JPS6344638B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filling and packaging method for processed cheese that is filled and packaged in a heated and molten state. relates to a filling packaging method with good peelability.

[Prior art]

Generally, processed cheese is made by adding butter, cream, emulsifiers, etc. to several types of natural cheese, crushing, mixing, heating and melting to emulsify.
Of the processed cheeses, most of the 150 to 400 g of home-use carton-filled cheeses are filled and packaged in a heated and molten state.

As shown in FIG. 1, cheese is tightly packaged in a cheese packaging material 1 and packed into a carton made of cardboard with an upper lid 2 and a lower lid 3.
The cheese filling method is as shown in FIG.
After a certain amount of molten cheese heated to approximately 75 to 85°C is filled into the container, the remaining unfolded portion of the packaging material 1 is folded in so that it is in close contact with the molten cheese, and the lower lid 3 is inserted. do. Then, the filled carton is pressurized from the top and bottom, left and right sides, and the heat-sealing and sealing properties of the cheese packaging material are completed, and the packaging of the processed cheese is completed.

Currently, the materials used as packaging materials for processed cheese are cellophane or moisture-proof cellophane, polyisobutylene, low molecular weight polyethylene,
Generally, a mixture of paraffin wax, microcrystalline wax, etc. was applied by heating and melting.

When this packaging material was filled with molten cheese, a part of the applied resin surface melted and the packaging material adhered more closely to the cheese surface, and heat sealing was possible only by the heat of the molten cheese.

[Problems to be Solved] However, a special blender is required to mix polyisobutylene, low molecular weight polyethylene, paraffin wax and microcrystalline wax. Moreover, since the melt viscosity of this mixed resin is high, a special device for exclusive use is required.

There is a risk that the coated resin will block if pressure is applied or the temperature rises, and temperature control of the processing atmosphere, handling operations for winding, etc. are complicated. Moreover, in order to obtain sufficient sealing performance with a packaging material using this mixed resin, a coating amount of the mixed resin was required to be 60 to 80 g/m ² . When using this packaging material to fill and package processed cheese as described above, there was a drawback that if too much pressure was applied, the mixed resin would protrude from the sealing portion and fuse to the lower lid. Furthermore, when the sealed cheese packaging material is opened, a portion of the mixed resin of the packaging material adheres to the cheese.

An object of the present invention is to provide a packaging method that eliminates the drawbacks of such conventional packaging materials for processed cheese and enables filling and packaging of processed cheese that can be filled with heat.

[Means for solving problems]

The present invention is a method for filling and packaging processed cheese using a packaging material consisting of a base material made of either cellophane or plastic film alone or a laminated material of the above material and aluminum foil or paper, and a resin layer.

The base material of the packaging material used in the present invention is polyethylene terephthalate film, polypropylene film, polyamide film, ethylene-vinyl alcohol copolymer film, or a film obtained by coating these films with vinylidene chloride resin, cellophane, moisture-proof cellophane, or aluminum foil. It is made of paper or a laminated material of these and the above-mentioned plastic.

Depending on the type of filler, the resin layer may have a high heating melt filling temperature, a high melt viscosity, and high hardness after cooling, but even for these fillers, the vinyl acetate content In addition to 15-40% by weight of ethylene-vinyl acetate copolymer (A) and tackifier (B),
This problem can be solved by adding low molecular weight polyethylene (C). The preferred blending ratio of low molecular weight polyethylene is (A):(B):(C)= by weight
35-92: 3-35: 5-30.

If a resin containing low-molecular-weight polyethylene is used as the resin layer, the heat-sealing strength will be excessive and the unsealability will be poor even when filling and packaging materials such as cheese and yokan that have a high heating melting temperature. It is possible to prevent the sealing performance between the filling material and the packaging material from being deteriorated due to the high altitude of the filling material.

This low molecular weight polyethylene is an ethylene-vinyl acetate copolymer with a vinyl acetate content of 15 to 40% by weight.
It has excellent compatibility with (A) and tackifier (B), and has excellent suitability for extrusion application using an extruder.

The resin layer of the packaging material used in the present invention consists of an ethylene-vinyl acetate copolymer (A) with a vinyl acetate content of 15 to 40% by weight, a tackifier (B), and a low molecular weight polyethylene.
Consists of resin with (C) added.

Here, if the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) used in the resin layer is 15% by weight or less, the sealing performance to obtain sufficient heat-sealability is also insufficient. Furthermore, if the vinyl acetate content exceeds 40% by weight, extrusion coating will not be suitable and the yield will decrease.
The heat sealing strength becomes excessive, making it difficult to open.

The tackifier is made of any one of aliphatic hydrocarbon resins, aromatic hydrocarbon resins, copolymerized hydrocarbons, or a mixture thereof and has a softening point of 90.
Consists of resin below ℃.

The tackifier is made of a resin obtained by adding either a rosin derivative or a modified rosin derivative to the above resin.

Here, the aliphatic hydrocarbon resin is produced by polymerizing a 4- to 5-carbon fraction containing monomers such as pentenes, isoprene, and piperylene (1,3-pentadiene) produced by thermal decomposition of petroleum naphtha as a raw material. This is the resin obtained. Aromatic hydrocarbon resins are mainly composed of 9-carbon hydrocarbons or α
- It is a resin obtained by polymerizing pure monomers such as methylstyrene and vinyltoluene.

The copolymerized hydrocarbon resin is a resin obtained by copolymerizing the respective monomers in the aforementioned aliphatic hydrocarbon resin and aromatic hydrocarbon resin.

Since these resins do not originally have functional groups such as carboxyl groups and ester groups, they are oxidized to 1 or less and have excellent stability against oxidation.

The rosin derivatives and modified rosin derivatives contained in the tackifier for ethylene-vinyl acetate copolymer will be explained.

Rosin includes gum rosin made from raw pine tar collected from living pine trees, rosin extracted from pine stumps using petroleum solvents, and tall oil rosin obtained from cooking waste during kraft pulp production. .

Rosin made of this resin has a softening point of 70 to 85°C and is highly compatible with ethylene-vinyl acetate copolymer containing 15 to 40% by weight of vinyl acetate. Due to its high content, it has poor stability against oxidation, and its color changes from light yellow to brown during the pelletizing process by heating and melting mixing with ethylene-vinyl acetate copolymer, and it has a strong pine resin odor, making it unsuitable as a packaging material for cheese. do not have.

However, modified rosin or rosin obtained by hydrogenating, disproportionating, or dimerizing these rosins or modified rosin can be used with methanol, glycols, etc.
In rosin derivatives and modified rosin derivatives esterified with alcohols such as glycerin and pentaerythritol, the abietic acid type conjugated double bond of rosin disappears, improving stability against oxidation and improving hue.

Furthermore, even when rosin is modified and esterified, the molecular weight and its distribution width do not increase so much, and the compatibility with the ethylene-vinyl acetate copolymer is as good as with rosin.

Regarding compatibility with ethylene-vinyl acetate copolymer (A) having a vinyl acetate content of 15 to 40% by weight, judging from the cloud point of the formulation, rosin resin is the best, followed by copolymer petroleum resin. . Other tackifiers are slightly inferior to ethylene-vinyl acetate copolymers, which have a lower vinyl acetate content than rosin-based resins. These differences in compatibility mean that the mixed resin of the ethylene-vinyl acetate copolymer and tackifier used in the present invention does not cause phase separation or deteriorate heat-sealability when heated and melt-mixed. do not have.

The carton top cover 2 is folded in with the resin layer of the packaging material as the inner surface, leaving an opening as shown in FIG. The remaining unfolded portion of the packaging material 1 is folded in so as to come into close contact with the cheese, and the lower lid 3 is inserted. This is a method for filling and sealing processed cheese in which pressure is applied from the top and bottom, left and right sides of the carton to improve the adhesion between the cheese and the packaging material and to seal the packaging material.

These resins are heat-melted and mixed using a screw extruder or a Banbury mixer to form pellets. These pellets can be extruded and coated using an extruder that is generally used for extrusion coating without slipping or surging.

[Effect]

Conventional resin layers are formed by heating and melting a mixed resin and melt-coating the mixture onto a base material, so the base material is limited to cellophane or moisture-proof cellophane, which have excellent thermal stability. Furthermore, it was difficult to control the amount of the mixed resin to be applied, and the application speed was slow.

On the other hand, since the resin layer of the present invention can be formed by extrusion coating, it can be formed not only on cellophane but also on plastic and other composite materials.

In addition, the coating amount can be adjusted extremely easily by controlling the extrusion amount or coating speed.
Since it is possible to apply a coating amount of 20 to 45 g/ ^m2 , which is about half of the conventional amount, sufficient heat sealing and sealing properties can be obtained with less than half the conventional amount of 20 to 45 g/ ^m2 . Complete sealing is achieved by pressure applied from the outside or outside, but there is no risk of the resin protruding from the sealed portion.

Furthermore, since the cohesive force of the resin layer is weak, the problem of the resin layer adhering to the filling when the package is opened can be solved.

<Example> A mixed resin having the composition shown below was extrusion coated on a polyvinylidene-coated polyethylene terephthalate film (30μ) at about 230°C to form a resin layer to obtain a packaging material.

Ethylene vinyl acetate copolymer (vinyl acetate content
19wt% melt index 15g/10min) 55 parts aliphatic petroleum resin (softening point 85℃, molecular weight 1300)
25 parts hydrogenated rosin glycerin ester (softening point 78℃)
7 parts Low molecular weight polyethylene (melting point 95℃, molecular weight 800~
850) 13 parts Processed cheese with a heated melting temperature of 89°C was filled and packaged in the packaging material for processed cheese obtained in this way using the method described above, and after applying pressure from the top, bottom, left and right sides for about 1 hour, it was left in the refrigerator for 2 hours. did. As a result, both the adhesion and transparency between the packaging material and the cheese, and the sealability in a 5-hour immersion test in a methylene blue water-alcohol solution were sufficiently satisfactory. In addition, the heat seal strength between the resin layer and polyvinylidene coated polyethylene terephthalate film is 200~
It was 240gr/15mm and easy to open.

〔effect〕

As described above, in the present invention, the resin layer of the packaging material used for packaging processed cheese is made of a composition consisting of an extrusion-coatable ethylene-vinyl acetate copolymer, a tackifier, and low molecular weight polyethylene. Processed cheese can now be packaged using only pressure, even with a lower coating amount.

As a result, compared to conventional processed cheese packaging, it is possible to significantly reduce the cost not only in terms of raw materials for packaging materials but also in terms of processing, and it is also possible to maintain performance that has not been seen before.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a processed cheese package;
FIG. 2 is an explanatory diagram showing the manufacturing process of processed cheese. 1...Packaging material, 2...Upper lid, 3...Lower lid.

Claims (1)

[Claims] 1 A base material consisting of either cellophane or plastic film alone, or a laminated material of the above material and aluminum foil or paper is softened with an ethylene-vinyl acetate copolymer (A) having a vinyl acetate content of 15 to 40% by weight. Consisting of a tackifier (B) with a temperature of 90°C or less and a low molecular weight polyethylene (C), the weight ratio of which is (A):(B):(C)=35-92:3-35:5 A packaging material with a resin layer formed by extrusion coating a mixed resin of ~30 to a thickness of 20 to 45 g/m ² is folded with an opening and stored in the top lid, and the cheese is heated and melted at 75 to 85 °C. A filling and packaging method for processed cheese in which the unfolded part of the packaging material is folded in so that it is in close contact with the cheese, the lower lid is inserted, and pressure is applied from the top and bottom, left and right sides to seal.