JPS5944261B2 - Flexible thermoplastic bag and method of forming the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to flexible thermoplastic bags or containers.

More particularly, the present invention relates to a flexible thermoplastic bag or container that essentially includes two airfoil-shaped pouch sections and has an upstanding neck section (i.e., fill port) located above them. The airfoil-shaped bouch is the storage area for the contents of the bag. The neck portion can be used for filling and removing contents from the container and provides an exhaust port for releasing gases and steam from the container during cooking. Various closure means can be used to close the fill port, such as an integral retractable zipper type fastener section. With the spread of high-frequency ovens and the fact that food taken out of the refrigerator is often cooked directly in such ovens, food that can be stored in a small space inside the refrigerator and can be used directly in the high-frequency oven has become popular. It has been desirable to have thermoplastic containers. Upright rigid containers are not always the most compact shape for storage in the refrigerator, often take up unnecessary space if not completely filled, and are not customarily used for cooking. A removable lid is required to allow for evacuation. Thermoplastic storage and cooking bags that can be placed on their side can spill their contents into the oven when opened to vent during cooking. With the popularity of high-frequency cooking, the plastic filler has a small size that can stand upright enough to avoid spillage, and also maintains enough flexibility to be housed when used in a refrigerator. It has been desired to do so so that essentially no storage space is required above the contents.

The bag containing the cassette is customarily placed on its side when its contents are cooked, as shown, for example, in FIG. 4 of US Pat. No. 3,851,574. A small refrigerator bag with an opening at the top is disclosed in US Pat. No. 338, for example.
No. 9783, these are not designed for exhaust or high frequency cooking, but are simply flat pillow-shaped packages. Upright bags such as U.S. Pat. No. 3,799,914 or 33,806
The typical one shown in No. 46 is designed to contain food in its upright portion, and if used in a high frequency oven for cooking, the bag would easily topple over. Other wide-bottomed packaging designs, such as those shown in U.S. Pat. No. 3,003,681, are also intended to contain the contents in the upright portion of the container, but are most efficient for stacking and cooking. It's not that. The above-described container has the characteristic advantages of being representative of the state of the art prior to the present invention, compared to high-frequency oven flasks, which are smaller in size and do not overflow under cooking conditions. It doesn't include improvements to what you should have in a good refrigerator. The bag of the present invention can be made of a thermoplastic material such as a synthetic resin in one layer or in multiple layers.

If formed from multiple layers, the inner and outer layers should be thermoplastic materials of different melting point temperatures such that the inner layer has a lower melting point temperature. The wing section is formed by forming a bag with the cassette and sealing at a low melting point temperature range. This is because the outer layers of the cassette do not seal together. If reclosable, the neck of the bag is provided with a zipper type fastener or other closure means.

The closing means may be designed to automatically open the engagement member of the fastener in response to an increase in steam pressure within the bag, thereby evacuating the package against pressure build-up during cooking. . If the package is not opened before cooking, this automatic venting action is a safety feature that prevents the package from bursting due to increased steam pressure during cooking. The engaging member of the zipper type fastener can be integrally formed in the neck portion of the bag, and may be formed of the inner layer of thermoplastic material of the bag in multiple layers or by heat-sealing the top of the bag material. The plastic material can be extruded to form the fastener member.

By forming the engaging member of the fastener with a thermoplastic material having a softening temperature that is sensitive to the normal heat when cooking food, such as the heat received in high-frequency cooking, the above-mentioned automatic exhaust feature can be achieved. It increases. As it softens during cooking, the engaging member of the fastener becomes more flexible, but does not melt.
This achieves that the package opens automatically due to the pressure built up within the package. By forming a substantial pouch or pouch in the wings, the feature that allows them to lie flat allows the containers to be easily stacked in the refrigerator without being filled. The filling port BIXS is placed on top of one of the wings during storage. This bag can be transferred directly from the refrigerator to the high frequency oven for cooking, and the filling opening is lifted to allow cooking to occur without overflowing. Food containers are typically flat bags that are placed on their sides, upright bags that flip over easily, or rigid containers that lack flexibility and take up extra space.

According to the present invention, they can be stacked on top of each other without turning over, can be stacked on top of each other in a filled state, can be stored in a small size when empty, and do not need to be filled or act as an air bleed port. A bag has been provided which has a neck portion which performs this function when the bag is held, and which also functions as a grasping portion. The bag of the present invention has particular application in refrigerated storage for high frequency cooking. In a refrigerator, the neck portion of the filled bags can be folded to stack the bags on top of each other in a flat layer. When used in cooking, the contents contained in the bag are flattened into a thin planar block for more rapid and even heating. The neck of the bag is designed to act as a shield to prevent splashing when opened for air bleed. For an understanding of the invention, reference is made to the accompanying drawings.

More particularly, FIG. 1 shows a disposable storage and cooking bag 10, which is preferably constructed from a transparent or opaque synthetic resin thermoplastic film material as described below.

Back 10 includes wing portions or bowch portions 12 and 14.
, which are shown in the closed position with solid lines.
The bowch portion is also shown in a slightly open position by dotted lines 12' and 14'. Wing sections 12 and 14
A neck or filling portion 18 extends upwardly from the contact point 16. Side panels 22 and 24 except for their lateral ends. The panels are separated along edges 26 and the opposite panels are sealed to each other at the lateral ends to close the sides of the filler portion 18 together. Filler portion 18 includes closure means having male and female fastener members 19 and 20, respectively.

The size and/or shape of fastener members 19 and 20 determines their strength to resist separation due to pressure imparted from within the bag. Therefore, it is preferred, although not essential, that the fastener member 19
and 20, when the steam pressure in the bag increases due to cooking of the contents such as frozen or non-frozen food or liquid, a fastener opens and discharges steam through channel 25 as shown in FIG. It is preferable that the design be such that it is possible to do so. The self-venting feature acts as a safety measure to prevent the bag from bursting due to the pressure that builds up during cooking. If the fastener part 19
If the fasteners and 20 are designed not to separate during cooking, the fastener parts must be opened prior to cooking. Suitable fastener member designs are well known in the art and are described, for example, in US Pat. Nos. 3,338,285 and 3,198,228. Filling port part 1
Various methods can be used to attach the fastener members to 8.

For example, members 19 and 20 are connected to side panels 22 and 24.
Can be formed from thermoplastic materials. If the material of side panels 22 and 24 is formed in multiple layers, members 19 and 20 are formed in the inner layer of each panel. In FIG. 2, the flies or layers of the multi-layer bag material are shown in cross-section facing each other in the filler section 18 (which includes the fastener device), e.g. The inner layers 38 of each panel 22 and 24 face each other. Preferably, members 19 and 20 are formed in inner layer 38. The inner layer 38 forming the fastener members 19 and 20 is preferably formed of a thermoplastic material that heat softens at temperatures typical of cooking the contents within the bag.

For example, inner layer 38 can be formed from a high or low density polyethylene resin having a melting point temperature of about 107°C to 137°C. Of course, the thermoplastic material must not melt at the cooking temperatures at which the food is cooked in the bag. If the fastener members 19 and 20 are made of a material that heat softens at cooking temperatures, the above-mentioned automatic venting feature can be further improved. If the thermoplastic material softens at cooking temperatures, the fastener material will become more flexible;
This allows the bag to be opened more easily and the pressure built up within the bag to be evacuated. A second method of assembling members 19 and 20 to fill port portion 18 is to extrude a thermoplastic material to form fastener members on the thermoplastic material forming side panels 22 and 24. be.

Once again, the fastener member is preferably made from a thermoplastic material that heat softens at cooking temperatures to assist in opening the closure to allow automatic evacuation of the bag 10, e.g. Members 19 and 20 can be formed from a low density polyethylene resin having a melting point temperature of about 107°C to 137°C, and side panels 22 and 24
It is extruded onto a high density polyethylene material forming itself or its inner layer. FIG. 3 shows the end of the bag 10 when filled, showing the end bulge 17 located below the wing sections 12 and 14, which end seals at the contact point 16. This arises from the fact that it is limited by.

FIG. 4 shows the top of the bag 10 and shows that the bag is essentially rectangular, e.g., in the exemplary embodiment, the sides 31 and ends 33 are
It shows that it is 3.2 mm x 203.2 mm (81n. x 81n.).

The fill port 18 is in an open position exposing the fill and bleed channels 25. FIG. 5 is a view taken from one side 31 of the bag 10, showing the tip of the fill port section 18 at the end 37 when the wing sections 12, 14 are filled.

If the neck portion is not made of sufficient height, i.e. at a height that, when filled, is slightly above, approximately equal to, or below the top 39 of the upper wing portion 14, the fill opening portion 18 Leakage or overflow will occur through the channel 25. Similarly, if it is too high, the fill port portion 18 will sag or buckle under its own weight and will require a large amount of material to form. As shown in FIG. 4, 203. , 2m71L x 203.2mm (81
1x81n. Regarding the bag
1n. ) is practical, and approximately 50.8 m
m (21 n.) was found to be preferable. By providing a practical height for the fill opening portion 18, it is precluded that the bag rests on a pan of soil to avoid overflowing, as in prior art bags. In the filled state, the food or other contents 27 contained in the bag 10
occupies the areal space of each of the wing sections 12 and 14 as shown in FIG. When the bag 10 is completely opened,
As shown in FIG. 3, wings 12 and 14 lie longitudinally on a plane. These are adapted to form the bottom 32 of the bag by means of their articulating surfaces 28 and 30, and are adapted to rest on any substantially flat surface. Surfaces 28 and 30 do not become stuck together during subsequent end sealing operations. This is because either surface is itself separated by the insertion of insulation during bag end sealing, or these surfaces remain stuck to each other at the temperature at which the bag is sealed. FIG. 2 shows a preferred embodiment in more detail in which the outer layer 34, the adhesive layer 36
and each fly of the inner layer 38 faces each other at the fill opening portion 18.

Inner layer 38 may be formed of a low melting point temperature olefin polymeric material, for example, and outer layer 34 may be made of a polyester or nylon type polyamide thermoplastic material having a substantially higher melting point temperature than the material of the inner layer. can. If the inner layer 38 is made of low or high density polyethylene resin, it will have a melting point temperature of approximately 107°C to 137°C, respectively. Approximately 0.95
High density polyethylene having a density of 7/Crii or higher is advantageously used because its melting point temperature is generally above the boiling point of water and will not weld during cooking. However, low density polyethylene (approximately 0.89 to 0.937/Cd
) and polypropylene can also be used. If the outer layer 34 is made of a typical nylon, such as Allied Chemical Company's nylon 6, it will have a melting point temperature of about 215°C, or if it is made of a typical polyester, such as polyethylene terephthalate. The temperature will be approximately 250°C. The adhesive layer 36 is made of an ionomer/copolymer such as the registered trademark Dayvon Surlyn resin, or a complex plexer modified polyolefin, or ethylene acrylic.
It can be an amide copolymer. If desired, inner layer 38 is 1.5 mm thick and outer layer 34 is 0.010 mm thick.
, and the adhesive layer 36 has a thickness of 0.007 mm (0.3
(mil) thickness. As yet another example, from 0.381 mm to 0.1 Ttm (11Z
Bags suitable for most applications have wall thicknesses of 50 to 80% of the total thickness (mils to 4 mils).
The inner layer accounts for 10-20%, the adhesive layer accounts for 10-20%, and the outer layer accounts for 1
It can be made from 0 to 40%. Typical values are 68%, 1401) and 18%, respectively. For example, the multilayer film is disclosed in US Pat. No. 3,354,506 or US Pat.
No. 557,265 may be used. A preferred method of forming bag 10 is to
and an outer layer 34 with an inner layer 38 made of a thermoplastic film material having a sufficiently lower heat softening temperature than the outer layer 34.

The two flies of thermoplastic surrounding material are arranged together such that the inner layer 38 abuts itself to form opposite sides. Surfaces 28 and 30 are part of outer layer 34 but are joined together to form bottom 32 of the bag. Bottom portion 32 is then cassetted so that surfaces 28 and 30 face each other. A hot bag or other sealing member applies heat along opposite side edges of the bag at a temperature above the softening temperature of the inner layer 38 and below the softening temperature of the outer layer 34. At this temperature, inner layer 38 is sealed, but surfaces 28 and 30 forming part of outer layer 34 are not sealed or joined together. In this way, the bag 10 has wing-shaped bag portions 12 and 14.
The uncassetted portion forms the bag's central neck portion 18, which is in open communication with the wing portions 12 and 14. By disengaging fastener members 19 and 20, fill opening portion 18 is separated from side panels 22 and 24 to release contents such as food or liquid 27.
can be opened to form a feed channel 25 for introducing into each wing section 12 and 14. A suitable amount of contents is introduced and the filling opening or neck portion 18 is filled.
wing portions 12 and 1 with no contents contained therein.
4. Filling port portion 18 is placed in a folded position in FIG.

This makes it easy to stack the filled container 10 with a number of other similar containers when it is desired to cool the contents 27, and to store it in the refrigerator until it is desired to cook, as shown in FIG. They are stored inside and stacked. Because the filling spout section is foldable, one bag can be placed directly on top of another, with the wing section of that bag resting on the wing section of the bag below. Advantageously, it has been found that because the neck portion of the bag has closing means, the width of each wing section 12 or 14 is greater than the overall height of the bag in the arrangement shown in solid lines in FIG. It will be done.

In one exemplary embodiment, the surface 28 of the wing section 12 or 14 at a distance Y1 as shown in FIGS.
Or 30 nobu is about 101.6m77! ~127mm
(4 to 51n.), and the height X of the filling opening portion, that is, the neck portion, is approximately 50.8m7! L (21n.? Yes.

With this arrangement, the volume of the container is formed by the wings, and the neck or fill opening portion 18 represents only a small portion of the bag. Batsugu is therefore an upright Batsugu. In fact, this is a bag that lies flat and does not overflow due to the upright neck part and the fact that this neck part is not intended to contain any contents. Various types of closure means (not shown here) can be used in the practice of the present invention to close the fill opening portion of the bag, as will be readily apparent to those skilled in the art. If the filling opening section is not so tightly secured by the closing means, gas or vapor within the bag is evacuated, while substantially closing the filling section prevents overflow of the contents from within the bag. This helps keep the filling port upright. Applicable closure means (other than integral zipper type fasteners as described and illustrated above) include, but are not limited to, U.S. Pat.
4805 and 2981990; U.S. Pat. No. 3,535,746
U.S. Pat. No. 3,633,247, U.S. Pat. No. 3,874,034
Plastic tie straps such as those described in U.S. Pat. Nos. 3,972,469 and 3,973,610: U.S. Pat.
399 and 3974960C; and U.S. Pat. No. 341
No. 7863, No. 3481461 and No. 356573
Metal de-fold (D) as described in No. 8
(eadfOld) 4V1 type closures (e.g. twist ties). ,]'jmuband, string,
Adhesive tapes and adhesives may be cited as further examples of other closure means which can be used to close the fill opening portion of the bag if the closure means must be placed adjacent to the bag during high frequency use. The closing means must not be disturbed by high frequencies.

That is, it must be non-metallic and must not be capable of melting under the conditions typical of high-frequency cooking.
Metallic and other high-frequency non-use closures are applicable for cooking by means other than high-frequency ovens. For example, it can be applied to boiling bag bags or to bags which are used solely for the purpose of containing and storing contents.
If the closing means are not integrally formed with the bag's neck, the height of the bag's neck will be such that the bag is empty and
The height is sufficient to facilitate opening and closing of the opening for filling or evacuation.

It is practical to have a net height of at least about 101.6 mm (41 n.), about 152.4 m77! (61n.
) height is preferred. Heights lower than 101.6 mm (41 n.) will not properly seal or close; heights higher than 152.4 mm (61 n.) are unnecessary and will cause the neck to close under its own weight. This results in drooping or bending.

Closing the neck section with the two airfoil bouch sections as close together as possible will provide the most upright stability of the neck section if tie straps or similar type closure means are used.

The bag of the invention can be formed without any closure means.

For example, a portion of the neck of the bag can be cut out to form an exhaust opening to allow steam to escape during cooking. Tl. Bags that are not intended for private use may not be provided with any closure means. The embodiments of the invention have been presented for the purpose of illustrating the invention, and it will be apparent to those skilled in the art that many modifications and adaptations can be made without departing from the scope of the invention. .

For example, different fly combinations, materials and their thicknesses may be used depending on the desired result.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a bag constructed in accordance with the principles of the present invention, illustrating the opening of the wing portions of the bag to the condition shown in dotted lines in a ready position for receiving the contents contained therein; FIG. Perspective view Figure 2 is an enlarged cross-sectional view of the bag's multilayer structure taken along line 2-2 in Figure 1;
FIG. 7 is an end view of the bag of FIG. 1, showing the pillow-shaped wing portion with the contents therein and the upright fill spout portion used for filling the container and bleeding the container during cooking;
4 is a plan view showing the filled bag of FIG. 3 with the filling port open; FIG. 5 is a side view of the filled bag of FIG. 3 with the filling port open; Figure 6 is a cross-sectional view of the filled bag taken along line 6-6 in Figure 4, and Figure 7 is the filled bag shown in Figure 3 with the filling opening bent when placed in a refrigerator. An end view showing stacking of bags. 10... Bag, 12, 14... Wing part or bowch part, 18... Net part or filling port part, 19, 20... Fastener member. , 22, 24... side panel, 25...
...Channel, 27...Contents, 28,30
...Bottom surface, 34...Outer layer, 36...
... Adhesive layer, 38 ... Inner layer.

Claims (1)

Claims: 1. A flexible thermoplastic bag having opposite wing sections and a central neck section extending from between the wing sections, the neck section communicating with the wing sections. an internal channel forming a means for communication with the exterior of the bag, the neck portion being shaped to accommodate contents therein, and the neck portion being laterally located adjacent to the wing portion. A flexible thermoplastic bag characterized in that it can be bent from a position extending upwardly. 2. The height of the neck portion is 101.6 mm (4 in.
2. A flexible thermoplastic bag according to claim 1, wherein the flexible thermoplastic bag is between 152.4 mm (6 in.) and 152.4 mm (6 in.) wide, and wherein closure means are provided in the neck portion. 3. The closing means is configured to automatically open so that steam can be exhausted from the bag when the steam pressure inside the bag increases due to heating of the contents stored in the bag. A flexible thermoplastic bag according to claim 2. 4. Flexible heat according to claim 3, characterized in that the material forming the closure means thermally softens at elevated temperatures so as to assist in the opening action of the closure means to vent steam from the bag. plastic back. 5. A flexible thermoplastic bag as claimed in any one of claims 1 to 4, characterized in that the height of the neck portion is less than half the height of the one wing portion. 6. The back wall is formed with an inner layer and an outer layer having different heat softening response temperatures, and when heat is applied at a predetermined temperature, the contact edge of the inner layer is formed without the outer layer being sealed. A flexible thermoplastic according to any one of claims 1 to 5, characterized in that the outer layer has a higher heat softening temperature so that the material is sealed. back. 7 comprising contents substantially completely contained in the wing portion of the bag, said contents being spread out laterally so as to receive uniform heating, and exit for said contents being provided only through said neck portion; Claims characterized in that this makes it possible to avoid overflowing the contents from the bag during heating of the bag, even if the closing means is opened to vent steam from the bag. The flexible thermoplastic bag according to any one of the ranges 1 to 6. 8. A method of forming a bag with a thermoplastic film material having an inner layer and an outer layer, the inner layer and selecting an outer layer and stacking the two plies of the film over each other such that the inner layer abuts itself to form opposite sides and a bottom, forming a cassette in the bottom of the film; applying heat along opposite edges of the sides at a temperature above the softening temperature of the inner layer but below the softening temperature of the outer layer;
This allows a seal to be formed on the inner layer without forming a seal on the outer layer along the gusseted bottom of the bag, with the gusseted portion forming the airfoil-shaped pouch portion and the non-gusseted portion forming the airfoil-shaped pouch portion. A method of forming comprising the steps of forming a central neck portion having an opening communicating with an airfoil-shaped pouch portion. 9. The method of claim 8, wherein the gusset at the bottom of the film forms a relatively long airfoil pouch portion and the ungusseted portion forms a relatively short central neck portion. .