9.Introduction to Weave Designs.pdf

Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Introduction to Weave Designs What is a Weave Design? The order of interlacement of warp and weft in a woven fabric is called as the weave design. Plain...

Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Introduction to Weave Designs What is a Weave Design? The order of interlacement of warp and weft in a woven fabric is called as the weave design. Plain weave is the simplest of all weaves. By changing the order of interlacement, unlimited woven fabric structures are possible to weave. A point of interlacement is the basic repeating unit of a woven fabric. Representation of Weave Design The interlacement between warp and weft at any point of interlacement can be of two possible types: By showing the above two interlacement possibilities on the paper, any weave design can be represented. Prepared By: Shakeel Ahmad Paracha Page 1 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Graphical Representation of Weave Design In this method a graph paper graduated into 8 x 8 boxes is used to represent weave structures. Vertical columns show ends. Horizontal rows show picks. Filled boxes show warp is over the weft. Empty boxes show warp is under the weft. Repeat of a Weave Design The basic portion of the weave design which is repeated again and again to form a woven fabric is called as its repeat. One basic repeat of weave design is enough to show, however, sometimes it is better to show more repeats so that the effect of the weave design may be clearly seen. Prepared By: Shakeel Ahmad Paracha Page 2 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Elements of Weave Design From any weave design, the following three elements can be found out: o Drawing-in draft (DID) o Lifting order (LO) o Reed plan (RP) These elements of weave design help to implement a particular weave design on the loom. Drawing-in Draft (DID) The order of passing the warp yarns through different heald frames is called as the drawing-in draft (DID). The drawing-in draft is obtained from a particular weave design. The drawing-in draft also shows the number of heald frames required to complete a particular weave design. Prepared By: Shakeel Ahmad Paracha Page 3 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Construction of Drawing-in Draft (DID) Example 1 Example 2 Example 3 Prepared By: Shakeel Ahmad Paracha Page 4 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Example 4 Example 5 Types of Draft Drafts are of following four types: o Plain draft o Straight draft o Pointed draft o Mixed or staggered draft Prepared By: Shakeel Ahmad Paracha Page 5 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Lifting Order (LO) The order of lifting of heald frames on every pick is called as the lifting order (LO). Lifting order is constructed from the weave design and its drawing-in draft. To construct lifting order of a weave design following rules must be observed: o The number of rows of the lifting order must be equal to the number of rows of the weave design. o The number of columns of the lifting order must be equal to the number of frames as shown by the drawing-in draft. Construction of Lifting Order (LO) Example 1 Example 2 Prepared By: Shakeel Ahmad Paracha Page 6 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Example 3 Example 4 Example 5 Prepared By: Shakeel Ahmad Paracha Page 7 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Example 6 Reed Plan (RP) The number of ends passing through each dent of the reed is called as the reed plan. Reed plan is also called as denting order or ends per dent. Reed plan is shown above the weave design: Types of Reed Plans Reed plans are of two types: o Regular reed plan o Irregular reed plan If the same number of ends per dent is used throughout the width of the fabric such type of reed plan is called as regular. In irregular reed plan different number of ends per dent at different places across the fabric width is used. Prepared By: Shakeel Ahmad Paracha Page 8 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) The Relationship between Weave Design, DID & Lifting Order The weave design, its draft and lifting order are strongly interconnected. DID and lifting order are generally constructed from the given weave design. It is also possible to construct weave designs by modifying the lifting order and drawing-in draft. In this regard, two possibilities exist: o Constructing weave design from a given lifting order by changing the DID. o Constructing weave design from a given DID by changing the lifting order. Construction of Weave Design from a given Lifting Order (LO) Example 1 A lifting order is shown above The above draft is chosen Prepared By: Shakeel Ahmad Paracha Page 9 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Weave design is constructed from above DID Weave design is constructed from above DID Prepared By: Shakeel Ahmad Paracha Page 10 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Example 2 Example 3 Construction of Weave Design from a given Drawing-in Draft (DID) Example 1 Consider the above drawing-in draft Prepared By: Shakeel Ahmad Paracha Page 11 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) The lifting order, as shown above, is chosen The weave design is constructed as above The weave design is constructed as above Prepared By: Shakeel Ahmad Paracha Page 12 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Example 2 Example 3 Example 4 Prepared By: Shakeel Ahmad Paracha Page 13 of 14  Textile Institute of Pakistan, Karachi. TEXT202 (Fabric Technology) Calculating Heald Count & Heald Wires per Frame The heald count is the number of heald wires or heald eyes per inch. It is important to have a correct number of heald wires and heald count in every frame used for weaving. The number of heald wires and heald count is found out from the DID of the weave design. o Example Ends per inch = 60 Fabric width = 60" Total ends = 60 x 60 = 3600 o Heald wires per frame Frame 1 → 2 x 3600 = 720 10 Frame 2 → 2 x 3600 = 720 10 Frame 3 → 3 x 3600 = 1080 10 Frame 4 → 3 x 3600 = 1080 10 Total wires = 3600 o Heald count per frame Frame 1 → 2 x 60 = 12 or 720 = 12 10 60 Frame 2 → 2 x 60 = 12 or 720 = 12 10 60 Frame 3 → 3 x 60 = 18 or 1080 = 18 10 60 Frame 4 → 3 x 60 = 18 or 1080 = 18 10 60 Total Heald Count = 60 Prepared By: Shakeel Ahmad Paracha Page 14 of 14