CN1075998C - Freezer storage bag - Google Patents

Abstract

The present invention provides a refrigerator bag which comprises a multilinked bag (90) provide with at least one lining bag (91) of an inner layer and one support bag (92) of an outer layer, wherein the lining bag of the inner layer is provided with a first side film (94) and a second side film (94'), which are connected along respective transverse edges to form edge sealing, the side films are provided with upper edges (95, 95'), and the lining bag is provided with hems which limit the bottom of the lining bag; the support bag of the outer layer is provided with two side films(96, 96') connected along respective transverse edges to form edge sealing, the side films are provided with upper edges which limit an opening of the multilinked bag, the support bag is provided with hems which limit the bottom of the multilinked bag, and the upper edge of the bag is connected to the inner side surfaces of the side films of the support bag, wherein the lining bag is made from thermoplastic material, and the thickness of the nominal side films is smaller than 2.0 mil(50.8 um).

Description

Freezer storage bag

The present invention relates to the packing of food on the whole, especially Rou Shi packing.Yet each side of the present invention also can be used for the commercial packing of food and packs, as being packed by the butcher in the supermarket even in the slaughterhouse.Others of the present invention relate to the method for preparing improved refrigerator bag, the method for using bag, the packing of meat and the thermoplastic film of particular type, and it is specially adapted to and carnivorous contacted packing.

Reusable storage bag is extremely common in the prior art.At present, the public can see plastic bag usually in carton, and this carton is marked with " special use " sign (as storage bag, large-capacity refrigerator bag, vegetables bag, refuse bag) that special recommendation is used.Bag itself also often indicates " special use " printed words, as " ZIPLOC ^_Large-capacity refrigerator bag ".

Here, term " refrigerator bag " is meant the pocket with remarkable function of storing food in refrigerator." refrigerator bag " has following several size: 7.57dm usually ³, 3.785dm ³, the 1.8925dm of fold arranged ³, 1.137dm ³And 0.5683dm ³

Term " refrigerator is air-dry " is meant anh implication, if food is not packed or is packed in the improper refrigerator environment that just is stored in low humidity, this dehydration phenomenon will take place (referring to the 305th page of " using plastic wrapping food " book, its author is Wilmer A.Jenkins and James P.Harrington, is published by Technomic publishing company in 1991).The customer describes the air-dry phenomenon of refrigerator usually with three main visual attributes: produce ice crystal, product dehydration and color change.

The air-dry phenomenon of refrigerator is still a complaint greatly in the customer, although thick plastics refrigerator bag has been obtained business success.In the short term, the air-dry phenomenon of refrigerator is recoverable process.Yet in the long run, the air-dry phenomenon of refrigerator can cause the complexity of food quality to worsen, and comprises that undesirable quality changes, and follows by chemical change, and as oxydative spoilage, taste, aromaticity, mouthfeel and the color of color degradation, lipides, these all can degenerate.The air-dry problem of the refrigerator of fresh meat is crucial especially, because this affects carnivorous color.

Above-mentioned " using plastic wrapping food " book has carried out fabulous summary to prior art, has compiled all information (gyp) about " packing fresh meat " in chapter 7.Curiously, this book is not mentioned the airdry problem of refrigerator, does not have about the airdry definition of refrigerator in the glossary yet.

The 143-147 page or leaf of " consumer report " in March, 1994 has a piece of writing to be entitled as the article of " maintenance food is fresh ".This article is too new, can not be as the prior art of this U.S. Patent application.But its content is interesting, is exactly the plastic bag that prior art lacks particular type, and therefore, this has improved patentability of the present invention on the contrary.

Such problem attempted to answer in this piece article of " consumer report ", that is: what packing (plastics, aluminium, paraffin paper, pocket, packing or reusable container) are the most suitable finishes following work: (1) " for a long time " keeps food fresh; (2) overall cost is minimum; (3) to the adverse effect minimum of environment.This article " first-selection " ZIPLOC ^_The refrigerator bag (seeing 145 pages) that fold is arranged.This article points out that if close too much air in the container, the food that is stored in the plastic container will suffer refrigerator air-dry.About " packing " (plastic film and refrigerator paper), because cost and environment, this article is opposed double casing, and, " our test shows that double casing does not have any too much protection ".The also not open anywhere or suggestion content of the present invention hereinafter described of this article.

Put down in writing various bags in the patent documentation, this bag has liner, promptly has duplicature, has certain space between two films.Some such patent relates to the transportation and the storage of food.U.S. Patent No. 4,211,091 (contriver is Campbell) relate to " insulation space bag ".U.S. Patent No. 4,211,267 (contriver is Skovgaard) have been introduced a kind of " portable bag ", can " take it home before frozen food thaws ".U.S. Patent No. 4,797,010 (transferring Nabisco Brands) discloses a kind of duplex paper bag, and it can be used as " fried food can heat, reclosable packing " again.U.S. Patent No. 4,358,466 (transferring Dow chemical company) relate to a kind of improved " bag from refrigerator to micro-wave oven ".Each side of the superincumbent opening of this bag has two wing pouches.U.S. Patent No. 5,005,679 (contriver is Hjelie) relate to " bag that carries with cooling room ".All these food bags all have very thick and film Food Contact with respect to hereinafter described the present invention.These its focus points of patent neither one are that refrigerator is air-dry.

About the book of " home freezing ", the present invention is also very interested.About " for refrigerator packing meat ", in " the home freezing pandect of Rodale " by name, suggestion has been proposed, the author of this book is Marilyn Hodges, publish by Rodale Test Kitchen staff (1984), the method of a refrigerator wrapper of the usefulness meat of this book suggestion is inconvenient only not, and, " with suction pipe sucking-off air " (attempting to prevent that blood from entering in the mouth), to reduce the dehydrating amount (seeing 173 pages) in the refrigerator.

Reach a conclusion by consumer survey, clearly be badly in need of improving the method for current packaging fresh meat, the another one fact is only in the U.S. huge retail market just to be arranged, the plastic package material of annual consumption millions of dollar.

The objective of the invention is to attempt to improve the performance of " refrigerator bag ",, and reduce so-called " refrigerator is air-dry " phenomenon in refrigerator so that final customer packs and stores the fresh meat of the not cooking.

In the scope of maximum, the invention provides a kind of refrigerator bag, it comprises a multi-joint bag, this multi-joint bag has lining bag and an outer field support pouch of at least one internal layer; The lining bag of internal layer has first side form and second side form, and both link together along transverse edge separately, have formed banding, and each side form all has upper limb, and the lining bag has flanging, and this flanging defines the bottom of lining bag; Outer field support pouch has two side forms, both link together along transverse edge separately, formed banding, each side form all has upper limb, this upper limb defines the opening of multi-joint bag, support pouch has flanging, and this flanging defines the bottom of multi-joint bag, and the upper limb of lining bag is connected on the medial surface of each side form of support pouch; Wherein, the lining bag is made by thermoplastic material, and its thickness is less than 50.8 microns.

According to a further aspect of the present invention, provide the device of making multi-joint bag, this multi-joint bag has lining bag and an outer field support pouch of at least one internal layer; Described device comprises: the element of the feeding first thermoplastic film band, the thickness of this first thermoplastic film band have the first horizontal film bandwidth between parallel edge greater than 25.4 microns; The element of at least one second thermoplastic film band of feeding, the thickness of this second thermoplastic film band have the second horizontal film bandwidth less than 50.8 microns, and the second horizontal film bandwidth is less than the first thermoplastic film width; The second thermoplastic film band is covered element on the first thermoplastic film band, make the second thermoplastic film band between the parallel edge of the first thermoplastic film band; The second thermoplastic film band is connected element on the first thermoplastic film band, and connection location is the parallel edge along the second thermoplastic film band; Element along laterally folded each film band; With, with the element of each folding film band of encapsulating method cut-out, to form pocket.

According to a further aspect of the present invention, provide the device that at least two film bands are linked together, this device comprises: the element of the first film band and the second film band is provided, and the first film band and the second film band have first width and second width respectively; The second film band is covered element on the first film band, make the second film band between the parallel edge of the first film band; The element of at least one sealing band is provided, and the material heat-sealable of sealing band is at least a portion of two film bands; Paste element, the parallel edge of described sealing band along the second film band sticked on the parallel edge of the second film band.

Contrast with the prior art of knowing, be surprised to find, the laminated plastics bag of particular type (being defined as multi-joint bag here) is more much better than corresponding individual layer refrigerator bag (weight is equal to or greater than the weight of multilayer bag), to be used as the refrigerator bag that function is arranged, preserving meat, and there is not the air-dry phenomenon of refrigerator.

Figure 1A is the front view of prior art, shows the thermoplastic single bag that repeats to seal with slide fastener.

Figure 1B is along the section drawing of 1B-1B line in Figure 1A.

Fig. 2 A is the front view according to double-ply bag of the present invention, and (ⅰ) having thin inner layer film is lining form; (ⅱ) between internal layer and skin, have " public banding "; (ⅲ) pore on the outer bag makes the space between internal layer and the skin communicate with the atmosphere in the outer membrane outside.

Fig. 2 B is along the partial section of 2B-2B line in Fig. 2 A.

Fig. 2 C is along the partial section of 2C-2C line in Fig. 2 A.

Fig. 3 A is the front view of another one double-ply bag of the present invention, and this double-ply bag has " different bandings ", has lining bag, and this lining bag longitudinally is connected on the whole length of inside face of side form of support pouch.

Fig. 3 B is along the partial section of 3B-3B line in Fig. 3 A.

Fig. 3 C is along the section drawing of 3C-3C line in Fig. 3 A.

Fig. 4 A is the front view of another one double-ply bag of the present invention, this double-ply bag has the lining bag, this lining bag longitudinally is connected on the part of whole length of inside face of side form of support pouch, and wherein, the interior space of the space between lining bag and the support pouch and lining bag communicates.

Fig. 4 B is along the partial section of 4B-4B line in Fig. 4 A.

Fig. 4 C is along the partial section of 4C-4C line in Fig. 4 A.

Fig. 5 A is the front view of of the present invention one three layers multi-joint bag, and this multi-joint bag has inner layer film between lining bag and support pouch, and wherein, the surface of lining bag has micropore.

Fig. 5 B is along the partial section of 5B-5B line in Fig. 5 A.

Fig. 5 C be in Fig. 5 A along the partial section of 5C-5C line, show selectable the 3rd inner layer film between lining bag and support pouch shown in Fig. 5 A.

Fig. 6 A is the front view of the packing of " meat in closing bag " of the present invention.

Fig. 6 B is along the partial section of 6B-6B line in Fig. 6 A.

Fig. 7 is the diagram of circuit of making test according to the present invention with the manual process of refrigerator bag.

Fig. 8 is the flow scheme according to making refrigerator bag of the present invention, and this refrigerator bag has public banding between lining bag and support pouch.

Fig. 9 A is the front view of a double-ply bag of the present invention, and this double-ply bag has the lining bag, and this lining bag preparation at least one medial surface has texture, particularly has the film of embossing.

Fig. 9 B is along the partial section of 9B-9B line in Fig. 9 A.

Fig. 9 C is that the foreskin leak free amplifies cross sectional drawing, and this foreskin sealing is connected on the side form of support pouch the upper limb of lining bag.

Fig. 9 D is the amplification cross sectional drawing of foreskin leak free another one embodiment, and this foreskin sealing is connected on the side form of support pouch the upper limb of lining bag.

Figure 10 is according to preparation bag of the present invention with the transparent view of a kind of technology of foreskin encapsulating method sealing bag;

Figure 11-the 16th, the cross sectional drawing and the planar view that amplify show the embossed pattern of various recommendations, and this embossed pattern is arranged on the surface of one of them or two lining bags.

Figure 17 is a cross sectional drawing of making a recommend method of bag according to of the present invention.

Define the particular term of using in this specification sheets below:

" multilayer bag " is to have the pocket of one deck with upper side wall.

" double-ply bag " is two pockets, and one is positioned within the another one, and double-ply bag can be divided into two independently pockets, and independently pocket can constitute double-ply bag (as the sacked goods in supermarket).

" duplex bag " is a kind of whole pocket, comprises the lining bag of outer field support pouch and internal layer, and wherein, lining bag partly (but not being fully) links to each other with support pouch.

" multi-joint bag " is a kind of whole pocket, has the lining bag of an outer field support pouch and an internal layer at least, and wherein, lining bag partly (but not being fully) links to each other with support pouch; Between lining bag and support pouch, can have extra play selectively.The simplest multi-joint bag is the duplex bag.

An embodiment of multi-joint bag of the present invention is on the whole by shown in Fig. 2 A-2C.Shown in Fig. 2 A, multi-joint bag 10 comprises that an outer bag is that support pouch 12 and an inner layer bag promptly serve as a contrast bag 12.Support pouch 12 by banding 21,21 ' and flanging 26 shown in line segment DC limit.Support pouch 12 has reusable closure elements 14, as adaptive sun sealing and cloudy sealing, can close multi-joint bag 10 with opening.Support pouch 12 has ventilation component, as the through hole on the sidewall 19 99.Lining bag 11 flangings 24 that have the banding shown in line segment ad and bc and limit by line segment dc.Lining bag 11 and support pouch 12 have common banding, that is: be the part of banding 21,21 ' banding length by the banding shown in line segment ad and the bc.

Shown in Fig. 2 A and 2B, the upper limb 28,28 ' of lining bag longitudinally is connected on the sidewall 19,19 ' medial surface 20,20 ' of support pouch, has formed the opening 13 of lining bag.Lining bag longitudinally is connected on the support pouch with the opening 15 of the multi-joint bag preset distance place that is separated by.The upper limb 28,28 ' of lining bag also can be connected by other following method on the sidewall 19,19 ' of support pouch.

Fig. 2 B and 2C show in greater detail, the sidewall of support pouch 19,19 ' and the sidewall 17,17 ' of lining bag except that line segment ad, bc and line ab, normally can be separated from each other, have space 23 between the two.Shown in Fig. 2 B, lining bag 11 is located longitudinally to be connected endlong on the sidewall 19,19 ' of support pouch at its edge 28,28 ', like this, when lid 14 when opening 15 takes off, food can be packed in the lining bag 11 by the opening 13 of opening 15 and lining bag, and, food contacts with lining bag 11, the operational ton of bag seldom serves as a contrast the shape that bag 11 has adapted to food, shown in Fig. 6 A and 6B.

Closure elements 14 can be any reusable lid.Reusable lid and how to make the example that how to be installed on the bag and can in following patent literature, find, as U.S. Patent No. 4,561,109, U.S. Patent No. 4,363,345, U.S. Patent No. 4,528,224 and U.S. Patent No. 5,070,584.

One or more pores 99 can be arranged on two sidewalls of any position at least one sidewall 17 or 17 ' of any position at least one sidewall 19 or 19 ' of support pouch 12 or lining bag or lining bag and support pouch or on the sidewall of lining bag and on the sidewall of support pouch usually.One or more pores 99 also can be arranged on the flanging 26 of the flanging 24 of lining bag or support pouch or at flanging 24,26 places of lining bag and support pouch pore are set all.Support pouch 12 preferably has more than one pore 99, and the position of pore 99 on the sidewall 19 of support pouch 12 is preferably in below the sealing area, and lining bag 11 is connected on the sidewall 19,19 ' of support pouch 12 herein.Pore 99 makes support pouch 12 communicate with ambient atmosphere, allow at lining bag 11 sidewall 17,17 ' and the sidewall 19,19 ' of support pouch 12 between have the space 23 of air.

Communicating with ambient atmosphere has increased lining bag film and the carnivorous amount of depending on, promptly surperficial area of contact.Pore makes liner depend on meat, and method is to make lining bag more be independent of support pouch to move, if the space between two retes is closed and fixing volume is arranged, the lining bag just is difficult to be independent of support pouch and moves.The support pouch film is harder than lining bag film usually, if stuffiness, harder support pouch film just is tending towards making the lining bag to leave meat.Pore is set on support pouch has also prevented to produce bubble, and can prevent in the manufacturing process of multi-joint bag bonding between the rete at rete lining cement place.

The quantity of lining bag and support pouch one of them or boths' pore and diameter should be tried one's best less and be as far as possible little, so that the customer can't see the existence of pore.Yet pore needs enough big, so that discharge the air between the rete serially in manufacturing process, makes the in use available hand of customer discharge the air that serves as a contrast between bag and the support pouch.Therefore, upward the number of required pore usually will be according to the size change of pore for each bag or all bags.

Usually, on support pouch or lining bag, have a pore at least, in fact, in the quantity of lining bag and support pouch one of them or the pore on both without limits.Quantity at lining bag and support pouch one of them or the pore on both can change between from least 1 to 28, and particularly, the quantity of pore is in 6 to 8 scope, and more especially, this quantity is in 9 to 17 scope.The diameter of pore is usually greater than 450 microns, and particularly from 450 to 750 microns, more especially from 450 to 500 microns.

The method that the lining bag is connected on the support pouch according to multi-joint bag of the present invention can be any method of the prior art.The lining bag can be connected along its upper limb continuously with equably, also can connect along the upper limb that serves as a contrast bag discontinuously.The suitable example of method of attachment well known in the art comprises: the sealing of hot gas fringing, extruded lamination (thermoplastic film that is pushing between the rete), hot-melt adhesive (be placed on the lining bag upper limb or under), hot pin heat seal, ultrasonic sealing, hot-rolling or band, bonding film band, infrared sealing, frequency of radio sealing or vibration sealing.The lining bag also can be connected in manufacturing process on the support pouch, and method is with following mode the profile of lid to be bonded on the edge of lining bag.Any above-mentioned method that two symphysis are connected together all depends on chemistry and the physical property that is used to make the film that serves as a contrast bag and support pouch to a great extent.Particularly, lining bag 11 usefulness hinge formula foreskins sealing 97 is connected the upper limb 28,28 ' of support pouch 12, and shown in Fig. 9 C, this point hereinafter will have detailed description.

For using multi-joint bag of the present invention, food that the user need pack or meat are packed into by the opening of multi-joint bag and are served as a contrast bag, then, push in the bag with handgrip food or meat, make the lining bag be adapted to food or carnivorous profile at surperficial 9 places, and air is discharged in the lining bag, then, the sealing support pouch enters in the lining bag significantly once more to prevent air.Fig. 6 A and 6B show the meat 300 that is packaged in the multi-joint bag, and this multi-joint bag has the lining bag 11 and the outer field support pouch 12 of internal layer.

The another one embodiment of multi-joint bag of the present invention is shown in the multi-joint bag 40 of Fig. 3 A and Fig. 3 B-3C.Multi-joint bag 40 comprises lining bag 41 and support pouch 42.Banding 44,44 ' (shown in Fig. 4 B) and flanging 26 that support pouch 42 has reusable closure elements 14, links to each other with sidewall 46,46 '.Lining bag 41 has as line segment ad and the banding and the flanging 24 that link to each other with sidewall 49,49 ' shown in the bc.Shown in Fig. 3 A and 3B, the upper limb 48,48 ' of lining bag 41 longitudinally is connected on the sidewall 49,49 ' medial surface 43,43 ' of support pouch, has formed the opening 13 of lining bag.The banding bc of lining bag 41 and ad banding 44,44 ' mutual " separation " with support pouch 42, this banding bc and ad with multi-joint bag 10 shown in Fig. 2 A is different, and the banding bc and the ad of multi-joint bag 10 are " coincidences " with the banding 2l of support pouch 26, a part of 21 '.In the embodiment shown in Fig. 2 A, the sidewall of support pouch 46,46 ' and the sidewall 49,49 ' of lining bag between have space 23.Lining bag 41 can be connected on the support pouch 42 along its upper limb 48,48 ', and method is as described below.Particularly, lining bag 41 seals 97 along its upper limb 48,48 ' by hinge formula foreskin and is connected on the support pouch 42, and this point describes in detail hereinafter, and has carried out more detailed expression in Fig. 9 C.

The another one embodiment of multi-joint bag of the present invention is shown in the multi-joint bag 50 of Fig. 4 A and Fig. 4 B-4C.Multi-joint bag 50 comprises lining bag 51 and support pouch 52, and support pouch 42 has reusable closure elements 14 being adjacent to top.Lining bag 51 has as line segment ad and the banding and the flanging 54 that link to each other with sidewall 57,57 ' (shown in Fig. 4 B) shown in the bc.Support pouch has the banding that links to each other with sidewall 58,58 ' (shown in Fig. 4 B) 60,60 ' and flanging 56.Can be clear that more that from Fig. 4 B the upper limb 53,53 ' of lining bag longitudinally is connected on sidewall 58,58 ' the inside face 59 endlong shown in the line segment ab of Fig. 4 A.In this embodiment, lining bag 51 has different bandings with support pouch 52.Can be clear that more that from Fig. 4 A and 4C the upper limb of lining bag 53,53 ' is not to be connected on the sidewall 58,58 ' of support pouch along sidewall 58, whole vertical width of 58 '.The banding ad that is connected contiguous lining bag of lining bag 51 and support pouch 52 and bc are in and have produced opening 63 on the support pouch 52.When lid 14 was opened, the opening 63 of support pouch 52 communicated with atmosphere.Lining bag 51 can be connected on the support pouch 52 along its upper limb 53,53 ', and method of attachment describes in detail hereinafter.

The another one embodiment of multi-joint bag of the present invention is shown in the multi-joint bag 70 of Fig. 5 A and Fig. 5 B-5C.Multi-joint bag 70 comprises lining bag 71 and support pouch 72 on the whole, and support pouch 72 has reusable closure elements 14.Lining bag 71 has as line segment ad and the banding and the flanging 74 that link to each other with sidewall 80,80 ' (shown in Fig. 5 B) shown in the bc.Support pouch has the banding that links to each other with sidewall 82,82 ' (shown in Fig. 5 B) 73,73 ' and flanging 76.Shown in Fig. 5 A and 5C, the sidewall 80,80 ' of lining bag 71 has several micropores 78 (being described hereinafter).Shown in Fig. 5 B, the upper limb of lining bag 83,83 ' longitudinally carries out heat seal endlong discontinuously on sidewall 82,82 ' length.The upper limb 83,83 ' of the lining bag that links to each other with the sidewall 82,82 ' of support pouch defines the opening 81 of lining bag.Shown in Fig. 5 C, multi-joint bag 70 has theca interna 77, and this theca interna 77 is clipped between lining bag 71 and the support pouch 72.

The upper limb 83 of lining bag, 83 ' and the sidewall 82 of support pouch, 82 ' interruption heat seal formed hole 75 and sealing area 79.Hole 75 is the positions that do not link to each other with the side 82,82 ' of support pouch on the upper limb 83,83 ' of lining bag.In this embodiment of the present invention, heat seal is on the sidewall 82,82 ' of support pouch discontinuously for the upper limb of lining bag 83,83 ', and theca interna 77 herein has been removed.In this embodiment, for example, theca interna 77 can be by neither not making with the thermosealed material of support pouch again with lining bag heat seal.Yet in any embodiment of the invention, what the lining bag can be interrupted is sealedly connected on the support pouch.Discontinuous between lining bag and the support pouch is connected other above-mentioned encapsulating method that the sealing that is interrupted in other words also can be adopted traditional lining cement, hotmelt, the sealing of hot air fringing or know in the prior art.

When closure elements 14 was opened, hole 75 communicated with the inboard of support pouch, and communicates with atmosphere, allowed the user from deaeration between lining bag and the support pouch, with the dependency of increase lining bag with support pouch.Hole 75 only distributes along the junction of lining bag with support pouch.The function in hole 75 function with pore 99 in itself is identical, but bigger than pore 99 and micropore 78 usually.

Micropore 78 distributes on the whole surface of at least one sidewall of bag usually equably.In addition on the one hand, micropore 78 also can distribute on the whole surface of at least one sidewall of bag usually unevenly.Micropore 78 is different with pore 99, because compare with the finely porous number on the sidewall of bag, the number in hole 99 is less.Generally, multi-joint bag of the present invention is not that existing micropore has pore again, because micropore allows air to shed, allows moisture to infiltrate into theca interna from meat yet.The sidewall of support pouch and lining bag can all have micropore.Particularly, also can have only the lining bag of the multi-joint bag shown in Fig. 5 A-5C to have micropore.

In fact, food such as meat place in the multi-joint bag 70, and meat contacts with lining bag 71.Moisture can permeate by the micropore 78 of lining bag 71, and moisture can be absorbed by water absorbing theca interna 77, and theca interna 77 slightly microdilatancies make lining bag 71 contact equably with the surface of meat.The lining bag contacts with meat equably and has prevented that meat is air-dry by refrigerator.

So-called " rectangular distribution " is meant that micropore all is consistent in itself on the whole surface of sidewall or film, distance each other also equates in itself.Micropore is preferably on the matrix with polka dot formula and forms.From 50 to 950 microns usually of finely porous diameters, particularly from 100 to 500 microns, more especially from 200 to 300 microns.The interior finely porous number of unit area is from 0.465 to 12.56/cm usually ²Particularly, hole density is from 0.775 to 7.75/cm ²More especially, from 1.24 to 4.65/cm ²On film, make finely porous method and apparatus in U.S. Patent No. 5,405, have in 561 illustrated.

Usually, tertiary membrane layer or theca interna 77 can be by making with the identical or different material of the material of making lining bag and support pouch.Available material comprises: thermoplastic polymer, cellulosic polymer, paper, cotton, polyvinyl alcohol, plastic optical fibre are (as TYVEX ^TM, can buy from DuPont company), poly-ester fibres is (as RAYON ^TMOr DACRON ^TM), elastic fibre is (as LYCRA ^TM) or the common absorbent material that exists with the rete form.Particularly, theca interna 77 is absorbent material films, as cellulosic ether or polyvinyl alcohol.More especially, theca interna is by the hydroxyprolyl-methylcellulose resin, makes as METHOCEL, and (trade mark of Dow chemical company) can be from being positioned at Rockville, the Polymer Films of CT, and Inc. has bought.

A preferred embodiment of multi-joint bag of the present invention is shown in the multi-joint bag 90 among Fig. 9 A.Multi-joint bag 90 comprises lining bag 91 and support pouch 92, and support pouch 92 has reusable closure elements 14.Lining bag 91 is limited by banding ad and bc and flanging 24.Support pouch 92 by banding 89,89 ' and flanging 26 limit.Lining bag 91 and support pouch 92 have public banding ad and bc.Shown in Fig. 9 A and 9B, the upper limb 95,95 ' of lining bag 91 is connected on the sidewall 96,96 ' of support pouch 92, and the foreskin sealing 97 that is positioned at machine direction longitudinally is positioned on inside face 101,101 ' the whole length.The upper limb 95,95 ' that links to each other with support pouch 96,96 ' defines the opening of lining bag.The sidewall 94,94 of lining bag and the sidewall of support pouch 96,96 ' are normally discerptible except that banding ad, bc and foreskin sealing 97 (hereinafter describing), shown in Fig. 9 B, have formed space 23 between the two.The sidewall 96 of support pouch 92 has several pores 99 below foreskin sealing 97.Shown in Fig. 9 A and 9B, lining bag 92 inside faces 98 with texture.Particularly, the surface of texture is embossing.Below in the sidewall 94 of lining bag, 94 ' foreskin sealing 97 also can have pore 99.

More particularly, shown in Fig. 9 C, hinge formula foreskin sealing 97 is to form like this, along the machine direction of lining bag and support pouch, the sealing band 100 of extruded material is covered the upper limb of lining bag 95 that is:.The following describes and paste sealing band and form foreskin leak free process.Sealing band 100 is connected on the sidewall of support pouch at regional 103 places usually, is connected on the lining bag at regional 102 places usually.In this embodiment, the upper limb of lining bag does not have heat seal on the sidewall of support pouch.Sealing bag 100 not only is connected on the sidewall 96 but also is connected on the upper limb 95, and this has formed hinge connection, and upper limb 95 can be taken off from sidewall 96, to form a T shape at this point of connection place.The intensity that sealing band 100 is connected on support pouch and the lining bag is preferably such, that is: in the test of T shape, lining bag film will lose efficacy.Being used to form hinge formula foreskin leak free sealing band 100 can be made by any suitable thermoplastic material or the combination of thermoplastic material, and the thermoplastic material heat-sealable is wanted on the bonded assembly thermoplastic film at least a portion.Particularly, sealing bag is a polyethylene, more especially, is low density polyethylene (LDPE) or the material compatible with the lining bag with other support pouch, and this point is described hereinafter.

Another hinge formula sealing of adopting among the present invention is such, and it can be connected on the support pouch, also can be connected on the lining bag, also can make lining bag material heat seal on support pouch.Shown in Fig. 9 D, heat seal formula foreskin sealing 110 comprises sealing band 112, and sealing band 112 sticks on the upper limb 95 of lining bag 95, contacts with support pouch 96, is connected with 116 places regional 114 usually.The upper limb 95 of lining bag also is fixed on the support pouch 96 firmly at regional 118 place's heat seals usually.When the sealing of heat seal formula foreskin formed, sealing band was passed to the lining bag to enough heats, makes its heat seal on support pouch.From the condition of the enough heats of sealing band transmission be, the temperature of sealing band, heat absorption capacity and quantity are enough big, and lining bag film enough approaches and not only but also enough low seal temperature.Sealing band 112 can be made by the material identical materials of making sealing band 100 with above-mentioned being used to.The material of following support pouch and lining bag must make both heat seals mutually, to form the foreskin sealing of heat seal formula.

Surprising is that the lining bag film of texture or embossing makes it have the performance of improvement.The face area that performance gives the credit to film that improves that is had through the lining bag film of embossing has increased, and the situation of this and not embossing is compared, and can depend on the surface of meat better.Embossing has also reduced the global stiffness of film effectively, and this has also improved the lining bag and has depended on carnivorous surperficial characteristic.

Usually, can on lining bag or support pouch, use any embossed pattern.For example, available embossed pattern and the shape rhombus (as shown in figure 11), honeycombed (as shown in figure 12), square, spherical (as shown in figure 13), triangle (as shown in figure 14), circular cone (as shown in figure 15), the pyramid (as shown in figure 16) that comprise lengthening.Evenly, Li San geometric scheme also provides the passage of air the process of air-out between rete.Can be used for other embossed pattern of the present invention and manufacture method thereof in U.S. Patent No. 5,113, be illustrated in 555.Particularly, the embossed pattern on the lining bag more especially, is square or uniform rhombus for the rhombus of lengthening, and its cross-sectional plane is a pyramid.Particularly, embossed pattern is outstanding from the inside face of lining bag, to contact with carnivorous or other food.Usually, be in the lip-deep every 2.54cm length of lining bag, to reach 6 to 50 in the density that forms the embossing of pattern on the lining bag, particularly, reach 10 to 20.

Usually, the support pouch of multi-joint bag of the present invention and lining bag are made by the compound of certain thermoplastic material or several thermoplastic materials, can comprise identical materials, also can comprise different materials.Can be by traditional casting or film-blowing process casting rete.For example, available thermoplastic material comprises that polyolefin is (as high density polyethylene, low density polyethylene, linear low density polyethylene LLDPE and polypropylene PP), thermoplastic elastomer is (as styrene block copolymer, polyolefin blend, elastomer blends, the thermoplastic polyurethane, thermoplastic copolymer and thermoplastic polyamide), poly-mer and copolymer (polyvinylchloride, poly(vinylidene chloride) PVDC, the saran copolymer, the ethylene/vinyl acetate copolymer, cellulose acetate, poly terephthalic acid second two fat PET, the poly-mer Surlyn that contains ionic bond, polystyrene, polycarbonate, styrene acrylontrile, aromatic polymer, linear polymer, the thermoplastic polyvinyl alcohol) and can be used for making the above-mentioned Available Material of theca interna.Particularly, support pouch and lining bag are made by polyethylene, more especially, are made by low density polyethylene (LDPE) (LDPE, density 0.92) and linear low density polyethylene (LLDPE, density 0.925).Particularly, the density of lining bag film is less than 0.930g/cc.

Usually, the horizontal 2% secant modulus TDSM of the lining bag film of multi-joint bag of the present invention is less than 2.75 * 10 ⁸Pa, particularly, less than 1.86 * 10 ⁸Pa, it determines that method is the method A according to ASTM D832-83, its interocclusal clearance is that 10.16cm, specimen width are that 2.54cm, initial strain are 0.635cm/cm/ minute and ram speed is 2.54cm/ minute.The modulus of film, and though along film laterally or machine direction, all is the performance of the rigidity of film usually.Usually, the thermoplastic polyolefin film is prepared by the cast film technology of knowing in the prior art, and the TDSM of this thermoplastic polyolefin mould is less than 1.86 * 10 ⁸Pa.By the TDSM of the thermoplastic polyolefin film of the film-blowing process known preparation from 9.03 * 10 ⁷-1.86 * 10 ⁸Pa.The example of resin of the such tensile properties of having of film can cast or cook a meal comprises LDPE748 and LDPE690, and they can have been bought from Dow chemical company.

The useful characteristic of another one of lining bag film is the Z value, and the Z value is determined by following formula:

t ³×TDSM

Wherein, t is the thickness of mould, and TDSM is above-mentioned transverse modulus.The Z value shows relative rigidity and the thickness of mould and the functional relation of modulus of film.Usually, the Z value of lining bag film is less than 6.7mm ³KPa.Particularly, the Z value of lining bag film is less than 2.2mm ³KPa, more especially, the Z value of lining bag film is from 0.22-1.1mm ³KPa, more especially, the Z value of lining bag film is from 0.33-0.66mm ³KPa.

Particularly, the Z value of support pouch is from 5.6-16.9mm ³KPa.

Usually, the nominal sidewall thickness of support pouch between the 25.4-102 micron, particularly, between the 33-76 micron, more especially, between the 38-50.8 micron.Nominal thickness is meant the thickness before carrying out any surface treatment such as indentation, texture and embossing.

Usually, the nominal sidewall thickness of lining bag is less than 50.8 microns, particularly, and between the 7.6-25.4 micron, more especially, between the 13-17.8 micron.

Particularly, the angle of contact of the inside face of lining bag in the time of 20 ℃ with respect to the beef broth raw material between 65-75 °, this angle of contact determined by preceding angle of contact, use be contact goniometer, for example, be the side angle instrument of No.A-100 with the model that can buy from Rame-Hart company.Angle of contact is the angle between a horizontal substrate and the tangent line, contact point place when this tangent line contacts with horizontal substrate on the surface of drop and drop surperficial tangent.Angle of contact is the function of surface tension of liquid.Angle of contact is more little, and it is high more that liquid depends on or be adsorbed on suprabasil degree.

The method of measuring angle of contact is as follows: 1. the drop (about 1 microlitre) that will measure is placed on the measurement surface (lining bag mould) of contact goniometer; 2. measure angle of contact in two sides of all five drops; 3. at the different parts repeating step 2 on lining bag surface, the result takes the mean, to determine average angle of contact.Angle of contact comprises the compound of LDPE748 and LDPE690 with respect to the example of beef broth raw material film between 65-75 ° in the time of 20 ℃, they can have been bought from Dow chemical company.

Multi-joint bag of the present invention also can have one or more layers of mould or substrate between support pouch and lining bag.The available film and the material of substrate comprise above-mentioned manufacturing lining bag and those materials of support pouch, also comprise paper, cellulosic polymer, fiber and elastic fibre.

Multi-joint bag of the present invention also can be made by the film of different colours, so that the structure of bag in the bag is showed the customer.For example, lining bag and support pouch can be different colours, and one of them or both can be transparent.

Multi-joint bag of the present invention also can comprise such lining bag and/or support pouch, and it comprises film or substrate through corona treatment, improving the wetting behavior of film, thereby improves film and printing characteristic meat absorption and/or film.Particularly, the inside face of lining bag has promptly passed through corona treatment with the contacted surface of food., be illustrated in 705 in U.S. Patent No. 5,328 with the useful method of corona treatment plastic film.

Multi-joint bag of the present invention also can have printing zone on support pouch and/or lining bag.Print surface is used for stamping literal in the above, with the interior relevant information of article of record and band.Print surface also can have and is positioned on support pouch and/or the lining bag, to cover pore tactfully.

Multi-joint bag of the present invention also can have the lining bag and/or the support pouch of passing through into the pleat processing.

Although without any special theory, should believe that multi-joint bag of the present invention prevents that the carnivorous airdry element of refrigerator from being the thin inner layer film of pocket, it is adsorbed on the carnivorous surface, and adapts with the surface of meat, thus prevent steam scatter and disappear and from the surperficial air-out of meat.Eliminate scattering and disappearing and having reduced the formation of ice crystal from the air on carnivorous surface of steam, the formation of ice crystal has caused the air-dry and carnivorous dehydration of refrigerator.

Fig. 7 is a block scheme of making the process of multi-joint bag of the present invention with hand-made.In the step shown in the square frame 200, the polyethylene lining form of internal layer is trimmed to required size, cuts the banding of existing polyethylene refrigerator bag, and launches the refrigerator bag.In the step shown in the square frame 210, lining form covers on the refrigerator bag of expansion and aims at, and the edge that makes lining form is within the lid profile reach of refrigerator bag.In the step shown in the square frame 220, with the bar type heat sealer lining form is connected on the film of refrigerator bag, make two film heat seals together with parallel edge along lining form.In the step shown in the square frame 230, the folding film that links together makes that cover the profile place adaptive mutually, seals the edge of each film, to make multi-joint bag.Banding can carry out with traditional heat seal.In the step shown in the square frame 240, unnecessary thermoplastic material is cut off, and checks the globality of bag.Then, bag is piled up on distributing box, shown in the step shown in square frame 250.

Making according to the present invention has the lining bag of at least one internal layer and multi-joint bag method of an outer field support pouch generally includes the following step: the feeding first thermoplastic film band, its thickness has the first horizontal film bandwidth between parallel edge greater than 25.4 microns; At least one second thermoplastic film band of feeding, its thickness have the second horizontal film bandwidth less than 50.8 microns, and second transverse width is less than the first thermoplastic film width; The second thermoplastic film band is covered on the first thermoplastic film band, be located between the parallel edge of the first film band; The second thermoplastic film band is connected on the first thermoplastic film band, and connection location is the parallel edge along the second thermoplastic film band; Along laterally folded each film band; With each the film band that folds with the encapsulating method cut-out, to form pocket.

Fig. 8 is a schematic flow sheet according to one embodiment of the method for the invention.Step shown in square frame 300, inner layer film i.e. second film can be extruded or be provided by the uncoiling station.The blown film of extruding the available thermoplastic material of knowing in the prior art of inner layer film or casting pressing method.In the step shown in square frame 310, support membrane i.e. first thermoplastic film is extruded, and it has the profile of zippered lid in each edge of film.Extrusion method can be with traditional casting or film blowing method.The example of a single-piece casting film method is in U.S. Patent No. 4,263, is illustrated in 079.Particularly, two films are all cast and are extruded.In the step shown in square frame 320, inner layer film i.e. second film adds or covers on first film.Second film is to aim at like this, that is: the edge of second film is between the lid profile of first film.Second film being covered and be aligned on first film available traditional director element such as roller and pressure roller finishes.In the step shown in square frame 330, the inner layer film i.e. parallel edge heat seal of second film is on first film at support membrane.Each film can be in the same place with lamination, warm-up mill and the heating tape heat seal of traditional heat seal element such as heating rod sealer, hot air fringing sealer, extruding.Particularly, each film is sealed together by the sealing of hinge formula foreskin.Forming foreskin leak free method step is described hereinafter.In the step shown in square frame 340, the film band that links together is folded, covers profile and merges together.Traditional method for folding of knowing in the folding available prior art of film band carries out.In the step shown in square frame 350, the sealed method of folding film band is cut off, and to form pocket, the pocket of making piles up together, and the pocket that piles up is placed in the packing chest.Each film that links together folding and the technology that cuts into pocket with encapsulating method is in U.S. Patent No. 5,062, is illustrated in 825.Particularly, before cutting off after each film is folding and with encapsulating method, positive closure elements and cloudy closure elements lock mutually.The pocket of making can pile up, transport, places in the packing chest, and its method is in U.S. Patent No. 5,302, is illustrated in 080, No.5,108,085 and No.5,185,987.Making of the present invention comprises that at least the method for the multi-joint bag of two pockets just links together plural film band.

One of them of first and second films or both can carry out texture by the method for for example embossing.One of them or all film bands can carry out corona treatment before or after linking together.Particularly, before second film covered on first film, second thermoplastic film carried out corona treatment and embossing.

Second film is an inner layer film covering to first is can prepare micropore before on the support membrane band, and the method and apparatus that is adopted is in U.S. Patent No. 5,405, is illustrated in 561.

Pore 99 can be arranged on one of them or two the film bands, and the method for employing can be such any method for preparing fenestra of knowing in the prior art, that is: its method and apparatus is similar to U.S. Patent No. 5,405, the method and apparatus described in 561.Also available laser or have punctured element that pin stretches out from rubber rollers therein one or two film band make pore.Particularly, the non-heating punctured element of 99 usefulness of the pore on the film is bored a hole to film and is made.Particularly, before each film covers mutually, have at least a pore 99 to be arranged at the i.e. sealing for connecting each film band of the first thermoplastic film band of support membrane band and sentence down.Pore 99 on the support membrane band can prevent air trapping between each film band, prevent to form bubble, prevent when the time by way of compressing roller or in the process of folded membrane band film take existing fold out of.

Particularly, after each film band links together, formed the profile of the lid of bonding first thermoplastic film.The profile of lid can be pasted on the film of the back extruding of knowing in the prior art then by the mould extruding to form desired shapes.The example of the extruding of the profile of lid and back method of attaching is illustrated in 223 in U.S. Patent No. 5,049.

For make multi-joint bag of the present invention prepare the film band recommendation method as shown in figure 17, and the method that connects two film bands is as shown in figure 10.Figure 17 provides the diagrammatic side view with the method that is connected each film band 400, and the transparent view of the method that Figure 10 linked together each film band before forming pocket.As shown in figure 17, method 400 comprises on the whole: the i.e. element of the first film band 410 of supporting is provided; The i.e. element of the second film band 430 of internal layer is provided; Tension Control element 440; Sealing by 450 expressions is a Connection Element on the whole.Element 410 comprises crushed element 412 on the whole, and it is aimed at casting roll 416 extruding.Crushed element 412 is squeezed in thermoplastic material 413 on the casting roll 416, to form the i.e. first film band 414 of supporting.Provide the element of the first film band also to can be known element in any prior art, can be used in U.S. Patent No. 5,049, the pressing method described in 223.Film band 414 arrives corona treatment element 420 by way of a traditional standard control element 418, and wherein, the first film band 414 carries out corona treatment by above-mentioned method, and the selectivity printing afterwards of thinking prepares the film band.

The internal layer i.e. second film band 432 is that uncoiling station 431 provides by roller.Second film 432 also can be provided by the known traditional blown film or the method for cast film in the prior art.The second film band has horizontal film bandwidth, and this width is less than the transverse width of the first film band 414.Film band 414 and 432 is fed to Tension Control element such as pressure roller 440, so that the strain facies of each film is adaptive.Hereinafter will illustrate in greater detail the strain adaptation method of each film.The first and second film bands 414 are aimed on roller 434 and are covered mutually with 432, have formed film band 436.Film band 436 is fed on the whole by 450 packing elements of representing.Film band 436 is at roller 438 place's change of directions, and is fed to packing element 450.Packing element 450 comprises that on the whole crushed element is squeezer 452, roller 454 and pressure roller 456.The packing element of a recommendation and is described hereinafter as shown in figure 10.Squeezer 452 provides sealing band 458.Sealing band 458 is fed on the film band 436, and covers the i.e. parallel edge of second film 432 of internal layer.Sealing band 458 on the film band 436 passes through between roller 454 and pressure roller 456, has formed the foreskin sealing.Crushed element is the profile 460 that squeezer 456 provides lid.The profile 460 of lid is connected on the relative parallel edge of the first film band 414, and the example of method such as U.S. Patent No. 5,049,223 are described, has formed the film band with foreskin sealing and lid profile, and promptly the film band 462.Then, fold, seal and cut off, pile up and pack having the film band 462 that covers profile, as shown in Figure 8.

One of them or two film bands can carry out texture or corona treatment by above-mentioned method.One of them or two film bands can carry out the micropore preparation as stated above or make pore disposed thereon.

Second thermoplastic film is that can be connected first thermoplastic film be on the support membrane to inner layer film, method has: extruding foreskin sealing (cover the edge of inner layer film, above be illustrated according to Fig. 9 C and 9D), the sealing of hot air fringing, extruded lamination (pushing thermoplastic film between each rete), hot-melt adhesive (place rete upper limb above or below), ultrasonic sealing, hot-rolling or band sealing, adhesive film band, infrared sealing, frequency of radio seal or Vibration Welding.Adopt the method for above-mentioned two retes of any connection all to depend on the chemistry and the physical property of film band to a great extent.Particularly, inner layer film is sealedly connected on the support membrane with the hinge formula foreskin of extruding, and shown in Fig. 9 C, this point is described hereinafter.Method as shown in figure 17 can be continuous method, also can be the method for step.Particularly, this method is continuous.

Figure 10 shows the second thermoplastic film band 432 is connected to method on the first thermoplastic film band 414, and is represented by 450a on the whole.As shown in figure 10, according to the present invention, along the parallel edge 470 of the second thermoplastic film band, the second thermoplastic film band 432 is connected on the first thermoplastic film band 414, in this process, the second thermoplastic film band 432 is aimed at and is covered on the first thermoplastic film band 414, has formed film band 436.This film band and passes through below sealing band squeezer 452 between pressure roller 472.The sealing band 458 of the thermoplastic material of molten condition is squeezed on the film band that advances along machine direction, covers on the edge 470 of the second film band, thereby makes two film band contacts and be connected, and be fixed together.The film that links together is brought into to by one group of pressure roller 454 and 456, has formed the foreskin sealing.Can adopt the second traditional sealing band squeezer (not illustrating), so that the relative parallel edge of the second film band is sealed on the first film band.Then, the film band 436 with foreskin sealing 459 is by way of traditional guiding roller 474 and 476 so that the film band 436 folding, cut off by encapsulating method, to form pocket.

Foreskin sealing 459 can be hinge formula foreskin sealing 97 (shown in Fig. 9 C), also can be foreskin sealing 110 (shown in Fig. 9 D) of heat seal formula.Particularly, foreskin sealing 459 is hinge formulas.Some advantages of foreskin encapsulating method comprise: film can higher speed connect continuously; The foreskin sealing looks that intensity is big, attracts the customer aesthetically; This method is responsive to the change of other method; With, to compare with well-known process of the prior art, this method does not produce the film tail.

Usually, sealing band can be pasted by any way, so that two symphysis are connected together.Particularly, the first thermoplastic film band has adaptive positive closure elements and cloudy closure elements along the opposite edges of film band, and sealing band is pasted equidistantly from lid profile separately.More especially, sealing band is pasted equidistantly from the first thermoplastic film band, and therefore, after each film band linked together, adaptive positive closure elements and cloudy closure elements Pasting were on first thermoplastic film in supporting.

Usually, sealing band can be made by any suitable thermoplastic material or the combination of thermoplastic material, this thermoplastic material at least can with a part of heat seal of wanting the bonded assembly thermoplastic film.Particularly, sealing band is a polyethylene, more especially, is low density polyethylene (LDPE).The suitable LDPE of Shi Yonging is LDPE748 in the present invention, and it can have been bought from Dow chemical company commerce.

When forming the sealing of hinge formula foreskin, the width of sealing band is the width of the first film band to supporting from 3mm usually.Particularly, the width of sealing band is from 3-76mm, and more especially, the width of sealing band is from 6-19mm.

Usually, the thickness that is used to form hinge formula foreskin leak free sealing band is from the 13-254 micron, and particularly, this thickness is from the 25-51 micron, and more especially, this thickness is from the 25.5-38.2 micron.

Sealing band pigmentable or color is arranged, or carry out texture, so that the structure of bag attracts the customer in the bag.

Because sealing band usually not the second film heat seal on first film, adopt sealing band to make each film bonded assembly advantage be, otherwise will use the heat seal method.Yet if the temperature of sealing band, heat absorption capacity, quantity are all enough, and inner layer film has suitable thickness and seal temperature, and the sealing band of extruding will be passed to inner layer film to enough heats, and it is heat-sealing on the support membrane.

Usually, internal layer is the width of the width of the second film band less than the first film band, and therefore, after pasting, any part of sealing band can not be suspended on the edge of the first film band.Particularly, internal layer is the width of the width of second film less than first film, and therefore, Yang Gai can be connected along the relative parallel edge of the first film band with the profile of cloudy lid.

Usually, this area is all known, be connected together two symphysis, needs adaptive % to stretch, promptly in the strain of two the film bands in point of connection place.Adaptive strain can prevent the cupping transverse curl phenomenon of appearance when tension force discharges.At machine direction, the stretching of each film band can have following relationship:

In the elastic region, $\mathrm{\σ}=\mathrm{E\ϵ}=\frac{T}{t}$

Wherein, σ represents stress

E represents modulus of elasticity

ε represents strain

T represents to stretch

T represents thickness

Can derive: $\mathrm{\ϵ}=\frac{\mathrm{\σ}}{E}=\frac{T}{\mathrm{tE}}$

For preventing that fold from appearring in machine direction when the lining form of internal layer is connected to outer membrane (MD), establishes ε _{Internal layer}=ε _Outer

For elastic membrane, know that in the prior art the material that is in extended state along machine direction is along laterally shrinking i.e. " necking down ", the function of its material behavior is exactly Poisson's ratio V.Poisson's ratio is the ratio of transverse strain and axial strain, poly Poisson's ratio normally 0.3.Adopt Poisson's ratio that transverse strain and axial strain are associated, carry out above-mentioned similar derivation, CD strain and prevent that the condition of MD Curl is as follows:

In fact, at machine direction and laterally all have adaptive strain normally desirable.Available a lot of method minimizes fold, comprising: connect modulus similarly each film band and/or the similar film band of connection Poisson's ratio.

For given material, low stretching can make fold minimize in the junction of each film, and it is also less to resume work.According to application, horizontal fold is compared with machine direction and is considered to inessential sometimes.

Therefore, two film bands all need the stretching that keeps lower, and each film band should have the strain of adaptive machine direction at the point of connection place.What know usually in this area is, along machine direction effectively the stretching of the recommendation of transport membranes band be the 10-25% that surrender stretches, unit is PLI.Surrender stretch 10% when following, the wrinkling inaccuracy that becomes of film.Can keep the 0-100% of yield point although the MD of each film stretches, have been found that at more than 25% of yield point a kind of danger is arranged, that is: the thin point in the part of film band has in fact surpassed the yield point of film, has caused stiff stretching.Have been found that in order successfully to connect the sealing band of extruding, stretch the 2-15% of the surrender stretching that is preferably in machine direction.

For the embodiment that recommends, the advantage that has been found that is the lightweight idler rollers that has adopted the low friction of band, so that dilatory the minimizing between lining form supply centre and the stickup foreskin seal point place.Even the stretching of lining form at supply centre place often be so to have formed compromisely, that is: this stretchings enough is hanged down preventing fold or elongation, this stretching also enough height to produce suitable traction.As a result, in the embodiment shown in fig. 10, between two film band supply centres and stickup foreskin leak free point, be provided with one group of pressure roller.Then, the front end that is stretching in pressure roller of each film band can be suitable in high value, as 15% of yield point.Pressure roller allows different stretching controles area.The strain of each film band can be suitable by the suitable stretching control between supply centre and the pressure roller.The velocity of rotation of backer roll is lower than pressure roller slightly, stretches to discharge a part of MD, makes in its desirable scope that is decreased to 2-15%.Can increase by second group of pressure roller selectively, so that each film band is by way of different pressure rollers, and have different stretching control, this occurs in before variant film band is connected just, as shown in figure 17.

See the method shown in Figure 17 again, the internal layer i.e. stretching of second thermoplastic film is controlled at 0.008929-0.1786kg/cm width (25.4 microns PE films) usually, employing be the pressure roller of knowing in the prior art 440.In the embodiment that recommends, each film band is by way of pressure roller, so that the strain facies of each film band is adaptive.Therefore, the stretching of each film band can be different, so that the strain facies of each film band is adaptive.Internal layer promptly second film to realizing by traditional edge guiding device and/or the method for the edge shearing of film band to width.

As shown in figure 10, the sealing band stickup that is stretching in of the film band that is connected is controlled at 0.003572-0.3572kg/cm width (PE film) usually, to avoid the elongation in the torrid zone.The stretching of the film band that is connected can be traditional pressure roller 472 control.The elongation of foreskin band can produce " wave " and/or fold on final product.

According to of the present invention make the thermosealed other methods of two film bands comprise the following steps: to supply at least can the heat seal at least the first and second film bands together; The second film band is covered on the first film band; Supply the sealing band of at least one material, its temperature, quantity and heat absorption capacity are enough to make the second thermoplastic film band to be heat-sealing on the first thermoplastic film band; With, supply described sealing band so that it is sealed on the film band that covers mutually.This method is identical with as shown in figure 10 method, and difference is, sealing band squeezer 452 can place any position of the top of film band 436, with at any some place of film bandwidth along machine direction each film band heat seal together.Particularly, sealing band is compressed between roller 454 and 456 after pasting.Can adopt a plurality of sealing band squeezers 452, provide a plurality of sealing bands 458, to form a plurality of heat seal formula foreskin bands, shown in Fig. 9 D with machine direction along the film band.The film band can provide by extruding or from the uncoiling station.Want the thermosealed film band can be by comprising can making by heat seal any thermoplastic material together of above-mentioned material.The width of film band can be identical, also can be different.Usually, sealing band can be by each film band heat seal any squeezable material is together made.Particularly, sealing band is made by thermoplastic material, and example comprises LDPE748, and it can have been bought from Dow chemical company.

Usually, the temperature of sealing band, heat absorption capacity and quantity are enough to make two film heat seals to be in the same place.Usually, the temperature of sealing band is a specific material non-degradable temperature when extruding.Usually, the thickness of thermosealed film to allow heat to be passed to this film, with on this film heat seal film band below from sealing band.Usually, the thickness that is used to form heat seal formula foreskin leak free sealing band is from the 13-254 micron.Particularly, the thickness of heat seal formula foreskin leak free sealing band is from the 38-76 micron, and more especially, this thickness is from the 38-50.8 micron.

Usually, the width that is used to form the thermosealed sealing band of foreskin of heat seal formula is extremely to support the i.e. width of the first film band from 3mm, and particularly, the width of sealing band is from 3-76mm, and more especially, this width is from 6-19mm.

At least the other method that two film bands is linked together according to the present invention comprises the following steps: to provide at least the first and second film bands, and they have first and second width respectively, and second width is less than first width; The second film band is covered between the parallel edge of the first film band; At least one sealing band is provided; With, described sealing band is sticked on the parallel edge of the second film band along the second film band.Particularly, sealing band 458 is sticked on the film band by one or more squeezers 452 (as shown in figure 10).Squeezer 452 can be arranged on any position of film band top, and can each film band being linked together, method is to form the sealing of hinge formula foreskin along machine direction.For example, a plurality of squeezers 452 can be respectively above the parallel edge of three or more film bands, successively each film band is linked together.Particularly, sealing band 452 is compressed between roller 454 and 456 after the parallel edge that affixes to the film band.

Particularly, being used to form hinge formula foreskin leak free sealing band 458 pastes equidistantly from each edge of first thermoplastic film.Usually, sealing band can be made by any suitable thermoplastic material or the combination of thermoplastic material, and the thermoplastic material heat-sealable is to some part at least of the film band that will link together.The film band that for example, link together can be the film that above-mentioned thermoplastic material, non-thermoplastic material, fiber, non-woven and co-extruded go out.Shown in Fig. 9 C, the substrate of film is linked together by sealing band.

When forming the sealing of hinge formula foreskin, the width of sealing band is extremely to support the i.e. width of the first film band from 3mm, and particularly, the width of sealing band is from 3-76mm, and more especially, this width is from 6-19mm.

Usually, the thickness that is used to form heat seal formula foreskin leak free sealing band is from the 13-254 micron.Particularly, the thickness of heat seal formula foreskin leak free sealing band is from the 25-50.8 micron, and more especially, this thickness is the 25.5-32.8 micron.Example of the present invention

Cause the experimental work of the each side of following claim of the present invention to comprise: time taking " the multi-joint bag " of making several different above-mentioned definition by hand; Meat is packaged in the multi-joint bag again; With, estimate the performance of multi-joint bag, this will compare mutually and compare mutually with the object of reference of the refrigerator bag that can commercial buy, and this work is all carried out in several months process neutralization afterwards in being stored in refrigerator.Model A

Model A is three layers a multi-joint bag, makes according to Fig. 5 A, 5B and 5C, has support pouch, lining bag, the 3rd layer and pore, and this pore communicates the interior space of space and the lining bag between lining bag and the support pouch.

More especially, the multi-joint bag of model A is made by following manner:

A. support pouch is that outer field polyethylene film (is used to make ZIPLOC ^_Storage bag, 44.4 microns);

B. lining bag is the polyethylene film (thickness is 44.4 microns) of internal layer, has 800 micropores, and finely porous diameter is 10 microns, is to make freely the come in and go out pore of interlayer of moisture;

C. the 3rd layer is outer absorbing membrane, and its thickness is 38 microns, and moisture accounts for about 10% (METHOCEL of weight ^_The cellulosic ether film, by being positioned at Rockville, the polymer film company of CT makes).METHOCEL ^_It is the registered trade mark (RTM) of Dow chemical company.More particularly, the typical characteristics of this film is found in the data sheet of this polymer film company, and discovery time is in June, 1986, and name of product is " an EM IIDO water soluble film ".The main component of this product is the hydroxyprolyl-methylcellulose resin, and its CAS number is No.009004-65-3.

Furtherly, should be noted that from Fig. 5 A the banding AD of support pouch and BC " overlap " with the banding ad and the bc of lining bag in itself.Model B

Model B all is three layers a multi-joint bag, in essence with the model category-A seemingly, difference is, the thickness of lining bag is 30.5 microns, rather than 44.4 microns, in addition, the lining bag does not have micropore, the stuffiness fully in itself of the space between lining bag and the support pouch.MODEL C

MODEL C all is the multi-joint bag of duplex bag, and shown in Fig. 2 A, 2B, 2C, 3A, 3B, 3C, 4A, 4B and 4C, the thickness of the support pouch of MODEL C is 44.4 microns, and the thickness of lining bag is 15.2 microns, serves as a contrast between bag and the support pouch without any " the 3rd layer "

MODEL C is second class (whether having " common banding " or " different banding " to use letter " C " and " S " expression respectively according to bag).The banding of lining bag is represented by line segment ad and bc in Fig. 2 A, 3A and 4A.The banding of support pouch is represented by line segment AD and BC in Fig. 2 A, 3A and 4A.Can be clear that in Fig. 2 A, banding is " jointly " in itself, and in Fig. 3 A and 4A, banding is " difference ".

Each bag is all by making by hand.Fig. 7 is the diagram of circuit of the multi-joint bag of analogue formation C.

Whether MODEL C communicates and can be divided three classes with following column space according to the space between support pouch and lining bag: (1) communicate with the inside that serves as a contrast bag (shown in Fig. 4 C); (2) stuffiness (shown in Fig. 3 A, 3B and 3C); (3) (shown in the pore 99 that dots among Fig. 2 A and the 2B) communicates with ambient atmosphere.Evaluation procedure

All multi-joint bag models in itself all with respect to reference to the bag estimate, method be these bags as reality packing the refrigerator bag of no bone beefsteak.

1. before in being packaged in bag, beefsteak is initially weighed.Has a beefsteak in each bag.Bag is placed in the commercial refrigerator, and the design temperature of this refrigerator is 0 °F (17.8 ℃).

2. the time and open and close refrigerator, to observe sample.

3. for model A and Model B, physical observation (comprise comformability, the formation of ice crystal of bag around beefsteak, appreciiable is done and turn pale) was all observed in preceding every day fortnight, and the per week observation once in subsequently eight months.For MODEL C, in three months, carry out physical observation.All carry out colour in the inboard of bag and the outside and take pictures, then, thaw, take pictures again.

4. for the beefsteak that thaws, measure the percent loss and the liquid amount of separating out of weight.In case the liquid amount of separating out is meant the fluid of the blood formula of discharging from freezing meat of thawing.

5. suitably write down the short term results of " the not effect of Yu Liaoing " model A, Model B and MODEL C

Model A and Model B are by stages simultaneously and in turn estimate.

It is because film is water absorbing, and wishes to help to prevent that moisture from separating out from the meat that is stored in the refrigerator that above-mentioned model A1 is estimated.

Yet the result of Yu Liaoing has not taken place immediately.Particularly find, between lining bag and support pouch absorbing membrane is set, it is fast especially that water accepting layer and lining bag change shape, and the shape of " adaptation " beefsteak.In other words, this is very useful to the air in the discharge beefsteak surrounding space.

Second big is in surprise, the lining bag of the multi-joint bag of Model B also wrap in tightly beefsteak around, become a short-term phenomenon.

The multi-joint bag that has obviously successfully caused design mock-up C of the multi-joint bag of Model B.Estimated the multi-joint bag of two kinds of MODEL C: MODEL C C2 and MODEL C S2.Surprised result has occurred once more.The multi-joint bag of MODEL C C2 more easily adapts to the shape of beefsteak, when packing and beefsteak is being placed refrigerator " before " come to this, as shown in Figure 6A.Hindsight arrives, and can carry out various observations according to the following fact, that is: for airproof multi-joint bag, the amount of the air between lining bag and the support pouch is unmodified in itself.The long-term effect of model A and Model B

In common refrigerator bag (object of reference), beefsteak has produced a large amount of ice crystals, and serious turn pale (the scarlet dun that is degenerated to) arranged.Eclipsedly do provablely by a large amount of, refrigerator is air-dry to be serious, all can find out this point on freezing and the beefsteak that thaws.

Beefsteak in three layers of multi-joint bag (the lining bag has pore) of model A is under the fabulous state.The formation of ice crystal is less significantly, is keeping cerise, does not see eclipsed phenomenon.Do not observe the air-dry phenomenon of refrigerator on beefsteak surface.

The effect that three layers of multi-joint bag of the inner layer film that does not have pore of Model B are produced is with viewed similar in model A.

Afterwards observing of a key is soluble with reference to the significant difference on capability and performance of bag with these three layers multi-joint bag, this is observed afterwards and recognizes, the interlayer and the internal layer of three layers multi-joint bag adapt to tightly around beefsteak, the space that air is existed has reduced, and has also therefore reduced the formation of ice crystal.

Relatively demonstration between loss in weight in treating process and the drop amount, the formation amount of the loss in weight of beefsteak and ice crystal has good correlationship.The loss in weight of beefsteak in eight months that is stored in the common refrigerator bag is serious, reach 20.5%, and the drop amount is 2.06%.Being stored in beefsteak in three layers of multi-joint bag (on the lining bag pore being arranged) and comparing with object of reference and have tangible less weight loss, be 4.3%, and the drop amount is 1.93%.For the beefsteak that is stored in three layers of multi-joint bag (the lining bag is gone up pore-free), the loss in weight of the minimum of testing is 1.9%, and minimum drop amount is 0.26%.The carnivorous ability of adaptation tightly of these three layers multi-joint bag is depended in difference between this three layers multi-joint bag and the reference bag on performance, and this minimizes space of air existence.This result who adapts is to cause the airdry dehydration of refrigerator to reduce significantly.

The conclusion that draws is that the quality that is stored in three layers of multi-joint bag of interior freezing beefsteak of model A and Model B is better than being stored in the quality of the beefsteak in the common freezer storage bag (object of reference).The air-dry phenomenon of refrigerator minimizes significantly, and this is because the internal layer and the interlayer of three layers of multi-joint bag are adapted on the beefsteak.The long-term results of MODEL C

The multi-joint bag of MODEL C C2 and MODEL C S2 is compared with the refrigerator bag that can commercial buy as object of reference, and its performance is also much better significantly.Hindsight arrives, and such High Performance will give the credit to the lining bag and be tending towards " adaptation " food, and the main space that can produce ice is minimized.Perhaps the superior performance that should be noted that these models is for erose food, and as stem cabbage and the chicken that bone is arranged, the palpability of the performance in process of the test will hang down.

The lining bag of MODEL C and the various characteristics of support pouch all will be tested, and compare with the individual features of the refrigerator bag that can commercial buy.For example, the relevant rigidity of the internal layer of MODEL C (by under establish an equation definite: Z=t ³* TDSM) to hang down 1-2 the order of magnitude (for example, 0.59mm than " the refrigerator bag " that can commercial buy ³KPa compares 34mm ³KPa).

Also carried out the another one test, that is: the multi-joint bag of above-mentioned MODEL C C has been compared with the multi-joint bag of the MODEL C C with embossing lining bag.This test comprises: repack five kinds of different meats; With, estimate multi-joint bag, comprise mutually and relatively estimating, and compare with the refrigerator bag that can commercial buy, employing be the Pyatyi standards of grading of simplifying.Underproof is that trade mark is the refrigerator bag (object of reference) of ZIPLOC with reference to bag.Model

The multi-joint bag that adopts is the duplex bag, and the thickness of its support pouch is 44.4 microns, and the thickness of lining bag is 15.2 microns.The internal layer of one of them multi-joint bag has embossing, and to call " embossing internal layer " in the following text, the internal layer of the multi-joint bag of another one is flat or smooth, to call " flat internal layer " in the following text.Two kinds of multi-joint bags are all made by polyethylene.Embossed pattern with embossing lining bag is uniform rhombus, and 16 such rhombuses are arranged on the per inch.

The test sample that twists thin beef, Denver's steak, no bone/no skin pigeon breast, fishball and pork chop plate all has five, and all pack into the multi-joint bag of flat internal layer, the multi-joint bag of embossing internal layer and trade mark of five samples is in the refrigerator bag of ZIPLOC.Has only a food in each bag.These bags all place in the commercial refrigerator under 0 condition.Refrigerator is opened in various time gap, with the O﹠A sample.Standards of grading

The formulation of standards of grading is to quantize in order to make the ice crystal that forms on the surface as the meat of test sample become appreciiable.Standards of grading are divided Pyatyi: "＜low-low ", " low-in ", " in ", " in-Gao " and " height ".

"＜low-low " be meant there is not or has only very little He very trickle ice crystal on the carnivorous surface, the area of ice crystal is from 1.6-3.2cm ², do not have the air-dry phenomenon of refrigerator.

" low-in " is meant because the film perk at some position has produced three-dimensional ice crystal in early days, with the surface of the contacted film of meat on do not have the air-dry phenomenon of refrigerator.

" in " be meant and on the surface of meat, produced some ice crystals that its area is greater than 3.2cm ², at least 1/4 carnivorous surface has lost and the contacting of film, and the air-dry phenomenon of refrigerator is very little even do not have.

" in-Gao " is meant on the surface 1/3 or more on carnivorous surface and produced some three-dimensional ice crystals, and this is owing to having lost more and the contacting of film, and the air-dry phenomenon of refrigerator has also occurred.

" height " is meant at least on 1/2 surface of meat and ice crystal occurred, and/or the air-dry phenomenon of refrigerator has occurred.The result

Reach at freezing time 17 week and eight months refrigerator test the results are shown in Table 1.Numeral in each evaluation type is the number (drawing from five test samples) of carnivorous sample, and carnivorous sample has specific evaluation attributes in the specific time.The result shows, two kinds of multi-joint bags of the present invention have all prevented the generation and the air-dry phenomenons of refrigerator of ice crystal, and the test that meat is carried out and the performance of object of reference compare.

Table 1

	Sample	Low-low	Low-in	In	In-Gao	High
							17 week
Twist thin beef	The flat internal layer object of reference of embossing internal layer	4 4 0	0 0 0	1 1 4	0 0 1	0 0 0
							Denver's steak	The flat internal layer object of reference of embossing internal layer	3 4 0	1 0 0	1 1 3	0 0 0	0 0 2
No bone/no skin pigeon breast	The flat internal layer object of reference of embossing internal layer	5 5 0	0 0 2	0 0 2	0 0 0	0 0 1
							Fishball	The flat internal layer object of reference of embossing internal layer	4 0 0	0 1 0	0 4 0	0 0 0	1 0 5
The pork chop plate	The flat internal layer object of reference of embossing internal layer	5 5 0	0 0 0	0 0 0	0 4 4	0 1 1
							Eight months
Twist thin beef	The flat internal layer object of reference of embossing internal layer	5 5 0	0 0 0	0 0 5	0 0 0	0 0 0
							The Buddhist steak	The flat internal layer object of reference of embossing internal layer	5 5 0	0 0 0	0 0 0	0 0 5	0 0 0
No bone/no skin pigeon breast	The flat internal layer object of reference of embossing internal layer	5 5 0	0 0 0	0 0 5	0 0 0	0 0 0
							Fishball	The flat internal layer object of reference of embossing internal layer	4 4 0	0 0 0	1 1 0	0 0 0	0 0 5
The pork chop plate	The flat internal layer object of reference of embossing internal layer	5 2 0	0 0 0	0 3 0	0 0 3	0 0 2

Although specific embodiment of the present invention is illustrated, should understand that those skilled in the art can find to carry out various modifications and variation, this is all within the spirit and scope of the present invention.

Claims (20)

1. refrigerator bag, it comprises a multi-joint bag, this multi-joint bag has lining bag and an outer field support pouch of at least one internal layer; The lining bag of internal layer has first side form and second side form, and both link together along transverse edge separately, have formed banding, and each side form all has upper limb, and this lining bag has flanging, and this flanging defines the bottom of lining bag; Outer field support pouch has two side forms, both link together along transverse edge separately, formed banding, each side form all has upper limb, this upper limb defines the opening of multi-joint bag, support pouch has flanging, and this flanging defines the bottom of multi-joint bag, and the upper limb of lining bag is connected on the medial surface of each side form of support pouch; Wherein, the lining bag is made by thermoplastic material, and the thickness of its nominal side form is less than 50.8 microns.

2. refrigerator bag as claimed in claim 1, wherein, the upper limb of lining bag is connected on the support pouch at the preset distance place with the opening of multi-joint bag.

3. refrigerator bag as claimed in claim 1, wherein, the nominal thickness of the side form of lining bag is from the 7.6-25.4 micron.

4. refrigerator bag as claimed in claim 3, wherein, the lining bag comprises thermoplastic film, described thermoplastic film comprises the copolymer of homopolymer and ethene.

5. refrigerator bag as claimed in claim 1, wherein, multi-joint bag comprises lining bag and support pouch; The lining bag additionally is connected on the support pouch by public banding along its transverse edge.

6. refrigerator bag as claimed in claim 5, wherein, the inside face of lining bag has the texture shape at least, and has passed through corona treatment.

7. as claim 1 or 6 described refrigerator bags, wherein, support pouch has adaptive positive closure elements and cloudy closure elements along its corresponding inside face.

8. as claim 1 or 5 described refrigerator bags, wherein, the upper limb of lining bag is sealedly connected on the side form of support pouch with hinge formula or heat seal formula foreskin.

9. as claim 1 or 5 described refrigerator bags, wherein, the side form of support pouch or lining bag or both combinations has at least one pore.

10. refrigerator bag as claimed in claim 1 further comprises an inner layer film between lining bag and support pouch.

11. refrigerator bag as claimed in claim 10, wherein, the lining bag has several well-distributed micropores; The upper limb of lining bag is discontinuous with being connected of side form of support pouch.

12. refrigerator bag as claimed in claim 10, wherein, inner layer film is hydroxyprolyl-methylcellulose or polyvinyl alcohol.

13. as claim 1 or 10 described refrigerator bags, its liquid storage capacity is at 0.5683dm ³To 7.57dm ³Between.

14. as claim 1-6 one of them or the described refrigerator bag of claim 10, wherein, the lining bag has color, this color is different from the color of at least a portion of support pouch.

15. refrigerator bag as claimed in claim 1, wherein, the banding of lining bag and the banding of support pouch are separated.

16. make the method for multi-joint bag, this multi-joint bag has lining bag and an outer field support pouch of at least one internal layer; Described method comprises the following steps:

The feeding first thermoplastic film band, its thickness have the first horizontal film bandwidth between parallel edge greater than 25.4 microns;

At least one second thermoplastic film band of feeding, its thickness have the second horizontal film bandwidth less than 50.8 microns, and the second horizontal film bandwidth is less than the first thermoplastic film width;

The second thermoplastic film band is covered on the first thermoplastic film band, make the second thermoplastic film band between the parallel edge of the first thermoplastic film band;

The second thermoplastic film band is connected on the first thermoplastic film band, and connection location is the parallel edge along the second thermoplastic film band;

Along laterally folded each film band; With

Cut off each folding film band with encapsulating method, to form pocket.

17. method as claimed in claim 16 comprises the following steps: to paste adaptive positive closure elements and cloudy closure elements along the corresponding parallel edge of the first thermoplastic film band; Wherein, each film is connected with sealing of hinge formula foreskin or the sealing of heat seal formula foreskin.

18. method as claimed in claim 16, wherein, the described first thermoplastic film band has adaptive positive closure elements and cloudy closure elements along corresponding parallel edge; The described second thermoplastic film band covers between the described closure elements of the described first thermoplastic film band.

19., further comprise the following steps: punching on the described first thermoplastic film band, on outer field support pouch, to form pore as claim 16,17 or 18 described methods.

20. make the device of multi-joint bag, this multi-joint bag has lining bag and an outer field support pouch of at least one internal layer; Described device comprises:

The element of the feeding first thermoplastic film band, the thickness of this first thermoplastic film band have the first horizontal film bandwidth between parallel edge greater than 25.4 microns;

The element of at least one second thermoplastic film band of feeding, the thickness of this second thermoplastic film band have laterally film bandwidth of second between the parallel edge less than 50.8 microns, and the second horizontal film bandwidth is less than the first thermoplastic film width;

The second thermoplastic film band is covered element on the first thermoplastic film band, make the second thermoplastic film band between the parallel edge of the first thermoplastic film band;

The second thermoplastic film band is connected element on the first thermoplastic film band, and connection location is the parallel edge along the second thermoplastic film band;

Element along laterally folded each film band; With

With the element of each folding film band of encapsulating method cut-out, to form pocket.

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