US3797453A

US3797453A - Apparatus coating sheeted material with a tacky substance

Info

Publication number: US3797453A
Application number: US00234776A
Authority: US
Inventors: A Rizzo
Original assignee: Afco Products Inc
Current assignee: Afco Products Inc
Priority date: 1970-08-21
Filing date: 1972-03-15
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

An apparatus for treating a continuous web of material which has been coated with a tacky substance having means for moving the web along a first path having an upward vertical component to permit the substance to dry at least partially and to lose at least a portion of its tackiness. Means are provided for changing the direction of travel of the web to a second path having a downward vertical component and includes an absorbent surface positioned to contact the web and change the direction of travel. The absorbent surface is capable of absorbing a fluid which prevents the adherence of the partially set tacky substance to the absorbent surface.

Description

United States Patent [191 Rizzo 1 Mar. 19, 1974 1 APPARATUS COATING SHEETED [73] Assignee: Afco Products Inc., Somerville,

, Mass.

[22] Filed: Mar. 15, 1972 [21] Appl. No.: 234,776

Related US. Application Data [60] Division of Ser. No. 66,104, Aug. 21, 1970, Pat. No. 3,681,121, Continuation of Ser. No. 580,656, Sept. 20, 1966, abandoned.

[52] US. Cl 118/69, 118/70, 118/257, I 118/419, 198/203 [51] Int. Cl. B05c 11/12 [58] Field '01 Search 118/70, 69, 104, 419, 420, 118/106, 257; 117/102 M, 119.2, 119.4; 34/3 1,759,600 5/1930 Wilshire 118/104 X 2,218,249 10/1940 Nadeau et a1 118/70 2,532,985 12/1950 Bannon et al,... 34/D1G. 3 2,843,505 7/1958 Riedel ll8/104X 2,892,263 6/1959 Hornbostel 34/DIG. 3 3,175,532 3/1965 Mugg1eton.... 118/119 3,387,585 6/1968 Farrell 118/104 3,524,425 Barnes et a1. 118/106 X Primary ExaminerMorris Kaplan 'Attorney, Agent, or F irm -Lane, Cutlien, ounfiei'a Ziems V [57] ABSTRACT An apparatus for treating a continuous web of material which has been coated with a tacky substance having means for moving the web along a first path having an upward vertical component to permit the substance to dry at least partially and to lose at least a portion of its tackiness. Means are provided for changing the direction of travel of the web to a second path having a downward vertical component and includes an absorbent surface positioned to contact the web and change the direction of travel. The absorbent surface is capable of absorbing a fluid which prevents the adherence of the partially set tacky substance to the absorbent surface.

5 Claims, 4 Drawing Figures PATENTEUHAR 191974 I 020/5 MAM/vs APPARATUS COATING SHEETED MATERIAL WITH A TACKY SUBSTANCE This is a division of U.S. Pat. application Ser. No. 66,104, filed Aug. 21, 1970, now U.S. Pat. No. 3,681,121, issued Aug. 1, 1972, which in turn is a continuation of U.S. Pat. application Ser. No. 580,656, filed Sept. 20, 1966, now abandoned.

This invention relates to an apparatus for coating a continuous web material with a tacky substance.

In the conventional process for making materials which are coated with a sticky or tacky substance, such as flashing, waterproofing and roofing materials, a continuous web material is passed through a dip-tank of the coating substance, which is preferably (but not limited to) an asphalt or bituminous compound. The

amount of coating on both ides of the web is controlled by the heat of the coating substance in conjunction with various mechanical means to smooth the coating. After leaving the dip-tank the coating substance on the web material is in a heated and sticky or tacky state. The web must then be cooled and the coating set so that it may be wound on a take-up roll without the layers sticking together.

' Oneconventional method to accomplish this cooling and setting is to drive the coated web vertically by means of a driven roll system at an upper position, preferably past cooling fans, over the driven roll system (at which point the web reverses direction) and to return the coated web to the lower position where it is finally wound on a suitable take-up roll after passing over a series of ground levelrolls. This vertical movement provides a maximum amount of space within which the coating may be cooled with a minimum of floor space being used. The vertical length of travel is limited, however, because the weight of the coated web often causes tension problems, which in turn createtearing and web breaking since the web is supported at its upper position by the aforementioned driver roll system. This limits the amount of cooling of thecoated web. lf the coating on the web is not sufficiently set and cooled, it will stick to the driven roll system at the top of the vertical run. If the coating is still hot and tacky when it reaches the. ground level rolls, sticking to these rolls will also occur. Finally, if the coated web is not completely cooled when it is wound on the take-up roll, the layers will stick to each other and will not be able to be unwound at their point of sale or use.

Various methods have been utilized to attempt to eliminate the tacky condition and to cool the coated web to overcome the aforementioned problems. Conventional coating materials such as asphalt or bituminous compositions have poor heating and cooling characteristics. Cooling of the heated coated web on both surfaces as it travels in the vertical direction between the dip-tank and the driven and idler rollers at the upper position of travel helps reduce the sticking problem somewhat but the sticking still occurs to an unsatisfactory degree. Refrigeration cooling has been attempted but is expensive and slows production to a level where it is not economically possible to operate the process. No appreciably favorable results have been obtained by refrigerating or similarly cooling the driven roll itself at its upper driving position.

It is at this-upper position at the superstructure where the greatest efforts and expense have been expended to eliminate the problem of sticking, so that the web may be wound into a finished product.

For example, various water treatment methods have been attempted at this point in the process with little success. An open tank placed at the upper position at the end of the vertical run has been filled with water with a metal driven roll immersed in it. While this presents a continuously wctted roll to the coated web, the metal surface of the driven roll does not pick up and transfer sufficient water to the coated web to eliminate the sticking problem. Another water treatment method attempted has involved the immersion of the coated web in water within an open tank in order to effect coding and reduce the tacky state of the coating. However, a water pick-up problem with the coated web results which renders this method unsatisfactory. The driven roll and the subsequent idler rolls have also been coated with a non-adherent plastic material, such as Teflon, with no success in eliminating the sticking problem.

The only method that has been commercially practicable and which is currently in use involvesthe application of a powder material such as; talc and/or mica to one or both sides of the coated web at the top of the vertical run at the upper superstructure position. However, this method has continuously presented problems both of housekeeping and application. In order for the tale powder to properly adhere to the coated web, fine mesh talc powder must be used. Although various attempts have been made to confine the application of the tale powder to the coated web, housekeeping problems occur, particularly due to the dust formed Thus dust affects both the machinery and the health of the employees and causes maintenance costs to be high. Attempts to completely enclose the upper superstructure position to make a relatively air-tight chamber were not effective since they resulted in the jamming of the equipment within the chamber. In addition, the tale dust escaped out of the slits through which the coated web was adapted to pass. This greatly reduced the effectiveness of this method.

Further methods of applying the tale powder were attempted such as placing the upper superstructure in a negative exhaust pressure chamber and applying the talc in a slurry state. Both ofthese additional methods have had similar shortcomings.

In addition to the foregoing, the use of materials such as talc presents secondary problems related to control of the amount of talc used. When too little of the talc powder is used, the layers of the coated web stick together and problems in unrolling the material from the take-up roll result. When too much of the tale powder is used, problems occur in the saleability of the product, since the excess powder decreases its attractiveness and presents handling problems.

In addition to those listed above, other attempts to eliminate the foregoing problems have been made by applying various release papers and/or plastic films on both sides of the coated web, such as wax-kraft paper, chemically treated paper, polyethylene films, mylar films, cellophane films, polyvinylchloride 'films and so forth. Some of these films have reduced the problems of sticking and facilitated the tale powder application but they have created other difficulties since the release papers or films must be removed from the finished product before it is wound on the wind-up roll.

This use of release papers or films is accordingly undesirable since it increases manufacturing costs.

Still further attempts have been made to eliminate the problems involved in the process by spraying the coated web with water on one or both sides during the vertical travel distance between the dip-tank and the upper superstructural position. However, this created a water collection problem since the water tended to run off down the coated web into the dip-tank.

The present invention provides an apparatus for continuously coating an elongated sheet of material with a tacky substance wherein the above-mentioned disadvantages are eliminated. This invention broadly involves the cooling and drying of the tacky substance by causing the coated sheet of material to pass over and in contact with an absorbent surface which contains an absorbed fluid which will prevent the coated sheet of material from sticking to the absorbent surface and which, in a preferred embodiment, will cool the tacky substance as it comes in contact with the absorbent surface.

It is accordingly a primary object of the present invention to provide a novel coating apparatus wherein a continuous web coated with a tacky substance is treated to prevent sticking.

It is a further object of the present invention to provide a novel coating apparatus wherein a continuous web coated with a tacky substance is wetted and cooled through contact with a liquid contained in an absorbent surface to eliminate sticking problems.

It is still another important object of the present invention to provide apparatus including a novel absorbent surface which makes possible the wetting and cooling of a tacky coated web to prevent sticking.

These and further objects and advantages of the present invention will become more apparent through reference to the following description and appended claims, as well as to the accompanying drawings wherein:

FIG. 1 is a diagrammatic representation of the coating process of the present invention;

FIG. 2 is an isometric view of the wetting and cooling endless belt apparatus of the invention;

FIG. 3 is a view of an alternate apparatus of the invention; and

FIG. 4 is aview of another alternate apparatus of the invention.

The novel apparatus and method of the present invention may best be described by reference to FIGS. 1 and 2 of the drawings. While the present process is applicable to the coating of any elongated sheet of material with a sticky or tacky substance, whether such substance is a hot melt material or one which is a cool fluid, the invention will be described in connection with a preferred embodiment involving an elongated web or sheet of material coated with a hot-melt asphaltic substance.

An elongated sheet of material to be coated passes from a supply roll 12 over an idler roll 14 into a dip tank 16 which contains asphalt 17 which is heated to a sufficiently fluid condition by conventional heating means (not shown). Since sheet 10 passes into tank 16 around

idler rolls

18 and 20, the sheet will be coated on both sides with the asphalt 17. The amount of coating on the web material 10 is controlled by heat in conjunction with spreader blades (not shown) which are mounted both above the dip-tank 16 and above the level of the asphalt composition within the tank 16 above the idler rolls l8 and 20.

As the asphalt coated web 10 leaves the heated diptank 16, the temperature of the coating is approximately 275 F. The coated web 10 travels vertically a distance of approximately 15-20 feed where it passes over an endless belt 24 which is carried by a driven roll 22 and idler roll 26. The structure including the novel endless belt 24 will be described hereinbelow in greater detail. The coated web 10 then proceeds downward to ground level to driven

rolls

28 and 30, over idler roll 32 and finally is wound on a'take-up roll 34.

In roofing materials, waterproofing, flashings and building product applications, consumers expect their products to be provided with decorative materials such as coarse mica flakes, roofing granules, sand and/or other materials. Where the coated sheets made in accordance with the present invention are destined for such applications, the decorative or like materials are applied to the coated sheet 10 by applicator mechanism 42 which is positioned immediately above driven rolls 28 and '30. When the coated web 10 reaches its lower position at the driven rolls 28 and 30, it is still slightly tacky. This permits the decorative materials to adhere to the surface of the coated web 10. The rate of flowof these materials from applicator mechanism 42 can be controlled by any conventional mechanical or electrical means. Excess decorative materials, which might fall off the coated web 10, can be collected in an open pan 44 which is positioned under the point of application and the collected material may be reused.

As indicated above, details of the novel endless belt structure of the present invention are shown in FIG. 2. An endless belt 24, which is preferably made of a solid woven cotton material which is adapted to absorb and hold water, is mounted on driven roll 22 and idler roll 26. The endless belt 24 is mounted over a tank 36 which is filled with a cooling fluid such as water so that the lower portion of the belt passes through the water and becomes wetted.

Water is introduced into tank 36 by means of a perforated pipe 38 which sprays water on the inner surface of the endless belt 24, as shown, with the excess water not adhering to the underside of the belt 24 fallinginto the tank 36. Spraying is regulated by a valve (not shown) which controls the flow of water. The level of water within the tank 36 is regulated by an overflow drain 40 which is positioned near the top of the tank. Endless belt 24 is driven through the tank 36 by the driven roll 22 and as it revolves it picks up water. At the end of the vertical run from the dip-tank 16, the hot and tacky asphalt coated web 10 passes over the wetted endless belt 24. As will be apparent from FIGS. 1 and 2, revolution of the driven roll serves not only to drive the endless belt 24 but to move coated sheet 10 through the coating system.

The endless belt 24 around driven roll 22 and idler roll 26 may be adjusted for tension by adjustable bearings on the arbors of the idler roll 26. Tracking can be controlled by crowning or movement of idler roll 26.

amount of water is picked up by the endless belt 24 and brought in contact with the coated sheet to cool and set the coating so as to eliminate sticking problems without the attendant water pick-up problems which occur when the coated sheet 10 is completely immersed in water as has been done in prior art processes. After the coated sheet 10 passes over the endless belt 24 at the idler roll 26, it is still sufficiently warm to dissipate the small amount of water film which was picked up from the. endless belt 24 and remains on the surface of the coated sheet 10. Further drying of this water, if necessary, can be accomplished by suitable radiant heat bulbs or other warm air circulation anywhere in the process during its downward travel. Since the coated web 10 does not stick to the endless belt 24, the problem of the coating sticking on the driven and idler rolls (as in prior art methods) is completely eliminated. As will be appreciated, the vertical distance which the asphalt coated sheet 10 travels from the dip-tank 16 to the driven roll 22 aids in cooling and setting of the asphalt coating. When the novel apparatus in the present coating process is used, the vertical distance from the dip-tank to the driven roll 22 may be reduced substantially without adverse effect, thus permitting a saving in the building height.

As will also be recognized, by increasing the length of endless belt 24, the coated sheet would be in contact with the wetted surface for a longer period and the cooling and setting effect on the coating would be enhanced correspondingly. Conversely, by decreasing the length of the endless belt, the coated web will not be I cooled as much. The endless belt length can be varied to provide the exact degree of cooling desired in a particular application. a i

As previously indicated, the cooling fluid (water, in the preferred embodiment) is fed into tank 36 by means of a perforated pipe 38. Since this pipe is arranged to spray water on the inner surface of the endless belt 24, this feed arrangement serves the dual purpose of feeding cooling fluid into tank 36 and enhancing thecooling effect on the endless belt.(and thus ultimately on the tacky coating on sheet 10). While this is accordingly a highly advantageousarrangement, the basic advantages of the novel system of the presentinve ntion can still be attained with a conventional cooling fluid feed arrangement in tank 36.

Various modifications of the foregoing system are possible and practical within the spirit of the present invention. For example, as shown in FIG. 3, the endless belt-driven roll-idler roll combination can be completely eliminated by wrapping a length of material 50 similar to the woven cotton belt of the above-described apparatus completely around the peripheral face of a driven roll 52 so that the periphery of this roll is completely covered. This roll is then partly submerged in a water tank 54 (as driven roll 22 was in tank 36) so that material 50 absorbs water as it rotates. By elimination of the idler roll (which is not necessary in the system of FIG. 3), the coated web travels directly to the lower position at which final decorative additions are made i and final winding of the coated sheet takes place. This construction would be practical'where the sticking and cooling problems are not as great as those described above.

Another variation of the single roll wetting apparatus shown in FIG. 4, eliminates the need of passing the roll through a water tank. In this embodiment, the driven roll is hollow and has a porous peripheral face 62. A water inlet 64 and water outlet 66 are provided in the ends of the roll 60 with roll 60 being mounted in appropriate rotary joints permitting pressurized water ingress and egress as roll 60 rotates. Water or other cooling fluid applied to the interior of the driven roll 60 under pressure is forced through the porous face 62 of the roll 60 and wets the coated web passing over it to wet it, as in the previous embodiments discussed above. The volume and pressure of the water is controllable and variable so more or less water can be presented to the coated web. A drip pan 68 is provided to collect excess water which falls from the porous face 62 of the driven roll 60.

The preferred material for use in fabricating the endless belt 24 (or the corresponding absorbant surface used in the embodiments of FIGS. 3 and 4) is a cotton belting, an excellent form of such belting being a 2-ply Easton white solid woven cotton belting (endless net length square lap). 'Other absorbent materials can be employed, however, to obtain the benefits of thepresent invention.

Similary, while the present invention is particularly adapted for treating tacky coatings such as asphaltic or bituminous substances, the'novel process and apparatus previously described are adapted for use for a variety ofpurposes, including the manufacture or processing of butyl products, neoprene, polyvinyl chloride, reinforced or non-reinforced sheets or films and the like, wherever cooling and sticking problems of the nature previously described are encountered. And while the present invention has been described in connection with hot melt materials, tacky coating substances which are not heated may be similarly employed, in which case any heating means provided in tank 16 will be unnecessary.

A variety of web orsheet materials can be coated in the process and apparatus of the present invention. Exemplary of such materials are metal foils, rag and asbestos felts, paper and. plastic films, non-woven ans woven cotton cloths, wire meshes, fiberglass cloths, burlap cloths and the like.

In addition to advantages previously discussed, with the novel coating process and apparatus of the present invention, the necessity for applying talc powder to the web is eliminated. This reduces costs and does away with the unhealthy environment and the housekeeping problems caused by talc dust. The process of the present invention also improves the appearance of the product and facilitates laminating or bonding of other webs onto the coated webs.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment and processes are therefore to be considered in all aspects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and. range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

l. Apparatus for treating a continuous web of material which has been coated with a tacky substance characterized as generally adhering to both relatively warm and relatively cool surfaces while tacky, comprising: means for applying said tacky substance to said web of material; means for moving said coated web of material along a first path having an upward vertical component to permit said substance to dry at least partially and to lose at least a portion of its tackiness; means for changing the direction of travel of said web from said first path to a second path having a downward vertical component, said changing means including an absorbent surface intermediate said first and said second path positioned to contact said web of material and change the direction of travel of said web as said web is moved along said paths after said substance has dried at least partially and lost at least a portion of its tackiness,,said absorbent surface being capable of absorbing a fluid which prevents the adherence of said partially set tacky substance to said absorbent surface, and means for supplying said fluid to said absorbent surface which will prevent said coated sheet of material from sticking to said absorbent surface, said fluid supplying means comprising an endless loop which defines said absorbent surface and which is fabricated of a material capable of absorbing said fluid and transferring said fluid to said absorbent surface, means for containing a body of fluid to be absorbed within which at least a portion of said absorbent surface is immersed, and auxiliary fluid supply means for providing a second source of sprayed fluid to said absorbent surface and for replenishing the fluid in said body of fluid.

2. Apparatus as defined in claim 1 further including means for driving said endless loop in contact with said sheet of material so as to move said sheet of material along said paths.

3. Apparatus as defined in claim 1 wherein means are provided to spray said fluid to be absorbed on the radially inward surface of said endless belt.

4. Apparatus as defined in claim 1 wherein said auxiliary fluid supply means include means to spray said fluid to be absorbed on the radially inward surface of said endless belt.

5. Apparatus as defined in claim 1 additionally including means for spraying said fluid to be absorbed on the radially inward surface of said endless belt, said containing means being positioned relative to said endless belt so that fluid to be absorbed which drains off said endless belt will fall into said containing means.

Claims

1. Apparatus for treating a continuous web of material which has been coated with a tacky substance characterized as generally adhering to both relatively warm and relatively cool surfaces while tacky, comprising: means for applying said tacky substance to said web of material; means for moving said coated web of material along a first path having an upward vertical component to permit said substance to dry at least partially and to lose at least a portion of its tackiness; means for changing the direction of travel of said web from said first path to a second path having a downward vertical component, said changing means including an absorbent surface intermediate said first and said second path positioned to contact said web of material and change the direction of travel of said web as said web is moved along said paths after said substance has dried at least partially and lost at least a portion of its tackiness, said absorbent surface being capable of absorbing a fluid which prevents the adherence of said partially set tacky substance to said absorbent surface, and means for supplying said fluid to said absorbent surface which will prevent said coated sheet of material from sticking to said absorbent surface, said fluid supplying means comprising an endless loop which defines said absorbent surface and which is fabricated of a material capable of absorbing said fluid and transferring said fluid to said absorbent surface, means for containing a body of fluid to be absorbed within which at least a portion of said absorbent surface is immersed, and auxiliary fluid supply means for providing a second source of sprayed fluid to said absorbent surface and for replenishing the fluid in said body of fluid.