US 6,195,844 B1 · Method and devices for producing a textile fleece

Abstract

A carding machine or other web production device [(1)] supplies a crosslapper [(2)] with two elementary webs [(15a, 15b)] constituting a lappable web [(16)] which is deposited in a reciprocating manner on a transverse output belt [(26)]. In the device [(1) means of] adjustment of the speed of rotation of doffers [(13a, 13b)], of condensers [(17, 18)], of detachers [(19a, 19b)], of the drum [(4)] and/or of the feeder [(7)], and/or [means of] adjustment of the drum-doffer spacing affect the weight per unit area of the elementary web produced taking account of the weight per unit area desired at each point in the width of the fleece [(67)] to be formed on the output belt [(26)]. There is determined the delay length exhibited by each elementary web cross-section undergoing the adjustment of weight with respect to the section of lappable web in the process of being deposited. From this there is derived the position at which each web cross-section will be deposited when it is undergoing the adjustment of thickness and consequently the weight adjustment to be applied to it. [Utilization] The present invention is useful for producing fleeces of highly varied profiles with great industrial flexibility.

Claims85

Dependent claims

A method of producing a textile fleece comprising the steps of:

in a carding machine, producing at least one elementary web while providing said elementary web with a weight per unit area which varies along a longitudinal direction of said elementary web;
feeding said elementary web into a crosslapper;
in said crosslapper, forming a fleece by folding a lappable web incorporating said elementary web alternately in one direction and in the other on a transverse output belt of said crosslapper, whereby said variable weight per unit area of the elementary web results in a substantially predetermined distribution of weight per unit area over the width of said fleece;
wherein said step of providing the elementary web with a variable weight per unit area comprises the step of performing, in the carding machine, adjustment of at least one operating parameter which is independent of a speed of rotation of a doffer collecting fibers for the elementary web from at least one carding drum of the carding machine.

1 more element

A method of producing a textile fleece comprising the steps of:

in a carding machine, producing at least one elementary web while providing said elementary web with a weight per unit area which varies along a longitudinal direction of said elementary web;
feeding said elementary web into a crosslapper;
in said crosslapper, forming a fleece by folding a lappable web incorporating said elementary web alternately in one direction and in the other on a transverse output belt of said crosslapper, whereby said variable weight per unit area of the elementary web results in a substantially predetermined distribution of weight per unit area over the width of said fleece;
varying the length of a web accumulation path between the carding machine and a lapper carriage of said crosslapper according to a difference between a speed at which the carding machine delivers the elementary web and a speed at which the lapper carriage deposits the lappable web on said output belt;
determining a length of web contained between a first web cross-section in the process of being deposited on the output belt in the crosslapper and a second web cross-section located at the point in the path of the fibers where said step of performing adjustment influences the weight per unit area of the elementary web;
determining on the basis of said length the point in the width of the fleece where the second cross-section will be deposited;
and
performing said adjustment of the operating parameter according to a weight per unit area programmed for said point in the width of the fleece.

5 more elements

The method of producing a textile fleece comprising the steps of:

in a carding machine, producing at least one elementary web while providing said elementary web with a weight per unit area which varies along a longitudinal direction of said elementary web;
feeding said elementary web into a crosslapper;
in said crosslapper, forming a fleece by folding a lappable web incorporating said elementary web alternately in one direction and in the other on a transverse output belt of said crosslapper, whereby said variable weight per unit area of the elementary web results in a substantially predetermined distribution of weight per unit area over the width of said fleece;
said step of providing the elementary web with a variable weight per unit area comprises the step of performing in the carding machine adjustment of at least one operating parameter which affects a web outlet speed of the carding machine;
and
the method comprises the step of varying the length of a web accumulation path between the carding machine and a lapper carriage of said crosslapper according to a difference between a variable web outlet speed at which the carding machine delivers the elementary web and a speed at which the lapper carriage deposits the web on said output belt.

3 more elements