Multiphase Weaving Machine: Principle, Advantages and Disadvantages

What is Multiphase Weaving?
Multiphase weaving is an advanced method of fabric production that enables the simultaneous formation of multiple sheds across the weaving width. A multiphase weaving machine is a type of loom designed to open multiple sheds at once across the width of a fabric to insert weft threads quickly. So significantly increases the efficiency of fabric production by operating on multiple weaving phases simultaneously. In these machines, more than one shed is formed at a time; therefore, they are also called multi-shed weaving machines.

Generally, weaving machines are categorized into two main types: single-phase and multiphase. In single-phase looms, a single weft yarn is inserted during one complete revolution of the loom. The warp opens fully across its entire width to form a single shed, and the weft yarn is inserted into this shed to complete the pick. Shuttle-less looms, such as rapier loom, projectile loom, air-jet loom, and water-jet looms are examples of single phase looms. These are also known as the second generation of weaving machines.

The main weaving motions of a classical weaving machine, namely shed forma­tion, weft insertion and beat-up, take place along the full width of the machine. These weaving machines are called single-phase weaving machines. All single-phase weaving machines or looms form one shed at a time, one weft insertion at a time and one beat-up at one time. In a multiphase weaving machine, several weft insertions take place simultaneously, and several shed formations take place at a time, significantly increasing efficiency.  Multiphase looms are classified as the third generation of weaving machines. They function based on two principles: either the shedding, picking, and beat-up actions occur across the width of the warp (in the weft direction), or they take place along the length of the warp (in the warp direction).

Multiphase weaving machine operates through wave-like motions across the weaving surface. The fabrics produced by these machines typically have slightly slanted weft yarns rather than forming a perfect 90° angle with the warp. This technique is mainly used for specialized fabrics, though its adoption is expected to increase in the future. A notable feature of multiphase weaving machines is their ability to create multiple sheds at different locations, enabling the sequential insertion of several filling yarns.

Sulzer Textil introduced their first revolutionary multiphase loom M8300 at International Textile Machinery Association 1995, with a working width of 190 cm running at 2,050 ppm with weft insertion rates of 3,894 m/min. There are several developments over the years. The machine has no healds and a non-reciprocating beat-up. The weft is inserted with the aid of compressed air at low pressure and at a uniform speed, with low weft loading. Shedding is based on the multilinker shed principle: sheds are formed positively by shed-forming elements that deflect the warp threads into the upper shed position.

Principles of Multiphase Weaving Machine:
There are two principles of multiphase weaving machines:

1. Weft direction shed wave principle
2. Warp direction shed wave principle

A. Weft Direction Shed Wave Principle:
In weft direction shed wave principle machines, a number of sheds are formed across the entire width of the machine for the insertion of weft. These sheds look like a wave from one side to the other. The weft carrier slides into each shed. As the weft carriers enter one section of the warp, a shed is formed, and as it leaves to the next section, another shed is formed in the next section. This will occur along the full width of the machine. As a result, at any time several shuttles will insert different weft yarn. Figure 2 shows weft direction shed wave principle. Due to the insertion of weft by many shuttles at a time, the weft insertion rate is very high.

The weft yarn is beaten up by a rotating reed. Figure 3 shows a beating up by a rotary reed.

Individual reed blades 1 are assembled in rotating shaft 2. When the reed blade rotates, weft yarn 5 is caught by groove 3 and pushed towards the fell of the cloth. As the reed blade rotates further, the weft yarn slips out of the groove, but the reed blade pushes the weft to the fell of the cloth.

B. Warp Direction Shed Wave Principle:
In these machines, several sheds are opened in the warp direction, one behind the other across the full width of the machine simultaneously. Weft yarns are inserted into each of these sheds simultaneously. Either rapier or air jet can be used for weft insertion. Figure 4 shows the warp direction shed wave principle.

A weaving rotor is used for shed formation. Figure 5 shows a weaving rotor. The warp ends pass over weaving rotor 4. The sheds are formed consecutively by shed-forming elements 1 on the circumference of the weaving rotor. The motion of the rotor causes the shed forming elements to open the sheds one after the other. Weft is inserted into the warp sheds across the full width of the machine either by rapier or by air jet. The beat-up combs placed between the shed-forming elements push the weft yarn to the fell of the cloth and beat up the weft.

Due to the simultaneous weft insertions by several weft carriers, the weft inser­tion rates of multiphase weaving machines are very high, between 3000mpm and 5000mpm. Heavy fabrics cannot be woven in multiphase weaving machines due to the nature of beat-up in these machines.

Advantages of Multiphase Weaving Machine:

1. Capable of weaving at extremely high speeds, producing up to 1.5 yards of fabric per minute.
2. Allows simultaneous insertion of multiple weft yarns, significantly boosting output.
3. Uses continuous wave-like motions for efficient and uninterrupted weaving.
4. Can produce fabrics up to 190 cm wide, making it suitable for large-scale production.
5. Reduces energy consumption compared to some conventional looms.
6. Highly automated, requiring less manual intervention during operation.
7. Ensures consistent fabric quality over large-scale production.
8. The continuous weaving process minimizes machine idle times.
9. Over time, the high-speed production and reduced labor costs make it economically advantageous.
10. Suitable for specific fabric types where high-speed production is essential.

Disadvantages of Multiphase Weaving Machine:
Multiphase weaving is another step toward increasing production speed; however, in spite of the serious efforts of several weaving loom producers, the so-called wave-shed weaving, which is a multiphase weaving process, has not become successful due to technology-specific disadvantages.

The main reasons of the failure of multiphase loom are:  

1. Miss-picks cannot be fixed easily.
2. The warp and weft yarns did not align perfectly at 90°.
3. In circular machine, limited range of option and lack of flexibility in the fabric width.
4. Difficult to create fancy designs
5. Usually only plain and twill weave are possible.
6. Uneven filling yarn tensions, as a result of several filling yarn carriers being activated at the same time.
7. The beat-up mechanism cannot handle heavy fabrics.
8. An extra rewinding process is needed because direct unwinding from the cross-wound package isn’t possible.
9. Restriction of purely mechanical filling yarn carrier systems with the disadvantage of output limitation.
10. Achieving consistent filling yarn insertion across the entire weaving width.

Conclusion:
Multiphase weaving machine is one in which several phases of the weaving cycle takes place at any instant such that several filling yarns can be inserted simultaneously. In this mechanism, more than one weaving shed is formed at a time. It represents a significant advancement in textile production, offering unparalleled speed, efficiency, and automation. Multiphase weaving machines are highly efficient, capable of producing fabric 190 cm wide at a speed of 69 meters per hour.

References:

[1] Thangamani, K., & Sundaresan, S. (2022). Fabric Manufacturing Technology: Weaving and Knitting. CRC Press.

[2] Adanur, S. (2020). Handbook of Weaving. CRC Press.

[3] Purushothama, B. (2016). Handbook on Fabric Manufacturing: Grey Fabrics: Preparation, Weaving to Marketing. Woodhead Publishing India in T.

[4] Gries, T., Veit, D., & Wulfhorst, B. (2015). Textile Technology: An Introduction. Hanser Pub Incorporated.

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