US3471350A

US3471350A - Method of making a carrier for forming wound packages

Info

Publication number: US3471350A
Application number: US723216A
Authority: US
Inventors: Richard V O'berry; William R Shuler
Original assignee: Star Paper Tube Inc
Current assignee: Star Paper Tube Inc
Priority date: 1966-02-18
Filing date: 1968-04-22
Publication date: 1969-10-07
Anticipated expiration: 1986-10-07

Description

METHOD oF MAKING A CARRIER FOR FORMING woUND PACKAGES R. V. OBERRY Er AL Oct. 7, 1969 original' Filed Feb. 18, 196e Enel-A125 V O'BEREY ana/WILLIAM l2. SHULER BYf/vwal Jfww ATTORNEYS Oct. 7, 1969 R, V Q'BERRY ETAL 3,471,350

METHOD OF MAKING A CARRIER FOR FORMING WOUND PACKAGES Original Filed Feb. 18, 1966 2 Sheets-Sheet lf/g PRESSURE- bi1-VICE G LU E APPLY! NG ana. G TUBE WIN uma APPARATUS OV EN INVENTORS IC HARD O' BERRY ATTORNEY .S

United States Patent O U.S. Cl. 156-184 5 Claims ABSTRACT OF THE DISCLSURE A method of forming a carrier adapted for forming packages of wound material wherein the carrier comprises a -convolute tube formed of wound sheet material having a curved arcuate flap formed integral therewith and extending from the periphery of the tube and substantially conforming to the curvature of the tube and being biased toward the tube to define an entrapment zone between the flap and the tube adapted to frictionally engage the innermost end of material wound on the carrier, and wherein the windings of the tube are adhesively secured together, with adhesive, which initially served to bond the ap against the tube to obtain the conforming ap curvature, having been rendered ineffective as by a heat treatment to provide the entrapment zone.

This application is a division of application Ser. No. 528,621, filed Feb. 128, 1966, now Patent No. 3,395,789. This invention relates to a carrier for 'forming wound packages and more particularly to a method `for making such a carrier. The carrier formed in accordance with this invention is so constructed as to entrap or frictionally grip the innermost end of a length of material such as a textile fabric wound thereon for facilitating the forming of a wound package therefrom.

In accordance with this invention, the carrier is formed of a sheet material such as paper wound to form a tube and having a flap secured longitudinally of the tube and extending circumferentially along the tube, and wherein the liap is sufficiently stiff and of an arcuate nature conforming substntially to the circumferential curvature of the tube to be inherently biased inwardly toward the tube to define an entrapping zone between the iiap and the exterior surface of the tube for frictionally gripping an end of material positioned therein when winding the material onto the carrier for facilitating the forming of a wound package therefrom.

With the foregoing in mind, it is the primary object of this invention to provide a method of forming such a carrier for facilitating the handling and winding of material on the carrier in making wound packages.

Some of the objects and advantages of this invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIGURE l is a perspective view of the carrier of this invention;

FIGURE 2 is a sectional view through the carrier of FIGURE 1, taken as indicated by the line 2 2 in FIG- URE l;

FIGURE 3 is an enlarged scale section view of a portion of the carrier of FIGURE 1, taken as indicated by the section lines in FIGURE 2;

FIGURE 4 is a perspective view of the carrier of FIGURE 1, with the ilap displaced from the tube;

FIGURE 5 is a perspective view of a partially formed package in accordance with this invention, including a "ice carrier as illustrated in FIGURE 1 and a length of material being wound thereon;

FIGURE 6 is a section View through the partially formed package of FIGURE 5, taken as indicated by the line 6 6 in FIGURE 5;

FIGURE 7 is a view similar to FIGURE 6 of a completed package in accordance with this invention;

FIGURE 8 is a schematic showing of a portion of an apparatus for practicing the method of this invention for making the carrier of FIGURE 1;

FIGURE 9 is a schematic elevation view of a portion of ithe apparatus of FIGURE 8, taken as indicated by the` line 9-9 in FIGURE 8;

FIGURE 10 is an elevation view, in partial section, of a portion of the apparatus illustrated in FIGURE 9, taken generally as indicated by the line 10--10l in FIG- URE 9;

'FIGURE ll is an elevation view, in partial section, of a portion of the apparatus illustrated in FIGURE 9, taken as indicated by the line 11-11 in FIGURE 9;

FIGURE l2 is a perspective view of a sheet of thin flexible material such as paper at an intermediate step in the method of this invention;

FIGURE 13 is a view similar to FIGURE 12, including a schematic showing of an alternate step in the method of this invention; and

FIGURE 14 is a schematic flow diagram illustration of certain steps of the method in accordance with this invention.

Referring now more particularly to the drawings, a package carrier or core in accordance with this invention, generally indicated at 10, is illustrated in FIGURES 1-4. As there shown, the carrier 10 comprises a tube 11 and an arcuate iiap 12 extending in circumferential and longitudinal directions along the tube 11. The tube 11 is in the form of a cylinder, preferably a right circular cylinder, with a cylindrical exterior surface 14, and the arcuate flap 12 is secured along a longitudinal portion of the exterior surface 14.

In order to facilitate the winding of a length of material about the carrier 10 to form a package, as will be described in greater detail hereinafter, the ilap 12 is relatively stiff, normally disposed in a circumferentially curved position substantially conforming to the curvature of the exterior surface 14 and adjacent thereto (FIGURE 2), and adapted to overlie the innermost or leading end of a length of material to be wound about the carrier and to cooperate therewith in aligning the first wind of material square with the tube 11 and in retaining the material during subsequent winding and handling. To this end, the proximal opposing surfaces of the tube 11 and the flap 12, namely the cylindrical exterior surface 14 and an interior surface 15 of the flap, respectively, together define an entrapping zone between the surfaces. The relative stiffness and circumferential curvature of the flap 12, obtained as a result of the method of this invention as will be described in greater detail hereinafter, contribute to the cooperation of the flap 12 with a length of material to be wound about the carrier 10, and render the trapping zone effective for facilitating the winding material, by normally biasing the flap 12 radially inwardly toward the tube 11.

Insertion of a leading or innermost end of material, during formation of a package using the carrier 10 of this invention as hereinafter described, is facilitated by the flap 12 having a substantially linear free edge 16. As here used with reference to the free edge 16 of the ap 12, linear means that the edge 16 is not sinuous or wavy, but defines a substantially straight line, which preferably is more or less parallel to a longitudinal line on the exterior surface 14 of the tube 11. Additionally, a minor surface area of at least one of the proximal

opposing surfaces

14, 15 of the tube 11 and flap 12, such as the minor surface area 17 of the flap 12 (FIGURE 4), has a residue of adhesive material thereon, which residue is ineffective to bond the opposing proximal surfaces together. The presence of the residue tends to increase the roughness of the minor area portion on which it is present, thereby increasing the coefficient of friction of that surface portion for aiding in holding the innermost end of material and facilitating the winding thereof. Further, if deemed desirable, a friction increasing material may form a component of the adhesive appearing in the residue thereof or may be applied to the interior surface 15 adjacent the minor surface area 17 or to the opposing exterior surface 14 of the tube 11. Where the residue is on the interior surface 1S of the ap 12, the minor surface area 17 extends adjacent the free edge 16.

Preferably, and in accordance with this invention, the carrier 10 is formed of a thin sheet of fibrous material such as paper or paperboard, having a thickness of from about ten points to about sixty points. In the paper industry, the use of points to indicate paper thicknesses refers to thousandths of an inch so that, stated differently, the thickness of the sheet from which the carrier 10 is formed is from about 0.010 inch to about 0.060 inch. For the purposes of winding material about the carrier 10, internal diameters of from about one inch to about six inches have been found preferable. Depending upon the material to be wound about the carrier 10, the length of the carrier may range from about 36 inches to about 200 inches. Expressed in terms of the ratio of the length of the carrier 10 to the internal diameter of the carrier 1 0, those ratios for which the carrier of this invention finds usefulness thus may vary Within the range of from 6:1 to 200:1. With carrier dimensions as set forth above, adequate and proper retention of material is obtained when the circumferential extent of the flap 12 is a minimum of about 11/2 inches, and the flap preferably has a longitudinal extent substantially the same as the length of the tube.

Preferably, the tube 11 of the carrier 10 is formed by a plurality of overlying convolution windings of the thin sheet material, and the arcuate flap 12 is formed integrally with the tube 11. The arcuate flap 12 is defined by the trailing end portion of the outermost or last convolution or winding, including the minor surface area 17, which is free from or not bonded to the remaining convolutions of the tube 11 (FIGURES 2 and 3). The major portion of the convolutions are relatively permanently bonded together.

The package of this invention, including a carrier as described above, and the manner of forming the package may best be discussed with reference to FIGURES -7. In FIGURE 6, a package in accordance with this invention, generally indicated at 20, is being formed. The package includes a carrier 21, similar to the carrier illustrated in FIGURES 1-4 and described above, and a length of material 22 being wound upon the carrier 21 as a core. As illustrated, the material 22 represents a length of carpet material, positioned with the leading or innermost end 24 of the length of carpet interposed between the fiap 25 and the exterior surface 26 of the carrier 21, so `that the flap 25 overlies that end 24 and the end is pos1t1oned 1n the entrapping zone defined therebetween as described above. When slightly more than one revolution of the carrier 21 has been made during Winding (FIGURES 5 and 6), the force necessary to proceed with winding'of the material 22 onto the carrier 21 reinforces the frlctlonal surface contact occurring in the entrapment zone, thereby assuring adequate retention of the material 22 on the carrier 21.

Further, as best shown in FIGURE 7 Where a completed package including a number of windings of material 22 is shown, the flap 25 provides a substantially continuous and smooth or tapering transition over the innermost end 24 of the material 22, thereby entirely avoiding the marking which has sometimes appeared in conventional packages formed about convolute tubes as cores.

A preferred method for making the carrier 10 of FIG- URES 1-4, in accordance with this invention, may be briefly stated as winding a thin sheet of suitable material such a paper or paperboard into a plurality of successive overlying convolutions, while the thin sheet has adhesive on one surface thereof. The winding of such a thin sheet into a convolute tube is such that the trailing end of the last or outermost convolution includes a minor surface area of the sheet and extends in an arcuate position contiguous with the exterior surface of the last preceding convolution. As wound, the sheet, or at least the portion of the sheet including the minor surface area, contains a predetermined quantity of moisture. Thereafter, the thus Wound sheet is treated to adhesively bond together a major portion of the convolutions. Simultaneously, the trailing end of the last convolution, including the minor surface area, is temporarily restrained in the arcuate position contiguous to and in intimate engagement with the last preceding convolution and the moisture content of the sheet is reduced to stiffen the trailing end into the arcuate form, so that the flap 12 provided thereby for the carrier 10 conforms to the curvature of the exterior surface of the tube and maintains the desired circumferentially curved position. In particular, the free edge of the trailing end portion of the last convolution, which is subsequently to be the free edge 16 of the flap 12, is temporarily restrained in a contiguous relation to the underlying convolution throughout its longitudinal length during the treatment, in order to assure that the free edge 16 of the carrier 10 has the linear characteristics described above.

The detailed steps of the method may best be described with reference to FIGURES 8-14, wherein a glue applying and tube winding apparatus, indicated generally at 30, suitable for use in practicing the method of this invention has been schematically illustrated. The apparatus 30 preferably may be similar to the apparatus disclosed and claimed in United States Patent No. 3,073,218, issued Ian. 15, 1963 to C. L. Roediger et al. and assigned to the assignee of the present invention, and a detailed description of the apparatus is not here required as reference may be made to that patent. In practicing the method of this invention using such an apparatus, a thin material 31 of indeterminate length, such as paper or paperboard, is fed from a suitable source of supply such as a roll 32 to a glue applying and tube winding apparatus 30. The material 31 is passed through a glue applying work station, generally indicated at 34, severed into appropriate lengths or sheets by a cutter means, and the sheets are supported on a work-support surface defined by a number of wires or cables 35 and wound in a plurality of successive convolutions about a suitable mandrel 36. Upon completion of the winding of a sheet of material 31 about the mandrel 36, the tube thus formed is removed from the mandrel.

In accordance with the method of the present invention, adhesives are applied to at least portions of one surface of the material 31 at the glue applying station 34 of the apparatus 30. At that station, the material 31 may be passed over an idler roller 39 to reverse the direction of the sheet (FIGURE 9), and then passed with one surface of the material 31 in contact with first and second

glue applying rollers

40, 41 rotatably supported in glue troughs, or

fountains

42, 43, respectively. As the surface of the material 31 is passed in contact with the

glue applying rollers

40, 41, the rollers are caused to revolve, and apply adhesive from the

fountains

42, 43, to the areas of material 31 in contact therewith. Preferably, the first and

second rollers

40, 41, respectively, are axially spaced apart (FIGURE 10), so that a void area or zone is provided, between the areas to which glue is applied, which is free of adhesive. The positioning of the second roller 41 should be such that one edge 44 of the material 31 passes thereover.

Upon leaving the glue rollers, the material 31 is passed over another idler roller 45, to again reverse the direction of travel of the sheet, and through the nip of a pair of

feed rollers

46, 47, to be fed onto a Work table surface as may be provided by a plurality of wires or cables 35. Suitable cutter means, such as a shaft 49 supported for oscillation and carrying a cutting edge 50 thereon and an anvil 51 positioned on the opposite side of the material 31 from the cutting edge 50 maybe provided at this point to sever the material 31 into length or sheets suitable for the longitudinal dimension or length chosen for the carrier being manufactured. As a severed sheet of the` material 31 is fed onto the work table surface, it may pass with the surface of the sheet opposite the adhesive" carrying surface of the sheet in contact wih a suitable moisture applying roller 53, rotatably supported in a water trough or fountain 54, when required and for purposes as described more fully hereinafter.

As severed into sheets suitable for Winding by the apparatus 30, a length of the material 31 will have the appearance illustrated in FIGURE 12. As there shown, the sheet 55, prepared for convolute winding into a carrier including a tube and a flap, may be seen to have a major surface area 56 of one surface to which adhesive has been applied by the first glue roller 40 4from the fountain 42. Additionally, the sheet 55 has a minor surface area 57 of the one surface, to which an adhesive has been applied by the second glue roller 41 from the fountain 43. The major and minor surface areas 56, 57 are spaced apart to leave a void surface area 58 therebetween which is free rfrom adhesive.

Preferably, the adhesive applied to the major area 56 is a first type of adhesive, having an initial tack and subsequent bond characteristic. By this characteristic, it is meant that the first type of adhesive is sufficiently tacky to secure the surface to which the adhesive is applied to another surface of the sheet 55 with which it cornes in contact, during the winding operation in the apparatus 30. Further, the first type of adhesive, as applied to the major area portion 56, will subsequently bond those surfaces in a substantially permanent manner. While a wide variety of adhesives or glues will have a suitable initial tack and subsequent bond characteristic, an inexpensive water soluble cornstarch type of adhesive is preferred in practicing the method of this invention for economic reasons.

The adhesive applied to the minor area 57 is preferably a second type of adhesive having an initial tack and latent release properties or subsequent release characteristic. That is, the adhesive material chosen for use as a second type of adhesive has sufficient tackiness to adhere together the minor area 57 to a surface with which it comes in contact during the Winding operation n the apparatus 30, and to temporarily maintain the adhesive tack. Subsequently, the second type of adhesive material has its bonding effectiveness substantially reduced, or has the same destroyed, to readily permit the release of the minor area from adhesive restraint. A resinous type glue or adhesive which is water soluble and substantially loses bonding effectiveness upon a reduction in moisture content, as by crystallizing, is preferred for the second type. One of many of these types of glues that are effective for this purpose is that commercially available as Swift & Co. 2822 adhesive.

As may be seen in FIGURE 12, the minor surface area 57 to which the second type o-f adhesive is applied extends immediately adjacent one side edge 58 of the sheet 55. The winding operation is then carried out in such a manner that the side edge 59 becomes the trailing edge of the sheet as convolute windings are formed, and the portion of the sheet S including the minor area 57 subsequently defines the flap 12 of the carrier 10 described above. Adhesively securing the edge of the trailing end portion of the outermost or last convolution and maintaining the adhesive restraint until such time that the moisture content of the sheet material has been reduced to stiften the flap defined by that portion are particularly important where the sheet material has a thickness of more than 25 points. Material of such thickness nor-mally has sufficient stiiness when wound, even with the necessary moisture content, to create a torque which would entirely unwind the convolute tube before the adhesive was set unless the edge is restrained along its full length longitudinally of the tube. Where a carrier `for carpet is being manufactured, the sheet thickness used normally is at Ileast 25 points.

Due to the arrangement of the apparatus of FIGURES 8-10 as described above, the first type of adhesive is placed in the wide trough or fountain 42, and is applied by the first roller 40 to a portion of the sheet 31 which will become the major surface area 56 of a severed length 5S of the sheet material. Similarly, a supply of the second typ'e of adhesive is provided by the fountain 43, to be applied by the second roller 41 to a portion of the sheet material 31 adjacent one edge thereof, which will subsequently become the minor surface area 57 of a severed length 55 of the sheet material. With the apparatus as described above, and the adhesive applying rollers 40', 41 being used, the applications of adhesives to the major and minor surface areas are concurrent.

In accordance with a modification of this invention, it is not necessary that the adhesive applications be concurrent. More particularly, as schematically illustrated in FIGURE 13, a suitable injection nozzle =60 :receiving an adhesive material suitable -for the second type from a pressure device 61 may be employed to deposit a thin strip or ribbon of adhesive material in a minor surface area 62 of a sheet 64, Such a modification may be adapted to the apparatus 30 of FIGURE 8 by positioning the eX- trusion nozzle 60 to overlie a severed length of the sheet material 31 as the same is fed rforwardly by the Kfeed rolls 46, 47 onto the Work table surface provided by the cables or wires 35'.

In order for a sheet being wound onto a convolute tube by the apparatus 30 to be easily formed into convolutions and for the trailing end portion to lie properly contiguous to the exterior surface of the immediately underlying convolution, it is necessary that the sheet material 31 contain at least a predetermined quantity of moisture at the time the windings are formed. The moisture must be suficient to permit ease in winding the sheet into the tube body and flap and to insure that the arcuate configuration obtained for the flap will be retained upon a reduction of moisture content of the paper. Under certain conditions of ambient humidity, with certain thicknesses of paper and when water soluble adhesives are used, sufficient moisture may be present in the paper or derived from the applications of adhesive to provide the necessary quantity of moisture. However, under conditions of lower ambient humidity, with paper of other characteristics, when a non-water soluble adhesive is used as the second type, or when a high solids content adhesive is used, the addition of moisture to at least the trailing end portion of a length of the sheet 31 may be required in order to obtain that predetermined quantity which will impart the desired characteristics during winding. It is in the latter circumstance that the application of water by the roll 53 is required.

In winding the glued or adhesive carrying sheet into a plurality of successive overlying convolutions, as by placing the side edge of a sheet remote from the side edge adjacent the minor surface area against a mandrel and rotating the mandrel t0 wind the sheet thereabout, the apparatus 30 illustrated in the drawings positions a sheet with the adhesive carrying surfaces upwardly, and winds the convolutions with the adhesive carrying surfaces directed inwardly. While this winding is preferred, it is contemplated that the carrier of this invention might be wound with the adhesive carrying surfaces of a sheet facing outwardly, by providing appropriate void areas so that the outermost or last convolution, including the trailing end portion which is to define the arcuate ap, would not be permanently adhesively bonded.

Subsequent to winding of a sheet to form a carrier including a tube and an arcuate fiap, the thus wound sheet is appropriately treated to set the first type of adhesive and permanently bond a major portion of the convolutions and to reduce the moisture content of the sheet to set the arcuate configuration of the trailing end portion. The reduction of the moisture content of the sheet, as well known in paper making and paper Working, causes the paper sheet to stiffen or set in the position in which it is restrained during the process of reducing the moisture content. Thus, the restraint of the trailing end portion of the last or outermost convolution in contiguous relation to the underlying convolution causes the trailing end portion defining the fiap to maintain the desired circumferential curvature thereafter, with the stiffness and the curvature contributing to the desirable result obtained with the carrier as described hereinbefore. As the moisture content of the sheet is being reduced, the trailing end portion, defining the flap, is restrained in the contiguous arcuate position until the moisture content is reduced to such a level to set the curvature in the flap. In particular, the edge of the trailing end is restrained in intimate engagement with the underlying convolution, in order to obtain the linear free edge desired for the fiap. Preferably, the restraint of the trailing end portion and the edge is an adhesive restraint, resulting from the application of the second type of adhesive to the minor surface area, and the adhesive tack of that surface area to the underlying convolution.

Subsequent to the setting of the adhesive to permanently bond the major portion of the convolutions and the reduction of moisture content to set the arcuate curvature of the fiap, the bonding effectiveness of the second type of adhesive is substantially reduced or destroyed. As the second type of adhesive provides the adhesive restraint holding the trailing end portion in the contiguous position, the trailing end portion or the fiap may thereafter be moved free from engagement with the underlying convolution. Where the second type of adhesive is a resinous type of adhesive, as preferred, the crystallization of the adhesive and substantial reduction or destruction of bonding effectiveness thereof results from the reduction in moisture present in the sheet. The bonding effectiveness may be substantially reduced or destroyed in other manners where other adhesives are chosen, Upon the complete destruction of the bonding effectiveness of a resinous type adhesive, a residue of adhesive material remains on one of the proximal opposing surfaces which were temporarily bonded together by the adhesive to provide the adhesive restraint.

Preferably, the treating of the thus wound tube to set the adhesive, reduce the moisture content of the sheet, and thereafter substantially reduce or destroy the bonding effectiveness of the second type of adhesive includes heating the convolute wound sheet. Heating the wound sheet, by passing the sheet from the glue applying and winding apparatus 30 to a tube drying oven 70 (FIGURE 14), will drive off moisture from water soluble adhesives to set the curvature of the convolutions and particularly of the trailing end of the last convolution, and will crystallize the second type of adhesive to thereafter release or permit ready release of the flap. It is apparent, however, that other methods of treatment such as air drying may be appropriate where time considerations and ambient con* ditions permit.

It is thus seen that a novel method of forming a carrier has been disclosed wherein the stiffness of the carrier flap and the arcuate nature thereof bias the flap toward the tube for defining therebetween a frictionally entrapping zone for engaging an end of material positioned therein and for facilitating starting the first wind of material square with the tube axis and the winding of the remainder of the material on the carrier in forming a wound package.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

We claim:

1. A method of making a carrier adapted to be used as a core for wound material, said carrier comprising a tube and a relatively stiff inwardly biased arcuate flap longitudinally secured thereto and extending circumferentially thereof, said fiap being adaptable to overlie and secure the innermost end of a length of material wound onto the carrier for facilitating the winding of the material thereon, said method comprising winding into a plurality of successive overlying convolutions a relatively thin sheet of fibrous material containing a predetermined quantity of moisture therein, while adhesively bonding together the successive convolutions in the tube-forming portions of the sheet by an adhesive of one characteristic and while adhesively bonding the trailing end arcuate flap forming portion of the sheet to the underlying convolution by an adhesive of another characteristic having latent release properties, and drying the thus wound sheet to reduce the moisture content in the wound sheet to impart stiffness and an inward bias to the flap while setting the adhesive on the tube forming portions and while rendering ineffective the bonding characteristics of the adhesive on the flap whereby the trailing end of the flap will readily separate from the tube.

2. A method of making a carrier adapted to be used as a core for wound material, said carrier comprising a tube and a relatively stiff inwardly ybiased arcuate flap longitudinally secured thereto and extending circumferentially thereof, said flap being adaptable to overlie and secure the innermost end of a length of material wound onto the carrier for facilitating the winding of the material thereon, said method comprising applying first and second types of glue to major and minor surface areas, respectively, of one surface of a relatively thin sheet of fibrous material containing a predetermined quantity of moisture therein, with the second type of glue having latent release properties,

winding the glued sheet into a plurality of successive overlying convolutions to form a tube with the trailing end of the last convolution of the sheet including the minor area thereof defining a trailing arcuate flap positioned contiguous to the exterior of the last preceding convolution, and

heating the thus wound sheet to reduce the moisture content to a predetermined level to impart stiffness to the tube and to the arcuate flap while setting the first type of glue for bonding the tube and while rendering ineffective the bonding characteristics of the second type of glue whereby the trailing end of the flap will readily separate from the tube.

3. A method according to claim 2 wherein the glue is applied uniformly over the major and minor areas of the sheet while a void area free of glue is formed separating the major and minor areas and with the glue in the minor area extending along and adjacent the edge of the trailing end of the sheet to serve for restraining the edge in a linear position against the underlying convolution until the heating destroys the bonding effectivness thereof.

4. A method according to 3 wherein the combined circumferential length of the void area and minor area is at least about 11/2 inches.

5. A method of making a carrier adapted to be used as a core for wound material, said carrier comprising a tube and a relatively stiff inwardly biased arcuate ap longitudinally secured thereto and extending circumferentally thereof, said fiap being adaptable to overlie and secure the innermost end of a length of material wound onto the carrier for facilitating the winding of the material thereon, said method comprising feeding a predetermined length of relatively thin weblike fibrous material from a roll in a predetermined path of travel, while applying a first type of glue to a major area of one surface portion of the predetermined length of material and while applying a second type of glue having latent release properties to an adjacent minor area thereof,

while applying a predetermined amount of moisture to at least the minor area portion of the material to raise the moisture content thereof to a predetermined level,

severing the predetermined length of material to form a sheet,

winding the sheet into a plurality of successive overlying convolutions to form a tube with the trailing end of the last convolution of the sheet including the minor area and defining a trailing arcuate flap contiguous to the exterior surface of the last preceding convolution, and

heating the thus wound sheet to reduce the moisture content to a predetermined level to impart stiffness and inward bias to the arcuate ap while setting the first type of glue for bonding the tube while rendering ineffective the bonding characteristics of the second type of glue whereby the trailing end of the fiap will readily separate from the tube.

References Cited UNITED STATES PATENTS EARL M. BERGERT, Primary Examiner I. C. GIL, Assistant Examiner U.S. Cl. XR.