US3357848A

US3357848A - Flocking method and machine

Info

Publication number: US3357848A
Authority: US
Inventors: John P Donahue; Sheldon T Wright
Original assignee: D & S Proc Co
Current assignee: D & S Proc Co; D & S Processing Co
Priority date: 1962-11-05
Filing date: 1962-11-05
Publication date: 1967-12-12
Anticipated expiration: 1984-12-12

Description

Dec. 12, 1967 J. P. DONAHUE E AL 3,357,843

FLOCKING METHOD AND MACHINE Filed Nov.

INVENTORS Jo/m P Dom/mu: SHELDON 7. A/ /ap/r' F F; La

United States Patent 3,357,848 FLOCKING METHOD AND MACHINE John P. Donahue, Hawthorne, and Sheldon T. Wright,

Ridgewood, N.J., assignors to D. & S. Processing Company, Clifton, N.J., a corporation of Delaware Filed Nov. 5, 1962, Ser. No. 235,411 5 Claims. (Cl. 117-28) The present invention relates to an improved method and machine for flocking and more particularly to a method and machine for flocking a flexible and stretchable base material. The flocking of various base materials such as woven and unwoven fabrics is Well known wherein a layer of adhesive is first applied to the base material and thereafter particles or short fibers of fabrics or other materials are applied to and embedded in the adhesive. The embedded particles, which are chosen from a variety of different materials depending upon the finish desired, are known as flock and the application of the particles to the base material is known as a flocking operation. The resulting products have the appearance and feel of suede or velvet.

The method and machine of the present invention are particularly adapted for applying a flock coating to a stretchable and elastic base material such as an expanded porous plastic. Known methods of flocking fail to provide a satisfactorily uniform coating of flock on such materials and in addition, known methods and machines also tend to damage the base material by subjecting it to physical manipulations which damage its form and appearance and by also subjecting the base material to excess temperatures which cause an undesirable expansion and other injury to the previously cured plastic base material.

One material which has a wide and growing use for garments such as jackets, coats and vests and other uses where a suede-like appearance is desirable has a knit or woven mesh fabric coated wtih a relatively thick, soft and stretchable layer of expanded vinyl. The surface of the vinyl is flocked to provide the suede-like appearance. This material is soft to the feel or hand, is easily cut and fabricated, and provides handsome garments with an excellent appearance and a pleasing drape. The materials may be waterproofed and have the long wearing qualities of superior suede leather.

Accordingly, an object of the present invention is to provide an improved method and machine for flocking.

Another object of the present invention is to provide an improved method and machine for flocking particularly adapted for forming a uniformly flocked coating on resilient or stretchable material.

Another object of the present invention is to provide a method and machine for flocking a base material which includes a stretchable plastic layer.

Another object of the present invention is to provide an improved method and machine for manufacturing a flocked and waterproofed suede-like material.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the inventon has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a diagrammatic side elevational view illustrating a preferred embodiment of the method and machine of the present invention;

FIG. 2 is an enlarged fragmentary perspective view illustrating the adhesive applying and the flocking sections;

ice

FIG. 3 is an enlarged perspective view partially cutaway showing an expanded vinyl base material; and

FIG. 4 is a sectional view of the flocked material taken along line 4-4 of FIG. 3.

FIG. 1 illustrates a preferred embodiment of the machine 1 for applying a flocked coating to a soft stretchable material such as the expanded vinyl material illustrated in FIGS. 3 and 4.

FIGS. 3 and 4 illustrate an expanded vinyl base material 2 which is typical of the materials which may be advantageously flocked in the machine and by the method of this invention. This expanded vinyl base material preferably has a flexible stretchable cloth base 3 formed of knitted or woven fabric which is coated with a layer 4 of soft plastic. This plastic coating is often porous or what is known as expanded and also may be relatively thick, soft, and stretchable. It is formed by including suitable blowing agents in a plastic such as a plastisol which are activated by the application of heat during the plastic curing operation. Chemically activated blowing agents are also used. Expanded layers of this nature remain soft and flexible during normal use at room temper-atures and higher temperatures, however, such materials are damaged by the elevated curing and drying temperatures normally used in known flocking processes.

In addition, the soft stretchable nature of this layer which provides the desired end use characteristics exposes it to physical damage when it is handled by the normal flocking devices wherein the base material is supported on roller systems, is passed between the rollers and is coated with adhesive or other substances using doctor blades or pressure rollers.

The method and machine of the present invention apply a flocked outer coating 5 to the expanded vinyl or other soft stretchable layer 4 which provides the finished product with the feel and appearance and other characteristics of suede or other leathers. As illustrated in FIG. 1, a roll 6 of the base material 2 such as the above expanded vinyl base of FIGS. 3 and 4 is first fed through an adhesive applying device 7 on a conveyor 8 adapted to move and support the material 2 without stretching.

squeezing, scraping or otherwise damaging the resilient plastic layer 4. A uniform layer of adhesive is applied to the upper surface of the vinyl by one or more nozzles or sprays '9. The spray velocity and pattern are adjusted for the desired adhesive thickness and pattern for the speed at which the base material 2 is passed through the adhesive applying device 7.

The use of a spray to apply the adhesive has been found to provide unexpectedly excellent results in flocking the above described stretchable, soft material. This method eliminates the possibility of damage to the base 2 by conventional adhesive applicators using doctor blades or leveling rollers while at the same time giving excellent control of adhesive thickness and distribution. Sprays also provide for ready adjustment for changes in the desired adhesive depth and also for changes in the particular adhesive used and a uniformly thick layer is obtained even though there are imperfections on the surface of the underlying layer 4. Additionally, the enclosed supply system of the adhesive spray eliminates the possible contamination which may occur with the open-type roller and doctor blade applicators of presently used machines.

One adhesive which has proved particularly effective is a water base emulsion of a vinyl-type resin.

While a reverse roll coater may be used in some instances where the uniformity of the flock coating and the control of the depth of the adhesive are not critical, such an adhesive applicator does not provide the excellent results obtained with the use of the above described spray system.

Immediately after the coating of adhesive is applied, the base material 2 is passed onto a second conveyor 11 of a flocking device 12. Here again, the base material 2 is carried through the flocking device 12 on the upper run of the conveyor 11 with the base material supported and carried forward by the conveyor 11 so that no stretching, squeezing or other forces or means are required in moving the base material 2 beneath the flock applicators. Conveyors 8 and 11 as well as all other conveyors in the machine move at the same speed.

In the embodiment illustrated, a uniform coating of flock is applied using one or more flock applicators 13.

The flocking device 12 is preferably arranged so that the flocking pattern and the flock density may be adjusted and controlled without the use of any members which engage or which result in pressure upon the surface of the base material 2. In the preferred embodiment illustrated, control of flock distribution and density is obtained by having the position of the flock applicators 13 above the base material 2 adjustable and by also having the flow rate of the flock from the applicators 13 adjustable. One particularly suitable embodiment of such a flocking device is illustrated wherein the flock 14 is applied from rotating perforated drums 15. The flock 14 is fed into the drums and is distributed uniformly along the length of the drums 15. The adjustable speed of the drive motors 16 controls the density of the flock flow which is generally proportional to the speed of the motors 16. The pattern of flock fall is controlled by having the height as well as the position of the support frame 17 for the distributors 13 adjustable.

The flock particles 14 are continuously fed to the interior of the hollow rotating drums and they are thereafter firmly embedded in the adhesive coating 10 by the combined force of gravity and the vibratory action of the base material 2 imparted to it by the rotating beater bars 18 positioned beneath and in contact with the flexible conveyor 11. By providing two or more generally similar flock applicators 13, a high degree of uniformity is obtained in the flock coating 5. Electrostatic planting of the fibers may also be employed by passing the material 2 between spaced

electrodes

19 and 20 which are charged by an alternating high voltage 21.

The flocked material is next passed through a curing furnace 22 where it is subjected to a heated atmosphere held below the curing temperature previously used in curing the plastic or vinyl layer 4 of the base material. For a typical expanded vinyl plastic, the temperature of the curing furnace is kept below about 270 F.

The improved results are obtained by using a curing atmosphere of uniform and closely controlled temperature which contacts a relatively large area of the flocked surface. This result is obtained in the preferred embodiment as illustrated by using thermostatically controlled hot air heaters 23 in combination with air directing louvers 24 which provide for a uniform distribution of the hot air over the entire surface of the material contained within the curing furnace 22.

Where the adhesive used is a water base emulsion type, the water is preferably first evaporated at lower temperatures in the neighborhood of 200 F. and thereafter the cloth is passed into a second atmosphere where the temperature is raised to the curing temperature which is, as noted above, held a few degrees below the particular plastic curing temperature for the resilient stretchable layer 4. As illustrated in FIG. 1, two such zones of differing temperatures and having a uniform temperature throughout each zone are provided by using separate thermostatically controlled heaters 23 and by providing a dividing louver 24 in addition to the air directing louvers 24 within the individual areas.

In handling a relatively long length of stretchable, flexible base material, it has been found that there is a tendency for longitudinal creases or pinches to form in the upper surface of the base material such as when the base material passes through the curing furnace 22. These wrinkles and scars mark the flocked surface and are highly objectionable for this reason. The wrinkles, scars, and marks tend to be permanently formed into the flocked surface during the curing or hardening step in the curing furnace 22. Applicants have found that the flocking of stretchable and relatively thick resilient material is facilitated and the tendency of wrinkles or pinches to form is eliminated by providing an upwardly facing convex curved surface beneath the conveyors which carry the base material and particularly the portion of the path through the curing furnace 22. This curvature is conveniently provided by a curved platen 26 as illustrated in FIG. 1. The improved results are obtained by a slight upward curvature which has been found to eliminate wrinkling and pinching without resulting in any significant stretching or deformation of the plastic layer or the flocked surface. Relatively slight curvatures provide an unexpectedly etficient wrinkle preventing action on the flocked material. The exact shape and amount of curvature are not critical. Ina furnace about 10 feet long, the uppermost portion of the curved platen surface may be only a few inches above the level of the platen ends.

The flocked material is now cooled by passing it over cooling rollers 27. The material is next preferably passed through a cleaning unit 28 where the flocked surface is vacuum cleaned and brushed to remove any excess flock not adhered to the base material 2.

In order to increase the utility of the material, particularly where it is to be used for outer garments or other products which must be made reasonably waterproof, the cleaned and flocked material is now given a coating of one of the conventional water repellents used for fabrics. Waterproofing this flocked material has presented special problems and applicants have found a particularly effective step to insure an adequate absorption of the Waterproofing liquid into the flock while at the same time preventing the over absorption and spotting which occurs where the waterproofing liquid accumulates or puddles as is the case with the present waterproofing operations. This is particularly important in the manufacture of the vinyl coated base material described herein as the vinyl coating itself is non-absorbent so that any excess waterproofing solution cannot be absorbed in the material base and thus remains at and tends to stiflien, mark and otherwise detract from the appearance and feel of the flocked surface. Applicants preferred waterproofing applicator provides a nozzle or spray 30 which is directed against the flocked material on an inverted run of the material so that the excess solution not readily absorbed by the flocked fibers flows or drips from the coated material. While the material is shown at 29 running on a generally level path durmg this waterproofing operation, it is clear that the base material may be run at an angle to the horizontal during the operation as long as the flocked surface is facing generally downwardly so that the excess solution may flow or grip from it and does not accumulate on the flocked surace.

The flocked material is now fed into a suitable drying oven 32 for the drying of the waterproofing solution. Where the waterproofing liquid includes a resin such as a vmyl plastic, this drying is carried out at an increased temperature governed by the curing temperature of the partlcular plastic being used. As in the curing furnace 22, thetemperature in the final drying enclosure 33 is held below the curing temperature of the plastic layer 4 to prevent. any damage to this layer from excess heat.

It will be seen that an improved flocking machine and method have been provided for stretchable, flexible material and particularly for material such as expanded vinyl or other cellular plastic materials.

The method and apparatus handle such material so that max1mum flocking speed and quality are obtained Without subjecting the material to any damage such as creases or scars or other marks caused by the physical handling or the temperatures used in the drying and curing steps and so that streaks occurring from the accumulation of dirt behind doctor blades are eliminated. A method and apparatus is disclosed which permits the manufacture of greatly improved suede-like or similar flocked products having a degree of stretchability and flexibility not heretofore obtained in such flocked material. The method and apparatus of the present invention are also particularly Well adapted for high speed operation with a minimum amount of supervision so that plants now using conventional flocking operations may be converted to the method disclosed herein.

The improved method and machine reduces adhesive consumption by reducing penetration from adhesive applicator pressure and the coating thickness is made independent of surface imperfections of the undercoat or vinyl layer. Improved product feel or softness also results from the reduced and controlled adhesive layer thickness. The improved Water repellent application combines with the improved handling and flocking to further prevent spots or marks.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and Without sacrificing any of its advantages, it is to be undersood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. An apparatus for flocking a web of material of soft, stretchable fabric coated with a flexible layer of expanded vinyl comprising the combination of a supply of indeterminate length of said fabric material, an adhesive sprayer for applying an adhesive coating of uniform thickness and a predetermined pattern onto the vinyl surface of said fabric material, means for directing an evenly distributed flow of flock downwardly onto the adhesive coating, an adhesive curing oven, a first conveyor means having a flat upper surface for carrying said fabric material in an unstressed condition with the vinyl layer uppermost through said sprayer and the flocking means whereby a uniform coating of flock is applied thereto, and a second conveyor means having an upwardly facing convexly curved surface for thereafter carrying the flocked fabric material through said oven over said curved surface with said vinyl layer and said Web of material in a wrinkle free condition for retaining said uniformity during the adhesive curing.

2. An apparatus as claimed in claim 1 including a spray means positioned for applying a liquid water repellent to the flocked surface and means for supporting the fabric material in an inverted position for the application of the water repellent.

3. The method of flocking a web of material of indeterminate length of soft, stretchable fabric coated with a stretchable layer of expanded vinyl comprising the steps of feeding a supply of said fabric material, spraying an adhesive coating of uniform thickness and a predetermined pattern onto the vinyl surface of said fabric material, planting flock on the adhesive, heating the flocked adhesive, transporting the fabric material on a conveyor means in an unstressed condition with the vinyl surface uppermost during said adhesive applying and flock planting whereby a uniform coating of flock is applied and thereafter transporting the fabric material over an upwardly facing convexly curved path while heating said flocked fabric material with the vinyl in an unwrinkled condition for retaining said flock uniformity during the drying of the adhesive.

4. The method of flocking as claimed in claim 3 wherein the fabric material is heated at about 270 F.

5. The method of flocking as claimed in claim 3 including after the heating step the spraying of a liquid water repellent on the flocked surface while supporting the material in an inverted position whereby excess repellent drops from the flocked surface.

References Cited UNITED STATES PATENTS 3 8,006 3/1863 Simpson 117-29 341,758 5/1886 Livingston 118-59 718,527 1/1903 Rushworth 118-59 1,055,430 3/1913 Thoma 118-59 1,598,924 9/1926 Mayer 117-7 1,701,612 2/1929 Glidden et a1. 36-7.3 1,810,328 6/1931 Slater 117-33 X 1,954,098 4/1934 Powers 118-67 X 2,014,947 9/1935 McCulloch et al. 117-33 X 2,027,307 1/1936 Schacht 117-17 2,120,758 6/1938 Lea 117-20 2,128,811 8/1938 Foster 117-20 X 2,128,907 9/1938 Bennett et al. 117-17 2,173,078 9/1939 Meston 117-17 2,218,445 10/1940 Wintermute 117-20 X 2,332,357 10/1943 Uifelman 117-33 2,345,376 3/1944 Bodle et a1 117-33 2,567,327 9/1951 Ewing 117-29 2,592,602 4/1952 Saks 117-17 X 2,663,097 12/ 1953 Giese 117-33 X 2,696,445 12/ 1954 Schwartz et al. 117-25 X 2,715,074 8/1955 Hirschberger 117-29 X 2,721,811 10/1955 Dacey et al. 117-135.5 X 2,735,786 2/1956 Schramm 117-135.5 X 2,784,630 3/1957 Koprow et al 117-33 X 2,811,130 10/1957 Friderici 118-314 X 2,820,716 1/1958 Harmon et al. 117-17.5 2,877,740 3/1959 Friderici 118-630 2,900,270 8/ 1959 Klein 117-25 2,903,376 9/1959 Donahue 117-33 X 2,942,300 6/ 1960 Masters 117-7 2,948,933 8/1960 Schrener et al. 117-20 2,976,839 3/1961 Okma et a1 117-17.5 X 3,036,927 5/1962 Jerothe 117-7 3,085,896 4/1963 Britl et al 117-33 3,150,023 9/1964 Penman 118-57 FOREIGN PATENTS 11,252 7/ 1904 Great Britain. 525,301 6/1921 France. 842,574 3/ 1939 France.

723,644 2/ 1955 Great Britain.

OTHER REFERENCES Organic Finishing, March 1953, pp. 19-24.

WILLIAM D. MARTIN, Primary Examiner. P. F. ATTAGUILE, Examiner.

Claims

1. AN APPARATUS FOR FLOCKING A WEB OF MATERIAL OF SOFT, STRETCHABLE FABRIC COATED WITH A FLEXIBLE LAYER OF EXPANDED VINYL COMPRISING THE COMBINATION OF A SUPPLY OF INDETERMINATE LENGTH OF SAID FABRIC MATERIAL, AN ADHESIVE SPRAYER FOR APPLYING AN ADHESIVE COATING OF UNIFORM THICKNESS AND A PREDETERMINED PATTERN ONTO THE VINYL SURFACE OF SAID FABRIC MATERIAL, MEANS FOR DIRECTING AN EVENLY DISTRIBUTED FLOW OF FLOCK DOWNWARDLY ONTO THE ADHESIVE COATING, AN ADHESIVE CURING OVEN, A FIRST CONVEYOR MEANS HAVING A FLAT UPPER SURFACE FOR CARRYING SAID FABRIC MATERIAL IN AN UNSTRESSED CONDITION WITH THE VINYL LAYER UPPERMOST THROUGH SAID SPRAYER AND THE FLOCKING MEANS WHEREBY A UNIFORM COATING OF FLOCK IS APPIED THERETO, AND A SECOND CONVEYOR MEANS HAVING AN UPWARDLY FACING CONVEXLY CURVED SURFACE FOR THEREAFTER CARRYING THE FLOCKED FABRIC MATERIAL THROUGH SAID OVEN OVER SAID CURVED SURFACE WITH SAID VINYL LAYER AND SAID WEB OF MAERIAL IN A WRINKLE FREE CONDITION FOR RETAINING SAID UNIFORMITY DURING THE ADHESIVE CURING.

3. THE METHOD OF FLOCKING A WEB OF MATERIAL OF INDETERMINATE LENGTH OF SOFT, STRETCHABLE FABRIC COATED WITH A STRETCHABLE LAYER OF EXPANDED VINYL COMPRISING THE STEPS OF FEEDING A SUPPLY OF SAID FABRC MATERIAL, SPRAYING AN ADHESIVE COATING OF UNIFORM THICKNESS AND A PREDETERMINED PATTERN ONTO THE VINYL SURFACE OF SAID FABRIC MATERIAL, PLANTING FLOCK ON THE ADHESIVE, HEATING THE FLOCKED ADHESIVE, TRANSPORTING THE FABRIC MATERIAL ON A CONVEYOR MEANS IN AN UNSTRESSED CONDITION WITH THE VINYL SURFACE UPPERMOST DURING SAID ADHESIVE APPLYING AND FLOCK PLANTING WHEREBY A UNIFORM COATING OF FLOCK IS APPLIED AND THEREAFTER TRANSPORTING THE FABRIC MATERIAL OVER AN UPWARDLY FACING CONVEXLY CURVED PATH WHILE HEATING SAID FLOCKED FABRIC MATERIAL WITH THE VINYL IN AN UNWRINKLED CONDITION FOR RETAINING SAID FLOCK UNIFORMITY DURING THE DRYING OF THE ADHESIVE.