System and method for in-line treatment of thread for use with a thread consumption device

1. A system for in-line treatment of thread for use with a thread consuming device, comprising:

a treatment unit having a plurality of nozzles arranged at different positions relative the thread, said thread being in motion in use, each nozzle being configured to dispense one or more coating substances onto the thread when activated; and

a control unit configured to set an activation timing of at least two of the nozzles such that each nozzle is configured to dispense the coating substance at different circumferential positions of the thread when the thread twists along its longitudinal axis,

wherein the activation timing of the at least two nozzles is set at least based on thread speed and on the twist per length unit of the thread.

2. The system according to claim 1 , wherein the control unit is configured to:

calculate a required longitudinal distance between the nozzles to be activated for allowing dispensing the coating substance on specific unique circumferential positions of the thread, and identify the nozzles of the treatment unit to be activated based on the known longitudinal distance between the nozzles and the required longitudinal distance.

3. The system according to claim 2 , wherein the control unit is configured to calculate the longitudinal distance based on the twist of the thread.

4. The system according to claim 3 , wherein the control unit is configured to set the longitudinal distance based on a forward feeding speed of the thread in conjunction with the twist of the thread or on a set activation timing of the nozzles.

5. The system according to claim 1 , wherein the control unit is configured to set a longitudinal distance between the nozzles to be activated, wherein the longitudinal distance is set by longitudinally moving at least one of the nozzles such that said at least one nozzle can dispense the coating substance on a desired unique circumferential position of the thread.

6. The system according to claim 1 , wherein the control unit is configured to set a longitudinal distance between a first position at which a dispensed droplet from a first nozzle is assumed to hit the thread and a second position at which a subsequently dispensed droplet from a second nozzle is assumed to hit the thread, and wherein the system further comprises means for changing the travel path of dispensed droplets in accordance with the longitudinal distance.

7. The system according to claim 1 , wherein the nozzles are arranged in a common plane.

8. The system according to claim 1 , wherein the control unit is further configured to set the longitudinal distance based on the twist per length unit of the thread, in accordance with 20π/ω≥d2, d3, d4>0.

9. The system according to claim 1 , wherein the at least two nozzles to be activated are provided on a common nozzle array.

10. The system according to claim 9 , wherein the treatment unit comprises multiple nozzle arrays, and wherein a specific nozzle array is assigned with a specific coating substance.

11. The system according to claim 10 , wherein one or more nozzle arrays are arranged in a common nozzle head.

12. The system according to claim 1 , wherein the nozzles are inkjet nozzles.

13. The system according to claim 1 , wherein the coating substance is a coloring substance.

14. The system according to claim 1 , wherein the control unit is further configured to set the longitudinal distance based on the level of wetting of the thread.

15. The system according to claim 1 , wherein the control unit is further configured to set the longitudinal distance based on a pre-set coating effect.

16. The system according to claim 15 , wherein said pre-set coating effect is selected from the group comprising homogeneous colouring pattern, one-side-only colouring pattern, random coloring pattern, or helical coloring pattern.

17. A thread consuming device, comprising a thread consuming unit and a system according to claim 1 .

18. The thread consuming device according to claim 17 , wherein the thread consuming unit is an embroidery unit, a sewing unit, a knitting unit, or a weaving unit.

19. A method for in-line treatment of thread, comprising:

providing a treatment unit having a plurality of nozzles arranged at different longitudinal positions along the thread, each nozzle being configured to dispense a coating substance onto the thread when activated; and

providing a control unit configured to set an activation timing of at least two of the nozzles such that each nozzles is configured to dispense the coating substance at different circumferential positions of the thread when the thread twists along its longitudinal axis,

wherein the activation time of the at least two nozzles is set at least based on thread speed and on the twist per length unit of the thread.