US3383054A

US3383054A - Coating nozzle

Info

Publication number: US3383054A
Application number: US657425A
Authority: US
Inventors: Anthony R Nugarus
Original assignee: Crompton and Knowles Corp
Current assignee: Crompton and Knowles Corp
Priority date: 1967-07-31
Filing date: 1967-07-31
Publication date: 1968-05-14
Anticipated expiration: 1985-05-14

Description

y 14, 1968 v A. NUGARUS 3,383,054

COATING NOZ ZLE Original Filed May 28, 1965 3 Sheets-Sheet l INVENTO R ANTHONY R. NUGARUS 34 Quad ATTORNEYS May 14, 1968 A. R. NUGARUS COATING NOZZLE 3 Sheets-Sheet 2 Original Filed May 28, 1965 FIGS FIG-IO Bla INVENTOR ANTHONY R. NUGARUS ATTORNEYS y 14, 9 8 A. R. NUGARUS 3,383,054

COATING NOZZLE Original Filed May 28, 1965 3 Sheets-Sheet 5 INVENTOR ANTHONY R NUGARUS ATTORNEYS United States Patent 3,383,054 CGATING NOZZLE Anthony R. Nugarus, Chicago, Ill., assignor to Crompton 8; Knowles (Iorporatiou, Worcester, Mass, 21 corporation of Massachusetts Continuation of application Ser. No. 459,660, May 28, 1965. This application July 31, 1967, Ser. No. 657,425

11 Claims. (6]. 239-597) This is a continuation of application Ser. No. 459,660, filed May 28, 1965 now abandoned.

This invention relates in general to a coating nozzle, and more particularly to a nozzle for handling a high viscosity and high pressure and temperature coating material, and still more particularly to a nozzle for defining and creating a thin film of coating material for application to articles to package the articles, although other uses and purposes may be apparent to one skilled in the art.

The nozzle of the present invention is particularly useful in a packaging machine that is used to apply a protective airtight film or sheet of coating material to articles, wherein the material for creating the film is solid or hard at normal room temperatures or predetermined temperatures and a highly viscous liquid at ele vated temperatures. Articles to be coated are normally placed on a conveyer that is capable of conveying the articles through a coating zone within which are located one or more of the nozzles of the present invention. These nozzles are capable of defining and applying an imperforate coating of material of predetermined thickness to the articles passing through the coating zone.

Heretofore, nozzles have been employed for defining thin films of coating material for packaging, but such nozzles have not been capable of efiiciently handling the coating materials available which are highly viscous liquid at elevated temperatures, and which must be discharged from the nozzle at high pressures and temperatures. For example, a coating material may have a viscosity of from between 100 and 100,000 centipoises at a temperature of between 150 and 500 F., while being discharged from a nozzle at a pressure of from 250 to 5,000 pounds per square inch. Further, the nozzle for handling such materials must be non-clogging and must be capable of defining a properly dimensioned film or sheet of material.

Accordingly, it is an object of the present invention to provide a new and improved nozzle for use in packaging machines to apply thin sheets or films of coating material to articles.

Another object of the present invention is in the provision of a coating nozzle capable of operating efiiciently and without failure under a varying range of temperature and pressure and of handling highly viscous liquids.

Still another object of this invention resides in the provision of a coating nozzle that is particularly useful for creating thin films or sheets of coating material wherein the material is forced through the nozzle at pressures of between 250 and 5,000 pounds per square inch at temperatures of between 150 and 500 F. and having a viscosity up to 100,000 centipoises.

A further object of this invention is to provide a coating nozzle for use in creating thin planar sheets of coating material and for creating a precisely dimensioned sheet of material for any particular application.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a diagrammatic view of a coating machine Patented May 14, 1968 illustrating the use of coating nozzles for coating articles passing along a coating zone on a conveyer;

FIG. 2 is a perspective view of a coating nozzle according to the present invention;

FIG. 3 is a perspective view of the coating nozzle of FIG. 2 taken from another side;

FIG. 4 is an exploded perspective view of the nozzle of FIGS. 2 and .3;

FIG. 5 is a side elevational view of the nozzle shown in FIGS. 2-4;

FIG. 6 is a top plan view of the nozzle of FIG. 5 showing some underlying parts in phantom and omitting other parts;

FIG. 7 is a top plan view of the nozzle head and illustrating the position of a shim;

FIG. 8 is a top plan view of the nozzle with the head removed and looking along line 8-8 of FIG. 5;

FIG. 9 is an axial sectional view taken through the nozzle of FIG. 5;

FIG. 10 is a side elevational view of a modified shim that is thicker at the discharge end;

FIG. 11 is a side elevational view of a modified nozzle according to the invention;

FIG. 12 is a top plan view of the nozzle of FIG. 11 showing some underlying parts in phantom and omitting other parts;

FIG. 13 is a top plan view of the nozzle head of FIG. 11 and illustrating the position of the shim arranged between the body and head;

FIG. 14 is a top plan view of a further modified nozzle in accordance with the invention; and

FIG. 15 is a side elevational view of the nozzle of FIG. 14.

Referring now to the drawings, and particularly to FIG. 1, the use of the nozzle of the present invention is illustrated in a film packaging machine generally designated by the numeral 10 which includes a pair of

endless conveyers

11 and 12 arranged to move articles 13 along a rectilinear path within a coating chamber. The article to be coated in the illustration is relatively rectangular in shape and includes six sides, front, back, top, bottom and opposed, all of which are desired to be coated, However, it will be appreciated that some articles may only demand a coating along one side and the nozzle arrangement will be accordingly set up. As shown, a first nozzle 14 defines a film 14a issued laterally of the conveyer and at 'a slight angle to cover the one side and back of the article. A second nozzle 15 is arranged to cover the front side of the article. A bottom coating nozzle 16 is arranged below the conveyers and defines an upwardly directed film 16:: which passes up through the space between the

conveyers

11 and 12 to coat the bottom of the article. A top coating nozzle 17 issues a film 17a from above the conveyer for coating the top side of the article.

Further nozzles

18 and 19 issue films 18a and 19a for coating the opposite sides of the article. Thus, with the arrangement shown, all sides or surfaces of an article can be effectively coated by nozzles according to the present invention.

The coating nozzle, generally indicated by the numeral 20, in the illustrated embodiment of FIGS. 2-9 includes generally a body 21, a head 22, and a shim 23. The shim is sandwiched between the body and head when the nozzle is in assembled condition.

The body 21 is provided with an opening or fluid channel 24 that is adapted to be connected at the end 24a to a source of high pressure heated coating material, and is provided at the other end with an orifice opening or inlet orifice 24b. The orifice opening 24b opens through a control surface 25 that extends angularly relative to the axis of the opening 24. The angle between the axis of the opening 24 and the control surface 25 may be defined as the deflecting angle and is indicated in FIG. 5 by the numeral 26. This angle may be between 100 and 150, but is preferably about 125. The orifice opening 24b is flared at 240 in the direction of material movement to facilitate the deflection of the material toward the discharge open ing of the nozzle. The surface 240 is formed along a radius 24cr of between /4 and inch, this surface being blended into the passageway and control surface. Looking at FIGS. 7 and 8, the surface 240 is blended laterally into the opposite sides of the orifice 2412. Such provides better distribution and flow of the coating material with less turbulence.

The coating materials employed may have a viscosity of between 100-60,000 centipoises with a temperature of IOU-500 F., and under a pressure of 250-1000 pounds per square inch. Moreover, the coating materials may be transparent or opaque, and are preferably non-exuding, non-toxic, and highly cohesive in nature. Further, the materials are preferably of a type that may be easily removed and/or stripped from an article receiving such a coating. L

The coatings possess a high degree of flexibility or pliability and resilience while being tough and hard at room temperatures. Such coatings are termed hot melt coatings on todays market, and may actually constitute wax blends, polyethylenes, cellulosic blends and like materials.

The body 21 is threaded at the end of the channel identified as 24a, the threading being indicated by the numeral 27, for the purpose of connecting the nozzle to a suitable fitting and a supply of pressurized coating material.

The shim 23 has an outer peripheral configuration substantially coextensive with the surface of the body 21 upon which it is positioned, and includes a relatively V- shaped cutout 28, thereby defining opposed arms 2) and 30 interconnected by a bight portion 31. The V-shaped cutout 28 includes opposed diverging surfaces 28a and 28b interconnected by an arcuate surface 280, the latter extending substantially coextensive with the back side of the orifice opening 24b. The outer ends of the

arms

29 and 30 terminate along the discharge end 25a of the control surface 25, this control surface being limited by the surfaces 28a and 28b of the shim 23.

The head 22 of the nozzle includes a flat surface that engages over the shim 23 and defines a deflecting surface 32 for spreading or deflecting the coating material coming through the orifice opening 24b. This deflecting surface is defined by the V-shaped cutout 28 of the shim. Otherwise, the flat surface of the head is equal in dimension to the upper surface of the body 21.

In order to maintain the head, shim and body in assembled relationship, tapped holes are provided in the body for receiving cap screws 33 which also extend through holes formed in the shim 23. When the head, shim and body are in assembled relation as shown particularly in FIGS. 5 and 6, they coact to define a liquid spreading channel and a discharge opening or orifice 34. The thickness of the orifice is dependent upon the thickness of the shim, and it has been found that the thickness must be at least .020 inch and preferably .030 inch. The thickness of the shim 23 is generally uniform throughout, and the deflecting surface 32 of the head extends parallel to the control surface 25 of the body. The spreading faces or surfaces 280 and 28b of the shim preferably extend substantially perpendicular to the control and deflecting surfaces.

A modified shim is shown in FIG. and generally designated by the numeral 23A, "and which is thinner at the bight portion 31a than at the terminal ends of the arms. This shim is evenly tapered from the bight portion end to the discharge end, and preferably at a 2 to 1 ratio. One satisfactory shim would have a .015 inch thickness at the bight portion end and a .030 inch thickness at the discharge end. Such a shim enables lowering of the pressure in one instance for one coating material while providing proper formation of the film.

The terminal ends of the body 21 and the head 22, the

first being designated by the numeral a and the second by the numeral 32a, are arcuate in shape and coact With the orifice opening 24b to control the discharge characteristics of the nozzle. These edges must also be sharp to provide a proper film. Increasing the distance between the orifice opening and the arcuate terminal edges will normally permit the defining of a longer film or sheet of coating material.

As seen in FIG. 7, the angle 35 between the surfaces 28a and 28b of the shim controls the spread of the material as it leaves the discharge opening 34 of the nozzle. Preferably, this angle should be about although it may vary between 20 and 90 depending upon the size of film or sheet or material desired. Moreover, it is preferable that the distance from points along the

arcuate edges

25a and 32a to the points along the edges of the channel 24 be substantially equal.

In order to accommodate the highly viscous coating materials at the contemplated high pressures, it is necessary to reduce the friction between the material and the parts of the nozzle head to an absolute minimum. Accordingly, the control surface 25 of the body and the deflecting surface 32 of the head are provided with an extremely fine finish. These surfaces are chromeplated and then ground and lapped to a finish of between 2 and 4 niicroinches. The shim is finished with good flat surfaces to provide a properly sealed assembly so that no leakage exists between the shim and the body and head.

Moreover, the finish of the opening in the body constituting the orifice opening, and particularly the flared surface 240, should also be machined to a finish to about 2-4 microinches. In any event, this finish and the other finishes should be less than 32 microinches in order for the nozzle to properly operate. As already mentioned, to obtain the proper surface finish, the finishes are chrome plated, ground and then lapped. While the fine surfaces reduce the friction of the material sliding therealong, they also provide a smoother and more even coating of material on the articles to be coated, and enable better thickness control of the coating.

Referring now to FIGS. 11, 12 and 13, a modified nozzle is shown and generally indicated by the numeral 20A. This nozzle includes a body 36, a head 37 and a shim 38, and differs from the embodiment of FIGS. 29 in that the control surface 39 and the deflecting surface 40 are much longer, and further in that the material passageway or channel 41 is venturi-shaped. Otherwise, the nozzle is the same including the finish on the parts. The characteristics of this nozzle will differ primarily in that a longer film will be developed.

Referring now to the embodiment of FIGS. 14 and 15, the nozzle therein shown is generally indicated by the numeral 45 and includes a body 46, a head 47, and a shim 48 assembled in the same relation as the parts in the other embodiments. This nozzle differs primarily in that the liquid passageway or channel 49 leading to the orifice opening 49a is supplied with the coating material by means of a transversely extending passageway 50 arranged in the body .6. Threaded

nipples

51 and 52 extend from opposite sides of the body 46 for connection to suitable fittings to supply coating material to the nozzle. Either or both nipples may be employed, and wherein one nipple is employed, the other would be closed off.

This nozzle is especially suitable as a bottom coating nozzle to be arranged for coating the bottoms of articles transversing the spacing between the

conveyers

11 and 12 and to be employed in the approximate position of the nozzle 16. Otherwise, the operation of the nozzle is substantially the same as the other embodiments and the finishes on the surfaces controlling the deflection and spread of the material are also of the same quality.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A nozzle for coating articles comprising a body having an inlet and a discharge orifice, said discharge orifice being defined by a pair of substantially parallel fiat surfaces and a pair of opposed diverging surfaces between said fiat surfaces and extending substantially perpendicular thereto, all of said surfaces terminating coextensively to define said discharge orifice as an arcuate slot, a passageway between said inlet and said parallel surfaces and extending at an angle thereto of between 125 and 150 degrees, said passageway opening through one of said flat surfaces and opposite the other of said flat surfaces and defining therewith an inlet orifice, and said inlet orifice being spaced from said discharge orifice and being flared on the side adjacent the discharge orifice to enable better fiow between the passageway and the area between said parallel fiat surfaces.

2. The nozzle of claim 1, wherein the angle between said diverging surfaces is between and degrees.

3. The nozzle of claim 1, wherein the finish on said fiat and diverging surfaces is not greater than 32 microinches.

4. A nozzle for coating articles comprising, a body, a head and a U-shaped shim sandwiched between said body and head, said body having a control surface and said head having a deflecting surface opposed from said control surface in substantially parallel relationship and coacting with the shim to define a film, said shim having a bight portion and a pair of arms interconnected at said bight portion and diverging therefrom with an angle therebetween of about sixty degrees, said shim arms and surfaces terminating coextcnsively to define an arcuate slot serving as a discharge orifice, a passageway extending through said body and opening through said control surface to define an inlet orifice adjacent the bight portion of said shim and being arranged so that the surfaces are inclined upwardly from the axis of the passageway and at an angle relative thereto between and degrees, and said inlet orifice being flared on the side adjacent the discharge orifice to enable better flow bet-ween the pa sageway and the area between the said control and deflecting surfaces.

5. The combination as defined in claim 4, wherein said surfaces have a finish not greater than 32 microinches.

6. The combination as defined in claim 4, wherein said surfaces have a finish of 2 to 4 microinches.

7. The combination as defined in claim 4, wherein said shim has a thickness of at least .020 inch.

8. The combination as defined in claim 4, wherein said shim is uniform in thickness throughout its length.

9. The combination as defined in claim 4, wherein said shim is tapered from the free ends of the arms to the bight portion.

10. The combination as defined in claim 4, wherein the thickness of the shim at the bight portion is about /2 the thickness at the terminal ends of the arms.

11. The combination as defined in claim 4, wherein said shim is gradually thickened from the bight portion end to the terminal ends of said arms.

References Cited UNITED STATES PATENTS 900,869 10/1908 Murphy 239-597 1,718,556 6/ 1929 Harrison 239-597 FOREIGN PATENTS 269,313 2/ 1966 Australia. 573,538 2/1958 Italy.

EVERETT W. KIRBY, Primary Examiner.

Claims

1. A NOZZLE FOR COATING ARTICLES COMPRISING A BODY HAVING AN INLET AND A DISCHARGE ORIFICE, SAID DISCHARGE ORIFICE BEING DEFINED BY A PAIR OF SUBSTANTIALLY PARALLEL FLAT SURFACES AND A PAIR OF OPPOSED DIVERGING SURFACES BETWEEN SAID FLAT SURFACES AND EXTENDING SUBSTANTIALLY PERPENDICULAR THERETO, ALL OF SAID SURFACES TERMINATING COEXTENSIVELY TO DEFINE SAID DISCHARGE ORIFICE AS AN ARCUATE SLOT, A PASSAGEWAY BETWEEN SAID INLET AND SAID PARALLEL SURFACES AND EXTENDING AT AN ANGLE THERETO OF BETWEEN 125 AND 150 DEGREES, SAID PASSAGEWAY OPENING THROUGH ONE OF SAID FLAT SURFACES AND OPPOSITE THE OTHER OF SAID FLAT SURFACES AND DEFINING THEREWITH AN INLET ORIFICE, AND SAID INLET ORIFICE BEING SPACED FROM SAID DISCHARGE ORIFICE AND BEING FLARED ON THE SIDE ADJACENT THE DISCHARGE ORIFICE TO ENABLE BETTER FLOW BETWEEN THE PASSAGEWAY AND THE AREA BETWEEN SAID PARALLEL FLAT SURFACES.