US3104599A - Fiber drum and its method of formation - Google Patents

Description

Sept. 24, 1963 H. CARPENTER, SR 4599 FIBER DRUM AND ITS METHOD OF FORMATION Original Filed Oct. 1. 1958 5 Sheets-Sheet 2 Sept. 24, 1963 H. 1.. CARPENTER, SR 314599 FIBER DRUM AND ITS METHOD OF FORMATION Original F iled Oct. 1. 1958 5 Sheets-Sheet s Sept. 24, 1963 H. 1.. CARPENTER, SR

FIBER DRUMAND ITS METHOD OF FORMATION 5 Sheets-Shet 4 Origin al Filed Oct. 1, 1958 INVENTOR Sept. 24, 1963 H. L. CARPENTERSR 3104,599

FIBER DRUM AND ITS METHOD OF FORMATION Original Filed 0ct. 1, 1958 5 Sheets-Sheet 5 Unted States Patent O 3,104,599 FIBER DRUM AND ITS METHOD F FRMATON Herbert L. Carpenter, Sr., Amityviie, N.Y., assignor to The Greif Bros. Cooperage Corporation, Delaware, Ohio, a corporation of Ulrio Original applicaton Qct. 1, 1958, Ser. No. 764,610, now Patent No. 3,G42,283, dated July 3, 1962. Divitled and this appiieatien June 19, 1961, Set. No. 127,885

8 Claims. (Ci. 93-55.1)

This application is a division of my application Serial No. 764,610, filed October 1, 1958, which has issued as Patent No. 3,042,288, dated July 3, 1962.

This invention relates t an improved fiber drum as well :as its method of fabrication, and is a continuationinpart of my application Serial Number 589,025, filed Iune 4, 1956, now abandoned.

Fiber drums and similar containers are usually made from convolutely wound 01 spirally wound iaminated layers of fibrous material, such as kraft paper. They are generally used for shipping and storing a variety of materials and -articles, as for example, raw materials, bulk chemicals, munitions, sensitive instruments including electronic tubes and the like.

These fiber drums and containers are frequent-iy subjected to rough handling especially during their period of use. In this connection, they may be dropped from the tailboard of a truck or from a shipping plat-form, and may even have ether containers and articles dropped upon them in shipping. In addition, loaded containers are frequently stacked one upon another, thereby placing an additional stress upon their walls, particularly those of the lowermost containers. Under such circumstances, fiber drums and containers must be of strong, sturdy construction and capable of withstanding the abuse to which they are subjected in shipment and storage.

Many of the cylindrical ioers drums and containers, having transversely circular cross-sections, as heretofore available, have been sufliciently strong to withstand this use and abuse. However, these cylindrical drums and containers have the inherent disadvantage that they are uneconomic in their space requirements. T1US, in their shipment and storage there is necessarily =a considerable amount of waste space between the cylindrioal sides of adjacent drums, which is multipliecl as these drums are stacked one upon another. In addition, an appreciable arnount of waste material results from the manufacture of the bottom closures and head for such fiber drums and containers.

Non-cylindrical containers having a plurality of sides, as for instance -rectangular containers, are efiicient in their utilization of shipping and stora-ge space, since they may be placed in contiguous relationship with minimum space wasted between their sides. However, ether dificulties and disadvantages are encountered with containers having this substantially rectangular configuration. 'Ihus, fiber containers having straight rectangular sides do not possess sufiicient strength to -withstand the use and abuse normally encountered during the contemplated shipment and storage. In this connection, there is a tendency for the-sides of these rectangular fiber containers to become transversely concave and to collapse inwardly When subjected to stresses and strains imparted and experienced under such conditions. Fur-thermore, because of the developed concave contour of the sides, it is extrernely dificult to maintain a ti ht seal het-ween the head or closure md the body of the container, with the result that there is a danger of content contamination and, additionally, inevitable sifting and loss of certain types of container content. Dfliculty -l1as also been encountered in winding and fabricating rectangular fiber shells, in that, the fiber 2 is frequently rnutilated or damaged, thereby weakening the finished shell wal].

Accordingly, it is -an object ofmy present invention to overcome the dificulties heretofore encountered in the fiber drum and container field and, accordingly, provide an improved fiber drum which is rugged and strong so that t can withstand the stresses and strains encountered in shipment and in storage; which is eflicient in the utilization of space and minimizes waste s=paee between the sides of adjacent drums in storage and shipment; and which, at the Same time, reduces the waste of material in the rnanufacture of c1osures and heads efo-r such drums.

Other objects of my invention include the provision of a fiber drum having a plurality of sides and its method of formation wherein such drum may |be rendered avail- :able in a wide range of sizes; wherein this drum provides up te 20 to 25% greater cubic capacity per unit of space requi=red for shipping or storage; wherein the drum is readily opened and elosed and easy to seal as well as reseal; wherein the drum has a ull open top facilitating the filling and dispensing of its contents; wherein the drum is adapted to include many protective linings, barriers and coatings suitable for the shipment and storage of hygroscopic, deliquescent and sensitive products; Wherein the drum may have interlinings tand barriers as well as a lined interior to provide protection and moisture vapor resistance; wherein such drums are well suited for supply in multiple strapped units thereby reducing shipping and handling charges; wherein the drum provides for easy nesting to conserve sto-r-age and shipping space; and wherein the drum is so constructed and arranged that it wil-1 nherently minimize any detrirnental effects of container breathing due to changes in the ambient.

Another object is a provision of a fiber drum having a plurality of sides, preferably tour, which is sturdy and streng so that the sides will not collapse When subjected to the wear and tear encountered in use and which anay be readily provided with an effective head and closure.

Still another object is a drum having convex sides and rounded corners with a similarly shaped slip-over cover, botl1 of which are si-rnilarly constructed trom convolutely wound fibrous material with the cover effectively embracing the periphery of the open end of the container even When subjected to extreme conditions of use tand abuse.

A further object is to provide an improved method for making fiber drums possessing the aforementioned superior characteristics.

Other objects and advantages will -become apparent from the =following desoripton of my invention which is to be taken in conjunction with the accmpanying drawings in which:

BIG. 1 is a perspectve view illustrating drums fabricated in accordance with my invention and which will prove to be helpful in better understanding the present invention as wel-l as its many salient features;

FIG. 2 is a perspective view of an uncut shell of fibrous material which is either convol-utel-y or spirally wound layers suitab-ly shaped aby means of :a winding mandrel;

FIG. 3 is a perspective view of the shell illustrated in FG. 2 after it has been subjected to a su-itable Cutting operation -to provide shells having reduced predetermined lengths;

E16. 4 is a schematic sectional view of a cut shell on a support prior to "the securement of a closure di-sc at one errd thereof;

FIG. 5 is a perspeetive view illustrating the cut shell in its initial stage of deformation during the disc securement cycle;

FIG. 5A is an enlarged sectional view more cleariy illustrating the comer crease production during this shell deformation;

FIG. 513 is similarly a sectional view illustrating the approxim:ate configunation of the crease onmed at; each of the corners f the defo=rmed shell of FIG.

FIG. 6 illustrates the final defornration stage of the partiaily deforrned shell of FIG. 5 to effect the desired surfaceto-surface contact of this shell with the internally positioned dise;

FIG. 6A is a partiai sectionai view of the -defiormed shell of FIG. 6 more clearly illustrating the securement of this shell with its disc;

FIG. 7 is a perspective view illustrating the np=plica tien of staples to more securely unite the disc with tle deformed zones of the cut shell;

FIG. 8 is en exploded perspective view illustrating the members employed in completing the formation of the shell end elosure;

FIG. 9 illustrates in seetion the disposition end secureme1rt of the rnembers illustrated in the preceding view to effect the desi-red end elosure;

FIG. 10 is an exploded perspective view of the finished shell together with a similarly wound 1iner prior to the insertien of the latter within the shell;

FIG. 11 is a perspective view of this line: properly mounted in the finished shell;

FIG. 12. is en exploded perspeetive view of the finished shell having an inner liner along with a telescopically slidab1le cover which is finished in a menner substantially simiiar to that of the shell =and With the inclusion of a liner to be interposed and located in the juneture -between the =e0ver and sheli liner;

FIG. 13 is a sectional view of the assembled components illustrated in FIG. 12;

FIG. 14 is a rag-mentary sectional view of the base of a drum body which may have incorp orated therein a suita-ble gasket to afiect a superior seal between the liner and the bottom closure assembly of the outer shell;

FIG. 15 is a duel compartmental drum incorporating rthe teaehings of my invention with certain parts breken away and sectioned and also with parts of the end closures removed for larity;

FIG. 16 is a longitudinaal sectional view of a completely sealed drum having =a plurality of liners and barriers and other applieatons for eeeting a superior hermetieally sealed condition for this drum with certain parts breken away arid =removed.

In earrying out my invention, I have found that a fiber drum which is efieient in i:ts use of space, and at the same time is sturdy and streng, 08.11 be obtained by orrning the body of fiche drum with a plurality of sides, prefenably four, which are transversely =con vex and are connecxted together by rounded corners. Furthermore, a drum cover embodying the same principles and similar menu;fiacturing techniques would naturally Ibe desirable and unction to supplement the superier drum char-acteristics as well as inherently reduce the cost of the entire drum construction.

A reprresentative number of fiber drums embodying my invention are shown in FIG. 1 and will serve te illusrate the many features supplied by this invention to the fiber drum art. Thus, in this view a series of sueh drums, each having iour arcuate sides and rounded corners connecting the sides, are arranged to -render numerous of the aforementioned object-s and advantages, 1among others, readiiy apparent. It should be understood at this time that drums having dfi'erent numbers of sides may also be made by 1adopting the principles of my invention, and accordingly be eflcient=ly stored in contiguous relationship and possess the optimum characteristics of the illustrated drums. Bach o f the sides of any drums are transversely convex so that the sides bow outwardly. By orming the sides in this marmer, I eliminate the tcn-dency of the sides, as en a rectangular fiber drum, te bow inwardly and thus collapse. This greatly increases the strength of the drum body or shell by attenuating and properly dis tributing -appiied orces and, in addition, assure a ti.ghter fit and se-al between the drum shell and its olosure. 'Ihus,

pressure aeting en the drum exterior is transmitted ing outwardly thereby roducing a much t-glrter and strenger seal of the drum closure. In the case of square or concave side walls, force applied to the corners. or side walls will eause flexure of the side wal-ls in an irrward direetien and consequently reduce the tightness end eiectiveness of such container closure.

The degree of curvature of the convex side wals may be varied considerably. As the degree of curva-ture inereases, tl1eir efficiency in the use of space decreases since greater waste space will be inevitab-le between the side walls of shells stored in centiguous relationship. On the other hand, the radius of curwature 0 the side vvalls should be selected so that they will be capabie of adequately aecepting the contemplated l0ads rand pressures. in this connection, it may be desirable te increase the thiclnness of these side walls in an efiont to maintain the radius of curvature at a maximum. I have found that :as the size of the centainer inereases optimum results are obtainahle by merely thicl enhg the side walls instead of decreasing their radius o;f curvature. Thus, the radius of curvature of 1he side walls of the contemplated sizes of drums will not differ appreciably, but tl1eir thi ckness wil] range between definite practical limits.

Additionally, I have found that the side walls should be integrally connected together by convexly rourrded corners substantially as illustrated. By -rounding the corners in this fashion, I have found that I oan avoid damage or mutilation to the fibers as vvell as enhance the proper continuation and stress distribution of the contem- .plated force applications. Naturally, the curvature of the corners Inay likewise =be varied considerably, depending en the size of the drum and the centemplated use and abuse.

The closures for rny drums may be similarly shaped and eonstructed so that the convex arch drum strmcture will not only prevent inw-ard collapsing of their side walls but will also iacilitate provisions for a "har more eiective seal -fior -their open top since any force against the corner of the shells tends to bow the side walls outwardly into tiglrt engagement with these closures.

111 the manufacture 0f drums embcdying the teaching of my invention, I initially provide ar1 elongated tube 20 which has incorperated throughout its oross-sectional configuration the aforementioned characteristies tand principles of arched sides and corners, by winding successive layers of fibrous material such as kraft paper around a central core or mandrel (net shown). This m1andrel presents the desired number of side supporting surfaces, each of which is transversely convex and connected by round corners. T he curvature of the side supporting surfaces and the corner supporting surfaces may be varied oonsiderably for obtaining the aferedescrihed curvature 0 tl1e side walls and corners ef the fiber shell depending upon the particular condtions and requirernents. In this connection, a web for 2. roll of kra:ft paper m1ay be suitably fed and guided through a predetermined p=ath and series of operations to the selected mandrel around w-hioh successive layers of the web are convoluteiy wound to produce a tubular wall of the desred thickness.

As is frequently the case, this convolutely Wound tube 20 will be appreciahly longer than :the desired length of ters reduce tube 20 into a number of shells 22 of prede- =termined lengths.

A shell 22 is then subjected to an operation whereby a closure disc 24 is to be mounted at one of its open ends. The disc 24 preferably -possesses a precut configuratiort in which its peripheral edges conform with the internal eontours of the shell 22. For purposes of the description immediately following, t should be understood that I am in the process of manufacturing the body side walls of a drum which are to embody the teachings of my invention. With this in mind, =a bottom =closure disc 24 is positioned inwardly a preset distance d from the bottom edge 25 selected for the shell 22 through the employment of suitable apparatus in a manner suhs-tantially as illustrated' in FIG. 4. This apparatus may inclu-de a shell mount 26 for embracing the internal faces of the shell 22 so that When the latter is positioned thereon it will be prevented trom undes irable shifting laterally during the securement of the disc 24 thereto. T 0 faclitate the proper location of the disc 24 with respect to the bottom edge 25 or shell 22, a shell platform 23 projects from the shell mount 26 so that this bottom end 25 of the shell 22 will project a predetermined distance cl beyond the upper end 29 of the shell m-cunt 26 equal to the sum of a and the thickness of the disc 24. The disc 24, which may also be formed from knaft paper, is then placed upon this upper end 29 after a suitable application of adhesive 39 to outer peripheral portions of its upper face over a sector having a width substantially equal to d. T he adhesive 30, for most practieal appleations, is prefenably a waterproof resin adhesve of the type that will set upon a11 increase in temperature.

While the adhesive 39 is still in a Wet state, portion 32 of the shell 22 of a length substantially equal to the distance d above the outer fase of the disc 24 is flanged i11- wardly to securely engage the corresponding surfaces Off the disc 24 by means of the adhesive 3l. T0 suitably provide =shell 22 with this flan=ge portion 32 the fold line 33 is conveniently formed. This is accomplished, with perticular reference :to FIGS. 5, SA and 513, by creasing the walls of shell 22 at a location d from the edge 25 and sirnulta-neously eornpensate for the necessary decrease in surface area by incorporating corner -creases 34 in the flan-ge portion 32 adjacent the rounded corners of the side walls. Ths particular folding and creasing may be accomplished hy suitable die pressing apparatus 35 so that the flange portion 32 will be nitially disposed at an acute angle with respect to the plane of the disc 24. Subsequent to this initial folding stage, a further die pressing application forces the internal faces of the flange portion 32 into engagement with the corresponding peripheral zones of disc 24. Thus, the fian"e portion 32 will form en inwardly norm-ally extending fiange anehored to the disc 24 by means of the adhesive 3 with the initially formed creases 34 cooperating to perrrrit this portion 32 to -a.ssume the proper configuration during the final fl-ange formation stage.

Since the adhesive 32 is of the temperature setting type, the final pressing stage is p=referahly accornplished by meld 36 which internally mounts a heating unit 38. Ths meld 36 may additionally inelude downwardrly projecting and peripherally extending segments 4% for shapin-g the shell 22 -alo-ng the fold line 33 and, additionally, for preventing the flanged portion 32 from being displaced outwardly during the final pressing stage. For most practical applications it has been found that the mol=d 36 should impart approximately 30 to 50 tons of -fiorce during the die closin.g cycle and supply about 350 F. temperature by means of the heating unit 38. In this con neetion, the die cavity of the meld 36 should reman closed for ap-proximately 6 seconds to accomplish the desired securement of the fiange portion 32 to the disc 24. Obviously, the temperature, pressure and cycle duretion incident to this final melding application will wny depending upon the dimensions of the shell 32 and disc 6 24, their constituent materials and theselected adhesive 3.

In en effort to provide a more positve securement of the flanged p=ortion 32 and disc 24, a series 0 staples 42 may be employed and suitably duiven through these two parts by hand, su=itable manual or automatic stapli-ng devices. In this regard, a suflicient num.ber of staples should be in-se-rted at flange corners to adequately secure the corner crease-s 34 to disc 24. As will be evident to those skilled in the art, staples necessarily present aPertures through w hieh foreign matter may enter the interior of a drum. Aceordingly, suitable structure is provided for coverng the exposed staples 42 both interiorly land exteriorly. Ths structure will not only function to rgidify and strengthen the formed closure of shell 22 but will cooperate to provide an etfective seal for this closed end ot shell 22. Thus, in FIG. 8 components for sueh structure -are illustrated, along with the partially eompleted drum shell, and include an outer layer 44 and nner layer 46 both of thinner gauge sheet material than disc 24.

These layers 44 and 46 have transversely convex peripheral side edges and r0unded corners thereby approximating the configuration of disc 24 in most respects.

As llustrated in FIG. 8, the lower face of layer 44 and upper aace of layer 46 are suitaubly coated with a waterproof resin adhesive of the tempe1ature setting type. The layers 44 and 46 are then positioned on the fl=anged portion 32 of shell 22 and tuner face of disc 24, respeetively. These parts are supported by means of a suitably shaped mandrel 43 which preferably ineludes, along, its upper face, a resilient layer formed from suitable material sueh as foam rubber.

The layers 44 and 46 together with the fianged portion 32 and disc 24 are then subjeeted to a suitable heat and pressure application -to securely unite these parts t0ge ther while at the same time initatng the setting of the adhesive coating applied to layers 44 and 46. Accordingly, an upper die 50 may he reciprocal with respect to the mandrel 48 and interiorly mounts a heating element 52. The die face is preferably provided with a downwardly extendng oentrally located projection 54 for forcing the central sector of layer 44 into engagement with proximate surfaees of the disc 24. The remaining die faces, which include the circumlferentially extending apron 55, facilitate the securement of the peripheral edges of this layer 44 to the fianged portons 32 as well as molding of edges of this layer substantially as shown. The resilient layer 49 will obviously prevent the staples 42 from being punchedthrough the layers 44 and 46 upon the down- Ward reciprocation of the die 5,9. In most of the contemplated fiber drum formations die 513 will exert approxmately 5()0 pounds force and prov'des 300 to 350 F. temperature for approximately 12 to 14 seconds. In this connecton, the pressure, temperature and duration of both will be dependent upon the particular requirements and conditions including the size of materals employed for the parts to be united as well as the type adhesive utilized.

The composite structure formed as a result of the die stamping partially illustrated in FIG. 9 can be employed as either a drum body outer shell or as a closure for such drum. In fabricating a drum closure I simply increase the size of the closure shell during the inital mandrel winding discussed in conneetion with the tubular body 20 illustrated in FIG. 2. This provision for a container closure will become apparent eventually from the fellowng description.

The adhesive employed, during the mandrel winding step, for uniting the -laminated layers of fibrous material in the drum body Outer shell 22 is preferably still wet and in a moist state. When the tubular shell 22 is thus wet and moist, its cross-seotional dimensions will be inherent- 1y greater than those available in a totally dry shell or employed for unng the fiber lamina in a cured condition. Therefore, while the outer shell 22 is in this wet condition, a super-dried liner 56 is inserted into the shell 22 to have ons of its encls resting upon the inner face of the inner layer 46. This liner 56 is preferably a -generally cylindrical tubular body made of laminated layers of fibrous material witl1 each side thereof transversely een vex and joined together by rounded corners. For all intents and purposes, this liner =56 will be longer than the efective length of the flanged outer shell 22 and will present outer cross-sectional dimensions slightly larger than the internal cross-sectional dimensions of the outer shell 22 wl1en both are subjected and exposed to normal arnbient conditions as is the case during ordinary drum use. Thus, the super-dried liner 56, whch will naturally shrnk in physical dimensions When in such condition will freely pass irrto the interior of the moist ancl conseqnently expanded outer shell 22 The liner ss will then absorb moisture from both the outer shell 22 and the ambient to thereby expand into tight face-to face contact with this shell 22 which, at the same time, will be suhjected to shrinking as a result of the dissipation of its moisture content and equalization thereof Wth that of the liner 56 and ambient.

In the process of overdrying, for the purposes of shrinking the inner liner 56, one or more of these liners may be passed through conveyor-type ovens. Ovens employed in practicing the present invention are approximately 60 feet long and have air, at elevatecl temperatures, crculating therethrough at relatively high velocity. The conveyor-mounted inner liners are usually subjected to the environment created by these ovens fo-r approximately 20 minutes in order to attain the desired liner shrinkage.

If desired, the insertecl end of the shrunk liner may be forced into firm engagement with the nner face of the inner layer 46 by means of a suitable press. Further more, to insure more positive engagement of the enter surfaces of the liner 56 and inner surfaces of the shell 22, the inner faoes of the roundecl corners of the transversely convex sides of the outer shell 22 may be coated with a suitable adhesive 58. n any event, the =finally assembled outer shell 22 With an internally secured mounted liner 56 will approximate the structure illustrated in FIG. 11.

As stated in the foregoing ancl as illustrated in FIGS. 12 and 13, a drum closure 6% is forrned in substantially the Same manner as the container outer shell 22. Accorcingly, both will possess an inwardly extending flange portion 32 which is secured to a disc 24 by means of an interposed adhesive 30 as well as a series of staples 42. The outer layer 44 ar1d inner layer 460i relatively reduced gauge are then adhesively secured to the disc 24 with the peripheral side edges of the outer layer 44 embracing the Outer surfaces of the flange portion 32 substantially as llllSllttd in EG. 13. The container closure 60 obviously has internal dimensoning equal to or slightly greater than the Outer dimensioning of the liner 56 under normal ambient conditions in order that it may be telescopically positioned and displaced on this liner 56. As illustrated in section in F=IG. 13, the bottom edges of the closure 60 will rest upon or be in close proximity to the upper edges of the outer shell 22 with the upper peripheral edges of the liner 56 adjaoent the internal faces of the inner liner 4-6 of closure 60.

After.the container outer shell 22 has dried sufficiently the bottom closure thereof is dipped in molten wax or suitable resin, depending upon the contemplated use of the container. The coating thus provided by this dipping applicaton insures a hermetically sealed bottom closure assembly for the enter shell 22 and consequently the drum body. In this connection, and as illustrated in FIG. 14, it may be founded to be desirable to employ a. gasket 64 between the bottom edges of the liner 56 and inner fases of the inner layer 46. As an alternative, a layer of wax may be provided en inner layer 46 so that the hottom edges of the liner 55 are embedded or nested thereby. Thus further means are provided for preventing any possible contarnination of the seleotecl contents for the drum body.

It will be ooservecl in F IGS. 12 and 13 that means in the form of a layer of sheet material 66 may be l.ltlllZd In FIG. 15 I illustrate a multi-compartmental drum which incorporates the teaohings of my invention. There it will he observed that I provide a drum particlarly suitable for shippirrg certain chemicals which are preferably separated shipping and mixed at sorne later time. Thus, a drum enter shell 22' having transversely convex sides whioh are connected together by rounded corners is initially provided as in the oregoing and will be in a substantially wet condition as a result of the state of the adhesive employed in securing together the convolutely wonnd lamina o=f fibrous material. A superclried shell lining 56 of predetermined leng th is then inserted into shell 22 and is separated fnorn a smilarly positioned reduced liner 56" by a separating disc 76. This dual-conrpartmental lined shell may be ep propriately gloed to the internally mounted liners. Subsequently, this composite structure is subjeoted to either normal ambient atmospheric conditions or the mentioned oven so that the drum shell 22' will shrink into firm suraoe-to-surface contact with the liners 56 and 56". A pair of slipover covers 60' and 6%) which are fabricated in substantially the same marmer as the aforedescribed cover 69 are then telescopically slipped over the open encls comrnnnicating Witl each of the drum compartments. Ooviously after eaoh compartment is filled with the desired chemical constituents of a particular fiorrnula, the appro-priate cover is teleseoped upon the exposed sector of the associated drum liner. Dhen with these slipover covers properly mounted, I seal the drum separately at both ends with an appropriate tape similar to that illustrated in FIG. 13.

-Referring now to FIG. 16 vvherein I illustrate a drum manufacturecl by following the teaohings of my present invention for the purpose of carrying particularly sensitve products, this form of drum is remarkably effective ancl superior in the carrying of sensitive pnoclucts either for long storage or throngh conditions of atmosprherio changes of humclty and temperature. I inconporate barriers and shields in my drum construction to thus provide a highly insulated drum which protects the contained product from any rapid temperature changes in the product area an-d thereby minimize and, in most instances, prevent internal pressnre ohanges resulting trom extensive temperature changkes in the amhient. Furthermore, as a result of these properly looated layers of barrier and shielding material, I minimze breathing of the drum as a consequenoe of minor c hanges in ambient temperature. These cornbinations of highly protective oharacteristics in the. various components of the drum, in addition to the superior insulative properties of the heads and wal1s of the drum, tend to preserve the dryness or moisture content of: materials in the product areas of the drum to an nnusual extent. Whene delicate products are packed in my drums, with a small amount of rust inhibitors, my drums not only ofr"er an unusual amount of product protecton "but freeclorn frorn a.ny sweating or extensive changes in moisture content that rnight otherwise result. Thus, in FIG. 16 I illustrate a drum providing sueh superior char- -acteristics. The drum ontside shell 122 is nitially formed, upon a suitahle mand-rel, with a l:rarrier 123 of one convol-ution of an =asphaltic oomposition, mylar or other suitable barrier matcrial. T hs shell 122 is then subjected to the various steps employecl in forming the drum bttom closure as previonsly disclosed. In this connection, a barrier 125 of suitable material such as an asphaltic composition, rnylar 01 the like is initially inc onporated into the closure disc 124. Obviously, when sta-ples are inserted throngh flange 13=2 into disc 124, apertures are necessarily formecl whioh may provide an access into the drum nte rior and thereby cause contamination of its contained product. Accordingly, in the cover sheets or layers 144 and 146, respectively, I inconporate barriers 145 and 147 "of suitable materials. These pa1ticular harrie1s function to minimize any detrirnental effects incident to the employment of staples 142. The slip-over cover 160 will include sirnilazr barriers and, acco-rdingly, the various parts thereof will be designated with idcntioal numerals. he drum liner 156 also has a barrier 157 incorporated therein during the initial winding thereof and is located pro-xinrate to the inner walls of the liner. As previously described, a gasket 164 may !be employed between the hottom edge of liner 156 and upper peripheral sectors of layer 146. The inner walls of liner 56 may be lined with a harrier 172 of an asphaltic composition, mylar or the like. Similarly, a barrier layer 174 may be positioned on the upper face of layer 146 and have its peripheral edges disposed adjacent the bottom edges of barrier 172. A herrier sheet 166 is =additionally provided and is ormed from sutable barrier material. T provide a more eiiective seal between the cover 460 and the drum body, I supplement the cover 16 9 with a urther disc 176. This disc 176 cooperates with the drum liner 156 to provide additonal deformation of the barrier sheet 166 when the cover 160 is slipped over liner 156. A barrier type of pressure sensitive tape 163, as previonsly disclosed, cooperates to complete the seal hetween the cover 169 and the, drum butt. Naturally, if desired, the bottom of the drum of this embodiment may =he dipped in wax in a marmer snbstantially similar to that previously described so that the bottom of this drum is sealed to its fullest extent. It should he clear that one or more of the barriers disclosed in connection with the dmm of this particular embodiment may be eliminated or modified, depending upon the particular conditions and reqnirements.

Certain applications of the above-described drum, having a lined outer shell with telescopically slidable closure, will necessitate the employment of properly located =barriers and shields to more positively prevent drum c ntent contamination under extremely severe conditions of use and abnse in the o=uter shell 22 or liner 56 and apron of closure 60 as well as in the disc 24 of the outer shell 22 and closure 60. This barrier or shield may be interposed within the tubular body walls when these bodies are initially wound upon the mand1el mentioned in the discussion of FIG. 2. Additionally, this barnier or shield may be of an asphaltic composition or foil such as aluminnm, myl-ar or ether suitable material.

I have found that sirnilar superior results are attainable by fabricating one or more parts of any of the aforedescribed drums from a resinous material such as the commercially available polyesters suitable for suc h purposes which may additionally include suitable reinforcing suoh as fiber glass filaments or strands in a marmer conventionally employed. In this connect-ion, the drum liner may be forrned from such material in order th at a major portion of the drum inner walls will incorporate the desirahle characterist-ics of die material selected, as for exarnple inertness and non-toxicity. The formation of this liner may be accomplished in accord ance with the aforedesc1ibed construction of this part or the resortment to one of the many conventional processes for fabricating products from snch materials.

Thus, the numerous aforementioned =objects and advantages, among others, are most efectively 1attained. Ac cording y, it is intended that my invention be defined by the appended claims which are to be accorded their full- 10 est scope and not be lirnited in any respect by the aoregoing description of my invention o several practical ernhodirnents thereof.

I claim:

1. The method of forming a drum comprising: forn1ng a closure disk; preforming a tnbular shell having a plurality of sides and made of adhesively secured laminated leyers or" fibross material with each side of said shell b"- ing transversely convex and the corners joining said sides together being rounded; preforming a snperclried liner for said shell having a plnrality of sides and made of fibrons material with each side of said liner being transversely convex and the corners joining said sides together being rounded; securing said disk t0 said shell to close one end of said shell; while the adhesive of said shell is Wet, inserting the snperdried liner in said shell and then equalizing the moisture content of said shell and said liner to cause relative shrinkage and expansion of said shell and said liner, respectively, to thusly provide surface to surface contact of the shell with the liner by placing said shell undei tension and said liner unde1 compression wherein a rigid container is formed whereby said shell and said liner resists loads as an integral onepiece unit.

2. The invention in accordance with claim 1 wherein the preforrned shell is formed with an inwardly extending fiange at said one end thereof and securing said disk to said fiange to close said one end of said shell.

3. The invention in accordance with claim 2 wherein the securernent of said disk to said flange is accomplished by first coating selected surfaces cooperating to provide the juncture between said disk and said flange, then stapling said flange to said disk.

4. The invention in accordance with claim 1 wherein at least one sheet similar in configuration to said closure disk is formed and attached to portions of said disk following securement of said disk to said shell to strengthen the closed one end of said shell.

5. The invention in accordance with claim 1 wherein a seal is located adjacent said disk with portons thereof in proximity to the internal walls of said shell, and said shell liner is placed in said shell with peripheral edges thereof in firm engagement with said seal.

6. The invention in accordance with claim 1 wherein a closure is forrned and placed over the open end of said shell, and at least one layer of barrier material is incorporated in the drum structure during the formation thereof for cooperating to tender the interior of the finished drum hermetcally sealable.

7. The inventon in accordance with claim 1 wherein said liner is longer than said shell and formng a removable closure for the other end of said shell similar in construction as said shell and having a closure disk secured to one end thereof simlar to the first mentioned disk, telescopically fitting said removable closure over the exposed exterior surface of said liner.

& The invention in accordance with claim 1 wherein, prior to the insertion of said liner in said shell, a bonding agent is interposed therebetween to fixedly secure one with respect to the other and increase the unitary coaction of both upon compression of the liner.

Reerenees Cited in the file of this patent UNITED STATES PATENTS 656,700 Pullen Aug. 28, 1900 1,798193 Denler Mar. 31, 1931 1,923,426 Eggers Aug. 22, 1933 1,992l82 Buist Feb. 26, 1935 2,133137 Hackett Oct. 11 1938

Claims (1)

1. THE METHOD OF FORMING A DRUM COMPRISING: FORMING A CLOSURE DISK; PREFORMING A TUBULAR SHELL HAVING A PLURALITY OF SIDES AND MADE OF ADHESIVELY SECURED LAMINATED LAYERS OF FIBROUS MATERIAL WITH EACH SIDE OF SAID SHELL BEING TRANSVERSELY CONVEX AND THE CORNERS JOINING SAID SIDES TOGETHER BEING ROUNDED; PREFORMING A SUPERDRIED LINER FOR SAID SHELL HAVING A PLURALITY OF SIDES AND MADE OF FIBROUS MATERIAL WITH EACH SIDE OF SAID LINER BEING TRANSVERSELY CONVEX AND THE CORNERS JOINING SAID SIDES TOGETHER BEING ROUNDED; SECURING SAID DISK TO SAID SHELL TO CLOSE ONE END OF SAID SHELL; WHILE THE ADHESIVE OF SAID SHELL IS WET, INSERTING THE SUPERDRIED LINER IN SAID SHELL AND THEN EQUALIZING THE MOISTURE CONTENT OF SAID SHELL AND SAID LINER TO CAUSE RELATIVE SHRINKAGE AND EXPANSION OF SAID SHELL AND SAID LINER, RESPECTIVELY, TO THUSLY PROVIDE SURFACE TO SURFACE CONTACT OF THE SHELL WITH THE LINER BY PLACING SAID SHELL UNDER TENSION AND SAID LINER UNDER COMPRESSION WHEREIN A RIGID CONTAINER IS FORMED WHEREBY SAID SHELL AND SAID LINER RESISTS LOADS AS AN INTEGRAL ONEPIECE UNIT.

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