CN102672947B

CN102672947B - Manufacture the method for laminated vessel

Info

Publication number: CN102672947B
Application number: CN201110063137.8A
Authority: CN
Inventors: 笹内克郎; 河田淳
Original assignee: Nakamoto Packs Co Ltd
Current assignee: Nakamoto Packs Co Ltd
Priority date: 2011-03-16
Filing date: 2011-03-16
Publication date: 2016-05-25
Anticipated expiration: 2031-03-16
Also published as: CN102672947A

Abstract

The present invention relates to manufacture the method for laminated vessel, it comprises: elementary stretching and heat setting process,, elementary stretching heated comprising the multi-layer sheet of A-PET layer, functional resin layer and sealant and then elementary heat setting, with secondary drawing and heat setting process, the multi-layer sheet of wherein processing in elementary stretching and heat setting process utilizes the mould of hot former to carry out molding by heating, carry out secondary drawing simultaneously, in same mould, carry out subsequently secondary heat setting.

Description

Manufacture the method for laminated vessel

The field of the invention

The present invention relates to laminated vessel, especially food container of convenience store (conveniencestore) etc., wherein foodProduct are placed on its neutralization and are sold, and more particularly, relate to the laminated vessel with excellent functional characteristic, if toleranceThe rice steamer of the dispense temperature to 125 from refrigeration condition DEG C boils sterilization temperature (retortsterilizationtemperature)Heat resistance, resistance to dropping (droppingresistance) and keep the quality of food.

Background technology

In the food supply retail shop (foodshops) that facilitates convenience store, department store, supermarket etc., food is as cooking rice(boiledrice), the such as ham of meat of daily dish dress dish (dailydishes), noodles, salad and processing, be positioned over foodContainer for example coils, in cup or bowl and sell. This type of food container is made up of container body and covering (cover). This containerBody is generally by utilizing vacuum forming machine, pressure forming machine (pressureformingmachine) or vacuum-extrusion formingMachine, by polypropylene, expanded polypropylene, containing the polypropylene of filler, polyethylene, polyethylene foamed, shaping polystyrene, foaming resistance toHot polymerization styrene, the sheet material of amorphous polyethylene terephthalate (A-PET) etc. carries out hot forming and manufactures. This coveringBe from sheet material, as A-PET, biaxial orientation polystyrene (OPS) or polypropylene (PP) (JP2005-329972A) form.

Recently, usually do, the food being packaged in food container heats by micro-wave oven as it is. Work as foodPass through microwave-oven-heating together with this food container time, the temperature of this food is increased to 100 DEG C of left and right. Therefore, food container is wantedAsk and there is the resistance to heat resistance up to 100 DEG C of left and right. The food container of retort food (retortfood) requires the rice steamer of resistance to 125 DEG CBoil sterilization temperature. In addition, food container wishes to have high transparency, can see clearly also with the food that makes to be packaged in whereinAnd can improve commercial value.

But above-mentioned common sheet material all cannot meet high-fire resistance and the high grade of transparency simultaneously. , A-PET and OPS have heightTransparency, but high-fire resistance and softening at approximately 70 DEG C do not there is. PP sheet has high-fire resistance but is poor in transparency.

So applicant has designed the method for manufacturing heat-resistant transparent container, the method comprises: elementary (primarily) drawsStretch and heat setting process, wherein amorphous polyethylene terephthalate sheet material is heated, tentatively stretches and be then preliminary hotSetting; And secondary (secondary) stretching and heat setting process, the sheet that wherein should process in elementary stretching and heat setting processMaterial utilizes heating by molding in the mould of hot former, carries out secondary drawing simultaneously, carries out subsequently secondary in same mouldHeat setting (JP4223520B2, EP1870226A2).

Meanwhile, subsist the every day with the operating period in 2 days, has the refrigeration food of the operating period of long periodThing, retort food with the operating period of long period etc. is to sell in the food supply retail shop in convenience store and supermarket, this foodContainer requires to have the ability of the quality of food that keeps corresponding with the operating period.

But, although the above-mentioned heat-resistant transparent container of being developed by applicant is ideal: it have high-fire resistance andThe high grade of transparency, but it is inadequate in the ability that keeps quality of food. In addition, its resistance to dropping (resistancetoDropping) also need to improve.

Summary of the invention

The object of this invention is to provide and there is the high grade of transparency and high-fire resistance, there is in addition excellent maintenance quality of foodThe laminated vessel of ability and improved resistance to dropping.

The inventor to study forwardly and finds in order to address the above problem, except high-fire resistance and the high grade of transparencyOutside also there is the good ability of maintenance quality of food and the container of resistance to dropping, can by carry out following elementary stretching andHeat setting process and secondary drawing and heat setting process, from comprising that A-PET layer, functional resin layer (as have oxygen obstruction energyPower or the resistance to performance that drops) multi-layer sheet produce.

Therefore, the invention provides the method for manufacturing laminated vessel, the method comprises: elementary stretching and heat setting process,, elementary stretching heated comprising the multi-layer sheet of A-PET layer, functional resin layer and sealant and then elementary heat setting;With secondary drawing and heat setting process, the multi-layer sheet of wherein processing in elementary stretching and heat setting process passes through hot formerMould utilization heating carry out molding, carry out secondary drawing simultaneously, in same mould, carry out subsequently secondary heat setting.

In another aspect of the present invention, above functional resin layer by one or more layer form, this one or manyIndividual layer is to be selected from ethylene-vinyl alcohol copolymer (EVOH) resin bed, Vingon (PVDC) resin bed, polyacrylonitrile(PAN) resin bed and m xylylene adipamide 6-nylon (methaxylilenediamine6-nylon) (MXD6-NY) are setThe oxygen barrier layer of fat layer and/or be the resin bed of resistance to dropping of nylon (NY) resin bed.

In another aspect of the present invention, above elementary stretching and heat setting process are carried out as follows: be used as and drawThe roller of stretching device carries out uniaxial tension with 2-4 draw ratio doubly in MD (longitudinally) direction under the draft temperature of 90-120 DEG C,Then at the temperature than the high 5-20 of draft temperature DEG C, carry out elementary heat setting.

In another aspect of the present invention, by elementary stretching and the prepared elementary stretched multi-layer sheet of heat setting processIn material, this A-PET layer has 20% shown in formula or higher degree of crystallinity below:

In another aspect of the present invention, in secondary drawing and the heat setting process, this multi-layer sheet is at 80-130 DEG CAt temperature, molding is carried out in heating, then in same mould and at the temperature of 20-200 DEG C, carries out secondary heat setting.

Of the present invention still aspect another, by secondary drawing and the prepared laminated vessel of heat setting processIn, this A-PET layer has 25% shown in formula or higher degree of crystallinity below:

In the present invention, in elementary stretching and heat setting process, the degree of crystallinity of A-PET sheet material is can be hot formedIn scope, improve, and in secondary drawing and heat setting process, the sheet material quilt of processing in elementary stretching and heat setting processBe molded as the shape of container, and degree of crystallinity is further enhanced to improve heat resistance, to make resistance to 125 DEG C or higher of containerTemperature. In addition, because functional resin layer is laminated, so oxygen obstruction ability, the resistance to performance that drops etc. can have by useThe resin bed of oxygen obstruction ability, the resistance to performance that drops etc. is guaranteed.

That is to say, laminated vessel of the present invention is have the ability of good maintenance quality of food and eating from refrigerationProduct are to the food container in the wide temperature range of retort food with applicability. Rigidity and heat resistance are by stretching to improve knotCrystalline substance degree is given, and keeps excellent transparency and the gloss of A-PET simultaneously. In addition, heat resistance can be by being controlled at secondaryMold temperature in heat setting and time come freely to be controlled by improving degree of crystallinity.

Of the present invention, aspect first, because above-mentioned functions resin bed is made up of one or more resin beds, this is one years oldIndividual or multiple resin beds are the oxygen blockings that are selected from EVOH resin bed, PVDC resin bed, PAN resin bed and MXD6-NY resin bedInterlayer and/or be the resin bed of resistance to dropping of nylon (NY) resin bed, this laminated vessel has very high oxygen obstruction abilityWith resistance to one or both in performance of dropping.

In a second aspect of the present invention because stretched multi-layer sheet material be by MD direction under 2-4 draw ratio doublyUnder the draft temperature of 90-120 DEG C, carry out uniaxial tension, then at the temperature than the high 5-20 of draft temperature DEG C, carry out elementary heatSetting and form, so, but the degree of crystallinity of this A-PET layer can control to 20% or higher lower than 30%, keeps good simultaneouslyGood transparency. In addition, it can be manufactured at an easy rate by the simple device of roller.

Aspect the 3rd of the present invention, by making stretching A-PET sheet material in the multi-layer sheet of uniaxial tensionDegree of crystallinity reaches by 20% shown in formula above or higher (it is heat shapable (thermoformable) degree of crystallinity), shouldDegree of crystallinity can reach 30% or higher (it realizes high heat resistance) in secondary drawing and heat setting process.

Aspect the 4th of the present invention, many by utilizing heating to carry out this uniaxial tension of molding at the temperature at 80-130 DEG CSynusia material, to realize secondary drawing, carries out secondary heat setting, this A-PET subsequently in same mould at the temperature of 20-200 DEG CThe degree of crystallinity of layer can be by by orientation caused crystallization and reach 25% or higher by the caused crystallization of heat setting, withTime keep transparency.

Aspect the 5th of the present invention, by making at the laminated vessel being formed by secondary drawing and heat setting processIn the degree of crystallinity of A-PET layer reach by 25% shown in formula or higher above, can give high heat resistance and keep simultaneouslyHigh transparency.

Brief description of the drawings

Fig. 1 is the schematic diagram of manufacturing the device of uniaxial tension multi-layer sheet.

Fig. 2 is the schematic diagram of thermal forming device.

Fig. 3 is the curve map that has shown the relation between temperature and crystallization time.

1 multi-layer sheet

2 preheat rolls

3 nip rolls (niproll)

4 warm-up mills

5 draw rolls

6 heat setting rollers

7 longitudinal uniaxial tension multi-layer sheets

Heating plate on 11

12 times heating plates

13 mold lobes (uppermold)

14 bed die lobes (lowermold)

15 embedded heaters

16 articles thermoformed therefroms.

Detailed description of the invention

Laminated vessel of the present invention is constructed A-PET layer/functional resin layer/sealant by following process from having layerMulti-layer sheet forms: elementary stretching and heat setting process, wherein heated, the elementary stretching of this multi-layer sheet and then elementary heatSetting; With secondary drawing and heat setting process, wherein elementary stretched multi-layer sheet material in the mould of hot former, utilize heat intoRow molding carries out secondary drawing simultaneously, carries out subsequently secondary heat setting in same mould.

This amorphous polyethylene terephthalate (A-PET) layer has shape and remains the ability of container, and composesGive heat resistance and rigidity. This A-PET layer is substantially in having noncrystalline state or the slight crystalline state of degree of crystallinity of about 5-7%.The typical thickness of this A-PET layer is 100-600 μ m, special 150-500 μ m.

This functional resin layer is given as the needed function of food container, specifically, give oxygen obstruction ability, resistance to fallPerformance etc. falls. The preferred layer of giving oxygen obstruction ability is EVOH resin bed, PVDC resin bed, PAN resin bed, MXD6-NY resin bed, and the preferred layer of giving the resistance to performance that drops is tear-resistant and the NY resin bed of deflection (flexing). Resistance to droppingCan refer to resistance to ability of breaking in the time dropping. This functional resin layer can be single layer or multilayer, and for example, oxygen barrier layerCombination with the layer of resistance to dropping. The typical thickness of functional resin layer is 15-150 μ m, especially 30-100 μ m.

Sealing layer plays a part to be used for airtight container by the heat-sealing between container body and covering. Because shouldSealant is positioned at innermost layer, thus use the resin that there is excellent foodsafety and keep the ability of food quality, as poly-Propylene (PP), polyethylene (PE) and LLDPE resin. PP resin is suitable for the container for retort food, and PE resin andLLDPE resin is suitable for chilled food and waits to boil the food of (tobeboiled). The typical thickness of sealant is 30-300 μM, especially 40-200 μ m.

The gross thickness of multi-layer sheet is 150-1000 μ m typically, especially 250-800 μ m.

The multi-layer sheet with the layer structure of A-PET layer/functional resin layer can pass through in A-PET layer/adhesive/functionIn the layer structure of resin bed/adhesive/sealant, the dry laminating of sheet material or film forms separately. Additionally, this multi-layer sheetBy coextrusion inflation method (coextrusioninflationprocess) or coextrusion T-mouth modeling method(coextrusionT-dieprocess), according to the layer/adhesive resin/sealing of A-PET layer/adhesive resin/functional resinThe layer structure of layer forms. This adhesive resin must have cohesive to will bond two layers, and can be selected fromThe PP of maleic anhydride graft polymerization or PE resin, ethylene-methyl acrylate copolymer (EMA), EVA etc.

This multi-layer sheet, in elementary stretching and heat setting process, carries out uniaxial tension, then carries out elementary heat setting.

Draft temperature (surface temperature of multi-layer sheet) suitable in elementary stretching is at 90-120 DEG C, preferably 95-110Within the scope of DEG C. When this draft temperature is during lower than 90 DEG C, the tension force bearing in this multi-layer sheet that stretches is large, and drawsThe thickness of stretched multilayer sheet material tends to inhomogeneous because of inhomogeneous stretching. In the time that this draft temperature exceedes 120 DEG C, this sheet materialCan whiten and surface roughening also can occur.

Suitable draw ratio is 2-4 times, and preferably 2.2-3.5 doubly. When this draw ratio is during lower than 2 times, by differential scanning amountHeat meter (DSC) is to observing cold crystallization point in the measurement of A-PET layer. Degree of crystallinity becomes lower than 20%. Draw ratio and degree of crystallinity itBetween relation be roughly shown in Table 1.

Table 1

Draw ratio (doubly)	2.0	2.2	2.4	2.6	2.8	3.0
							Degree of crystallinity (%)	21.8	23.6	25.6	26.7	27.7	29.0

Can find out from above result, when draw ratio is 2.3 times or when lower, the secondary at the temperature of 130-200 DEG CHeat setting is necessary. But, when draw ratio is 2.4 times or when higher, because this degree of crystallinity exceedes 25%, above secondary heat is fixedShape is optional.

Typical stretching device is the uniaxial tension device that uses warm-up mill, and it can be that single stage stretches in short scopeOr the multi-step of two or more steps stretches.

Elementary heat-set temperature is not specifically limited, and relaxes because of annealing but consider orientation, preferred heat settingTemperature is than the high 5-20 DEG C of draft temperature. When this heat-set temperature is during lower than above scope, during not higher than draft temperature+5 DEG C, shouldThe percent thermal shrinkage of sheet material is large. When this heat-set temperature is higher than above scope, that is, and while exceeding this draft temperature+20 DEG C, at thisOn the surface of A-PET layer, there is surface roughening and bleach slightly. In the above-mentioned scope of heat-set temperature, preferred heat is fixedShape temperature is higher, because reduced the speed of the thermal contraction of elementary stretched multi-layer sheet material, and has reduced in formation hot formingDistortion when goods. This thermo setting time normally 1-6 second, preferably 2-5 second. In order to meet orientation lax of this sheet material, heatSetting roller rotating speed be conditioned than draw roll slow about 0.5-10%.

In by elementary stretching and the prepared elementary stretched multi-layer sheet material of heat setting process, preferably, this A-PETLayer has by 20% shown in following formula or higher degree of crystallinity:

When this degree of crystallinity is lower than 20% time, be difficult to make degree of crystallinity reach 30% or higher by secondary drawing process.

Subsequently, be heated to 80-130 DEG C by the elementary stretched multi-layer sheet material of above elementary stretching and heat setting manufacturingAfterwards, carry out molding by the mould of hot former, carry out secondary drawing simultaneously, in same mould, carry out subsequently secondary heat and determineShape. This secondary heat-set temperature is 20-70 DEG C for not needing stable on heating container, because do not need to improve the knot of containerCrystalline substance degree, or be 130-200 DEG C for the stable on heating container of needs (wherein degree of crystallinity can improve). Heat in mould is fixedThe shape time is 2 seconds or higher, preferably 3 seconds or higher.

Fig. 3 represents crystallization rate (insoluble catalyst), and ordinate represents that flexible chain and abscissa representCrystallization temperature. Flexible chain be time of experiencing in the time keeping in temperature constant until reach 50% crystallization (minute).This crystallization temperature is the temperature that crystallization occurs. Generally, best crystallization temperature is important, and it is approximately 130 DEG C for PET resinTo approximately 200 DEG C. This degree of crystallinity can be measured by density-gradient sedimentation method or DSC method. In a kind of front method, this knotCrystalline substance degree is according to being 0% under 1.335 density and being 100% to calculate under 1.501 density. At this DSC, (differential is sweptRetouch calorimetric) in method, the sample of 10mg is heated with rising temperature, for example, under the programming rate of 10 DEG C/min, adds from 20 DEG CHeat is to 300 DEG C, and nitrogen flows through under the speed of 50ml/min simultaneously, then measures heat from DSC figure (thermogram), and from heatCalculate degree of crystallinity.

From this figure, can find out, best crystallization range is 130-200 DEG C, preferably 140-190 DEG C, more preferably150-180 DEG C. That is, when crystallization temperature is during lower than 130 DEG C, the free degree of molecule is little, and when higher than 200 DEG C, opposing knotBrilliant driving force is little, reduces crystallization rate.

This manufacturing process is not critical, and can be vacuum mo(u)lding, extrusion forming or vacuum-press molding.

Preferably, this A-PET layer of the laminated vessel of manufacturing has 25% or higher degree of crystallinity. This degree of crystallinity existsIn formula above, indicate.

Explain and manufacture according to the method for laminated vessel of the present invention below with reference to accompanying drawing.

In Fig. 1, multi-layer sheet 1 is that unwinding out, is then preheated to 70-90 DEG C, simultaneously from its storage coiled materialBy the preheat roll 2 being clamped by nip rolls 3. Then, this sheet material 1 is further heated by the warm-up mill 4 being clamped by nip rolls 3To 90-120 DEG C, the roller 5 stretching 2-4 that are then stretched in the vertical doubly. The multi-layer sheet 1 of this uniaxial tension is by heat setting roller 6Be heated to the temperature than the high 5-20 of the temperature being heated to by warm-up mill 4 DEG C, to be completed longitudinal uniaxial tension by heat settingMulti-layer sheet 7.

As shown in Figure 2, longitudinally uniaxial tension multi-layer sheet 7 between upper heating plate 11 and lower heating plate 12 to be addedHot to 80-130 DEG C (as the surface temperature of this sheet material), and carry out hot forming by mold lobe 13 and 14 compactings of bed die lobe. HeatThe sheet material being shaped keeps 5 seconds under compacting state, then takes out. Because bed die lobe 14 is to be heated to by embedded heater 20200 DEG C or higher temperature, articles thermoformed therefrom 16 heat setting at 20-200 DEG C.

Embodiment

Embodiment 1

Use by main extruder (90 μ m ф) and three secondary extruders (50 μ m ф) (by ModernMachineryCo., Ltd. manufacture) composition moulding type (formtypes) five-layer co-squeezing go out machine. PET resin is joined to main extruderIn, then respectively by EVOH resin (" H101 ", by KurarayCo., Ltd. manufactures), LLDPE resin (" UF945 ", byJapanPolyethyleneCorp. manufacture), and adhesive resin (" ADTEXDU8500 ", by JapanPolyethyleneCorp. manufacture) join in three secondary extruders. Then these resins for main extruder at 270 DEG CAt temperature and for three secondary extruders, at 260 DEG C, extrude, there is PET to produce (250 μ m)/adhesive resin(10 μ m)/EVOH (15 μ m)/adhesive resin (10 μ m)/LLDPE (coextruded multilayer sheet of 75 μ layer structure m).

Subsequently, this multi-layer sheet by roll shape uniaxial tension machine (" T-17 " type, by NIPPONSEIKOSHO, Ltd. systemMake) stretch. This stretching condition is to set preheat roll temperature at 80 DEG C, and heating roller temperature (draft temperature) is at 95 DEG C, draw rollTemperature at 80 DEG C and heat setting roll temperature at 100 DEG C. This multi-layer sheet is to carry with the speed of 10m/mim, and by stretchingRoller 5 is stretched 2.5 times through a step. The heat setting 3.0 seconds in by heat setting roller 6 of the sheet material of this stretching, obtains 144 μ mThe stretched multi-layer sheet material of thickness.

Elementary stretched multi-layer sheet material is transparent and there is no microgroove. This A-PET layer is separated, by differential scanning calorimetry (DSC)(DSC) measuring degree of crystallinity is 26.0%, and does not observe cold crystallization peak.

The melting behavior of elementary stretching A-PET sheet material is by differential scanning calorimetry (DSC) (" DSC220 ", SeikoDenshi)Measure. In this measurement, 10mg sample is under the nitrogen flow of 50ml/min, with the programming rate of 10 DEG C/min from 20DEG C be heated to 300 DEG C. This degree of crystallinity is calculated by formula below:

Subsequently, this elementary stretched multi-layer sheet material is shaped as container (has the box-like of fillet; Major axis: 15cmx minor axis:The 11cmx degree of depth: 3cm) and sliced ham is packaged in wherein, subsequently by hot forming packing machine (" MultiPackR535 ",Germany manufactures, and by JapanFoodMachineryCo., Ltd. sells), with the temperature of heating plate of 100 DEG C and at room temperatureMold temperature, be used as covering O-NY (15 μ m)/(40 μ m) film seal LLDPE. Form to regenerate to produce and specifyForm, and forming speed is gratifying, 10 (shots)/min.

The evaluation of<oxygen obstruction ability>

Oxygen obstruction ability (is manufactured " OX-TRAN, Model2/21 " by MOCONCo. by oxygen permeability meter(registration mark)) at 30 DEG C and under the humidity of 80%RH, measure. Measurement result is 1.3ml/m².D.atm, this forThe quality that keeps food under normal temperature is enough.

Container is immersed in hot water, observes and whether be out of shape. As a result, until 85 DEG C do not found deformable containers, confirmUp to the heat resistance of 85 DEG C. Although do not stretch, A-PET has the heat resistance up to 70 DEG C, and it can bear short boiling and go outBacterium. In addition, the attenuation of pet layer is possible.

The measurement of<degree of crystallinity>

The A-PET layer of container is separated, and its degree of crystallinity is by dsc measurement, and to record be 26.8%. Because the temperature of mouldBeing room temperature (it is more much lower than the best crystallization temperature of the 130-200 shown in Fig. 3 DEG C), is little by the caused crystallization of heating, and only in the secondary drawing process in shaping, carry out slightly oriented crystalline.

Embodiment 2

Go out machine by the five-layer co-squeezing that uses moulding type in the same manner as in Example 1, by the PET identical with embodiment 1Resin joins in main extruder, respectively by PVDC resin (by AsahiChemicalIndustries, Co., Ltd. systemMake), PP resin (" PM731M ", is manufactured by Sun-AllomerLtd.) and adhesive resin (" ModicAPP565 ", byMitsubishiChemicalCorporation manufactures) join in three secondary extruders. Then these resins squeeze for mainGo out machine and at 260 DEG C, extrude at the temperature of 270 DEG C and for three secondary extruders, to produce (500 μ that there is PETM)/adhesive resin (10 μ m)/PVDC (25 μ m)/adhesive resin (10 μ m)/PP (coextruded multilayer of 100 μ layer structure m)Sheet material.

The multi-layer sheet of manufacturing is stretched 2.5 times, and then carries out heat according to mode in the same manner as in Example 1 and determineShape, and obtain the thick elementary stretched multi-layer sheet material of 258 μ m. This elementary stretched multi-layer sheet material is transparent and there is no microgroove. This A-Pet layer is separated, and measuring degree of crystallinity by DSC is 25%, and does not observe cold crystallization peak.

Subsequently, elementary stretched multi-layer sheet material heats by heater, so that surface temperature becomes 90 DEG C. Softening stretchingMulti-layer sheet is by using vacuum-Press forming machine (" FKC " type, by AsanoLaboraatories, Ltd. manufactures) 0.5Under the air pressure of MPa, carry out molding by vacuum-press molding method. The mould using is upper diameter, the 80mm with 100mmEnd diameter and the cavity type aluminum die of the degree of depth of 35mm, and the Temperature Setting of this aluminum die is at 140 DEG C, this is at PET resinBest crystallization range within. In mould sealing, this thermo setting time is 5 seconds.

Articles thermoformed therefrom keeps the transparency of stretching A-PET sheet material, and has the shape consistent with mould and do not becomeShape.

The measurement of<degree of crystallinity>

The A-PET layer of container is separated, and its degree of crystallinity is by dsc measurement, and to record be 36.5%.

In container, fill with water, then with have PET (12 μ m)/O-NY (15 μ m)/easily peel ply (35 μ layer structure m)The covering of making seals by sealing. Then, by using hot water static type rice steamer to boil (statictyperetort), by temperatureDegree raise 10 minutes-at 125 DEG C, keep the time code of 30 minutes-cooling 15 minutes, carry out rice steamer and boil sterilizing. Boil sterilizing at rice steamerAfterwards, container is indeformable, does not whiten. Therefore, container has the heat resistance of 125 DEG C.

The evaluation of<oxygen obstruction ability>

Carry out the container that rice steamer boils sterilizing and be opened, taken out water, then dry. Then, being similar to embodiment 1 evaluatesOxygen obstruction ability, and to record be 1.6ml/m².D.atm, this is enough for the quality that keeps food.

Claims

1. the method for manufacturing laminated vessel, the method comprises:

Elementary stretching and heat setting process, wherein

The multi-layer sheet that comprises A-PET layer, functional resin layer and sealant is heated, elementary stretching and then elementary heat setting;With

Secondary drawing and heat setting process, the multi-layer sheet of wherein processing in elementary stretching and heat setting process utilizes hot formingThe mould of machine carries out molding by heating, carries out secondary drawing simultaneously, carries out subsequently secondary heat setting in same mould,

Wherein this functional resin layer is made up of one or more layer, these one or more layers be selected from EVOH resin bed,The oxygen barrier layer of PVDC resin bed, PAN resin bed and MXD6-NY resin bed and/or be the resin of resistance to dropping of NY resin bedLayer,

Wherein this elementary stretching and heat setting process are carried out as follows: use roller as stretching device in MD (longitudinally) directionUnder the draft temperature of 90-120 DEG C, carry out uniaxial tension with 2-4 draw ratio doubly, and then than the high 5-20 DEG C of draft temperatureTemperature under carry out elementary heat setting,

Wherein, in secondary drawing and heat setting process, this multi-layer sheet carries out mould by heating at the temperature of 80-130 DEG CMould, and at the temperature of 20-200 DEG C, carry out secondary heat setting in same mould, described A-PET is amorphous poly-terephthaldehydeAcid glycol ester, described MXD6-NY is m xylylene adipamide 6-nylon.

2. the process of claim 1 wherein by the multilayer of elementary stretching and prepared this elementary stretching of heat setting processIn sheet material, this A-PET layer has 20% shown in formula or higher degree of crystallinity below:

。

3. the process of claim 1 wherein in by secondary drawing and the prepared laminated vessel of heat setting process, this A-Pet layer has 25% shown in formula or higher degree of crystallinity below:

。