US2268004A - Container closure - Google Patents

Description

Dec. 30, 1941. l. l.. wlLcox CONTAINER CLOSURE Filed NOV. 26, 1938 mgm. ww;

Il (Il INVENTOR. ISAAC L. w/Lcox Patented Dec. 30, 1941I CONTAINER CLO SURE Isaac L. Wilcox, Fulton, N. Y., assigner to Oswego Falls Corporation, Fulton, N. Y., a corporation of New York Application November 2s, icas, serial No. 242,536

(ci. 21S-3s) Claims.

This invention relates to container closures formed of sheet fibrous material, for example a bottle cap of the hood or cover-all type formed from paper board and provided with a skirt portion encircling the neck of the bottle immediately below the top thereof.

The invention further relates to a closure of the type referred to, the skirt portion of which is formed with overlapping folds or pleats which are secured together by means of an adhesive.

The invention has as an object, a container closure formed of fibrous material which is coated with a substance rendering the cap impervious to water, which substance possesses the characteristics of being non-tacky and non-adhesive at all temperatures to which the cap is normally subjected, and which is rendered tacky and adhesive by the application of heat at a comparatively high temperature, the coating serving as the adhesive for securing the skirt portion of the closure about the neck of the container.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawing in which like characters designate corresponding parts in 4all the views.

Figure 1 is a plan view of a disk or sheet of brous material from which the closure is formed and illustrating the coating on one side thereof.

Figure 2 is a view, similar to Figure l, illustrating the coating on the `opposite side of the blank.

Figure 3 is a side elevational view of the closure applied to the container or bottle and a contiguous portion of the bottle.

Figure 4 is a fragmentary view of the sheet illustrated in Figure 2 showing the coating thereon greatly enlarged.

Figure 5 is a view taken on line 55, Figure 3.

Certain types of container closures, such as milk bottle caps, are subjected to excessive moisture. For example, when the bottles are packed in ice. Accordingly, if the caps -are formed of fibrous material. such as paper board, it is necessary that the caps be coated with some substance formed, such as during the application of the closure to the container, the wax cracks and water will leak into the tiny fissures and eventually wick throughout the cap or closure. If the cap is heated, the hot paraflin will rapidly soak into the paper and accordingly make the surface of the paper moisture absorbent. melting point of paraflin is so low that the parain will soften and run in summer weather. This prevents the closures from being arranged in stack formation inasmuch as the closures would become stuck together in the stack. It is not vuncommon for temperatures within freight cars and warehouses to reach 13D-140 degrees Fahrenheit. The use of paraffin also excludes the possibility of using an adhesive to secure the overfolded portions of the closure together. The adhesive properties of the parain are not of sucient strength to permit that substance to itself serve as an adhesive. Accordingly, caps coated with parafn must be secured to the bottle by some other additional securing means, such as a n wire ring, staples, 'or the like, which adds mato render them impervious to water and substantially impervious to moisture. Heretofore, it has been common practice to coat such caps with paraffin. However. paraiin is not satisfactory as a coating. In the rst place. the parafn is not a reliable moisture repellent coating due to the fact that it is of necessity used sparingly and when the parafncoated paper is bent or deterlally to the cost of the cap and the time consumed in applying the same.

The closure of this invention is coated with a substance that is non-tacky or non-adhesive at any temperatures to which the closures are ordinarily subjected.

Certain thermoplastics, for examplev those of the vinyl resin order and certain hot melts, are particularly well suited for an impervious coating and also serve as a strong adhesive to secure the overfolded portions of the closure together. Such substances possess the further advantage that they are at normal temperatures, and up to F., non-tacky and non-adhesive and accordingly, caps coated with such substances may be shipped in nested or stack formation, and may be separately removed from such formation for application to the bottle without the caps sticking together. However, to render these substances tacky and adhesive, the application of heat at considerably high temperatures is necessary.

When the sheet, or the closure formed therefrom, is coated in the usual manner on both sides with the `thermoplastic and subsequently heated suiciently to reactivate the thermoplastic, the closures or blanks swell and blister to such an extent that they are not usable. This swelling or blistering results from the moisture in the sheet or cap being converted into steam or vapor by the high temperature, and due to the fact that the Closure is coated with an impervious or gas The` tight substance there is no avenue of escape for the steam and vapors, and a pressure builds up sufficient to split and separate the layers of the sheet.

` material, such as paper board, being preferably of circular contour. One side: of the sheet l is coated over its entire area with the moisture repellent substance, as shown in Figure 1, and a selected area only on the opposite side is coated with such substance, as shown in Figure 2. The coating on the opposite side, as illustrated in Figure 2, is preferably a spot or stippled coating.

That is, the coating is applid to closely arranged but unconnected areas Il on the surface of the sheet.' This coating is better illustrated in Figure 4.

The cap is applied to the tcp of the bottle B by placing the sheet I0 over the mouth of the bottle and heating the same, or the sheet may be heated just previous to placing the same over the top of the bottle. The application of the heat renders the coating on both sides of the disky tacky and adhesive. The peripheral margin of the disk is then formed downwardly about the top of the bottle, and the disk may be pre-scored in the usual manner to form the conventional pleated portions I2 permitting contraction of the skirt about the neck of the bottle. The pleated portionwis held in overlapping contracted position for a short length of time during which the coatings on the cap adhesively secure the pleats and become hardened. The overlapping pleats are then flrnily secured together, thus securing the cap to the top of the bottle. In the applicaytion of the cap to the bottle, the entirely coated side of the disk is positioned upwardly so as to form the outer surface of the cap. This provides an outer surface entirely impervious to water or moisture: .Th'e spot or stippled coating on the under side of the cap provides a practical impervious surface and supplies sufficient adhesion to the contiguous portions of the pleats as at Il.

In addition to the functions outlined, the coating of the inner side of 4the cap over a selected area also performs the important function of permitting the escape of steam or vapor from within the sheet or disk through the uncoated area during the application of heat to reactivate the coating, whereby the disk does not blister,

swell or warp, and can conveniently be molded into hood cap form on the top of the bottle.

Closures made in accordance with my inven-v when reactivated by heat, provides a powerful adhesive by which the overlapping pleats or folds are permanently secured together and accord.-

ingly, the closure can not be removed from the container by facilities ordinarily available and be again replaced on the container without disclosing the fact that the closure has been tampered with.

What I claim is:

1. A container closure formed of sheet ilbrous material, both sides of said closure being coated with a tough, elastic, gas-tight, material rendering the closure moisture repellent, said coating being applied to one side of the closure in the form of a continuous sheet extending over the entire surface of said side, and said coating being applied to the opposite side of the closure in the form of a spot coating extending over the entire surface of said opposite side.

2l A container closur'e formed of sheet fibrous material, both sides of said closure being coated with a tough, elastic, gas-tight, material rendering the closure moisture repellent, said coating being applied to one side of the closure over the entire surface thereof and being applied -in the form of small unconnectedareas over the entire surface of the opposite side of the closure.

3. A container closure formed of sheet brous material, both sides of said closure being coated with a tough, elastic, gas-tight, material rendering the closure moisture repellent, said coating being applied to one side of the closure over the entire surface thereof and being applied in the. form of small unconnected areas over the entire surface of the opposite side of the closure, said coated areas exceeding the uncoated areas.

4. A container closure formed of sheet brous material comprising a container mouth covering portion and a marginal portion foldable about the neck of the container, the outer side of said closure being coated with a tough, gas-tight, material rendering said `side impervious moisture, said coating material being normally non-adhesive and being rendered adhesive by the application of heat sulcient to vaporize any moisture within the thickness of the closure, said material when rendered adhesive serving to secure said folded portion about the neck of the con. tainer, the entire surface of the inner side of the closure being coated with like material, said coating being broken to provide venting areas to permit the escape of vaporized moisture from within theclosure sheet, the vented areas being of such dimensions as to prevent any substantial absorption by such areas. r

5, An article of manufacture formed of sheet fibrous material, one side of said sheet being coated with a tough, gas tight, material rendering said side impervious to moisture, said 'coating -material being normally non-adhesive and being

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