**4.1.1 Production of Plissé or pleated fabrics**

Plissé or pleated material is a folded material, which can be achieved in different methods such as weaving, shrinking and finishing (Routte, 2002);


Plissé or pleated woven fabrics can be produced on weaving machines equipped with two warp beams in addition to a special pleated device or a variable beat up.

Pleated woven fabric is produced on weaving machines equipped with a special pleated device as follows:

With a weft density of 40 picks/cm, this means that the beating-up point needs to be shifted only 0.25 mm weft by weft. At the end of the woven pleat, which may be up to 20 mm long,

Fig. 6. Movement coordination of pleated fabric and take-up device (Kienbaum, 1996 as

Fig. 7. Beat-up motion during pleat formation (redrawn from Marfurt, 1998).

Weaving a pleat uses only some of the warp threads which are wound onto a separate warp beam. The small proportion of warp threads in the pleat area is compensated for by a greater weft density. The remaining warp threads are left lying underneath the fabric while the pleat is being woven (a). The fabric is no longer taken off, and the sley stays back a given distance in each weft (b). Once the pleat has reached the desired length, all the warp threads are again used in the weaving of the fabric. The sley executes its complete movement, known as full beating. The threads wound onto the separate warp beam yield, and the pleat

the device must return to its normal beating-up position.

cited in Badawi, 2007).

falls into line (c) (Marfurt, 1998).

Fig. 4. The appearances of a). a smooth pleated fabric b). a tough pleated fabric (Kienbaum, 1996 as cited in Badawi, 2007).

In this method, at the beginning of pleat formation, both back rest and breast-beam take the most far on the right lying position as illustrated at point A in Figure 5. When the intended pleat length is reached, they are farther on the left (B). The distance between the two limit points A and B is determined by the pleat length. After the last weft insertion within the pleat length and with beginning of the next inter-fabric part, the pleated length is formed by returning back of the back rest and breast-beam into the starting position (A), at that moment the back rest pull the tight warp to the back position (A) (Badawi, 2007).

Fig. 5. Device for pleated fabrics weaving (Kienbaum, 1996 as cited in Badawi, 2007).

The coordination of pleated fabric and take-up mechanism are shown in Figure 6. The height of the formed pleat is equal to about half of the pleat length before the backwardmovement of the tight warp yarns (Kienbaum, 1996 ; Hennig, 1968 as cited in Badawi, 2007).

Pleated woven fabric is also produced on weaving machines equipped with a variable sley beat up.

Manufacturing of pleated woven fabric on weaving machines equipped with a variable sley beat up can be briefly explained as follows;

The mechanism allows the beating-up point of the sley to be shifted by small but precise steps from the normal beating-up point. While the pleat is being woven, the fabric take-up remains idle so that the weft density is achieved by shifting the beating-up point of the sley.

Fig. 4. The appearances of a). a smooth pleated fabric b). a tough pleated fabric (Kienbaum,

In this method, at the beginning of pleat formation, both back rest and breast-beam take the most far on the right lying position as illustrated at point A in Figure 5. When the intended pleat length is reached, they are farther on the left (B). The distance between the two limit points A and B is determined by the pleat length. After the last weft insertion within the pleat length and with beginning of the next inter-fabric part, the pleated length is formed by returning back of the back rest and breast-beam into the starting position (A), at that

moment the back rest pull the tight warp to the back position (A) (Badawi, 2007).

Fig. 5. Device for pleated fabrics weaving (Kienbaum, 1996 as cited in Badawi, 2007).

The coordination of pleated fabric and take-up mechanism are shown in Figure 6. The height of the formed pleat is equal to about half of the pleat length before the backwardmovement of the tight warp yarns (Kienbaum, 1996 ; Hennig, 1968 as cited in Badawi, 2007). Pleated woven fabric is also produced on weaving machines equipped with a variable sley

Manufacturing of pleated woven fabric on weaving machines equipped with a variable sley

The mechanism allows the beating-up point of the sley to be shifted by small but precise steps from the normal beating-up point. While the pleat is being woven, the fabric take-up remains idle so that the weft density is achieved by shifting the beating-up point of the sley.

1996 as cited in Badawi, 2007).

beat up.

beat up can be briefly explained as follows;

With a weft density of 40 picks/cm, this means that the beating-up point needs to be shifted only 0.25 mm weft by weft. At the end of the woven pleat, which may be up to 20 mm long, the device must return to its normal beating-up position.

Fig. 6. Movement coordination of pleated fabric and take-up device (Kienbaum, 1996 as cited in Badawi, 2007).

Fig. 7. Beat-up motion during pleat formation (redrawn from Marfurt, 1998).

Weaving a pleat uses only some of the warp threads which are wound onto a separate warp beam. The small proportion of warp threads in the pleat area is compensated for by a greater weft density. The remaining warp threads are left lying underneath the fabric while the pleat is being woven (a). The fabric is no longer taken off, and the sley stays back a given distance in each weft (b). Once the pleat has reached the desired length, all the warp threads are again used in the weaving of the fabric. The sley executes its complete movement, known as full beating. The threads wound onto the separate warp beam yield, and the pleat falls into line (c) (Marfurt, 1998).

Velvet fabrics are a class of pile fabrics which are divided into two as warp pile fabrics and weft pile fabrics known as velveteen according to the pile direction. Warp pile fabrics, also known as velvet, can be produced with two weaving methods; wire weaving technique and face to face (a.k.a. double plush) weaving technique. The advantage of face to face weaving technology is two fabrics are effectively woven at the same time one above the other joined together by the pile warp ends which cross from top cloth to bottom cloth according to the design and during this weaving process a knife situated between the two cloths continuously traverses the width of the fabric cutting the pile warp threads to create two cloths each with a cut warp pile surface. It is important to appreciate that a surface pile tuft is formed only when a pile end crosses from the top cloth into the bottom cloth and is cut on the loom by the traversing knife, and it is in this way that the surface pile design and colour are created. When it is not required on the surface of the fabric the pile is woven or 'incorporated' into the ground structure either in the top or bottom cloth (Fung&Hardcastle, 2001). Therefore, two different pile structures such as cut pile or loop pile can be obtained

Weaving machines based on face to face weaving technique are equipped with a 3 position shedding device (dobby or Jacquard machine), so as to form two overlapped and properly spaced out sheds and to permit to the pile warp to tie up the two fabrics together. Into each of the two shed a weft is inserted, usually by means of a pair of superimposed rods driven by the same gear (Castelli et al., 2000). With this technique, 3D woven spacer fabrics can also

Fig. 9. Fabric control mechanism (Dornier, 2007).

**4.1.3 Production of velvet fabrics** 

based on the pile cut or not.

be easily woven.
