US2377532A - Method of fabricating collapsible tubes - Google Patents

Description

June 1945- H. F. WATERS METHOD OF FABRICATING COLLAPSIBLE TUBES Filed July 30, 1942 2 Sheets-Sheet l INVENTOR. Harry fl Wafers June 5, 1945. H. F. WATERS METHOD OF FABRICATING COLLAPSIBLE TUBES Filed July 30, 1942 2 Sheets-Sheet 2 I IN V EN TOR. flaw/ y f. Wafer:

BY M Z2 .M

Patented June 5, 1945 UNITED STATES PATENT OFFlCE.

METHOD OF FABRICATING COLLAPSIBLE TUBES Harry F. Waters, New York, N. Y.

Application July 30, 1942, Serial No. 452,960

1 Claim. (Cl. 93-551) This invention relates to improvements in methods and apparatus for forming collapsible tubes, and, more particularly, for continuously -treating cellulosic base tubulatures and applying the dispensing closures thereto.

The present invention, as intimated above, is directed to a continuous method and apparatus for fabricating and treating non-metallic collapsible tubes, and desirably, tubes of cellulosic material of the type known as reverted or regenerated cellulose. In my applications Serial No. 436,377, filed March 26, 1942, for Non-metallic dispensing tube and container; Serial No. 438,- 269, filed April 9, 1942, for Dispensing tube; Serial No. 436,378, filed March 26, 1942, for Collapsible container; Serial No. 436,379 filed March 26, 1942, for Collapsible containers; Serial No. 438,- 270, filed April 9, 1942, for Moisture-vapor transmission resistant envelope package; Serial No. 442,034, filed May 7, 1942, for Collapsible tube construction, there have been shown a variety of novel dispensing tubes of reverted cellulose or other non-metallic materials, including dispense ing closures and a variety of internal and external protective and decorative coatings. The present disclosure is concerned primarily with methods and means for carrying out the several forming, printing, drying and coating steps of my said applications.

The features of novelty of the present invention will best be understood by reference to the accompanying drawings, in which preferred fabrication steps are disclosed with reference to the apparatus suitable therefor. vIn the drawings, like numerals refer to similar parts throughout the several views, of which Fig. 1 is an elevation of an untreated tube blank;

Fig. 2 is a view similar to Fig. 1 showing the application of printing to the tubulature;

Fig. 3 is a view of a wetted or imbibed tube blank mounted on a mandrel for drying to shape;

Fig. 4 is an elevation, partly in broken section, of a tube shrunk in place on a mandrel, and over a dispensing outlet;

Fig. 5 is an elevation of a plurality of mandrels mounted on a conveyor, and being transported through a drying oven;

Fig. 6 is a detail through the dispensing end of the tube of the type shown in Fig. 4 with the upper end of the tube shrunk over the closure member, and a clamping nut mounted on the dispensing nozzle;

Fig. 7 is a view similar to Fig. 6 showing the end of a tube shrunk to shape on the end of a plain mandrel;

Fig. 8 is a vertical section through a series 0 mandrels showing the manner of printing the tubes;

Fig. 9 is a view similar to Fig. 7 showing the rolling over of the end of a tube on the mandrel;

Fig. 10 is a horizontal elevation, partly. in section, of a tube with a dispensing closure being blown off of a supporting mandrel;

Fig. 11 is a schematic view showing a method of introducing a dispensing nozzle in tubes of the type shown in Figs. 7 and 9;

Fig. 12 is a vertical elevation of an inverted, capped tube showing the coating of the inside by filling with a fluid protecting agent;

Fig. 13 is a vertical section of a capbfid tube having an internal protective coating applied by means of a spray, and

Fig. 14 is a broken vertical elevation of an 26 to adapt presently existing mechanical set-ups forthe purpose. Collapsible tubes have been made with soft metals exclusively, and manufacturing steps in this field have been developed around such soft metals. A feature of the present invention has been to devise process steps for the treatment of non-metallic tubes, .such as those of reverted cellulose, set out in my applications, hereinabove identified. The process steps described herein are developed around the controlling thought that, due to the war emergency, existing tube-treating equipment would have to be utilized, because new equipment was not available. 3

Considering the method and apparatus steps more specifically, and with particular reference to the drawings, a tube I 0 of reverted cellulose, and of suitable dimensions, is extruded from a suitable machine, not shown, and subjected to a plasticizing and/or pickling step. The regenerated cellulose may include 10 to 25 percent of a plasticizer, such as glycerine, and the pickling solution may be essentially an aqueous glycerine solution. In the pickling treatment the normally dry tubes or pellicules soak up moisture and swell. Before pickling they may have suitable printing indicia printed thereover, as indicated at H in Fig. 2.

When the tube blank It has been pickled sufliciently, or when it is taken off the extrusion machine, it may be mounted on a mandrel 20, which is carried on a spindle 2|. The pellicule or casing ill will be considerably oversized, leaving flns or margins II. This will be particularly true if the blanks lo, have been flattened after extrusion, to permit printing and shipping inthe flat. The spindles 2| may be carried, in spaced relation, on a traveling chain or carrier 35, through an oven to, where, under a suitable degree of heat, and, usually in the presence of a current of air, the pellicule rapidly shrinks and conforms to the shape of 'the mandrel 20. Where a dispensing nozzle 50 is mounted at the free end of mandrel 20 and usually on a spindle 22, the open end I! of the casing l will shrink'thereon and thereover, all as indicated in detail in Figs. 6 and '1. The dispensing nozzle 50 may comprise a disc section with nozzle outlet 52, having threads 53, and an aperture 54. The member 50 will be seen to be of T-cross-section, with chamfered shoulders 55, terminating in a ring or annulus 56. A coacting plug or nut 51 is adapted to be screwed upon the threads 53 of the nozzle, and this nut is provided with a rounded edge section 55 adapted to engage edge 55 in a ring or annular engagement and clamp the upper edge or overhang of the tube In firmly in position. It will be noted that in addition to the tube It being shrunk in place on section 5|, of the dispensing member, the upper portion is clamped between the two parts ,of the closure. Due to the fact that the surface 55 is conical, and that of 58 is spheroidal, there is a self-adjusting, line contact eifected by and between the cooperating parts of the closure,- without requiring the clamping of any extended areas or portions of the tube member II. Where the casing m is shrunk on a. mandrel without a dispensing closure, the top section I! may be bent over, while the tube is yet wet, by means of a forming roll 60. This step may take place while the mandrels are supported on the chaincarrier 30.

When lock nut 51 is screwed in place and the tube i0 is thoroughly dry, the tube may be blown off the mandrel by applying air to the tapped nozzle 53. Thereafter a cap 59 may be applied to the tube, and the latter waterproofed or otherwise treated, by inverting and filling with a proofing or coating material I0. Where several coats are to be applied, such as an anchor coat and various proofing coats, the material II will vary accordingly. Thus, wax or rubber compositions may be applied, as well as nitrocellulose coatings, vinyl resins, gutta percha, and other materials.

Another method, as shown in Fig. 13, comprises introducing a tube 80, having a rosette or series of apertures 8| at the nip thereof, into the tube, and spraying the inside thereof. This type of operation is particularly suited for use on the tubes when they are carried horizontally through an apparatus in the manner shown in Fig. 5. In such cases the tube l0 may be caused to revolve rapidly, and the spray nozzle 80 introduced into the closed end, when the spray is turned on, and the tube slowly withdrawn to the open end, when the spray is shut oil. The travel of the tube II is desirably wholly automatic. This centrifugal spraying is analogous to centrifugal casting of metals and results in a dense, but thin, internal coat of uniform characteristics. The coatings applied in this manner are appreciably thinner than those obtained by dipping, and the finished job is smoother and much more even. Upon completion of the coating steps the tubes may be removed from the machine and hung up vertically for drainage of excess coating material 12. The tubes may be externally coated, in any desired manner, by dipping or spraying, and the open bottom, may be provided with a thermoplastic coating to permit heat-sealing, if the latter is desired, or, after the tubes are filled, they may be crimped or closed in the usual manner.

While the invention has been described above with respect tothe shrinking of the tube on and over the closure member, the tube may be shrunk on a plain mandrel and the top edge turned or shaped, after which the dry tube is blown ofl the mandrel, and a closure 50 inserted into the tube casing to assume the dotted line closing position shown in Fig. 11. Thereafter the lock out 51 may be applied to complete the assembly.

In the printing of the tubes, as indicated in Fig. 8, a series of mandrels 20, secured on carrying chain 30, and adapted to be rotated thereby, are moved successively against a printing roll 90, having a printing blanket 9| secured to the surface thereof. As the several mandrels and printing roll counter-revolve in mutual contact, the tubes l0, shrunk to form on the mandrels, will be printed with the desired indicia.

It will now be appreciated that there has been described a novel method and apparatus for forming and treating collapsible tubes of reverted cellulose and like materials, and the necessary intermediate steps in the treatment of such members, including printing, shaping, application of closures, drying and unitary or multiple coating steps necessary to give the desired finished product.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:

The method of forming collapsible dispensing tubes of reverted cellulose which comprises placing a wet oversize cellulose tube blank on a mandrel with an excess of tube material extending over one end of the mandrel, subjecting said tube to controlled preliminary shrinking, rolling the shrunk'en but still damp tube over the end 7 of the mandrel to set the tube structure, completing the drying of the tube, removing the dry tube from the mandrel, pushing a shouldered dispensing nozzle into the tube and into permanent contact with the formed shoulder of the tube, and securing the formed shoulder of the tube to the dispensing nozzle.

HARRY F. WATERS.

Images