GB1003894A - Methods and apparatus for doffing and drafting fibrous webs - Google Patents

Abstract

1,003,894. Doffing and drafting carded webs. CHICOPEE MANUFACTURING CORPORATION. June 1,1962, No. 17437/65. Divided out of 1,003,893. Heading D1N. During removal from a doffing cylinder fibres are simultaneously drafted by the action of an endless belt and an associated pressure roller or other member which grip the fibres on the doffing cylinder and transport them at a higher linear speed than that of the doffing cylinder. The belt 30 extends over a bar 22 which is adjustable angularly and for clearance relative to the doffing cylinder 12, the clearance preferably lying between 0. 005 to 0. 150 inch. A nip roll 32 with a diameter from about 0. 75 inch to 3 inches rests upon the belt and is also adjustable relative to the doffing cylinder 12 with preferred clearances of from about 0. 007 to 0. 040 inch. The action of the belt is to press against the fibres on the doffing cylinder to compact the web which is then led into the nip between the belt and the roller 32. Linear speed ratios between the belt 30 and the cylinder 12 may lie between 1.1 to 1 up to 10 to 1 or higher, with optimum results at about 3 to 1. The materials from which the nip roll is made may be metal, leather, rubber, plastic, fabric or film and the fibres treated may include, as well as textile fibres, short papermaking fibres, such as woodpulp and wood fibres, cotton linters, mineral fibres such as asbestos, glass, rockwood or other fibres down to about 1/ 1 inch or less. The gripping zone between the belt 30 and the roller 32 or an alternative member should be as long as the longest fibre being doffed. An alternative to the roller 32 is a second belt that extends over an arcuate shoe (Fig. 6, not shown). Specification 946,694 is referred to.