Printing method and printing device for fabrics

A printing method performed by use of a printing device usable for fabrics, the printing device including a print head that performs printing on a fabric material, a supply roll around which the fabric material is wound, a support roll that winds therearound the fabric material fed from the supply roll and guides the fabric material toward a position below the print head, a winding roll that is driven to rotate to wind therearound the fabric material which has passed the position below the print head, and a feed roll provided on a moving route of the fabric material between the position below the print head and the winding roll and being contactable with the fabric material, wherein the printing device feeds the fabric material toward the winding roll by a prescribed length each time that one cycle of a print operation is performed by the print head so that the printing is performed on the fabric material intermittently, the printing method comprising the steps of:

• performing, after one cycle of the print operation, a first feed operation on the fabric material of intermittently rotating the feed roll by a first motor to pull the fabric material from the position below the print head and feed the fabric material toward the winding roll by a prescribed length by the rotation of the feed roll;
• performing, along with the first feed operation, a second feed operation on the fabric material of intermittingly rotating a supply/feed roll or the supply roll by a second motor to feed the fabric material toward the position below the print head, the supply/feed roll being contactable with the fabric material at a position upstream with respect to the support roll in a moving direction of the fabric material;
• detecting a tensile force of the fabric material at a position upstream with respect to the position below the print head in the moving direction of the fabric material;
• comparing a detected tensile force value based on the detected value of the tensile force of the fabric material to a preset target tensile force value;
• and
• controlling the second motor based on a result of the step of comparing.

A printing device usable for fabrics, comprising:

• a print head that performs printing on a fabric material;
• a supply roll around which the fabric material is wound;
• a support roll that winds therearound the fabric material fed from the supply roll and guides the fabric material toward a position below the print head;
• and
• a winding roll that is driven to rotate to wind therearound the fabric material which has passed the position below the print head;
• wherein
• the printing device feeds the fabric material toward the winding roll by a prescribed length each time that one cycle of a print operation is performed by the print head so that the printing is performed on the fabric material intermittently;
• the printing device further comprises:
• a feed roll provided on a moving route of the fabric material between the position below the print head and the winding roll and being contactable with the fabric material;
• a first motor that rotates the feed roll;
• a supply/feed roll acting as the supply roll, or a supply/feed roll different from the supply roll and contactable with the fabric material at a position upstream with respect to the support roll in the moving direction of the fabric material;
• a second motor that rotates the supply/feed roll;
• a drive control device that is programmed to perform a first feed operation to control the first motor so as to intermittently rotate the feed roll and pull the fabric material from the position below the print head and feed the fabric material toward the winding roll by a prescribed length, and a second feed operation to control the second motor so as to intermittingly rotate the supply/feed roll along with the first feed operation and feed the fabric material toward the position below the print head;
• and
• a tensile force detection device that detects a tensile force of the fabric material at a position upstream with respect to the position below the print head in the moving direction of the fabric material;
• wherein
• the drive control device includes:
• a memory that stores a target tensile force value of the fabric material;
• a comparator that compares a detected tensile force value, based on the detected value of the tensile force that is detected by the tensile force detection device, to the target tensile force value stored in the memory and outputs a deviation signal;
• a drive indicator that receives the deviation signal from the comparator and outputs a drive command signal corresponding to a driving amount of the second motor;
• and
• a feed control device that is programmed to control the second motor in accordance with the drive command signal from the drive indicator.