US 4,403,374 A · Means for controlling density of non-woven fiber webs

Abstract

A vertical feed chute includes a feed roll for feeding fibers from a surge section in its upper end to a formation section in its lower end. A stationary, perforated condenser plate is secured to the lower, discharge end of the chute, and has thereon a concave surface which extends beneath the chute discharge opening, and beneath a metering roll that is mounted to rotate in the discharge opening in confronting relation to the condenser plate. A mat of fibers is drawn from the discharge opening into a nip between the condenser plate and metering roll where the mat is compressed and then fed to the input of a carding machine, or the like. The metering roll is mounted for limited reciprocable movement normal to its axis, and toward and away from the concave condenser surface. In one embodiment the roll is positively driven by pneumatic means toward or away from the concave surface depending upon the density of the mat entering the nip. In another embodiment the metering roll is mounted to reciprocate in response to changes in the thickness of the mat; and this movement is used either to increase or decrease the rate at which fibers are fed to the formation section of the chute, thereby to effect a corresponding increase or decrease in the thickness of the mat.

Claims9

Dependent claims

Apparatus for forming a non-woven fiber mat, comprising

a fiber feed chute having in its upper end a surge section for receiving air-borne fibers from a supply thereof, and in its lower end a formation section for forming fibers into a predetermined configuration,
means intermediate the ends of said chute for feeding fibers downwardly from said surge section to said formation section,
a metering roll mounted to rotate adjacent the lower end of said chute, and for limited reciprocable movement transversely thereof,
a stationary condenser mounted beneath an opening in the lower end of said chute and having thereon a concave surface extending beneath said roll to form therewith a nip which communicates with said opening in the chute,
said roll being operative during rotation thereof to draw fibers from said chute and to compress them into a non-woven mat as they pass through said nip and between said roll and the concave surface on said condenser,
sensing means for monitoring the density of the fiber mat passing between said roll and said condenser, and
means for adjusting the density of said mat when said density differs from a predetermined value,
said adjusting means including means for positively moving said roll toward said condenser, when said mat density falls below said predetermined value, and to move said roll away from said condenser, when said mat density exceeds said predetermined value.

5 more elements

Apparatus for controlling the density of a fiber mat produced by a vertical fiber feed chute, comprising

a vertical feed chute for supplying fibers to a discharge opening in the bottom of the chute,
a perforated condenser secured to said chute and having thereon a stationary concave surface which extends downwardly beneath said opening,
a metering roll mounted to rotate it in said opening about an axis parallel to the axis of curvature of said concave surface, and in spaced, confronting relation to said surface,
said roll being operative, when rotating, to draw a continuous fiber mat from said opening, and to cause the mat to pass between said concave surface and the periphery of said roll thereby to compress said mat,
means mounting said roll for limited reciprocable movement at right angles to its axis toward, and away from said concave surface, thereby to adjust the distance between said surface and the periphery of said roll,
means for sensing at any moment the density of the mat passing between said concave surface and said roll, and
control means responsive to said sensing means positively to more said roll in one of the two directions in which it reciprocates, when the density of said mat differs from a predetermined value.

4 more elements

Dependencies are inferred from the claim text.

Means for controlling density of non-woven fiber webs

Life of this patent

Means for controlling density of non-woven fiber webs

Life of this patent

Abstract

Claims9