US 2308197 A
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Jano l2, 943. M. s. MEYER PACKAGEy OPENING MEANS Filedl Aug. 21, 1941 3mm/WM M750/7 Meyer- Patented jan. i2, 1943 PACKAGE OPENING MEAN S Milton S. Meyer, Wellington, New Zealand, as-
signor to Wngfoot Corporation, Wilmington, Del., a corporation of Delaware Application August 21, 1941, Serial No. 407,730
This invention relates to a tear tape which may be used with any type of severable wrapping lm, but which is designed particularly for use with a film of unoriented material. That is, a film which has no appreciable grain. A film such as Cellophane which is formed by extrusion has a grain and an ordinary tear tape may be used satisfactorily with such a iilm, because when one starts to tear Cellophane it will tear in a straight line. However, lms of unoriented material, such as Pliolm (rubber hydrochloride) and films of cellulose esters, such as cellulose acetate or proprionate or nitrocellulose, or films of synthetic materials, such as polyvinyl compounds and other film-forming elastoplastics which are cast from a solution are unoriented. They have no grain. When one starts to open a package enclosed in such a lm, if the ordinary tear tape is employed, the lm will tear with a jagged edge, and the course of the tear cannot be readily directed. With the tear tape of this invention the course of the tear can be directed, and a substantially smooth edge is produced on the film. The invention will be described more particularly in connection with a tear tape of rubber hydrochloride used with a rubber hydrochloride wrapper, although it is to be understood that both the tear tape and the wrapper may be composed of l other material.
The tear tape of this invention is readily torn longitudinally into three sections, and the edges of the torn tape are relatively free from irregularities. They are substantially smooth. When such a tear tape is formed on or affixed to the Wrapper, the wrapper will tear with the tape. Whereas with the ordinary tear tape a wrapper of unoriented material will not tear in any predetermined direction and will give a jagged edge, with the tear tape of this invention the direction in which the wrapper is torn is controlled, and a relatively smooth edge is produced by the tear.
The invention will be further described in connection with the accompanying drawing in which Fig. 1 is a top View of a wrapped package; Figs. 2 and 3 are top views of packages with a diierent wrapper and tear tape arrangement; Fig. 4 is an end View of Fig. 1; Fig. 5 is an enlarged end view of the tear tape, and Fig. 6 is an enlarged section of the closure shown in Fig. 3.
A The tear tape may be formed in diierent ways. The preferred form of tape has the same composition as the wrapping material. The packages shown in Figs. 1, 2 and 3 are covered with Pliolm l, and the tear tapes shown are preferably composed oi 'rubber hydrochloride. The edges 2 and 3 of the wrapper are overlapped in the usual way, and they are united in the stippled area fi by the application of heat and pressure. Instead of a heat-seal the closure may be formed by an adhesive or in any desiiedmanner. The tear tape I0 is advantageously located beneath the wrapper l.
As shown most clearly in the end View illustratedin Fig. 5, the tear tape may be made of three sections or strips o1` material Il, l2 and I3 united to a base material lil, or, if preferred, these three sections might be united directly to the wrapper I. The middle section has high tensile strength and the outside sections are iormed of material which cannot easily be torn lateral- 1y. With this construction, with the three sections united directly to the wrapper l, or to the base I4 which in turn is united to the wrapper I throughout its area, if short cuts are made in the wrapper (and also the base material lli, if one is used) in each of the spaces i5 and i6 between the sections to separate an end of the middle section from the side sections so it may easily be torn away from them, it is possible by grasping the free end of the middle section to separate it irom the section on either side and also to tear away the portion of the Wrapper l lto which it is united. A path of substantially uniform width is thus cut into the wrapper. Its direction is guided by the sections or banks il and i3. The section i2 must have sufficient tensile strength to stand the pull required to make this tear.
If the tear tape is to be used with a Plioiilm wrapper it is advantageously made of rubber hydrochloride. The base it may be made of ordinary rubber hydrochloride im, or it is preferably made oi film which has been heated and stretched several hundred per cent, and preferably thebase lll is built up of several plies of such stretched film, for example, three plies, each of which has been stretched several hundred per cent and all of which have been united by heat and pressure. The method of stretching and laminating several plies of rubber hydrochloride iiim using, in the lamination, the heat required for stretching, is old. in the art. As a specific example, the base l@ may be made from three plies of Pliolm, each 0.001 in thick which are heated and stretched to one-sixth their original thickness and united while hot by passing them between pinch rolls.
` rThe sections il, i2 and I3 may each be made in the same way. Tlfrey may be banks of stretched rubber hydrochloride film lam-.hated together.
in this way have great resistance to lateral tear. 'Ihus when one starts to strip away the middle section I2 the banks II and I3 guide the direction in which the lm tears.
the wrapper in a substantially straight line. Itv
will, of course, be appreciated that the base I4 may be eliminated entirely, and the sections II,
I2 and I3 may be united directly to the wrapper.
I asoialil'i strips of rubber hydrochloride material formed the initiale` section of the tear tape, together with the portion of wrapper I which is united toit, will be torn away from the side portions of the tape,
and the narrow slit thus formed in the wrapper between the side sections or guides will have relatively smooth edg.
Instead of providing a tab as shown in Fig. l the ends of the sections -II and Il may be cut away so as to -leave the section I2 protruding to form the tab 2i shown in Fig. 2. Depending upon the construction of the package the heat seal may be carried straight across the package, or it may be dropped away from the end of the If united to the base material, and if the three 4 sections and the base are all com-posed of rubber hydrochloride lm, they may be united to one another in a single processing step. For example, the several plies of illm required to make the tape will be heated and while hot will be stretched and then with pinch rolls' they will be united to one another to form the tear tape. The several plies forming the sections II, I2 and Il may be united to one another and also to the base Il in a single operation. Ii' the base I4 compriseses several plies these maybe similarly united in the same operation.
It will be found desirable to ilx the tear tape so that the middle section may be easily grasped and torn away from the other sections. If the nlm is made as shown in Fig. 5 with the sections II, I2 and I3 all composed oi' stretched rubber hydrochloride iilm and the base I4 composed of one or more plies of stretched rubber hydrochloride ulm, the tear may be started by cutting the end of the tear tape so that it makes a suitable tab, such as the tab 20 of Fig. 1 or the tab 2i of Fig. 2. 'I'he base I4 being of oriented material, it will tend to tear longitudinally and if the end of the middle section can be easily grasped it will be easy to tear it away from the other sections.
Following the usual practice the nlm and tearv tape will be fed in the usual way to the wrapping machine and will be simultaneouslyr wrapped around the package. l Heat may be applied to unite the whole of the bottom area of the tear tape IIJ to the wrapper I, or an adhesive may be used for this purpose. The iilm and tear tape will be fed to the wrapping machine from large rolls. Sections will Abe cut to length in the usual way, and the wrapper and tear tape will be cut simultaneously. 'Thus in forming-the tab 20 or 2| on the outer edge of the Wrap, a complementary depression 22 or 2l is cut in the under edge of the wrap.
It will be noted that the edges of the tab 2l if' projected would come within the openings Il and I6 between the sections of the tear tape. 'I'he tab 20 may be easily grasped as shown in Fig. 4.
ZBy pulling lt the base I4 of the tear tape will readily tear along the openings IB and It, and
tear tape somewhat as shown in Figs. 2 and 3.
Fig. 4 shows another form of the invention in which the wrapper and tear tape are cut oi! straight, and preferably in the same operation the edge of the wrapper and tear tape are slit a short distance along the lines 2l and 2l. This forms the tab 20 shown most clearly in the enlarged detail in Fig. 6. This tab is composed of the middle section of the tear tape I2 and the base to which it is united and, of course, some of the wrapper I to which the tear tape is united. Looking in the direction 'indicated by the arrows I-I in Fig. 3 one will see beyond the tab 26 the section Il oi the tear tape covered by the wrap per 1.
lto facilitate the tearing thereof.
It will be obvious that many variations in the` construction of the tear tape are possible. For instance, the banks or guides II and I3 may be formed of any suitable material which will resist lateral tearing. The different parts of the tear tape may be made of diiferently colored materials to add to the attractiveness of the package. .The tear tape may, of course, be located in any position desired. It may be used on boxes as'shown away from the remaining sections.
What I claim is: i
In combination with a package enclosed in a rubber hydrochloridenlm. a tear tape united to the illln which tear tape comprises a ply of rubber hydrochloride film the width of the tape and adhered thereto three strips of permanently elongated rubber hydrochloride nlm. the sum oi the widths of the three strips being no greater than the width of the tear tape and at one end of the tear tape at each side of the middle strip and between the middle strip and the two side strips. a slit in the wide ply of rubber hydrochloride nlm M. S. MEYER..