US3379175A - Flock-applying apparatus - Google Patents

Description

April 23, 1968 F, 'r, SPENCER 3,379,175

FLOCK-APPLYING APPARATUS Filed April 8. 1966 Ja e/5Z0) Ira/was .gwwa r 122" a United States Patent 3,379,175 FLQCK-APPLYENG APPARATUS Francis T. Spencer, Biddeford, Maine, assignor to West Point-Peppercii, lino, iioston, Mass, a corporation of Georgia Filed Apr. 8, 1966, er. No. 541,321 6 Claims. (Cl. 118636) ABSTRACT 0F THE DISCLOSURE An electrostatic grid structure interposed in the path of downwardly failing flock fibers dropped freely from a dispensing device, said grid structure comprising parallel, spaced rotatable elements charged to a high electrostatic potential, and means for rotating said cylindrical elements at a constant predetermined angular velocity.

This invention pertains to apparatus for applying flock fibers to an adhesively-coated surface-more particularly to apparatus of the kind wherein the flock fibers, in tip proaching said surface, are caused to fall freely through an electrostatic field whereby the fibers tend to arrange themselves in parallel relation.

In the cop-ending application for Letters Patent, Ser. No. 494,691, filed Oct. 11, 1965 by Francis T. Spencer, there is disclosed a soft, drapeable material comprising a reinforced ply of foam plastic having an adherent layer of flock of a character and so applied as, for example, to simulate the nap produced by napping woolen fabric or even to have the appearance of natural fur. Flock fibers of a denier of from 3 to 6 and of a length of from 2 to 6 mm. are suggested as useful in making such material.

In accordance with the procedure described in the aforesaid application, the flock fibers are deposited in spaced relation, that is they are relatively sparse as compared with usual procedure, and in order to get the desired results, for example, heat insulation; pleasing appearance; or ornamental effects, these fibers should be predominantl perpendicular to the base fabric and arranged with substantially uniform distribution so that the completed material provides a substantially uniformly level surface defined by the tips of the fibers.

In accordance with customary prior practice, the flock fibers are discharged from a hopper by gravity and, in dropping, pass through an electrostatic field which has the purpose of orienting the falling fibers so that they become substantially parallel as they continue to fall and eventually drop into contact with the adhesively-coated surface of the base fabric which is being rapidly vibrated up and down by beater devices disposed below it. T e electrostatic field is usually produced by the use of a grid comprising stationary steel tubes of the order of of an inch in diameter spaced a short distance apart and which are charged to a very high potential by appropriate electrical apparatus. The lines of force first extend outwardly from these bars in a generally radial direction but then bend downwardly toward the earth.

While the customary flocking apparatus, such as above briefiy outlined, is reasonably satisfactory, when applying the short flock fibers, particularly those of a coarse denier, it has been found, in manufacturing material of the general type of that described in the aforesaid application and in the practice of which flock fibers of low denier, for example, but without limitation, not substantially exceeding 8, and of a length of 2 mm. or more, there is a tendency for these long and fine flock fibers gradually to build upon the grid bars, especially upon the upper portion of the grid bar. This is due, apparently to the fact that the lines of force which emanate from the grid bars tend predominantly to curve downwardly away from the grid bars so that directly above each grid bar there is a space within which the forces acting upon such a long and fine fiber, which has settled down onto the bar, are not such as to detach the fiber from the bar. Eventually, when a mass of fibers has been built up to a certain size, the mass falls off from the grid barusually breaking up into small balls which, as they contact the upwardly and downwardly vibrating base fabric, are tossed up and down repeatedly, and these small balls of dense flock fibers, in dropping back onto the upstanding flock fibers which are just about to adhere to the base fabric, form peck-marks or depressions in the flock layer which spoil the desired smooth appearance. Thus, it is necessary to stop the machine at frequent intervals and clean off the flock by hand from the grid bars.

The object of the present invention is to provide apparatus for applying low denier flock, for instance, from 3 to 6, and, for example, of the order of 2 mm. or more in length, in the manufacture of flocked fabric, whereby the above difficulties are overcome, and to produce a deep flock layer devoid of irregularly distributed cavities or fortuitously located areas wherein the fibers are nonparallel or abnormally dense, or are not perpendicular to the base fabric. In the attainment of this object, in accord ance with the present invention, the grid bars, whereby the electrostatic field is produced, and which in prior devices are stationary, are so mounted that they may be rotated at a s eed which may vary in accordance with the character of the fibers, but which may be within a range, for example, of from 5 to 30 rpm. With such an arrangement the build up of fibers on the grid bars is completely prevented with the result that the final product is no longer damaged by the droppin and bouncing of masses of material falling from the grid bars.

In the drawings:

FIG. 1 is a fragmentary front elevation illustrating one desirable embodiment of the invention;

FIG. 2 is a fragmentary section, to larger scale, on the line 22 of FIG. 1, showing one of the rotary electrodes, in accordance with the present invention, whereby the building up of fiber masses on the electrode is prevented; and

FIG. 3 is a fragmentary diagrammatic vertical section illustrating a modified construction of grid bar.

Referring to the drawings, the character F designates a portion of the machine frame which supports bearings for parallel, horizontal, rotary shafts 10 and 10a, each of which has fixed thereto a drum D. These drums support an endless belt B having a horizontal upper run which contacts a table T of electrical-conducting material, and which carries the base fabric K. (FIG. 2) which, in accordance with customary practice, will have an adhesive upper surface onto which flock fibers S drop after falling through the electrostatic field. The shaft 10 is provided with a sprocket which receives a chain C which is driven continuously by an electric motor M through the intermediary of a variable-speed, speed-reducer R. Above the endless belt, suitably supported hoppers 11, 11a are arranged to discharge flock so that it will fall through the electrostatic field onto the surface of the fabric S. These flock-distributing hoppers may be of customary type, each having a shaft 12 or 12a, respectively, carrying agitating means of any desired type (not shown) driven by the motor M through suitable connections A and having slots in their lower portions through which the flock is discharged.

An auxiliary frame 13, below the hoppers, supports hangers 14 and 15 of insulating material, desirably having bearings 16 (FIG. 2) of nylon which receive trunnions 1'5, which may also be of nylon, fixed in plugs P secured in the opposite ends, respectively, of tubular bar-elece trodes E. It will be understood that, if desired, each grid bar may be mounted upon a shaft extending through it, from one end to the other, rather than on trunnions.

As here shown (FIG. 2) the trunnion 15a which extends outwardly from the rear end of the electrode E is provided with a sprocket which is embraced by a chain 17 which also embraces a sprocket 18 on the rear end of the shaft 10a which carries the drum D. By this means the electrode E is constantly rotated. A sprocket 26, also fixed to the trunnion 15a, is embraced by a chain 21 which also embraces a sprocket on the trunnion at the forward end of the next electrode E (FIG. 1). In a similar way, the electrodes E and E are driven. Since the apparatus may be, in general, similar to those in customary use, except that customarily the electrodes are stationary, it appears unnecessary to describe the mechanism and electrical connections in further detail-it being understood that, for example, the electrodes or grid bars will be charged to one polarity, for example positive, while the support for the material to which the fibers are to be I applied will be charged to the opposite polarity, for example negativethe charge being established and maintained by any suitable or conventional apparatus such as diagrammatically indicated at T (FIG. 1). While the desired arrangement for rotatably supporting the grid bars or electrodes by the use of electrically insulating material is desirable, it will be understood that equivalent means is contemplated as within the scope of the invention.

To avoid difiiculties which might be experienced in so supporting a rotating grid bar as to prevent leakage of the charge, a modified arrangement, as illustrated in FIG. 3, shows the grid bar E as stationary, being supported at its opposite ends in frame elements 14a of insulating material with a suitable conductor W connected to the bar near one end and through which the charge is supplied to the bar. In this instance, the bar E or at least that portion of which functions for the purpose of the present invention, is housed within a non-conducting, rotary, hollow guard cylinder G having hollow trunnions T at its opposite ends, through which the ends of the grid bars pass, and which are received in hearings in stationary frame members Z which, desirably, should also be of insulating material, one of the trunnions T having fixed thereto a sprocket wheel W which is embraced by a chain 17a, like the chain 17 of FIG. 2, by means of which the guard cylinder is slowly rotated. With this arrangement, using a cylinder of non-conducting material, the lines of force emanating from the bar E pass outwardly through the walls of the guard cylinder G so as to provide the functional effect of the usual stationary grid bars. However, since the cylinder G is slowly rotating, any tendency of the flock fibers, as they fall downwardly between the grid bars, to build up on the upper part of the cylinder G is nullified by the rotation of the cylinder and thus the same beneficial efiects are obtained as by the arrangement shown in FIGS. 1 and 2.

While reference has hereinabove been made to the use of the apparatus for making flocked material having a deep flock layer, desirable for heat-insulation; or to simulate napped woolen material or natural fur, it is to be understood that the apparatus herein described is likewise useful in applying flock of any length or denier, and in the manufacture of such articles or fabrics as hosiery, draperies, blanket bindings, artificial furs, bed blankets, childrens bed-clothing, etc., or for purely ornamental effects.

It is also to be understood that the apparatus as illustrated and hereinabove described is by way of example and that the invention is broadly inclusive of all modifications and means, for preventing build-up of fibers on the grid bars, which fall within the terms of the appended claims.

I claim:

1. In combination, in apparatus for applying flock fibers of a denier within a range of from 3 to 6 and of a 4 length not substantially less than 2 mm. to an adhesivelycoated base, a container for flock. fibers having a discharge aperture through which fibers may fall, a grid,

electrically charged to one polarity and comprising spaced bars so located below the container that flock fibers, falling from the container, pass between said bars, an element charged to the opposite polarity for supporting the base to which the flock. is to be adhered; characterized in having means for rotatably supporting the individual bars of the grid, and means for rotating said bars at such a speed as to prevent the build-up of flock fibers upon said bars.

2. In combination, in apparatus for applying flock fiber of a denier not substantially exceeding 8 and of a length exceeding 2 mm. to an adhesively-coated surface and which comprises means for supporting said surface, an electrostatic grid above said surface whose electrical po tential is opposite to that of said surface, and means above said grid for so discharging flock fibers that the fibers fall between the bars of the grid and onto said surface; characterized in that the grid comprises a plurality of spaced parallel bars, means for supporting the individual bars to rotate, and means for rotating the several bars.

3. Apparatus according to claim 2, wherein each grid bar is cylindrical and tubular, insulating means supporting each respective bar, and motor means for rotating each of said bars.

4. Apparatus according to claim 1, and wherein the flock container has therein an agitator operative to stir the flock fibers within the container and to discharge fibers from the container, and wherein each of the grid bars comprises a hollow cylinder, means for supporting each cylinder to rotate about its own axis, the supporting means being such that the cylinder is insulated from the earth, an

" electric motor, and means for transmitting motion from the motor for actuating the flock agitator in the hopper and for rotating each of said hollow cylinders.

5. In combination, in apparatus for applying flock fibers to an adhesively-coated base, a container for flock fibers having a discharge aperture through which fibers may fall, a grid, electrically charged to one polarity and comprising spaced parallel cylindrical elements so located below the container that flock fibers, falling from the container, pass between said elements of the grid, and an element charged in the opposite polarity for supporting the base to which the fibers are to be adhered, characterized in that said cylindrical elements are hollow and rotatable, and power-operable means for rotating said cylindrical elements at a predetermined angular velocity,

6. In combination, in apparatus for applying flock fibers to an adhesively-coated base, a container for flock fibers having a discharge aperture through which fibers may fall, a grid, electrically charged to one polarity and comprising spaced parallel cylindrical elements so located below the container that fibers formed .on the container pass between said elements, further characterized in that said cylindrical elements are hollow and are of a nonconducting material, each of said elements housing a fixed grid bar of conductive material, means insulating each of said fixed bars from the earth, further characterized in having power-operated means for turning said rotatable cylindrical elements at a predetermined uniform angular velocity thereby to prevent the build up of flock fibers upon said cylindrical surface.

References Cited UNITED STATES PATENTS 2,245,301 6/1941 Schacht 118638 X 2,715,585 8/1955 Schwartz et a1 1l8-636 X 2,742,018 4/ 1956 Lindquist 118-636 3,114,482 12/1963 Dunaway.

3,269,356 8/1966 Friderici 118640 CHARLES A. WILLMUTH,Prima1y Examiner.

PETER FELDMAN, Examiucn

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