Food packaging material having uniform coating of oil, method of manufacturing the same, mold for manufacturing the same

The present invention relates to a food packaging material for packing food, more particularly to a food packaging material having a uniform coating of oil, a method of manufacturing the same, and a mold for manufacturing the same. The food packaging material includes a plurality of grooves formed on one surface of the food packaging material; and an oil layer uniformly applied to the one surface of the food packaging material, being put into the grooves. According to the present invention, there are provided a food packaging material which continuously maintains a uniform coating of oil and thus minimizes sticking of contents to a surface of the packaging material, a method of manufacturing the same, and a mold for manufacturing the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of International Application No. PCT/KR2011/008064, filed Oct. 27, 2011, which claims the benefit of Korean Application No. 10-2011-0095170, filed Sep. 21, 2011, in the Korean Intellectual Property Office. All disclosures of the document(s) named above are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a food packaging material for packing food, more particularly to a food packaging material having a uniform coating of oil, a method of manufacturing the same, and a mold for manufacturing the same.

2. Description of the Related Art

Food packaging materials are used to package food. Food packaging materials have been improved to enhance stability of food storage, whereas a problem that contents stick to a food packaging material is not solved.

For example, as to a food packaging material used as a top of a spoonable fermented milk product, when a consumer buys a fermented milk product and pulls the food packaging material, some contents stick to the food packaging material. In this case, consumers mostly give up the contents on the packaging material. The same problem occurs with respect to a food packaging material for packaging high-viscosity retort food, such as retort curry.

FIG. 1illustrates a conventional food packaging material. In order to solve the above problem, there is a try at coating the surface of a food packaging material10with edible oil.

In this case, however, as shown inFIG. 1, force caused by surface extension of oil acts in arrow directions, so that the edible oil forms a plurality of agglomerated oil drops20. When the edible oil is not uniformly applied, contents are not prevented from sticking to the packaging material.

SUMMARY OF THE INVENTION

Technical Problem

The present invention is directed to solve problems mentioned above and provides a food packaging material which continuously maintains a uniform coating of oil and thus minimizes sticking of contents to a surface of the packaging material, a method of manufacturing the same, and a mold for manufacturing the same.

Solution to Problem

In accordance with an aspect of the present invention, a method of manufacturing a food packaging material having a uniform coating of oil includes (a) preparing a mold including a plurality of prism bodies and (b) forming a plurality of grooves on one surface of a food packaging material corresponding to the prism bodies by pressing the mold to the food packaging material.

The method may further include (c) applying an oil layer to the one surface of the food packaging material on which the grooves are formed.

The preparing the mold (a) may include (a-1) preparing a first metal layer, (a-2) depositing a photoresist layer on the first metal layer, (a-3) forming a plurality of photoresist holes disposed at predetermined intervals by patterning the photoresist layer, and (a-4) forming the prism bodies on the first metal layer.

The photoresist holes may have a cylindrical shape or a polygonal prism shape and are arranged in a grid pattern.

The prism bodies may be formed on the first metal layer by galvanoplasty.

The prism bodies may be formed on the first metal layer disposed in the photoresist holes.

The first metal layer may be deposited on a silicon layer disposed under the first metal layer.

The first metal layer may include titanium.

The prism bodies may include nickel or gold.

In accordance with another aspect of the present invention, a mold for manufacturing a food packaging material having a uniform coating of oil includes a first metal layer, a photoresist layer formed on the first metal layer and including a plurality of photoresist holes disposed at predetermined intervals, and a plurality of prism bodies formed on the first metal layer disposed in the photoresist holes.

The prism bodies may have a cylindrical shape or a polygonal prism shape and are arranged in a grid pattern.

The first metal layer may be deposited on a silicon layer disposed under the first metal layer.

The first metal layer may include titanium.

The prism bodies may include nickel or gold.

In accordance with still another aspect of the present invention, a food packaging material having a uniform coating of oil to package food includes a plurality of grooves formed on one surface of the food packaging material and an oil layer uniformly applied to the one surface of the food packaging material, being put into the grooves.

The grooves may be arranged at predetermined intervals in a grid pattern.

The grooves may have a cylindrical shape or a polygonal prism shape.

Advantageous Effects of Invention

As described above, the present invention provides a food packaging material which continuously maintains a uniform coating of oil and thus minimizes sticking of contents to a surface of the packaging material, a method of manufacturing the same, and a mold for manufacturing the same.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments are described below in order to explain the present invention by referring to the figures. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Description of unnecessary parts or elements may be omitted for clarity and conciseness, and like reference numerals in the drawings refer to like elements.

Hereinafter, a food packaging material having a uniform coating of oil, a method of manufacturing the same, and a mold for manufacturing the same according to exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2ais a perspective view of a food packaging material having a uniform coating of oil according to an exemplary embodiment of the present invention, andFIG. 2bis a cross-sectional view of the food packaging material ofFIG. 2, taken along line A2-B2.

Referring toFIGS. 2aand 2b, the food packaging material having the uniform coating of oil (hereinafter, “food packaging material”)100according to the exemplary embodiment of the present invention is used to package food, for example, used as a top for a fermented milk product or a packaging material for retort food. The food packaging material100includes a plurality of grooves110which are formed on one side thereof for a uniform coating of oil and an oil layer120.

The grooves110may be formed in a minute size by microelectromechanical systems (MEMS), which will be described in detail.

The oil layer120is applied to a surface of the food packaging material100having the grooves110in order to prevent food from sticking to the surface of the food packaging material100.

In particular, the oil layer120is put into the respective grooves110to relieve force due to surface tension of oil, described with reference toFIG. 1, and thus the oil layer120is not separately dispersed as agglomerated oil drops but is uniformed applied.

Further, as compared with the packaging material ofFIG. 1, a coating of the oil layer120is stably maintained for a long time, and the oil layer120in the grooves110functions to push water or food, so that the food does not stick to the packaging material. Accordingly, a minimum amount of food sticks to the packaging material.

Also, the uniformly applied oil layer120prevents the food packaging material100from being in direct contact with food, thereby avoiding harmful effects transmitted from the food packaging100.

Here, the grooves101may be arranged at predetermined intervals in a grid pattern in order to uniformly form the oil layer120, shown inFIG. 2a.

Further, the grooves110may have a cylindrical shape or various polygonal prism shapes, such as a triangular prism, a rectangular prism, a hexagonal prism, etc., and may have the same height.

FIGS. 3ato 3dillustrate a method of manufacturing the food packaging material ofFIG. 2a.

Referring toFIGS. 3ato 3d, the method of manufacturing the food packaging material according to the present embodiment includes (a) preparing a mold and (b) forming grooves, and may further include (c) applying an oil layer.

Referring toFIG. 3a, in the preparing the mold (a), a mold200having a plurality of prism bodies210and a food packaging material100are prepared.

Here, the grooves110are not yet formed in the food packaging material100, which is formed of synthetic resins, such as polypropylene (PP) and polyethylene terephthalate (PET).

Further, the prism bodies210are provided to form the grooves110and formed in a corresponding shape to the grooves110. Thus, the prism bodies210may have a cylindrical or polygonal prism shape and be arranged in a grid pattern.

Referring toFIG. 3b, in the forming the grooves (b), the food packaging material100and the mold200are arranged, and then the mold200is pressed to the food packaging material100, thereby forming a plurality of grooves110on one surface of the food packaging material100corresponding to the prism bodies210.

That is, when the mold200is joined to the food packaging material100using heat and pressure, parts of the food packaging material100corresponding to the prism bodies210are pressed by the prism bodies210, thereby forming the grooves110.

These grooves110are formed based on a shape of the prism bodies210. Thus, when the prism bodies210have a cylindrical shape, the grooves110are formed in a cylindrical shape. When the prism bodies210have a polygonal prism shape, the grooves110are formed in a polygonal prism shape.

Referring toFIGS. 3cand 3d, in the applying the oil layer (c), the mold200bonded to the food packaging material100is removed, and then the oil layer120is applied to the one surface of the food packaging material100on which the grooves110are formed.

FIGS. 4ato 7billustrate a process of manufacturing a mold used in a method of manufacturing a food packaging material. With reference toFIGS. 4ato 7b, the method of manufacturing the food packaging material is described in detail.

According to an exemplary embodiment of the present invention, (a) preparing a mold includes (a-1) preparing a first metal layer, (a-2) depositing a photoresist layer, (a-3) forming photoresist holes, and (a-4) forming prism bodies.

FIG. 4aillustrates the preparing the first metal layer (a-1), andFIG. 4bis a cross-sectional view ofFIG. 4a, taken along line A4-B4.

Referring toFIGS. 4aand 4b, in the preparing the first metal layer (a-1), a silicon layer300is prepared, and a first metal310is formed on the silicon layer300.

Here, The first metal layer310may be formed on a silicon layer300in order to uniformly form the first metal layer310.

Further, the first metal layer310may include titanium and may also include other metals.

Referring toFIGS. 5aand 5b, in the depositing the photoresist layer (a-2), a photoresist layer320is deposited on the first metal layer310.

Here, the photoresist layer320may include a positive photoresist or a negative photoresist. For example, AZ9260 may be used as a positive photoresist, and SU-8 may be used as a negative photoresist.

Referring toFIGS. 6aand 6b, in the forming the photoresist holes (a-3), the photoresist layer320deposited on the first metal layer310is patterned. Thus, a plurality of photoresist holes330disposed at predetermined intervals are formed in the photoresist layer320.

That is, the photoresist holes330may be formed in the photoresist layer320by exposing and developing processes of photolithography.

Here, the photoresist holes330may have a cylindrical shape or a polygonal prism shape and be arranged in a grid pattern. The first metal layer310under the photoresist holes330is exposed to the outside.

FIG. 7aillustrates the forming the prism bodies (a-4), andFIG. 7bis a cross-sectional view ofFIG. 7a, taken along line A7-B7.

Referring toFIGS. 7aand 7b, in the forming the prism bodies (a-4), prism bodies210are formed in the photoresist holes330. As the first metal layer310is exposed to the outside through the photoresist holes330, the prism bodies210are formed on the first metal layer310. Thus, the mold200including the prism bodies210is completely formed.

Here, the prism bodies210may be formed by galvanoplasty. Thus, the prism bodies210may be formed on the first metal layer310and disposed in the photoresist holes300.

In this case, since the photoresist layer320is nonconductive, the prism bodies210of a metal material grows only on the first metal layer310having conductivity.

To this end, the prism bodies210may be formed of nickel (Ni) or gold (Au) or may also include other metals.

Using MEMS, a plurality of prism bodies210having a considerably minute size may be formed on the mold200, and accordingly the food packaging material100may also be formed with considerably minute grooves110.

The mold200to manufacture the food packaging material according to the embodiment of the present invention may be manufactured by the above described process, and thus the mold200includes the first metal layer310, the photoresist layer320, and the prism bodies210(seeFIGS. 7aand 7b).

The first metal layer310may be formed on a silicon layer300, and the photoresist layer320having the plurality of photoresist holes330is disposed on the first metal layer310.

The prism bodies210are formed on the first metal layer310disposed in the photoresist holes330to be exposed to the outside.

The mold200thus manufactured facilitates formation of the minute grooves110in the food packaging material100, so that each food packaging material100is not involved in a complicated process including photolithography. Thus, costs, time, and labor force involved in manufacture may be reduced.

Although the spirit of the present invention was described in detail with reference to the preferred embodiments, it should be understood that the embodiments are provided only for explaining the present invention and the present invention is not limited thereto. Further, it should be understood that the present invention may be modified in various ways by those skilled in the art, without departing from the scope of the present invention. The scope of the present invention described above is determined by the following claims and not limited to the detailed description described herein, and equivalent changes and modifications within claims are included in the spirit and scope of the present invention.