PRINCIPLE

The WIREFLEX machine is a special type of weaving machine conceived for the production of pile fabrics. The weft is inserted in the bottom shed of a double shed opening. The pile is obtained by inserting steel rods or wires in the top shed.
Pile yarns supplied from a creel form loops above the steel wires.
During extraction of the wires the pile can be cut or uncut (loops) or a combination of both.

The Weft

The weft is inserted from the left-hand side of the machine where a carrier rapier head takes the weft yarns by the tip towards the middle of the weaving machine. At that point the weft end is transferred to the puller rapier head that pulls the weft through to the right-hand side where the puller rapier is opened in order to release the weft. The rapier heads are fixed to a set of flexible rapiers. Weft insertion speed - apart from the wire insertion - can go up to 200 Rpm.
The total weaving speed will be lower as the wire motion reduces the speed considerably. Depending on the type of yarns used, on the density to be woven and on the types of wires used the industrial weaving speed will be situated between 110 and 160 Rpm on a 150 cm wide machine and in between 75 and 90 Rpm on a 300 cm machine.

The Pile Formation

Through the combination of ground warp ends and the weft the base fabric is obtained. The pile ends are woven over the wires and fixed into the base fabric in such a way that loops are being formed over the wires. A certain number of wires is woven into the fabric (10, 12, 16, 20 or 24 wires in total). Each wire is inserted into the shed between the weaving reed and the fabric border. The wires that are woven into the fabric are being extracted one by from the fabric. For each insertion of a wire another wire is extracted.
The wire that has been extracted is reinserted into the shed.

The Pile Wires

Pile wires are specially made very fine steel rods rolled in several passages into the final dimension as requested for the specific pile height that one wants to obtain.
The wire can have a circular section in diameters going from 0.7 to 2.6 mm. It can also be of rectangular form, whereby the angles will always be rounded. Section dimension here can be e.g. 0.1 x 1.8 mm.; 1 x 2.0 mm.;
1.2 x 2.0 mm.; 1.2 x 2.4 mm.; 1.3 x 2.4 mm.; etc.
The first figure in the dimension being the thickness of the wire and the second figure being the height of the wire.
For carpet applications - with higher pile - obviously other dimensions are at order. The surface of the steel wires must be hardened and polished in order to reduce the friction between the wire and the pile yarns to a minimum.

Wire without blade holder

These wires are plain steel rods, made to the specific dimension of the loop height that needs to be obtained. When such a wire is extracted from the fabric it leaves loops in the fabric.

 

Wire with blade holder

These wires are equipped with a milled blade holder in which a cutting blade can be inserted. When such a wire is extracted from the fabric, the blade cuts the loops in a way that cut velvet is obtained.

It is eventually possible to weave with mixed sets of wires, whereby wires with blade holder are alternated with wires without blade holder. With this combination one can obtain both loop pile and cut pile in the same fabric.

The Wire Insertion Motion

The wires are inserted in sequence, this means that for each wire that has been inserted, another wire must be extracted. In order to provide a perfect guiding of each wire during the insertion, each wire is pulled out of the fabric into a specially milled steel guide. During the extraction sequence this guide is located in the front position. For the insertion sequence the guide is moved to the back position by means of a servo motor. Also here the acceleration and deceleration of the movement is perfectly under control.

Also insertion motion of the Wireflex machine is completely driven by means of servo motors. This means that the insertion speed of the wires can been perfectly controlled both for acceleration and deceleration. Also the speed curve during the extraction of the wires is controlled in the same way. This allows the use of more delicate yarns for the pile. The use of servo motors provides vibration free insertion and extraction of the wires.

The electronics of the system also offer the possibility of changing the insertion/extraction rate of the wires during the weaving process:

One possibility is inserting one wire every second pick
Second possibility is inserting one wire every third pick
Third possibility is inserting one wire every fourth pick

Eventually combinations of these sequences can be programmed, whereby e.g. for a certain length of fabric one can weave one wire every second pick, followed by a length of fabrics with one wire every third pick and back to the original sequence of one wire every second pick, thus creating special effects in the fabric.

Fabric Construction

The basic weave construction of the "épinglé" fabric is a 1/1 weave whereby on every second pick a wire is inserted. The pile ends that have been brought in the top shed position will form loops over the inserted wire. When the wire is extracted the loops are fixed into the basic fabric by the wefts in between the loop rows. If the wires that are used are equipped with a cutting blade then instead of loops, rows of cut pile are formed.

The pile can be made by a single colour frame so that all pile ends are similar in colour.
Pattern can be obtained in the pile structure by lifting selected groups of pile ends during wire insertion. This selection is operated
by means of a Jacquard machine.

When different colour frames are used,  the colour of the loops (or cut piles) can also be selected. It is obvious that for weaving with more colour frames a higher number of patterning hooks in the Jacquard will be needed. Also the pile density (number of piles per centimetre) will define the need for hooks in the Jacquard. Also complex structures whereby round wires and cutting wires are inserted in an alternating sequence lead to alternating row op loop pile and cut pile. Here again different pile colour can be used. If a Jacquard machine is used for the ground weaves it is possible to enlighten the ground structure of the fabric with Jacquard patterns.

In combination with up to 8 different weft types (or weft colours) high quality fabrics can be produced with elaborated patterns and colour combinations both in the ground and in the pile.

 

Shedding Motions

In relation to the type of fabrics to be realised different types of shedding motions are available and can eventually be combined.

For the ground fabric following shedding motion are available:

1/1 CAM MOTION	This is a very simple mechanical cam motion that is build into the weaving machine and provide a continuous 1/1 weave with two heddle frames for the ground fabric.
2/2 CAM MOTION	This is basically identical to the 1/1 cam motion only here the heddle frame move in a 2/2 sequence.
CAMBOX MOTION	Here a cambox motion of Stäubli is used in order to obtain a fixed yet somewhat more complex weave structure  (1/2, 1/3, 1/4, 1/5, etc.). If one wants to change the weave structure the cam set must be changed.
DOBBY	A Stäubli mechanical (electronic upon demand) dobby is used allowing to realise more complex and evolving weave structures during the weaving process. The maximum number of heddle frames is 8.
JACQUARD	A two position Jacquard machine can be used for the ground weave. The use of a Jacquard allows for the realisation of so called operated ground weaves, whereby elaborate designs can be woven into the ground fabric, independent of the pile design. Anyhow the basic weave structure needs to provide for the necesarry fixation of the pile ends. The number of hooks will be defined by the number of warp ends used and the number of repeats to be woven over the fabric width.

For the pile following shedding motions are available:

DOBBY	A special 3-position dobby of Stäubli can be fitted into the machine allowing the production of plain velvet, plain loop, or velvet/loop combination, however without design possibilities for neither for the ground nor the pile.
JACQUARD	A special 3-position Jacquard is used allowing the pile ends to be brought into top-, bottom-, or middle position. Different types of machines can be offered:
Giropan, mechanical machines	The designs are put on the machine by means of punched cards (Vicenzi type). The number of hooks will be defined by the number of warp ends used and the number of repeats to be woven over the fabric width. The number of hooks will always be double compared to the number of harness attachments as a pulley connected to two Jacquard hooks is used to obtain the 3 positions.
Giropan/Takemura combination machines	This is a standard mechanical Giropan Jacquard equipped with an electronic selection device (Takemura). This device replaces the punched cards and allows to transfer design information to the Jacquard by means of computer disks. The number of hooks will be defined by the number of warp ends used and the number of repeats to be woven over the fabric width. The number of hooks will always be double compared to the number of harness attachments as a pulley connected to two Jacquard hooks is used to obtain the 3 positions.
Stäubli electronic Jacquard	A full electronic Jacquard of modern and state-of-the art concept offers full flexibility in design. As special Stäubli Jacquard eventually combines the 2-position movement for the ground fabric and the 3-position movement for the pile in a single machine. The number of hooks will be defined by the number of warp ends used and the number of repeats to be woven over the fabric width. The number of hooks for the pile will always be double compared to the number of harness attachments as a pulley connected to two Jacquard hooks is used to obtain the 3 positions.

 

The Harness

If a 1/1 or 2/2 cam motion is used for the ground, robust wooden heddle frames allowing two rows of heddle per frame are used.
If a cambox or dobby is used for the ground, standard aluminium heddle frames (12 mm. division) are used.
In case a Jacquard is used for the ground weave a harness with vulcanised fibre cumber board is used. For the pull down action traditional steel weights are used. The use of weights rather than springs is preferred because of the large amount of dust that is created by the friction of the warp and pile ends. Springs would be clogged up too quickly.
For the pile a similar harness as for the ground fabric is used. The number of harness ends is defined by a combination of parameters, such as: the pile density 
(number of pile ends per cm.), the number of colour frames, the number of repeats of the pattern over the total fabric width.

The Beam Left-Off Motion

For the realisation of the ground fabric, the warp is presented to the weaving machines on warp beams. Depending on the construction of the ground weave, the number of warp ends used and the warp tension needed, the machine can be equipped with a single beam let-off motion or with a double let-off motion, whereby the two beams are installed in tandem position.
The let-off rate is electronically controlled. The tension is obtained by a lever system with tensioning weights.
The number of ends on the warp beam will be defined by the type of weave construction and the way the pile needs to be integrated into the fabric. One can e.g. choose to weave with only two ground warp ends per pile, or with 3,4 or even up to six ground warp ends per pile. The higher the number of warp ends per pile, the higher the definition of the pattern in the ground fabric will be. Also the way of fixation of the pile will be better.

The Pile Creel

As the consumption of pile yarns during the weaving is individual for each pile end in relation to its use in the chosen design, it is impossible to put the pile warp on a warp beam. Therefore each pile end is fed from a individual yarn package. All pile packages are cylindrical bobbins put on a vertical creel composed of 5 to 8 vertical doors fitted with package holding pins on each side of the doors. The number of doors and the total number of pins is defined by the number of pile ends needed in the fabric. In order to build up a tension on the pile yarn and also to compensate for the yarn movement during the shedding special compensator weights are used. The weights are hung over the pile ends close to the yarn package.

 

Application Of Wireflex Machines

- Weaving of velvets for furnishing applications
- Weaving of low pile prayer carpets
- Weaving of tapestry panels
- Weaving of loop pile cotton rugs or bedcovers
- Weaving of special technical fabrics
- Other creative applications …

Material used for ground fabric : cotton, polyester, acrylics, wool,silk, blends, technical fibres

Material used for pile : cotton, linen, wool, acrylics, viscose, silk, blends, technical fibres

A Wireflex weaving machine in nominal width of 150 cm. weaving furnishing fabrics in a loop and pile construction