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Publication numberUS3194275 A
Publication typeGrant
Publication dateJul 13, 1965
Filing dateJan 15, 1963
Priority dateJan 15, 1963
Publication numberUS 3194275 A, US 3194275A, US-A-3194275, US3194275 A, US3194275A
InventorsBiggs Jr William A, Dunlap Jr Charles K
Original AssigneeSonoco Products Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Spirally wound paper tube
US 3194275 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

July 13, 1965 w. A. BIGGS, JR., ETAL 3,

SPIRALLY WOUND PAPER TUBE Filed Jan. 15, 1963 2 Sheets-Sheet 1 INVENTORS: WILLiAM A. B|6G ,J\2and C$ERLES K. buNLAP, J12.

United States Patent 3,194,275 SPIRALLY WQUND PAPER TUBE William A. Iiiggs, .112, and Charles K. Dunlap, In, Hartsville, 5.0, assignors to Sonoeo Products {lump-any, Hartsville, S. C., a corporation of South Qarolina Filed Jan. 15, 1963, Ser. No. 251,614 3 Claims. (Cl. 138-144) This invention relates to paper tubes and more particularly to a spirally wound paper tube for the winding of sheet material such as textile material and the like.

It is a common practice today to utilize wound, multiply paper tubes as carriers or cores for sheet material such as paper, cloth, carpet material and the like. Such tubes or cores used for the winding of heavy sheet material such as carpet material are required to be of high strength to resist crushing and buckling when subjected to the forces generally encountered when wound with such carpet material and the like. Carpet material is generally wound in long lengths on its tubular carrier producing a very heavy load and although the spiral tube of the invention may be used for the winding of any material where a strong carrier is desired, it is particularly useful for the winding of such heavy carpet material.

Paper tubes in use today as a carrier for long lengths of carpet material are required to have both a high resistance to radial crushing and a high beam strength which, as is well known, is measured by the ability of the tube to withstand a centrally positioned load with the tube supported only at its ends. Such present day tubes or cores are generally made by convolutely winding a paper web into a tube as a convolutely wound tube has by its nature a beam strength greatly in excess of a spirally wound tube together with a satisfactory degree of crush strength. Furthermore, the convolute tube when subjected to a beam load fails by a buckling or pleating of its walls whereas the spiral tube fails by splitting along its spiral tube seam or what is known as seam splitting. Such seam splitting is highly undesirable in that it pinches the material wound on the core with resulting damage to the material.

Primarily because of its lower cost of production, there has been a continuous search for a spiral tube which will provide the beam and crush strength of the convolutely wound tube for use in such areas of use as described above. While spirally wound tubes have been well known from the earliest times, a suitable spiral tube'for such a use has not heretofore been obtained. In addition to the high radial crushing strength of spiral tubes in comparison with convolute tubes, their uniform concentricity and radial dimensional stability, the low production costs common to the spiral tube has intensified the search all to no avail. Some progress has been made in increasing the beam strength of such spiral tubes by increasing the Wall thickness of the tube and with the use of stronger paper but the resulting tubes still have far less than the desired strength and the slight strength increase obtained is offset by the high cost and increased bulkiness of the tubes.

Accordingly, a primary object of this invention is to provide a new and novel spiral tube having a high beam strength and high crush strength.

Another object of this invention is to provide a new and novel spiral tube for use as a core or carrier for heavy sheet material such as carpet material and the like.

A further object of this invention is to provide a new and novel spiral tube for use as a core for heavy sheet material which tube has a beam strength and crush strength substantially the same as a corresponding convolutely wound tube and which fails by buckling rather than by seam splitting soas to avoid damage to the material wound on the tube.

Still another object of this invention is to provide a Patented July 13, 19%5 new and novel spiral tube having a high degree of dimensional stability so as to remain substantially constant in length throughout changes in moisture content.

This invention further contemplates the provision of a new and novel spiral tube wound at a winding angle not heretofore considered possible which is characterized by a beam strength and crush strength substantially equivalent to that of a corresponding convolutely wound tube, which utilizes spiral tube winding equipment presently available and which may be manufactured from readily available inexpensive materials at a relatively low production cost.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.

In general, the objects of the invention and related objects are accomplished by providing a plurality of strips of paper which are spirally wound in overlapping relationship with adhesive therebetween to form a spiral tube. The paper strips which contain fibers common to paper have the fibers extending lengthwise in the direction of the longitudinal axis of the paper strips or what is generally referred to as the paper machine direction. The winding angle of the paper strips is within the range of between 15 to 27 degrees and preferably an angle of approximately 17 degrees so that the long axis of the strips and consequently the fibers in the strips approach closely a parallel relationship with the axis of the tube to provide a tube of high beam strength and high crush strength together with ahigh degree of dimensional stability.

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a plan view of a spiral tube winding apparatus illustrating the winding of the tube of the invention;

FIGURE 2 is a side view of a tube constructed in accordance with the invention;

FIGURE 3 is a graph illustrating the relationship between tube beam and crush strength and tube winding angle;

FIGURE 4 is a graph illustrating the relationship between the ratio of tube beam and crush strength with tube winding angle; and

FIGURE 5 is a graph illustrating the relationship between tube length change under varying moisture conditions with tube winding angle.

Referring now to the drawings and to FIGURES 1, 2 in particular, there is shown in FIGURE 2 a spiral tube designated generally by the letter T which is constructed in accordance with the invention. The spiral tube T is wound on slightly modified conventional spiral tube winding apparatus portions of which are shown in FIGURE 1. The apparatus of FIGURE 1 includes a frame designated generally by the numeral 11 arranged to support a winding mandrel 12 around which a continuous belt 13 is looped in the conventional manner for advancing the tube T in the direction of the arrow P. The belt 13 is mounted in the conventional manner on drums or pulleys 14, 16 at least one of which is rotatableby suitable driving means and the pulleys 14, 16 are arranged for adjustable sliding movement on a frame 17 positioned for angular adjust ment on a base 18. The spacing between the drums 14, 16 is adjusted by means of threaded shafts 19, 20 arranged to be manually rotated by means of hand wheels 21, 22 respectively for belt tensioning purposes.

The spiral tube T of the invention is wound from a pinrality of plies or strips of paper containing fibers common to paper and, in the specific embodiment illustrated, the

glue from the strips'as shown in FIGURE -1.

' not applied to the intermediate strip 28 and it is broughtv belt 13as shown.

. paper strips are seven in number including an inner strip a '23; intermediate strips 24,;25, 26, 27, 28.and outer strip area-275 '29. The'paperstrips 23 through 29 are formed in a conventional manner on a papermaking machine but, all of the; strips employed in the construction oftthe tube T of the, invention are made by the ;Well-knownvtechnique of the arrows I. In" other words, the paper strips 23 to 29 have their longitudinal axis parallel to what is referredto as the paper making machine direction. This is accomplished by cutting thepaper web parallel to the 7 direction the web travels during its formation on'the paper machine to form the strips 23-29." o

'Inthe manufacture of spiral tubes under present day practice, the ,winding angle, 'identified in FIGURES 'JI, 2

as X"; is generally'withingthe range of 50 to 80 degrees and as has been explained tubes made at a winding angle within this range do not have the desired beam strength. In'accordance with the inventiomthe winding angle X- at which the strips 23fto 29"are wound on the winding mandrel 12 iss within the range of 15 to 27 degreespreferably within 'the rangeiof ,17 to 22 degrees. In tthe specific embodiment illustrated, the winding anlge X;j is

' wherein-the fibers of thestrips lie'substantiallyoparallel a with the longitudinal axis'of'r the strips or in: the'idirectio'n The results-shown in Table'Iwere obtained byfwinding multi-ply'spiral' tubes having a3" inner. diameter, and a 0.150? wallthickness at iwinding angles-ranging frornamaximum of 37 /4" to aminimu'nr (Jil n/l3. The paper strip widths, of course, vary in accordance with the winding angle. The physical limitationsgOfthe spiral tube V winding machine would not pfi rriitfthe winding anglei to V a be reduced'below approximately ISdegrees as at this point 1' the length of. the winding belt and the spacing of the belt} drums for winding a tubeat this'winding angle becam e prohibitively large in addition to the beamstrengthttest as described above, ,a crush strength test was c onducted I on specimens of these various tubes both; of which tests",

are considered in the-industry as standard. As is'welhj known, thecrush 'strength'test is carriedout by loading a standard 3'v'j1ength offtub'e ;betweenflat platens until failure. o a

strength ratio as shown in'the graph of FIGURE 4- and as will be explained hereinafter.-

As shown in FIGURE 1,;the inner paper strip 235 which formsthe inner ply of the tube is wound on the mandrel,-

thereto by a suitable lubricatingv device. 31.: Paper strips 24 through 27 whichv are :preferably Wound onto the;

mandrel fr oin'theside opposite the inner strip 23 as shown which is provided with scrapers'33i for removing excess in dry over a set of guide rolls 34.

vancediover a glue applicator 36'. Strip 29 is then vwound Glue is together with theother strips on the mandrel below the which not only aid in compressing the wound paper strips together for increased adherence but additionally serve; to prevent the mandrel 12 from moving out. of, alignment as a result of thewinding forces exerted'by the belt 13 on the mandrel.

a 7 Suitable support rollers 37 are pro-" 7 vided on the spiral tube winder as shown in FIGURE; 1'

' wound tube thereby avoiding.thefpossibilityof injury to 7 material wound Ion'the' tube. ,Thisis considered to bee tive tothe longitudinal axis of the tube as shown in FIG- URE 2.- V a a The novel results accomplished with the spiral tube" ofthe invention are shown clearly in FIGURES 3-5 and in Table I belo'wz' t TABLE 'I Beam. Paper Strip Width Winding Crush Beam i Strength] (inches) Angle Strength Strength Crush t (degrees) (lbs;) ribs.) Strength I V V Ratio.

37 79 r 281 3. a? 79 u 310 3.93 29 73 V 325 4.45 25% 64 Y 349 5A5. 21% 69 382 5.54 17% 70 400 5. 70'

The results of the beam strengthi and lcrushl-te'sts are :7 tabulatedin Table '1 and are plotted on theg'raphtshown" FIGURE 3f: It will be noted that' throughoutgthef o winding anglelrange of. approximately V37,'to"17' degreesi V t there-Was a 431%, increase"in=beainf strength;with an ack- V companying crush strengthidecrease with; onlyi'about 12%;: o

A ratio:of beamstrength to crush strength'wasutilized as representative of both of, theidesirable.strengthiactors;-

' in a tube lofthe inventioh .andFIGURE4 shows the"yari ous ratios plotted on a graphi IAsiexplaine d'abov, the; last beamystrength to crushstrength ratio obtained was t at the ,17 degree angle':approximately as itheaphysicallimitationsfof the ,spiraltube winding; machine militates against the winding of sp'iraltub'es to anyts ubstantial 'de f gree below this winding angle. 1 Poin'ts'Afand B plotted at the zero winding angleiposition'offltthegraphof FIG- UREA are strength-ratio figures for twoconvolutely-w wound tubes of the same diameter and wall thicknesston which the same testswere run and the strength ratios ob-' tained can be'considered tolbe those corresponding ma 1 theoretical-spiral'tube havinga zero degree winding angle. a

Iti'will be no tedxthat throughout the winding-angle range .of approximately '17 to -27fidegrees the vgbeani't l' strength/crush strength ratio 'was' s ubstan'tially the same 1 and approaches subs'tantially that of'the convoluteftube': samples A'and B.Z The beam strength/crush strength ratio droppedoft sharply above a. winding anglef crap;

prox mately 27. degrees and has 'beenzexplained above; a I winding angle below approximately 17 degrees couldjno t for all practical purposes'be measured. jIt will also be; noted that the beamjstrength/crush 'stren'gth ratio' of the tubes appeared to beat a r'naxirnumiat awinding angleof "between l7 and 22 degrees i i In additionto the atthe low winding angles of the tubespf the invention,

it wasno ted that the seam splitting upon failure common to spirally Wound tubes subjected tofa beam test didnot oc- C111.i)ill2 rather'that the. tube buckled asin the convolutely completely new and unexpected result and considerably enhances the commercial'app'eal of the tubes V The novel resultsoftthe inventionarebelieved to :be. i obtained as a result of the close app'roachoftheffibers'in the paperostrips' used to wind the tube Tto a parallel relationship with the longitudinaliaxis 0f thetube-T. 'As' a result of this positioning of the fibers ofthestrips forming the tube, a highfresistance is offered to collapse of the tube under a beamload such as thetbearn strength 'of t V a convolutely wound tube which is wound with'the fibers extending transversely of, the cross gwound papershe'et on; in other-words; parallel to' the=longitudinal axis of the: convolute tube. The'tube T io f the invention can be 'said to have strength characteristics closely app'roximatg ing those. of a convolutelywvoundtube. t

Other new and unexpected Tresults developed when: V spirally 'wound lpaper tubes wound. atjldw winding angles I high strength characteristics obtained.

in accordance with the invention were subjected to dimensional stability tests. In conducting one such dimensional stability test on the tubes of the invention, six spiral tubes having an inner diameter of 3", a 0.150" wall thickness and a length of 30" were wound at winding angles of 3616; 3155; 2854; 2536; 2149; and 1716 using seven plies of paper. In the test, the moisture content of these tubes was changed from 6% to 25% as the change in tube length resulting from this moisture content change was measured.

The resulting percent changes in length of these tubes are plotted on the graph of FIGURE 5 and it will be noted that the percent change in tube length varies from a figure of 0.82 at the higher tube winding angle of 37 16' to a percent change in length figure of 0.47 at the lower winding angle of 1716. Here again as in the beam strength/ crush strength ratio graph the reduction in the percent change in tube length becomes increasingly small as the tube winding angle falls within the 15 to 27 degree range so that,

' as shown in FIGURE 5, a curve drawn through the plotted points indicates a gradual decrease in curve slope at these lower tube winding angles.

Point C in the graph of FIGURE 5 indicates the percent change in length under the same moisture content change specified above in a spirally wound tube having an inner diameter of 3%, an outer diameter of 4" and a length of 30" but wound at a winding angle of 59 degrees. It will be noted that the length change with moisture content change at the higher winding angle far eX- ceeds that of the winding angle range of the invention. The graph of FIGURE 5 thus reveals clearly that a substantial increase in dimensional stability is obtained at the lower angles of wind and the maximum dimensional stability is obtained within the range of winding angles comprising the invention.

It can be seen with the novel construction of this invention that a multi-ply spirally wound paper tube wound at winding angles not heretofore considered possible or contemplated produces completely new and unexpected results in that a spiral tube is provided having strength characteristics heretofore unobtainable in a spiral tube and obtainable only with a convolutely wound paper tube. This strength increase in the tube of the invention does not require an increase in paper nor in paper strength but is due primarily to the unusually low tube winding angle together with the use of paper strips having their fibers oriented so as to approach closely a parallel relationship with the longitudinal axis of a tube wound therefrom. The range of winding angles contemplated by the invention appear to provide the maximum strength improvement desired for spiral tubes, and at the same time are within the practical considerations involved in the manufacture of such tubes.

Not only does the low angle of wind spiral tube of the invention have improved strength characteristics but seam splitting common to spiral tubes occurring upon tube failure which is generally injurious to material wound thereon is eliminated and the tube buckles in the nature of a convolute tube. Furthermore, unusually high dimensional stability is obtained in the spiral tube of the 5 invention in that changes in moisture content produce only very small length changes far less than those common to spiral tubes Wound at the higher winding angles considerably widening the application for such spiral tubes wherein length changes must be held to a minimum.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is the aim of the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed is:

1. A spirally wound paper tube comprising, a plurality of fiber containing paper strips spirally wound in overlapping relationship with adhesive therebetween to form a spiral tube, each of said paper strips having its fibers lying generally in the direction of the longitudinal axis of said strips, said strips being wound at a winding angle of between about 15 to 25 degrees thereby providing a dimensionally stable tube of high beam strength and crush strength.

2. A spirally wound paper tube comprising, a plurality of fiber containing paper strips spirally wound in overlying relationship with adhesive therebetween to form a spiral tube, each of said paper strips having its fibers lying generally in the direction of the longitudinal axis of said strips, said strips being wound at a winding angle of between 17 to 22 degrees thereby providing a dimensionally stable tube of high beam strength and crush strength.

3. A spirally wound paper tube comprising, a plurality of fiber containing paper strips spirally wound in over- 4 lying relationship with adhesive therebetween to form a spiral tube, each of said paper strips having its fibers lying generally in the direction of the longitudinal axis of said strips, said strips being wound at a winding angle of approximately 17 degrees thereby providing a dimensionally stable tube of high beam and crush strength.

References Cited by the Examiner UNITED STATES PATENTS LAVERNE D. GEIGER, Primary Examiner.

LEWIS J. LENNY, Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
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US2749643 *Dec 31, 1952Jun 12, 1956Columbia Products CoHollow shaft for fishing rods
US2825364 *Oct 14, 1954Mar 4, 1958CullenFlexible supports for fluid-driven drill bits
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3424204 *Oct 27, 1964Jan 28, 1969Sato IsaoReinforced paper pipe
US3455521 *Mar 18, 1966Jul 15, 1969Sonco Products CoForming tube for glass fibers
US3516448 *Aug 20, 1965Jun 23, 1970Rolls RoyceBore hole type wells
US4650459 *Oct 21, 1985Mar 17, 1987Kimberly-Clark CorporationConvolutely wound paper tampon tube
US4792326 *Mar 30, 1987Dec 20, 1988Kimberly-Clark CorporationPaper, binder, and superabsorbent; tampon applicators
US4872933 *Aug 5, 1988Oct 10, 1989Kimberly-Clark CorporationLaminating a web of paper with adhesive film and super-absorbent material; wrapping, sealing to produce tampon disposable tube
US4874139 *Oct 31, 1988Oct 17, 1989Daniel KewinTubular core assemblies for rolls of paper or other sheet material
US5393582 *Jun 4, 1993Feb 28, 1995Sonoco Products CompanyEnhanced crush strength construction multi-grade paperboard tubes
US5472154 *Jul 2, 1993Dec 5, 1995Sonoco Products CompanyHigh spiral angle winding cores
US5505395 *Jan 21, 1994Apr 9, 1996Sonoco Products CompanyMulti-grade paperboard winding cores for yarns and films having enhanced resistance to inside diameter reduction
US6540174Jan 22, 1999Apr 1, 2003Ahlstrom Cores OyPaperboard core with an improved chuck strength, for the paper industry, and a method of fabricating such
US7951440Sep 23, 2004May 31, 2011The Procter & Gamble CompanyDispensing paper-roll core systems
US8075699Feb 17, 2011Dec 13, 2011The Procter & Gamble CompanyDispensing paper-roll core systems
US8556206May 2, 2011Oct 15, 2013Sonoco Development, Inc.Folded core for carpeting
DE102010056339A1Dec 18, 2010Jun 21, 2012Technische Universitšt DresdenStiffened hollow profile has cavity middle layer, which is placed between base layer and top layer as middle layer, where cavity middle layer consists of inclined-wound core path or cavity path
WO1999039902A1 *Jan 22, 1999Aug 12, 1999Ahlstroem Alcore OyA paperboard core with an improved chuck strength, for the paper industry, and a method of fabricating such
Classifications
U.S. Classification138/144, 242/609.4
International ClassificationB31C3/00
Cooperative ClassificationB31C3/00
European ClassificationB31C3/00