selectively bound to different weft yarns, creating localized slanting effects without requiring modification of the entire backing fabric structure.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If patterning pile yarns are bound in a backing fabric with Jacquard machine, then fabric with various patterns can be obtained, but the slanting effect obtained with some kinds of warp yarns might be not significant enough to provide a clear shadow effect

Engineering Contradiction:
Improvepattern designVSAvoidslanting effect visibility
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention creates asymmetric binding patterns where the first binding pattern and second binding pattern produce different slanting directions. By selectively applying these asymmetric binding patterns to different pile yarns or different sections of the fabric, significant slanting effects are achieved. The asymmetry in binding geometry causes the pile yarns to emerge at different angles, providing clear shadow effects that are visible even with relatively matt pile yarns.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention applies different binding patterns to different local regions of the fabric. The first binding pattern is applied to create slanting in one direction, while the second binding pattern is applied to create slanting in another direction. This local differentiation of binding quality allows precise control over where and how shadow effects appear in the final fabric, enhancing the visibility and clarity of slanting effects in specific zones.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If weft yarns are inserted on three levels into carpet fabrics, then shadow effect can be achieved, but each pile warp yarn follows only one type of path with respect to the corresponding weft yarns

Engineering Contradiction:
Improveshadow effectVSAvoidpile yarn path variation
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention dynamically switches between different binding patterns using the Jacquard machine's ability to selectively control the second binding warp yarn. This allows each pile yarn to follow different paths (first type of path or second type of path) depending on the local pattern requirements. The dynamic switching enables the same weaving mechanism to produce multiple pile yarn path variations, achieving both shadow effects and design versatility.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3165645B1Method for weaving pile fabrics and pile fabric with shadow cut pile zones
Publication Date: 2021.09.01 STAUBLI BAYREUTH GMBH
  • EP3165645B1 patent drawingFigure 1
  • EP3165645B1 patent drawingFigure 2
  • EP3165645B1 patent drawingFigure 3

AI summary

In this method for simultaneously weaving two pile fabrics (C1, C2) with shadow cut pile zones on a face-to-face weaving machine, an upper backing fabric (F1) and a lower backing fabric (F2) are woven one above the other with at least one filling warp yarns (f1, f2), at least one binding warp yarn (b1, b1', b2, b2'), weft yarns (Wi, Wb) comprising inner weft yarns (Wi), which are inserted on a pile side of the filling warp yarns, and back weft yarns (Wb), which are inserted on a back side of the filling warp yarns. Patterning pile yarns are interlaced in the upper backing fabric (F1) and in the lower backing fabric (F2). Weft yarn groups (G1, G2), made of an inner weft yarn (Wi), a back weft yarn (Wb) and another inner weft yarn (Wi), are inserted in at least one backing fabric (F1, F2), in successive weft insertion cycles, and at least one patterning pile yarn (PY) follows a path where in a first series of weft insertion cycles (P1-P13) and at least in a first backing fabric (F1, F2), the patterning pile yarn (PY) turns externally around a first inner weft yarn (Wi), then internally around a second consecutive inner weft yarn (Wi) before it turns externally around a consecutive back weft yarn (Wb) and in a second series of weft insertion cycles (P19-P32) and at least in the first backing fabric (F1, F2), the patterning pile yarn (PY) turns externally around a back weft yarn (Wb) before it turns internally around a first consecutive inner weft yarn (Wi) and externally around a second consecutive inner weft yarn (Wi).