US 3380481 A
Description (OCR text may contain errors)
April 30, 1968 0. K. KRAUS CLOSED TUBE WITH FASTENER MEMBERS 3 Sheets-Sheet 1 Filed March 2. 1962 INVENTOR Oifa har/ Kraus BY Z1 44 Q April 30, 1968 0-K. KRAUS 3,380,481
CLOSED TUBE WITH FASTENER MEMBERS Filed March 2, 1962 3 Sheets-Sheet INVENTOR. 0X50 Kar/ A ra us April 30, 1968 0. K. KYRAUS 3,380,481
CLOSED TUBE WITH FASTENER MEMBERS Filed March 2. 1962 3 Sheets-Sheet 3 INVENTOR. 0/50 Ker/K7454;
United States Patent 3,330,481 CLOSED TUBE WITH FASTENER MEMBERS Otto Karl Kraus, Rego Park, N.Y., ass-R noir, by inesne assignments, to Minigrip, Inc., New York, N.Y., a corporation of New York Filed Mar. 2, 1962, Ser. No. 176,926 4 Claims. (Cl. 138-118) ABSTRACT OF THE DISCLOSURE An elongated flexible closed one-piece tube having integrally formed longitudinally continuous interlocking elements formed thereon for slitting, cutting and sealing to form closeahle and reusable pouches or bags therefrom.
The present invention relates to an improved pouch having a flexible closure and method of making the pouch, and more particularly to a tube and method of making a continuous tube which can be converted into a reusable air tight and water tight pouch with reclosable closure elements thereon.
The present invention contemplates the manufacture of a flexible bag or pouch by the formation of a closure including an elongated flexible closed one piece integral tube. The tube is formed by extruding through a single annular die opening and has continuous interlocking elements extended axially along the tube at circumferentially spaced locations, which are extruded simultaneously therewith and integral with the material of the tube.
The tube profiles are then joined and the tube is then separated or slit longitudinally between the interlocking elements in one or more places to form one or more continuous strips that can then be made into different types of bags or pouches,
An important advantage of the tube is the ease in which it can be turned into a reusable air tight and water tight pouch. Pouches heretofore have been made by much longer and more expensive processes, e.g. the closure strips or zipper for closing the pouch has been made in one extrusion process and the film for the bag by another process. The Zipper and film are then combined by a process requiring two or three different steps.
Accordingly it is an object of the present invention to provide an improved method for forming flexible closure strips and bag walls and structure for providing the strips and walls wherein the strips and walls can be extruded as a single integral unit and extrusion can be accomplished through a single annular die opening avoiding disadvantages of extrusion and sealing processes and dies of the type heretofore used.
Another object of this invention is the provision of a method of making a unitary closed tube with fastener profiles thereon which can be positioned at different locations on the tube for forming bags wherein the side walls of the bag and the fastener strips are integral.
A further object of the invention is the provision of a continuous integral tube with a series of integral interengageable profiles, which when joined, and the tube cut and processed, make possible the manufacture of air tight and water tight reusable containers in a much more economical and rapid method than heretofore.
A general object of the invention is to provide an improved structure and method of forming material for bags with closures which effect a saving in time and cost of manufacture over structures and methods heretofore available.
Other objects, advantages and features will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments thereof in the specification, claims and drawings, in which:
FIGURE 1 is a perspective view with a vertical section taken therethrough of a bag utilizing a tube with integral closure strips of the type embodied in the present invention;
FIGURE 2 is an elevational view shown in somewhat schematic form of a die with a tube being extruded therefrom;
FIGURE 3 is an end elevational view shown in somewhat schematic form of a tube constructed in accordance with the principles of the present invention;
FIGURE 4 is also an end elevational view showing a tube of modified construction;
FIGURES 5 through 8 are fragmentary end elevational views shown in somewhat schematic form of arrangements of closure elements on tubes;
FIGURE 9 is a fragmentary perspective view illustrating separating the material of the tube to form separate strips;
FIGURES 10 through 14 are fragmentary perspective views illustrating ways of cutting tubes having the structure of the present invention;
FIGURE 15 is a fragmentary perspective view showing a tube with perforations situated in the wall;
FIGURE 16 is a fragmentary perspective view illustrating a manner of separating the tube of FIGURE 15;
FIGURE 17 is a fragmentary perspective view showing the formation of openings in the tube wall;
FIGURE 18 is a fragmentary perspective view showing another step in preparing a tubesuch as shown in FIGURE 17;
FIGURE 19 is a fragmentary perspective view showing a tube with a reinforced wall portion;
FIGURE 20 is a fragmentary perspective view showing a tube with a gusset fold; and
FIGURE 21 is a schematic perspective view showing another arrangement of tube structure.
As shown on the drawings:
FIGURE 1 illustrates a pouch or bag 10 having side walls 11 and 12 arranged to form a container and being integral with each other. Their side edges are closed by seams 13 to complete the container, and the top is closed by a flexible closure structure provided by first and second closure strips 14 and 15. The closure strips are situated at the top of the bag It} and are integral with the bag walls. Flanges 2t and 21 are integrally attached to the strips to extend upwardly therefrom, and are an integral part of the container, and are extruded with the container and strips, being joined when extruded, and later cut during processing. In all arrangements the closure strips are integral with the bag walls 11 and 12 and formed of the same material.
On the inner facing surfaces the closure strips are provided with interlocking elements shown in the form of longitudinally extending ribs 16 and grooves 17. These ribs and grooves are approximately complementary shaped so that the ribs will press into the grooves when a closing pressure is applied to the outer surfaces of the strips 14 and 15. Similarly the ribs will be pulled out of the grooves when the strips are forcibly pulled apart such as by gripping the upstanding flanges 20 and 21 on the strips.
It will be understood that the invention embodies use of various types of interlocking members of the type which lock when they are pressed together and separate when forcibly pulled apart, such as illustrated for example in the Madsen Patents 2,558,367 and 2,637,085. Closure and separation of the strips may be accomplished manually such as by pressing the strips together between the thumb and forefinger, and drawing them apart with the hands.
The closure strips are made of a resilient plastic material and are conveniently manufactured by being extruded from a die along with the tube to which they are integral ly attached. Thermoplastic and thermosetting organic synthetic resins are suitable for use, and of particular importance for this use are the vinyl type resins such as polyvinyl chloride, polyvinyl acetate, polyvinyl chloridepolyvinyl acetate copolymers, and similar vinyl resins, and polyethylene. Rubber, either natural or synthetic, is not a preferred material since, in the case of rubber, it is more difficult to control the degree of rigidity for interlocking engagement between the strips. However, by proper compounding and vulcanizing the rubber, the degree of rigidity can be controlled to make rubber acceptable for purposes of the instant invention.
In accordance with the principles of the invention, such as illustrated in FIGURE 2, an elongated flexible closed integral annular tube 22 is provided with interlocking elements 23 and 24 formed integrally on the surface of the tube and extending axially therealong. As previously stated the interlocking elements may be of different shapes and configurations, and for convenience of illustration are shown as being single elements, and the elements generally will be characterized by providing a rib with overhanging shoulders or locking surfaces 25 which are receivable in a mating co-acting groove 26.
In accordance with the method of the invention the tube 22 is extruded through a die 27 having an annular continuous opening 28. The interlocking elements 23 and 24 are simultaneously extruded so as to be integral with the tube, through projecting conformations in die opening 28. Plastic is supplied to the die from a plastic feeder 29 which incorporates suitable plastic feeding and supply mechanism which need not be described in detail as will be appreciated by those versed in the art.
FIGURE 2 illustrates the interlocking elements 23 and 24 as being formed on the outer surface of the tube 22, and the elements in question can also be formed on the inner surface.
While the tubes of the different figures are shown as being of different diameters, it will be understood that a diameter is chosen in accordance with the size of bag that is required, and the sizes shown are chosen for convenience of illustration.
'In the arrangement of FIGURE 3, a tube 29 is formed with one of the interlocking elements 60 on the inner surface of the tube and the other interlocking element 31 on the outer surface. This arrangement will be advantageous in certain environments depending upon the use to which the strips are to be put, and depending upon the handling methods and mechanism for cutting .the tube, as will be discussed. The tube 29 is shown with the male interlocking element on the inner surface of the tube and the female element 31 on the outer surface, but it will be understood that these positions may be interchanged.
FIGURE 4 illustrates a tube with plural sets of interlocking elements on the surface, with the sets shown on the inner surface. A tube 32 is shown formed in the same manner as the tube in FIGURE 2, and has a male interlocking element 33 and a female element 34 adjacent each other on the inner surface, and also has a male element 35 and a female element 36 adjacent each other at the other side of the inner surface of the tube. The elements have complementary shapes so that either of the female elements may be used :with either of the male elements to provide for variations in cutting the tube longitudinally.
In FIGURE a tube 37 is formed with interlocking elements on its inner surface, with female elements 38 and '39 at one side of the tube, and male elements 40 and 41 at the other side of the tube. The elements described above could also be formed on the outer surfaces of the tube.
FIGURE 6 illustrates a tube 42 with elements provided on the outside or outer surface of the tube, with a male element 43 and a female element 44 on one side, and with a female element 45 and a male element 46 at the other side of the tube, diametrically opposite the first set of elements 43 and 44. In some instances the positions of either of the elements may be interchanged, that is, the locations of the elements 43 and 44 may be changed.
FIGURE 7 illustrates a tube 47 with multiple profiles or interlocking elements arranged on the inside and outside of the tube, with male elements 48 and 49 within the tube opposite each other, and female elements 50 and 51 outside of the tube opposite each other. In some instances it may be desired to reverse the locations of each of the male and female elements, that is, the positions of elements 48 and 50 could be interchanged, and the positions of elements 49 and 51 could be interchanged.
FIGURE 8 illustrates a tube 52 wherein the interlocking element-s or profiles are arranged so that the female and male elements are on opposite sides of the tube surfaces, and the male elements 53 and 54 are side-byside on one side of the tube within the inner surface, and the female elements 55 and 56 are side-by-side on the outer surface of the tube, positioned substantially diametrically opposite the male elements. Again, the positions of both female elements can be interchanged with the positions of both male elements.
As will be appreciated from the descriptions and illustrations of the foregoing figures, the structure incorporates an elongated flexible closed integral tube with axially extending interlocking elements or profiles on the surface thereof, with the positions of the profiles changeable to accomplish the different desired results.
FIGURE 9 illustrates a closed integral tube 57 with interlocking profile elements 58 and 59 thereon. To prepare the structure for use as a flat strip with male and female elements near the edges, a knife 60 is used to slit the tube in a longitudinal or axial direction forming a severing line 61. The severed strip which will result will have edges with profiles thereon, and it will be observed that this will form a flat strip for attachment to other strips, or can be doubled for use as a bag with the elements 58 and 59 brought together in interlocked face-toface relationship. For use as a bag, the diameter of the tube can be made much larger to provide adequate material for the bag walls. Separate bags may be formed along the length of the continuous tube by bringing the material radially together and forming flat seams to complete individual containers having the general appearance of the container of FIGURE 1, with a base of the bag being formed by the double layer of material, unless provision is made for a bottom open bag. The side seams 13 may be formed by various methods, such as by heat sealing the layers together and cutting the bag from the supply length, such as by applying a heated cutting and sealing wire if a thermoplastic material is used.
FIGURE 10 illustrates a method of severing a closed integral tube 62 with interlocking profile elements 63 and 64 on the inner surface. A knife 65 forms a severed line 66 extending axially between the elements 63 and 64. Another cut is formed by a knife 67 along a severance line 68 opposite the first severance line 66, and this will result in separate fastener strips with the interlocking elements 63 and 64 at their upper edges. When the interlocking elements of these strips are joined and after the side seams have been made, the result will be a bottom open bag for bottom loading.
FIGURE 11 illustrates another method of severing tubes such as those illustrated in FIGURES 9 and 10. A tube 69 has interlocking elements 70 and 71 on the inner surface, and is severed longitudinally along the line 72 by a knife 73. The position of the severance line 72 is such that it is closer to one of the interlocking elements than to the other. In other words, the distance shown at 74 is less than the distance shown at 75, and this will result in the flange 76 being longer than the flange 77 which will afford convenience in separating the strips manually.
FIGURE 12 shows the method of forming separate strips from a tube 78 having male and female interlocking elements 79 and 80 on the inner surface at one side of the tube and similar female and male elements 81 and 82 at the other side of the tube. A cut 83 is made by a knife 84 between the elements 81 and 82, and a similar cut 86 is made by a knife 85 between the other elements. This forms two separate strips 87 and 88, each with a male and female element at their side edges, and as will be seen from the showing of FIGURE 12 this arrangement could be used to form two rows of pouches in a manufacturing operation.
FIGURE 13 shows a method of severing a closed integral tube 89 having male and female elements 90 .and 91 on the inner surface at one side, and female and male elements 92 and 93 on the inner surface opposite the first pair of elements. Severances are made between each pair of elements along a line 95 by a knife 94, and along a line 97 by a knife 96. Additional cuts are made between the male and female elements 90 and 92 by a knife 98, and between the elements 91 and 93 by a knife 99, thereby providing four separate closure strips 100, 101, 102 and 103, each of which has a closure element at its edge. This arrangement could be used to form two rows of bottom open pouches in a manufacturing operation.
FIGURE 14 illustrates a method of severing a closed integral tube 104 in a manner similar to that previously described, but where the tube has adjacent male elements 105 and 108, and adjacent female elements 106 and 107. The tube is severed by a longitudinal severance line 111 between the female elements by a knife 112, and between the male elements along a longitudinal severance line 109 by a knife 110, thereby providing strips with male and female elements at their respective edges.
FIGURE 15 illustrates a tube 113 with interlocking elements 114 and 115 and a severance line 116 therebetween. The severance line is provided for manual separation by perforations or cut slots such as may be formed by a perforating wheel 117. This eventually provides a pouch whose fastener elements when engaged cannot be separated until the perforation is torn.
FIGURE 16 illustrates a tube 118 with a pair of interlocking elements 119 at one side of the tube on the inner surface, and another pair of elements 120 within the tube at the other side. Between the elements of the pair 119 and of the pair 120 are rows of perforations 122a and 122b. The tube is separated by knives 123 and 124 which form longitudinal cuts between the pairs, thus providing two separated continuous strips which can be further separated by tearing the perforations 122a and 122b, or
for eventually creating two sets of bottom open perforated pouches.
FIGURE 17 illustrates a closed tube 125 with an interengaging pair of interlocking elements 126 and 127 on the inner surface. In a parallel line at separated intervals are provided holes 128 and 129 adjacent and between the elements 126 and 127. The holes may be made in a suitable manner such as by punches 130 and 131. The tube is severed by a cut 133 formed by .a knife 132. The holes 128 and 129 will provide means for receiving a hook such as that provided on a peg board. If a tube is eventually made into bags, each of the bags will have a series of holes along its top for conveniently suspending or hanging the bag.
FIGURE 18 illustrates a combination of the previous features, with a tube 134 having interlocking elements 135 thereon, and rows of holes 136 provided by punches 137, between the elements. Between the holes is a row of weakening perforations 138 provided by a perforating wheel 139, and thus the completed tube provides a unit which can be easily separated at the weakened points and for providing bags which will have holes along their tops.
FIGURE 19 illustrates a continuous closed tube 140 with interlocking elements 141 and 142 wherein the wall of the tube is thicker at one circumferential location than another. This can easily be controlled by the size of the opening in the extruding die. The tube has a thickened portion 143 provided in the tube wall between the interlocking elements 141 and 142. Holes 146 and 1147 which are longitudinally spaced extend through the thickened portion and are arranged in rows, and a cut 144 is formed by a knife 145 between the rows of holes. In this illustration the thickened portion is used for strengthening the material around the holes. It will be understood that the invention contemplates thickening the Wall structure of the tube at any location where such thickening is necessary to perform a particular function such as strengthening a point of weakness or for serving a particular purpose for which the strips or the eventual container is designed. For example, if the tube were used to form a series of bags, it may be desirable to have a thickened portion along the base of the bag where the greatest amount of wear and scuff, and where a fold occurs.
FIGURE 20 illustrates a tube 148 with a pair of interlocking elements 149 in the inner surface. The tube is of a size to form a completed bag, and has an inwardly folded gusset 150 along one side at a location which will form the base of the bag. When a slit is formed by a knife 151 between the interlocking elements 149, the bag will be ready to be formed, and a bag with a base gusset will result. As will be appreciated, if the tube is made of a thermoplastic material, lengths can be severed therefrom, and the bags completed by applying a heated member such as a wire across the bag to simultaneously cut this bag from the supply length and form the seam.
Thus it will be seen that I have provided a closure structure and a method of forming of the structure which meets the objectives and advantages above set forth. The structure provides a joined tube on which has been extruded one or more profiles. Substantial advantages are achieved in the extrusion process of extruding a continuous enclosed tube as opposed to a strip, and the method and structure have a wide range of adaptability.
The drawings and specification present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes, alternative constructions, combinations of different disclosures herein and methods falling within the scope of the principles taught by the invention.
In the arrangements of FIGURES 15 and 16, double rows of perforations may be provided. Then when the material is folded and the fastener elements interlocked, a double strip will be formed at the bag top which can be torn off. The area between the perforations may be colored differently than the rest of the material for easily distinguishing the top double strip.
In the arrangement of FIGURE 21, an elongated continuous flexible plastic tube 152 has fastener profiles 153 and 154 extending therealong for forming closure elements. To separate the tube and form flanges at the top of the bag which is to be constructed, a knife blade 156 is run along between the fastener elements 153 and 154 along a line of severance 157. The tube is provided with an integral colored line located between the male and female profiles 153 and 154. The colored line will be extruded simultaneously with the tube. With the line of severance 157 formed in the middle of the line, the opening flanges will each be marked with a colored outer edge. If desired, the colored line 155 and the line of severance 157 can be related so that the cut is along the edge of the colored line 155, and then only one of the flanges will be colored for ease of separation. It will be understood that any of the structures of FIGURES 2 through 20 may be provided with a colored line or colored lines between the male and female interlocking profiles and the tubes cut axially along the center of the colored line or lines, or along the edge or edges thereof.
I claim as my invention:
1. A structure for use in making a reclosable container comprising,
an elongated closed flexible integral tube, a first interlocking element integral with the tube on the inner surface thereof, and a second interlocking element integral with the tube on the outer surface thereof,
said elements being shaped for cooperative pressure interengagement and forcible separation.
2. The structure as defined in claim 1 and including means defining a separational line extending longitudinally along the tube for separating the tube material between said interlocking elements.
3. The structure as defined in claim 1, said tube having longitudinally spaced holes positioned between the interlocking elements.
4. The structure as defined in claim 1 wherein one of said interlocking elements comprises a rib having overhanging shoulders and the other of said elements comprises means forming a complementarily shaped groove for receiving said rib.
References Cited UNITED STATES PATENTS 3,198,228 8/1965 Naito 15692 X 3,246,672 4/1966 Naito 138118 3,291,177 12/1966 Naito 150-3 2,666,466 1/1954 Sharat 15692 3,038,217 6/1962 Harris 156244 2,558,367 6/1951 Madsen 15692 2,637,085 5/1953 Madsen 15692 X 2,791,807 5/1957 Morin 15443 2,144,755 1/1939 Freedman 15692 EARL M. BERGERT, Primary Examiner.
H. F. EPSTEIN, Assistant Examiner.