JPS6133905A - Manufacture of packaged food - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing packaged foods, and more specifically, it is possible to integrate filling, molding, and packaging of heat-flowable foods, and to produce packaged foods with excellent appearance. Regarding the method.

Conventionally, the method for producing packaged foods by packaging foods that become fluid when heated to high temperatures, such as candy and chocolate, is to mold the heat-flowable food into the desired shape using a pouring mold in advance. After being taken out, the materials are twisted and wrapped in a film or the like, or they are transferred to a container obtained by thermoforming a resin sheet and banked.

However, these methods are undesirable from a safety and health standpoint, as the steps are complicated, the work efficiency is low, and there is a risk of contamination with dust and germs.

For this reason, some types of food products are poured into transparent containers made of polyvinyl chloride resin or polystyrene resin, molded and hardened, and sealed with a lid.

However, although this method can be applied to foods that become fluid at relatively low temperatures, it cannot be applied to foods that require fluidity at high temperatures, such as candy and chocolate, due to their heat resistance. There is. In order to solve these problems, it has been proposed to use polypropylene resin or polycarbonate resin, which have excellent heat resistance, as the material for the container.

However, polypropylene-based resins have poor transparency due to their crystallinity, making it difficult to distinguish the contents, as well as insufficient gloss and lack of a luxurious feel, resulting in low commercial value and impractical use. Therefore, in order to improve the transparency, it is possible to use a container obtained by thermoforming after stretching or rolling to a considerable degree to obtain a sheet with excellent transparency, but Therefore, there is a drawback that the container shrinks or deforms when filled with fluid food at high temperature, making it impossible to package it with a good appearance.

Furthermore, when such a material sheet is used, there is a major drawback in that the shapeability in thermoforming is insufficient and a container having a complicated uneven pattern cannot be obtained. In addition, since the degree of stretching of the material sheet is high, the forming temperature during thermoforming must be relatively low, and therefore the molding pressure must also be high in order to form the container. becomes increasingly high. Therefore, when filling food, it is necessary to adopt a method such as vacuum adsorption of the container to the mold, making it difficult to put it into practical use.

Furthermore, when polycarbonate resin is used, foods such as candy and chocolate adhere to the polycarbonate resin and cannot be peeled off. Moreover, it has a disadvantage that it has low moisture resistance, and the contents absorb moisture during long-term storage.

The present invention aims to eliminate these conventional drawbacks and provide a method capable of producing heat-flowable packaged foods.

That is, in the present invention, after filling a container with a heat-flowable food, closing it with a lid material, and manufacturing a packaged food, a polypropylene resin is extruded into a film and rapidly cooled to obtain a haze level of 20.
% or less sheet at a magnification of 1 at a temperature below the melting point of the sheet.
．． A container obtained by stretching the stretched sheet to 5 times or less and then thermoforming the stretched sheet at a temperature below its melting point is filled with the heat-flowable food in a fluid state, and then the container is closed with a lid material. The present invention provides a method for manufacturing a packaged food.

In the method of the present invention, the target food is not particularly limited as long as it becomes fluid when heated;
, especially foods that exhibit fluidity at high temperatures such as 120° C. or higher. Specific examples include ame 5 tyokolate, cheese, and the like.

In addition, there is no problem even if it contains AME 15 and various chemicals.

In the method of the present invention, polypropylene resin is used as a raw material for the container. Examples of the polypropylene resin include propylene homopolymers, block copolymers and random copolymers of propylene and other copolymer components such as ethylene, and mixtures thereof. In particular, from the viewpoint of heat resistance, it is preferable to use propylene pomopolymers and block copolymers. In addition, the melt index of this polypropylene resin is usually 0.2 to 10 g/
It's 10 minutes.

In the method of the present invention, if necessary, nucleating agents such as silica, talc, p-tert-butylbenzoic acid, aluminum, dibenzylidene sorbitol, alkylene bisphenol, β, β'-thiopropionic acid ester, etc. are added to the polypropylene resin. A heat stabilizer and the like can also be added as appropriate.

In the method of the present invention, the above raw materials are melt-extruded into a film using a T-die extrusion device or the like.

Next, the extruded molten resin film is rapidly cooled.

- Here the quenching temperature is below 100°C, preferably below 60°C. In addition to water cooling, methods for rapid cooling include using a chill roll or an air knife, but in order to obtain a sheet with good transparency, water cooling is preferable. A method of introducing and rapidly cooling is preferred. Also,
When the film-like body is rapidly cooled using a chill roll or an air knife, it is preferable to add a nucleating agent as described above.

Thus, the extruded molten resin film is rapidly cooled to obtain a sheet having a haze of 20% or less, preferably 15% or less, and a thickness of 0.1 to 21%.

Furthermore, this sheet was heated to a magnification of 1.5 at a temperature below its melting point.
Stretch to less than double. In other words, each time it is rapidly cooled, it is heated,
Perform roll stretching or roll rolling. Here, the sheet may be heated using a roll, an oven, or the like.

The stretching ratio should be 1.5 times or less, preferably 1.3 times or less, more preferably 1.02 to 1.2 times, taking into consideration the heating temperature of the food to be packaged, the shape of the container, etc. Make a selection.

This stretched sheet is then thermoformed at a temperature below its melting point to obtain a container. That is, the stretched sheet is solid state thermoformed at a temperature below its melting point, specifically at a temperature 5 to 30°C lower than the melting point, preferably at a temperature 5 to 25°C lower than the melting point. Examples of thermoforming methods include vacuum forming and pressure forming, but in the method of the present invention, it is preferable to employ vacuum forming, which has a relatively high forming temperature. If the molding temperature is lower than the melting point by more than 30°C, the moldability will not be sufficient, and molding will not be possible with vacuum alone, resulting in
This is not preferable because it requires a compressed air of cm 2 or more and the container is highly stretched due to the rolling effect caused by low-temperature forming.

The heat-flowable food product is heated and melted and filled in a fluid state into a container formed into a desired shape in this manner. Here, heat-flowable foods include, for example, candy, sugar, starch syrup,
It can be filled by heating and melting a candy material such as water.

Finally, the container filled with the heat-flowable food is covered with a lid material, such as aluminum foil, in a ridged manner.

Close with plastic single layer film, plastic multilayer film, laminate film, etc. The closing means is not particularly limited, but is usually accomplished by heating.

In this way, a packaged food product molded into a desired shape can be manufactured.

According to the method of the invention, filling of hot flowable food products.

Molding and packaging can be continuously integrated. Therefore, the method of the present invention greatly contributes to the simplification, hygiene, energy reduction, and labor saving of food packaging equipment and operations.

Moreover, according to the method of the present invention, it is possible to obtain a packaged food product that has excellent transparency and gloss, and has a good appearance without shrinkage deformation. Therefore, a packaged food with a luxurious feel and high commercial value can be obtained.

Further, in the method of the present invention, the sheet material used has excellent transparency and vacuum formability, and it is possible to obtain a packaged food having a complicated uneven pattern.

Furthermore, since the method of the present invention uses a polypropylene resin, it has excellent mold releasability, solvent resistance, moisture permeability resistance, and safety and hygiene properties.

Therefore, the method of the present invention can be particularly effectively used for packaging high-temperature fluid foods.

Next, examples of the present invention will be shown.

Examples 1 to 2 Isotactic polypropylene (melt index 2.0 g/10 min, melting point 168°C) was heated to a resin temperature of 240°C.
T-die extrusion equipment N (extruder 60tmφ, L/D=28
．． A transparent molten resin film was extruded using a gouging width of 550 mm and a gouging lip opening of 1 crane. The width of the extruded molten resin film through which cooling water at 2°C flows is 3 widths and the height is 501 cm. Introduced into the slit at the upper water tank water level of 5N, cooled with water, and the thickness was 0.4
A clear polypropylene sheet with a haze of 13% was obtained. Subsequently, it was heated to 130°C using a heating roll, and then the magnification was 1.03 times (Example 1) and 1.15 times (Example 2).
) to obtain a stretched transparent sheet (haze level: 6%).

This sheet was indirectly heated to a sheet temperature of 150 to 156° C., and a container was obtained by vacuum forming using a mold having 10 semi-elliptic recesses each having a depth of 19 mm and an opening of 25×15 m. This container is filled with melted candy ingredients (sugar, starch syrup, water) at the temperatures shown in Table 1, heat-sealed with aluminum foil, and packaged to check for shrinkage of the container at each filling temperature. , American mold releasability and moisture permeability were evaluated. The results are shown in Table 1.

Comparative Example 1 In Example 1, a polycarbonate seal with a thickness of 0.2 m was used instead of the polypropylene sheet, and a heating temperature of 165°C and a molding pressure of 4 kg/cm were used in a hot plate air pressure forming machine. After molding a container of a similar shape, it was packaged and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Reference Example 1 The seal obtained in Example 2 was molded using a hot plate air pressure molding machine at a temperature of 135° C. and a molding pressure of 4 kg/cm 2 , and then packaged and evaluated in the same manner as in Example 2. The results are shown in Table 1.

From Reference Example 1, it is clear that the temperature of the container subjected to low-temperature thermoforming (pressure forming) cannot be increased during filling and molding of the heated fluidized food because the degree of stretching is high.

Claims (1)

[Claims] (1) After filling the container with heated fluid food, close it with a lid material,
In producing packaged foods, a sheet with a haze of 20% or less obtained by extruding a polypropylene resin into a film and rapidly cooling it is stretched to a magnification of 1.5 times or less at a temperature below the melting point of the sheet, and then this stretching process is performed. 1. A method for producing a packaged food, which comprises filling a container obtained by thermoforming a sheet at a temperature below its melting point with the heat-flowable food in a fluid state, and then closing the container with a lid.