Method of manufacture of the laminated paper of the high density and with the high oxygen permeability and the paper of the high-density produced by this method

FIELD: pulp-and-paper industry; methods of production of the laminated paper of the high density and the high oxygen permeability.

SUBSTANCE: the invention is pertaining to the field of the pulp-and-paper industry, in particular, to the barrier substance and the method of its realization. The method allows to produce the laminate of the paper coated with the polyolefin, at that the paper is manufactured out of the wet fibrous mass, which is not enabled to dry before manufacture of the paper, and before the polyolefin application on the paper - the paper is modified in such a manner that its surface energy has changed approximately up to the value equal to the surface energy value of the polyolefin. The presented method ensures the manufacture of the barrier substance with the stable quality and the good barrier properties with respect to the gas and may be used for packaging, in particular, for the food products.

EFFECT: the invention ensures the manufacture of the barrier substance with the stable quality and the good barrier properties with respect to the gas and may be used for packaging, in particular, for the food products.

12 cl, 5 dwg, 4 tbl, 3 ex

 

The technical field to which the invention relates.

The present invention relates to a material having barrier properties and intended for use as a packaging material, in particular for food products, as well as to a method for manufacturing a material with good barrier properties with respect to oxygen (i.e. high kislotonepronitsaemost).

The level of technology

Approximately 4/5 of all food can lose and/or absorb gases, water vapor, flavor, aroma and other properties and therefore must be stored in a protective environment.

An especially serious problem may present exposure to gaseous oxygen, since it is known that the oxygen negatively affects the taste, texture, color, nutritional content, and other properties of food products. In addition, gaseous oxygen contributes to several well-known processes that affect the duration of preservation of food, such as the proliferation of germs, change the color, lipid oxidation (rancidity), rotting fruit, etc. So the food products of this type during storage must be protected from oxygen contained in the atmosphere. In practice this often means that the retention time of the food product is determined by the rate of transport of oxygen through the packaging (this couples the Tr is usually denoted by the abbreviation SEC).

Food products are often sold in small quantities in individual packaging. This leads to the fact that the costs associated with packaging and wrapping materials themselves become a very important competitive factor. Therefore, for manufacturers of food products is very important factor of competitiveness becomes inexpensive packaging materials, with an excellent balance between cost and barrier properties against oxygen. This has led to a steady increase in demand for new and improved packaging materials having both low cost and satisfactory barrier properties. In the result, the current achievements in this sphere of activity going on at a rapid pace. At the moment, for most food excellent consider materials with value SPK 1 ml of O2/m2×24 h×105PA or less.

In addition to the economic and functional aspects of packaging of food products is becoming increasingly important aspect of the relationship with the environment because the food industry has to deal with a very large volume of sales, paired with extensive use of individual packaging of small quantities of goods. In the sale of food products have already moved far from lane the ode, when small quantities of packaging waste has traditionally been thrown on the garbage dump. This solution is no longer considered satisfactory, because there are serious problems associated with, for example, leakage of wastewater from garbage dumps in the groundwater. In addition, the increasing population and the corresponding increase in quantities of waste means that in many densely populated areas of the world fit dumps simply missing. Therefore, manufacturers of packaging materials impose more stringent requirements in terms of the manufacture of their products from reproducing materials, opportunities for recycling or safe combustion and conversion into thermal energy.

An example of a well-known and long-used packaging material with excellent characteristics (values SPK reduced to 0.003 ml of O2/m2×24 h×105PA, exceptional tightness for odors, etc.) is a laminate of aluminum foil and, for example, cardboard. In this case, problems associated with the new requirements of environmental standards. Among other factors this refers to the difficulties of recycling packaging material (for re-melting aluminum foil is too thin) and the formation of toxic aluminum oxide with which igenii.

It is well known that excellent barrier properties may be a laminate of polyolefin on some types of paper or cardboard. Examples of such solutions can be found in patent documents NO 166359 and EP 0754719, where it is proposed to cover the greaseproof paper with polyethylene. For packaging of food products this material is very promising as it provides a desired combination of favorable cost and high degree of reproducibility of raw materials while burning it is not dangerous, and this process has a high calorific value and does not form toxic compounds. Moreover, the material can be easily reprocessed.

Typically, such materials barrier against oxygen will reach a value below 100 ml of O2/m2×24 h×105PA. This value can be considered an excellent result, as with a purely additive addition SPK paper and polyethylene (which is usually for laminates) barrier against oxygen is projected in the range of 1000-4000 ml of O2/m2×24 h×105PA. In other words, the paper coating polyethylene should create some additional favorable effect.

In the patent application of Norway No. 19984666 (on the basis of which filed the international application WO 00/20212) featur what is the explanation for this favorable barrier effect, what happens when the imposition of polyethylene to paper with high fiber content. It is assumed that the favourable barrier property occurs as a result of formation in the crystalline polyethylene layer. Here, it is assumed that this phenomenon represents a structural change occurring due aimed perpendicular efforts during the coating process. This change distributes molecules of polyethylene on the paper surface, thus forming the surface crystalline layer polyethylene. This layer is also called transcrystallization. On this basis, was drafted patent claims for a method of manufacturing such barrier materials. It emphasized the importance perpendicular pressures and temperatures of the coating process. It was shown that by this method was provided value SPK about 25 ml of O2/m2×24 h×105PA, and sometimes even 1 ml O2/m2×24 h×105PA, which represents a significant improvement compared with the methods described in patent documents NO 166359 and EP 0754719. Using the above interpretation of the model was proposed by the author of the present invention and will be explained below in further description. The prevailing generally accepted theory of the formation of the Deposit barrier against oxygen boils down to the polyethylene clog the pores of the paper.

No matter for what reason it is favorable barrier property when applying the polyolefin to the paper, it is known that attempts to make the barrier materials with the best value SPK existing methods of production of these materials are faced with a huge variation in the magnitude of the SEC. This means that it is unknown how and why it creates a barrier. As a consequence, the production of barrier materials on the basis of a laminate of a polyolefin and paper/cardboard continue to influence of random factors. Taking into account the direct proportionality between the length of storage of food products sensitive to oxygen, and value SPK packages such uncertainty about the magnitude of the SPC packs becomes for many food producers totally unacceptable.

Tasks inventions

Therefore, the problem to which the present invention is directed, is to develop a method of production of packaging materials containing polyolefin laminate paper/cardboard, and forming a layer that is impermeable to oxygen, must be regulated in such a way as to ensure stable product quality.

Another object of the invention is to develop a packaging material containing the crystals is at paper and polyethylene and having a very low rate of oxygen transfer in a very small range of variation in this parameter when changing from one batch to the next.

Brief description of drawings

Figure 1 illustrates experimentally confirmed the correlation between the average surface energy of paper and polyethylene laminate consisting of paper, polyethylene coated type HDPE (high density polyethylene), and the transfer rate of oxygen (BTS)reached the laminate. The lower and upper graphs refer to several types of paper, obtained, respectively, from wet and dry fibrous mass. Letters a, b, C, d, e, f, g, h, l are indicated by different types of paper, and a symbol "'" denotes the correct paper type, which is coated with a polymer other side.

Figure 2 illustrates experimentally confirmed the correlation between the average surface energy of paper and polyethylene laminate consisting of paper, polyethylene coated type LDPE (low density polyethylene), and the transfer rate of oxygen (BTS)reached the laminate. FP180 and FP177 mean different types of paper type "super bee bread", is widely known in this field. The letters u and m indicate different sides of the paper (different sides have different barrier properties because they have different surface energy).

Figure 3 is a photograph obtained by scanning electron microscope (magnification 200x). Depicts the inner boundary of the polyethylene film is the type of HDPE after you remove the paper. Sample 1 is a laminate with the SEC to 51.1 ml of O2/m2×24 h×105PA, and the sample 2 has the SEC, 3,1 ml of O2/m2×24 h×105PA. Both samples show approximately the same degree of blistering.

Figure 4 illustrates the correlation between the value of the monoclinic fraction and value SPK in samples with the relevant securities of the type "paper from wet sulfite fibrous mass having different surface energy. The percentage of monoclinic crystalline phase increases with increasing perpendicular effort, i.e. with increasing pressure to squeeze the roll.

Figure 5 presents the image of the coating based on HDPE, obtained by the method of phase contrast in atomic force microscope (AFM - atomic force microscope).

Figure 2-4 the following notation is used: Candor: paper that is not glued hydrophobic AKD; FL812/SB: hydrophobic paper, processed in a steam chamber.

Disclosure of inventions

The problem to which the invention is directed, can be solved by the method described in the patent claims and in the further description of the invention.

The method is based on research conducted by the author in the framework of the research project. These studies showed that the barrier is formed due to structural of the of eneny in polyethylene when applying it to the paper. When the polymer mass attached to the surface of the paper, before the impact of prokachivanija using compressive loads are perpendicular to the efforts of orienting the polymer molecules at the surface of the paper. Together with the cooling of this process initiates the formation of transcrystalline layer at the surface of the paper. As a result of plastic cannot be viewed as a passive sealing material, as is done in the prevailing explanation for the synergistic interaction between plastic and paper. This property is known from an earlier patent application of the author (Norwegian patent application No. 19984666, on the basis of which filed the international application WO 00/20212).

However, the results also demonstrate two new features. One of them is that the formation of transcrystalline layer facilitates the use of paper made from wet fibrous mass, i.e. referring to a variant, when the fibrous mass to the manufacture of paper is not allowed to dry. When normal paper production used virtually exclusively fibrous mass with the dried fibers to, among other factors, to reduce transport costs. However, the drying leads to the process of keratinization in which the fibers in the fibrous mass are stretched and becomes the be more crystalline, and long, thin fibers become needle-like shape. The experiments of the inventor show that this process prevents the formation of gas-tight crystal layer in the polyolefin. So if you want a low value SPK, you should avoid using the dry paper fibers. The process of keratinization occurs when the percentage of water in the fibrous mass has a value of less than about 30 wt.%. Quickly dried fibrous mass contains approximately 10 wt.% water. Accordingly, the term "wet fibrous mass is applied to a fibrous mass with a water content of 30 wt.% and above, and the upper limit here is pure water.

The second feature is the detection of the fact that in forming a gas-tight transcrystalline layer plays an important role in the difference of the surface energies of paper and polyolefin. In this case, there is an almost linear correlation, from which it follows that reducing the specified difference crystalline layer becomes more dense. This effect is illustrated by the bottom graph in figure 1, where the value of the SEC are presented as a function of the average surface energy of the paper and the polyolefin film for a few modifications paper, polyethylene coated type HDPE. On the decree of the nom graph presents only the paper, obtained from the wet fibrous mass. From this figure it is seen that the graph reaches the zero value SPK for paper, which has the same surface energy as the film HDPE, which has this value according to the measurement is of 38.4 mn/m, the same trend can be observed for the graph in figure 2, illustrating the same dependence, but for various modifications of paper, polyethylene coated type LDPE. In this case, the value of the SEC reaches zero for the paper with the same surface energy as the film LDPE (36,2 mn/m). On both figures in the graph are presented as mean values of the surface tension of paper and plastic film. However, it has the same trend and the same zero point as a graph characterizing the surface tension of one paper, because the surface tension of polyethylene remains constant no matter what kind of paper it laminated. The only difference is smoother profile graph, i.e. a decrease in the gradient, which in this context irrelevant.

The obtained results are very unexpected and surprising, since they contradict theory that is prevalent in this area. Specialist in this industry are not familiar with the details of the process of making paper and traditionally focuses on the importance of real type b the sorcerers (which is a standard type, obtained from the dry fiber weight) and on how to handle the paper before laminating it with polyethylene. This approach can be illustrated, for example, two recent technical publications: Vähä-Nissi, M. "HD Paper as Barrier Material. Dr. techn. thesis, Tampere University of Technology, 1988 (1) and Vähä-Nissi, M., Kuusipalo, J. and Savolainen, A., Paper and Timber, v. 83 (2), 138-141, (2001) 2). In the studies described in these publications used the standard paper type (dry fiber weight) and the influence of the surface energy of paper on the SEC of the final laminate. Here are considered the importance of increasing the surface energy of the paper, because according to the results obtained in publications (1) and (2), the increase of this parameter during the coating process leads to improved adhesion between the materials and to improved barrier properties. The expert in this field it is known that the surface energy of the paper can be increased by using different oxidation processes, including treatment with ozone. This prevailing theory can be illustrated, for example, the top graph in figure 1.

According to this theory, the barrier properties are due to the fact that the polyolefin clog the pores of the paper, and it is due to the improved adhesion, will clog the pores even more tightly, the higher the surface energy of the surface of the paper. In this those theory assumes, that the interface is good contact between the materials, minimize working space as polyolefin film, through which the oxygen (film of polyethylene with a thickness of 25 μm, the SEC has about 7000 ml of O2/m2×24 h×105PA). This theory has been tested by the author of the present invention by studying the surface of polyethylene films. In the plastic phase, adjacent to the paper, it was found significant, the inclusion of gas bubbles of approximately 6-8% of the total area. In addition, samples were identified with good barrier against oxygen and the area covered by bubbles, which has at least the same area as the samples with poor barrier against oxygen.

This is illustrated in figure 3, where samples 1 and 2 have the SEC respectively 51,1 ml of O2/m2×24 h×105PA and 3.1 ml of O2/m2×24 h×105PA. From this figure it can be concluded that, despite the very large difference in the values of the SEC, both samples show intense blistering at about the same space. Hence unambiguously implies that the prevailing theory cannot be correct. Barrier effect should occur or due to factors that are radically different from the mechanism C is cupaniana long or due to additional factors that should be included in the scheme any barrier.

As already indicated, conducted by the author of the invention of the study polyolefin film after coating showed that the barrier property is directly related to the formation of the crystal layer to the polyolefin surface of the paper. The formation of this crystalline layer is illustrated in figure 5 presents the image of the coating layer from the side of the paper obtained by the method of phase contrast. Bright areas in the image correspond to a more "solid", i.e. crystalline structures, and darker areas - more than a soft (amorphous) structures.

During a more detailed study it was found that, in contrast to the main volume of the polyolefin having orthorhombic structure of cells, this layer has a monoclinic crystal structure. Further, it was found that the barrier properties are also influenced by the ratio of percentage content of monoclinic crystal structure and orthorhombic structures of cells. The correlation is of such a character, in which the laminate, the higher the percentage of monoclinic crystal structure, the lower the value of the SEC. This pattern is illustrated for several paper types in figure 4, where the laminate presents the SPK value is a function of the percentage of monoclinic crystal structure in polyethylene film.

From an earlier patent application of the inventor (patent application Norway No. 19984666, on the basis of which filed the international application WO 00/20212) it is known that the formation of the monoclinic crystal structure greatly perpendicular efforts during coating. A simple way to implement such efforts is the application of strong pressure roll during application of the polyolefin film. For this purpose it is preferable to apply a pressure of more than 250 kPa, and most preferred is a pressure roll 400 kPa or higher. However, you can get a good, dense crystalline layer, and storing it in time. Thus, it was shown that the storage of the value of the SEC, it may substantially improve. This effect can be seen in Tables 2 and 3 in Example 3 contained in the description hereinafter. From these data it is seen that when storing the value of SEC is reduced to the same value as during the application of pressure roll 400 kPa. This may mean that when the paper has the same surface energy as the polyolefin film, thermodynamic energy conditions in the laminate will be favorable for the formation of the crystal layer (Δfor such a formation less than 0). This is a very big advantage, because when the layer is thermodynamically stable, barrier properties will also be with abiline in time. When storing the film not only does not lose its properties, but, on the contrary, it can be expected that they will improve.

Thus, the method according to the invention based on the discovery of new facts related to the fact that in the case of coating paper with polyolefin barrier properties of such laminates should not correlate with plugging of the pores of the surface of the paper according to the prevailing theory, and with the formation of transcrystalline layer of the polyolefin film at the surface of the paper. In addition, this layer contributes to the combination of the application of the wet fibrous mass in the manufacture of paper and bring the magnitude of the surface energy of paper during coating as close as possible to the surface energy of the polyolefin. Usually this corresponds to a lowering of the surface energy of paper that is completely contrary to generally accepted expert opinions in this area, according to which more than the surface energy of the paper during the coating, the lower the value SPK laminate.

For lowering the surface energy of the paper to the magnitude of the surface energy of the polyolefin is possible to use all known methods of surface treatment of paper. Such processes should be considered to be within the competence of the specialist in this area. Thus, within the boundaries of the concept of the present invention, the ti processes are combined with the use of paper, obtained from the wet fibrous mass. These methods include steaming before polishing (calendering), the sizing in the mass of neutral hydrophobic agent, a high degree of grinding fibrous mass, surface sizing or any other chemical surface treatment of paper.

The best approximation to the optimal conditions to obtain low SEC for a laminate consisting of paper, polyethylene coated, is created by the following factors: the use of finely sulfanilimide fibrous mass, and during the production of paper, this mass is not subjected to pre-drying, gluing in the mass of paper neutral hydrophobic agent and surface treatment of paper steam before final calendering (rolling).

The implementation of the invention

Hereinafter the invention will be described in more detail with reference to examples of implementation of the method.

All the numerical values of the surface energies used in this application, calculated on the basis of the study of the limiting wetting angle (edge angles) in water and tetrabromomethane on the surface of samples of the respective materials. These angles were measured on the device Fibro DAT 1100 Mk II according to the documents Tappi (Technical Association of the Pulp and Paper Industry) T558 and ASTM (American Society for Testing Materials) D5725 in research is the Institute of paper industry (Trondheim, Norway). All measurements of the speed of transport of oxygen (SEC) was performed according to the document ASTM D3985 (Standard test method for transferring gaseous oxygen) on the device OXTRAN 10/50. These measurements were carried out at the company Matforsk (Norway).

Example 1. Mapping barriers against oxygen in the tissues that contain paper made from wet sulfite and dry sulphate of fibrous masses

44,7
Table 1: measurement Results of the SEC for covered HDPE high density (OD) of paper produced from dry (sulfate) and wet (sulfite) fibrous mass. For each paper are also given surface energy. The HDPE film (CG 8410) has a surface energy of 38.4 mn/m
SamplePaperSPK*Surface
energy (mn/m)
ISuper Perga Parchment, 4440:51,1of 45.7
dry sulfate fiber
weight
IISuper Perga Parchment, 4450:28,2
dry sulfate fiber
mass, D
IIISuper Perga Parchment, 4460:48,530,9
dry sulfate fiber
mass, Z
IYSuper Perga Parchment, 4470:3,143,2
wet sulphite fiber

mass, Z
* Data About2/m2×24 h×105PA

From the data in Table 1 shows that compared to paper made from the dry sulphate of pulp, paper made from wet sulfite fibrous mass, all other things being identical conditions coating provides significantly improved barrier against oxygen.

Example 2. Comparison of barrier against the oxygen in the laminate, which contains paper made from wet sulfite fibrous mass, and processed in the steam chamber, and the laminate containing the same paper, but not the past pointed to by the th treatment.

Processing in the steam chamber lowers the surface energy of the paper and provides a better barrier for HDPE. In all respects this indicates the improvement of the contact between the materials. The result is reduced averaged surface energy and, thus, decreases Δ (the Gibbs free energy for the formation of new crystal structures on the surface of the paper during storage (especially for LDPE). Ultimately decreases the SEC. This pattern can be observed according to Tables 2 and 3, where the polyethylene grades CG 8410 and SA 7230 refer, respectively, to the types of HDPE and LDPE. This is true for Table 4.

tr>
Table 2: Results of measurements of the SEC for covered high-density PE (EAP) paper produced from wet (sulfite) fibrous mass (FL 812). SA 7230: 36,2 mn/m, FL 812: 40,4 mn/m
PolymerThe pressure roll

kPa
SEC ml of O2/m2×24 h×105PASEC after storage ml of O2/m2×24 h×105PA
CG 84102501,321,61
CG 84104001,291,31
SA 72302503,492,02
SA 72304001,591,41

Table 3: Results of measurements of the SEC for high-density (EAP) paper produced from wet (sulfite) fibrous mass (FL 812) 39,6 mn/m, covered with PE and processed in a steam chamber
PolymerThe pressure rollSECSEC after storage
kPaml O2/m2×24 h×105PAml O2/m2×24 h×105PA
CG 84102501,551,55
CG 84104001,070,92
SA 72302508,132,36
SA 72304001,751,78

Example 3: Comparison of barrier against the oxygen in the laminate, which contains paper made from wet sulfite fibrous mass and glued in the mass, and the laminate containing the same paper, not glued in mass

Table 4: measurement Results of the SEC for covered high-density PE (EAP) paper, which made the C wet (sulfite) fibrous mass (Candor paper) and not glued in the mass of glue AKD. The surface energy of 50.9 mn/m
PolymerThe pressure rollSECSEC after storage
kPaml O2/m2×24 h×105PAml O2/m2×24 h×105PA
CG 84102504,655,02
CG 84104004,634,53
SA 7230250of 6.684,77
SA 72304004,963,33

Compared to the piece of paper that was taped in the mass, Candor paper demonstrates less satisfactory barrier against oxygen. However, this barrier is better barrier obtained for taped in the mass of paper higher density, which contains 60, 90, or 100% pre-dried sulphate fibrous mass.

1. A method of manufacturing a barrier material with good barrier properties against gas, in particular, for use in the packaging in the food industry, and the barrier material includes a laminate of paper coated with polyolefin, characterized in that the paper is produced from wet fibrous mass, which do not allow to dry before making paper, and on the overlay paper polyolefin paper modify so that its surface energy is changed to approximately the value of the surface energy of the polyolefin.

2. The method according to claim 1, characterized in that the wet fibrous mass is a woody fibrous mass in which the percentage of water is not less than 30 wt.%.

3. The method according to claim 2, characterized in that the fibrous material is a cellulosic fiber with a high or medium degree of grinding, and surface energy of the paper change so that it was very close to the surface energy of the polyolefin.

4. The method according to claim 3, characterized in that the paper is produced from wet cellulosic fibrous mass to a high degree of grinding with a high content of hemicellulose, such as sulfite fibrous mass or polysulfide fibrous mass.

5. The method according to claim 4, characterized in that the processing of paper produced by steam treatment in the system of the paper machine.

6. The method according to claim 5, characterized in that the paper glue in the mass of neutral hydrophobic agent such as alkylbetaine dimer (AKD).

7. The method according to claim 1, characterized in that the imposition of the polyolefin to the paper is carried out at a pressure of roll not less than 250 kPa, preferably not less than 400 kPa.

8. The method according to claim 7, characterized in that as the use polyolefin is polypropylene or polyethylene, such as low density polyethylene (LDPE) or high density polyethylene (HDPE).

9. The method according to claim 8, characterized in that in the case of HDPE surface energy of the paper change prior to coating so that it was as close as possible to 38,4 mn/m, and in the case of LDPE surface energy of the paper change prior to coating so that it was as close as possible to 36,2 mn/m

10. The method according to any one of claims 1 to 9, characterized in that several layers laminated to each other to form a more stable dimensions fabrikat, in which at least one of the layers in the laminate may consist of a layer of cardboard or laminated cardboard.

11. Barrier material for use in the packaging, in particular for food products containing fibrous layer, preferably of cellulose material, covered by a polyolefin, at least on one side, characterized in that manufactured by the method claimed in any one of claims 1 to 10.

12. The barrier material according to claim 11, characterized in that the fibrous material, together with the additional fibrous layers and/or cardboard material is laminated through an outer polyolefin layer, and the outer surface of the laminate is covered with an additional protective layers consisting, in particular, of the polyolefin.



 

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SUBSTANCE: film consists of polyolefin, preferably of polyethylene or polypropylene, and is provided with sealable layer on outer surface thereof. The sealable layer is applied in accordance with predetermined pattern. The film is metallized at least from one film side.

EFFECT: increased ability of film areas connection during article packing due to decreased liability of contamination absorbing.

10 cl, 6 dwg

FIELD: laminated material for manufacture of packaging containers by folding and thermal sealing and packaging containers for liquid food products manufactured from said material.

SUBSTANCE: packaging material 10 has central layer 11 of paper or cardboard and layer 12 of polyolefin with mineral filler on one side of central layer. Layer 12 with mineral filler has thickness of from 30 micron to 100 micron and has mineral particles in an amount of from 40% to 70% by weight of layer 12 with mineral filler. Both sides of central layer are provided with water-impermeable coating of polyolefin.

EFFECT: increased rigidity and provision for manufacture of containers with improved capturing properties.

8 cl, 4 dwg

FIELD: production of layered packing materials.

SUBSTANCE: layered packing material produced by applying two or more wet covering layers on substrate and drying thereof comprises at least one layer having thickness of not more than 20 mcm in wet state and at least one oxygen barrier layer or at least one oxygen scavenging layer. Oxygen barrier layer is formed so that total oxygen permeability of layered material does not exceed 150 cm3/m2 during 24 hours under 1 atm pressure.

EFFECT: possibility of layered material usage for forming packages to be filled and sealed.

9 cl, 2 dwg

FIELD: packaging materials.

SUBSTANCE: sleeve-like shell is composed of inner layer A, central layer E and outer layer G. Inner layer A tightly fits the contents and mainly consists of aliphatic polyamide or copolyamide and/or polyamide or copolyamide including aromatic links. Central layer E is mainly formed of aliphatic polyamide or copolyamide and/or polyamide or copolyamide including aromatic links. Outer layer G is also formed of aliphatic polyamide or copolyamide and/or polyamide or copolyamide including aromatic links. Located between inner layer A and central layer E is polyolefin intermediate layer C preventing water vapors from penetrating through the layer. Connected with layer A is adhesive layer B. Layer E is coated with adhesive layer D. Oxygen-barrier intermediate layer F is located between outer layer G and central layer E.

EFFECT: increased impenetrability for water vapor and oxygen, increased shelf life of products packed in above shell.

11 cl, 2 tbl, 8 ex

FIELD: food industry; packages.

SUBSTANCE: invention relates to laminated material designed for use in packages and featuring low absorbing action. Proposed material consists of skeleton layer made of paper or cardboard, outer polymeric coating applied to one side of skeleton layer and combination of layers arranged on opposite side of skeleton layer. Said combination includes first barrier layer in contact with skeleton layer, first binding layer in contact with first barrier layer, second barrier layer in contact with first binding layer, second binding layer in contact with second barrier layer and inner polymeric coating in contact with second binding layer, being essentially surface in contact with food product. First and second barrier layer are formed mixture of aromatic polyamide resin and polyamide 6. First and second binding layers are formed of modified polyethylene or other polyolefin. Invention provides description of package made of such laminate.

EFFECT: improved structural and mechanical stability of material and articles made of such material, simplified technology of production of material and reduced cost of production.

14 cl, 2 dwg

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