Cutting a collapsible tube for biopharmaceutical use

Process for cutting into sections and closing a flexible tube, comprising:

• using a pinching closing unit that cuts a flexible tube, the pinching closing unit comprising a pinching closing device (1) and at least one cutting element (2) with a frontal cutting edge,
• whereby the pinching closing device (1) comprises two cross-sections (3a, 3b), each of the two cross-sections having two hollow parts (4a, 4b and 5a, 5b), the two cross-sections (3a, 3b) being a first cross-section (3a) and a second cross-section (3b), at least one pair of the hollow parts (4a and 5a or 4b and 5b) having two indentations (11a, 11b), wherein a first of the two indentations (11b) is a female indentation and a second of the two indentations is a male indentation (11a),
• using combination means (24a, 24b, 27, 32) to place the hollow parts (4a, 4b and 5a, 5b) of each of the two cross-sections (3a, 3b) into an extension of one another and thereby making between the hollow parts of each of the two cross-sections (3a, 3b) a transverse passage for cutting (22), the transverse passage (22) having an access (26) for the at least one cutting element (2),
• wherein the pinching closing device (1) has i) an open state where the two cross-sections (3a, 3b) are separated from one another, and ii) a closed state where the two cross-sections (3a, 3b) are drawn together and closed on one another and kept closed by locking means (25a, 25b),
• wherein in the closed state, a surface (13, 14) of the two indentations (11a, 11b) form a positive pinching closing passage (23) for pinching and closing the tube, the positive pinching closing passage (23) being limited by the surface[s] (13, 14) of the two indentations (11a, 11b) and having, in transverse straight cross-section, a general U shape,
• wherein the at least one cutting element (2) has a shape and dimension[s] such that the at least one cutting element, via the access (26), passes into the transverse passage (22) and thus cuts the tube with the tube being pinched and closed by the pinching closing device (1),
• with the pinching closing device (1) in the open state, positioning a pinching region of the tube in the first indentation (11b) of the first cross-section (3a), and bringing the second cross-section (3b) opposite the first cross-section, then drawing the first and second cross-sections (3a, 3b) together and closing the first and second cross-sections (3a, 3b) on one another to bring the pinching closing device (1) into the closed state, and, with cooperation of the locking means (25a, 25b), closing the first and second cross-sections (3a, 3b) on one another until the tube is positively pinched and closed in at least one positive pinching closing zone by the surface (13, 14) of the two indentations, whereby the tube is held in place thus pinched and closed between the two cross-sections (3a, 3b),
• with the pinching closing device (1) in the closed state and using the at least one cutting element (2), cutting the tube at a location between the hollow parts (4a and 5a, 4b and 5b),
• wherein in said cutting step, a frontal cutting edge of the at least one cutting element (2) passes into the transverse passage (22) and cuts the tube into the two sections without the frontal cutting edge making contact with the pinching closing device (1),
• after said cutting step, dissociating the combination means (24a, 24b) from the hollow parts (4a and 4b, 5a and 5b) of each of the two cross-sections (3a, 3b), wherein the at least one pair of the hollow parts (4a and 5a or 4b and 5b) having the two indentations (11a, 11b) remains attached to an end part of the tube that has been cut, and
• wherein the at least one cutting element (2) is accessible from outside of the pinching closing device when the pinching closing device is clamped on the tube.