US2830326A

US2830326A - Art of extruding cork for the manufacture of bottle caps and the like

Info

Publication number: US2830326A
Application number: US360023A
Authority: US
Inventors: Weisenburg Andrew
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-06-08
Filing date: 1953-06-08
Publication date: 1958-04-15
Anticipated expiration: 1975-04-15

Description

April 5; 1958 A. WEISENBURG 2,830,326

' ART OF EXTRUDING CORK FOR THE MANUFACTURE OF BOTTLE CAPS AND THE LIKE 3 Sheets-Sheet 1 Filed June 8, 1953 INVENTOR April 15, 1958 A. WEISENBURG 2,330,326

ART OF EXTRUDING coax FOR THE MANUFACTURE OF BOTTLE CAPS AND THE LIKE 3 Sheets-Sheet 2 Filed June 8, 1953 IN VENTOR MAX 1 A TTOKNE Y5- April 15, 1958 A. WEISENBURG 2,830,326

ART OF EXTRUDING coRK FOR THE mumc'ruas 0F BOTTLE CAPS AND THE LIKE 3 Sheets-Sheet 3 Filed June 8, 1953 wm im III/l/II/IIIIII ATTORNEYS United SW68 a ent 0 ART OF EXTRUDING CORK FOR THE MANUFAC- TURE 0F BOTTLE CAPS AND THE LIKE Andrew Weisenburg, Langhorne, Pa.

Application June 8, 1953, Serial No. 360,023

8 Claims. (CI. 18-55) I This invention relates to a method for the manufacture of articles of granulated cork, particularly rods of cork from which bottle caps, seals, gaskets, packing rings and the like may be cut.

The invention will be described in connection with th production of rods to be cut into disks for bottle cap seals.

I am aware that this is a relatively old art. The processes and machines used therefor are slow in production, and produce rods of relatively short length, in consequence of which a large number of machines must be employed for a given production, with consequent high costs in equipment and in labor, etc. Moreover, generally speaking, the rods produced are not consistently uniform as todensity, which is an important consideration.

The chief objective of this invention is to make it possible to produce rods of comparatively great length, and at high speed, whereby it is possible to obtain large production with relatively few machines, at low cost in investment and in labor. I accomplish this objective while also securing a rod of improved uniformity as to the desired density.

Briefly stated, the preferred way of practicing the invention consists in mixing granulated cork with a binder which, when the mixture is subjected to heat and pressure, will unite the particles together; successively forming slugs of the cork and binder mixture, the amount of material in each slug being substantially the same; then forming the rod by successively forcing slugs through a long extrusion tube (or die or mold) of a construction permitting radial expansion of the mixture at progressive points or regions within the tube as it passes therethrough; heating the tube substantially throughout its length; and finishing or sizing the discharging end portion of the rod in a finishing or sizing tube where the rod is cooled.

This combination of steps results in a realization of the objective. To illustrate, by utilizing a long tube a plurality of slugs can be successively introduced into and forced therethrough; by providing a plurality of successive regions for progressive radial expansion, the rod being formed can be forced through the tube without the de- 55 velopment of unduly high frictional resistance or binding of the cork against the tube wall, as the cork swells during the heating operation. Thus great speed of rod production is possible While at the same time undesired densifying of the cork rod being formed, is avoided and the rod exits with uniform density of the desired degree. By heating the long tube substantially throughout its length, it is possible to secure the desired final setting (or polymerization or coagulation) of the binder, with low temperature, thus avoiding discoloration and charring of the cork. The latter is objectionable because it imparts a taste to the contents of the bottle. The heating of the long tube substantially throughout its length also makes it possible to secure the desired degree of final setting of the binder with low heat, despite the rapid progress of 0 the rod through the tube. Likewise, the lubricating properties of the binder are thereby more effectivelyrnade available during the passage of the rod through the tube,

ice

which again affects friction, speed and densification. By feeding in equal amounts of charge, a uniform rate of feed results and the temperature relationship set for a given speed, is not disturbed. Likewise the combination of the steps results in a bringing about of a state of equilibrium as hereinafter set forth, so that the finished product thereafter discharges with substantial uniform density.

Another objective of the invention is to facilitate the starting up of the rod-forming operation after shut-downs, as will hereinafter more fully appear.

The manner in which the method is carried out and typical examples of machines that may be used for the method will be apparent from the following description and drawings, wherein- Figure 1 is an elevational view partially in section, taken on the line 1-1 of Figure 2 illustrating a machine for carrying out the process;

Figure 2 is a plan view taken along the line 2-2 of Figure 1; I

Figure 3 is a view partially in section taken along the line 3-3 of Figure 1;

Figure 4 is a plan view partially in section illustrating another type of machine used to practice the method; and

Figures 5 through 10 illustrate the manner in'which slugs are formed and forced through the extrusion tube.

Referring first to Figures 1 and 3, the two banks of extrusion tubes are generally designated by the reference characters D and D, the cork and binder hopper by H, having downwardly extending legs h-l andh-Z, thelegs being secured to the frame F. The plungers are designated by the reference characters P and P, the support for the plungers by S, the piston rod for reciprocating the plunger holder and the plungers by C, and the hydraulic cylinder for actuating the-piston rod by C, the cylinder being secured to the frame F. The slug-forming mechanism is generally designated by the reference characters M and M, which is adapted to reciprocate from left to right as viewed in Figure l. The rod being extruded is designated by R.

It will be apparent that each tube has a plunger and a cork-feeding hopper leg associated therewith. All of the extrusion tubes are identical in construction and, therefore, description will be made only with reference to tube a shown in Figure 3. a v

The tube d is generally tubular in shape and is comprised of a plurality of threaded

tubes

1, 2, 3, 4 and 5, which are joined together by the couplings 6, '7, '8 and 9. Tube 5 is the finishing or sizing tube and has a diameter designed to give a rod of required cross-sectional dimensions. From an inspection of Figure 3, it will be apparent that the inside diameter of the tube is greater at successive points along the axis thereof. This is accomplished in the embodiment shown by using tubes of different diameter. Tube 1 has the smallest diameter, and the succeeding tubes become progressively larger. Tube 5 has the largest diameter and is designed to extrude a rod of the required dimensions. I The arrangement of the tubes as described permits radial expansion of the slugs or mass of cork and binder with progression along the extrusion tube. This feature is used in the control of the density of the formed rod. The tubes 2, 3 and 4 are equipped with heating coils 1t 11 and 12, which extend substantially throughout the length of the portions 2, 3 and 4. A single heating coil can be used. In the preferred embodiment, however, individual coils, individually controlled, are used, so that the amount of heat developed byeach may beindependently adjusted. The details of. the control system are not shown because such systems are well known to-. those skilled in the art. For example, in its simplest tome-a-ceilnsawbe conneeted to the source of power through a manuallyl operable rheostat.- The 'heat from the coils is used to set the binder. The setting gradually progresses until about the ti'rne the end of tube 4 is it is desirable te -nave tube 5 or slightly larger" diameter thanftube 4'.

Tube 5 is reterably cooled in any preferred manner as by roviding awater jacket wi'th inlet and outlet for cir- V to" reeeive' theplunger 203 Betwe'irthe 'top' an'd b'ottom plates of the frame are secured side'plates21'and'2'2; be tween which the slugforniing mechanisms M and' M are adapted to reciprocatel The mechanisms M and M are-identical in=construc tion and refernce will' be made onlywith respect to mechanism M, It is pointed out that these parts are adaptd-to reciprocatein unison by means of conventional mechanism not shown.

The' slug forming mechanism M is generally elongated and extendsbetweenthe plates 14- and 17 (Fi ure 1); while the sides bear on

endplates

21 and 22. meehanism'has a pluralityof bores or flasks which reciprocatebetwe'en an extrusion" tube and acork hopper. For ex'ainple', the flask 23"-(in th'eform of'a' tube) reciprocate's betw'cen -theimouth24'of'tube d and the'mouth 25 of QPprfle'g 26j'wh'ile the fla'sk' 27 reciprocatesbetweehfth'emouth 28 or hopper le -'29 and the mouth 24 of tube d5 i In the preferred"embodiment; the axes of the tubes D and D" and' the hoppers H" are arranged in a vertical plane as this facilitates the" fla'sk being filled 3 each time with'aii equal amount'of material. .Theplungers P and P"also rrio've'in -a' vertical plane and the slug-forming mechanism M' reciprocates in a horizontal plane.

The binder which I prefer to use is the thermosetting type} for example, gelatin; casein, albumen, urea, phenolic, alkyd or other resinous materials. Other binders may be used which will react tocoagulate the granules of cork together;

The-manner in which a"slugof cork and" binderis' formed and" forced through the extrusion tube will I be described in connection with Figures 1 and .Sthrou'gh 10.

Injth'e' operativeposition? of thernechanism, as seen The are filled" with a 'ma'ss ofcotk and binder. Thus, as

seen in Figure 5, when the flask 27 is I below" the "mouth 28o the ho per-reg, a-mas-s ot co'rkand' binder; which hasdi'opped" down fr'o'm the' hoppe'r le'g 29, is disposed therein: Thememb'er-Mthen moves tothe right'between thep'lates" l'4 and 17, resultin'g'in a slu'g 30 being posi tionedatfthe mouth 24' orthetube (seeFiguie 6) The plunger'20is then moved-upwardly tomove the slug into the'tu'be '1. As will be 'apparentfrom' Figure 7, theslug 3U is=- compressed asit is rr'ioved into the" tube 1 by the plunger 26. The plunger 26is then retracted'fr om the" the'right againwithj the charges in position to be again operatedupon by the p'lhn'gers; The plungers then move upwardlyand the" second slug-31 is thenforr'ned in the tube beneatlitlfe' slug @0, advancing the slug along 7 the'tiibe The operation is then repeated and a new charge brought inposition, as illustrated in Figure 10.

These"o eratinns continueuntil theentire length of the" Assuming that the empty machine is started up, the operation goes on as .2 above described and thetube Vbe= comes filled. The leading portions of the rod being extruded from the tube 5 will be useless until equilibrium conditions are reached within the tube. These equilibrium conditions will obtain when the tube has been filled once and the lowermost slug portion reaches the top, and when the filledtube has again been filled and the-lowermost slugportion'hasreached the top. From then on; there will be equilibrium and the rod will discharge with uniform density.

It will, ofcou'rse; be understood that the contents of the hoppers-are kept ina free-fiowingcondition as by stirring, as is well understood in this art. Thus, there will be no hang upand each flask'will always be filled with an equal amount of cork mixture when the flasks are in charge receiving position.

While the rod is being formed and forced through the extrusion tubes; heat is applied as b'efo're described:- for substantiallythroughoutthe'length'of the tube. Hence; in" portion-22. of the tub'es sorn'e' expansion will take-place for which reason such portion of the tubesis somewhat larger-in diamete'r 'thair the portion 1. Similarly portion 3 of the tubeis somewhat larger in diameterthan p'ortion" 2, portion4 of the extrusion tube is greater than portion 3, and'po'rtion 5is 'soniewhat'greater than portion 4. Thus, asthe rod is being formedand moves through the ex t'rusio'ri' tubes andbecbms hotter and'hotter, rovisien is madefonradialexpansion insuc'cessive regions,f each of somewhat 'la'rger' diameter, thus allowing for the swell ing whicho'ocur's'during the heating; thus avoiding objectionable' friction resistance which would produce'an undesrr'eddegree ofcor'npacting andenabling the cooling portion"to act a's th'e final sizingmemberand"ensuring that the rod-will discharge with the particular density" desired and with unifbr'mity 'of such density; A's pre viously pointed out, when the equilibrium conditions whichdetermine the ultimate density are reached,- fro'tn then on the rod being formed will be of substantialunh formity as to density. By variation of the amount of expansion permitted or the length of the tube portions;

or'both, control of the ultimate density obtained is made possible:

While; as indicated; there maybe some variation" in diameter and alsoin the length of the respective portions per minute, of a 1 inch diameter rod, having desirable density cliar'acteristicsl The flasks in such instance would be about 6" long and of 0.9375" 1. D. The portionsof the-extrusion tubes would be of the following dimen-- Tube 1, 0193751. 1):, 3-9 long Tube 2, 10000 I. D., .15 long Tllbe 3, 1 .03101; D., 15" long Tube 4, 1.0520 1. D., l 5'long Tube 5, ll0625 I. D., 6-15" long One foot per minute is a-relatively quite high rate of extrusion as compared to present practice, and by my in ven'tion it is possible; to even substantially exceed one foot per minute'without impairing of. the results; To

obtaina given density; if the strokes per minute be increased then the length of the tubes is correspondingly increased, and vice versa, if the strokes be decreased then the length of'the'tubesis decreased.

The portion 1' of the'tubenecd only be long enough to ensure'that the slugintroduced therein is sufiiciently compacted to ensure no flowing back of the material. Uually-froni3 to 9 inches of length are sufficient-for the purpose.-

It will be seen that the process :is such that high rates of production can be obtained, which means that such production can be obtained with much fewer machines than heretofore required for such production.

Rods may be extruded anywhere from to to 30 feet or longer, as desired.

Ordinarily I may operate at a temperature of from about 300 to about 350 F., but I prefer to operate at a temperature of about 330 R, which are relatively low temperatures.

When following the process herein described, I find that I do not have to change the cork and binder mixture as is frequently required in conventional practice. This enables me to make up relatively large batches of cork mixture which will last for an appreciable period of time before being used up.

An alternative type of machine which may be used to practice the invention is shown in Figure 4. This is a rotary type apparatus having hoppers H-2 and tubes D4. The plate 33 carrying the flask 34 is adapted to move relative to the hoppers and tubes. The plate 33 may rotate continuously relative to the hoppers and tubes or the motion may be reciprocatory.

With either of the above described types of machines, conventional mechanism to coordinate the motion of the plungers and slug-forming mechanism is provided. Such mechanism may take a variety of forms. No particular mechanism is shown, as such apparatus is well within the purview of those skilled in the art.

While I have shown two embodiments of apparatus for practicing the method, it will be apparent that other types of apparatus may be used.

When starting up cork extruding machines after, say;

overnight shutdowns, it is sometimes quite diflicult to dislodge the cork left in the tubes. I have discovered quite surprisingly that if the temperature be increased for some period of time at shutdown or before starting, no particular difiiculty is encountered in starting. To this end, I raise the temperature and heat for a suflicient length of time so that the mixture remaining in the tube will be set. Once the mixture remaining within the tubes is set, it can readily be discharged upon again starting up the machine. As illustrative, I may raise the temperature above normal operating temperature about 25 F. for a period of about 4 or 5 minutes.

While I have described and claimed the invention in relation to rods, it will be understood that the invention is not specifically limited thereto. It will also be seen that in certain aspects the invention is broader than the preferred procedure set forth.

I claim:

1. The method of continuously extruding a mixture of granulated cork and thermosetting binder in the form of a rod comprising the steps of: sequentially forming slugs of the mixture each having the same volume and the same cross-sectional area; and forming a rod therefrom by pressure moving the slugs one after another into and through at least three sequentially serially arranged heated binder-setting rod-forming stages in each of which the rod has a cross-sectional area slightly greater than it has in the immediately preceding stage.

2. The method of continuously extruding a mixture of granulated cork and thermosetting binder in the form of a rod comprising the steps of: sequentially forming slugs of the mixture each having the same volume and the same cross-sectional area; forming a rod therefrom by pressure moving the slugs one after another into and through a multiplicity of sequentially serially arranged heated rod-forming stages in each of which the rod has a cross-sectional area slightly greater than it has in the immediately preceding stage; and cooling the rod in the last stage.

3. The process of claim 2 characterized by that the rod is heated in at least three of said stages.

4. The method of continuously extruding a mixture of granulated cork and thermosetting binder in the form of a rod comprising the steps of: sequentially forming slugs of the mixture each having the same volume and the same cross-sectional area; forming a rod therefrom by pressure moving the slugs one after another into and through an extrusion tube; heating the rod being formed for a substantial portion of its length to set the binder; allowing the rod to radially expand in a plurality of successive regions lengthwise of the tube; and cooling the last portion of the rod about to discharge from the tube.

5. The method of continuously extruding a mixture of granulated cork and thermosetting binder in the form of a rod comprising the steps of: pressure feeding the mixture to and through a rod-forming extrusion tube; heating the rod being formed for a major portion of its length in the tube to set the binder; allowing the rod radially to expand in cross-sectional dimension in successive regions of the length being heated, progressively larger for each succeeding region in the direction of travel; and cooling the portion of the rod about to discharge from the tube.

6. The process of claim 5 characterized by that the desired density of the rod leaving the tube is obtained by controlling the amount of expansion in the said regions.

7. The process of claim 6 characterized by that de-. sired density of the rod leaving the tube is obtained by controlling the amount of expansion in the said regions and by controlling the length of said regions.

8. In a method of extruding a rod formed from a mixture of granulated cork and a thermosetting binder, the steps comprising: filling a flask with said mixture through an end thereof at a filling station to form a charging slug, transferring said flask to a discharge station at which said slug is aligned with the end of a die tube and with a packing plunger, reciprocating said plunger through said flask and well into said tube to compress said slug against a previously deposited slug in a position far enough from said end to insure against rebound of said slug into said flask, repeating said operations to provide a flow of said mixture through said tube, and heating said tube to set said binder, and characterized by the application of heat to a pluralityof zones along the length of said tube, and by the radial expansion of said mixture in said zones.

References Cited in the file of this patent UNITED STATES PATENTS 1,453,617 Bond May 1, 1923 1,711,962 Nagy May '7, 1929 2,307,055 Menger et a1. Ian. 5, 1943 2,477,258 MacMillin July 26 .1949 2,560,491 Smith et al. July 10, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,830,326

Andrew Weisenburg April 15, 1958 It is hereby certified that error appearsv in the printed specification oi the abovenumbered patent requiring correction end that the said Letters Patent should read as corrected belo Column 6, line 36, for the claim reference numeral "'6" read-,- 5

Signed and sealed this 27th day oi May 1958.

(SEAL) Attest: KARL 3;, AEINE Attesting Officer ROBERT C. WATSON Comissioner of Patents