PACKING INSIDE BAG FOR VISCOUS MATERIAL

Abstract: The present invention provides a packing inside bag for a semisolid viscous material which is constructed by folding one rectangular blank sheet whose inner surface has re­ lease properties, said inside bag being characterized by comprising a rectangular bottom surface 1 formed so as to fit to an outside box, and a front wall 3, a rear wall 3a and pairs of side walls (8, 8a and 9, 9a) which are uprightly rais­ ed along the four side edges of said bottom surface 1, said inside box being constructed by folding said blank sheet so that first lugs A, A′ extending uprightly along the centers of said side walls may be put on said opposite side walls, and so that second lugs B, B′ may be formed which are com­ posed of irregular quadrilaterals extending outward via folds 4, 5 in parallel with said bottom surface from the op­ posite side edges thereof, said irregular quadrilaterals be­ ing formed by putting triangle portions D, D′ on extensions C, C′ of said first lugs A, A′.

Description: 1. BACKGROUND OF THE INVENTION (1) FIELD OF THE INVENTION The present invention relates to a packing inside bag for receiving a viscous semisolid material therein. (2) DESCRIPTION OF THE PRIOR ART A viscous semisolid is usually heated in order to lower its viscosity to a fluid state, and is then packed into suitable containers or packages, so that articles of the semisolid are manufactured. Examples of containers and packages which are now employed include metallic containers, corrugated cardboard boxes baked with a release agent which will be charged directly with a semisolid material, corrugated cardboard boxes or cardboard tubes into which semisolid material units previously wrapped in release agent-baked films or papers are packed, and release agent-baked deep drawn plastic dishes. However, these conventional packages do not satisfy all the requirements, necessary for the specific packages, such as perfect sealing properties, easiness of taking out contents, excellent volumetric effiency and economy at storage. For example, a viscous semisolid material generally tends to bring about a so-called cold flow, and thus when a package containing such a material falls, the latter might flow out through a narrow small crevice, and in the case of the metallic containers, there are drawbacks such as the breakage of containers and the trouble in taking out a viscous material therefrom. Further, when the corrugated cardboard box is directly charged with the viscous material, it will be difficult to maintain its perfect sealing state, and a cutter or the like will be required at the time of taking out the contents therefrom and cut chips might be mixed therewith. The plastic dishes have the problem that the release effect is insufficient. Furthermore, the suggestion that pieces of the semisolid material are wrapped one by one in each wide sheet is expensive, since such a wide sheet must satisfy an especial process standard. After all, these containers and packages are all unsatisfactory to pack the semisolid materials thereinto. Furthermore, it is known to insert inside bags into a carton package for moist and hygroscopic materials. According to US-A-2 048 122 this inside bag is produced of a paraffin coated paper the coating of which does not extend to the side seams. The bag is produced by folding the paraffin coated paper and the side seams must be adhesively fixed by glue. In FR-A-1 257 588 it is disclosed to fix the side seams of the inner bag in a similar manner by a thermoplastic adhesive by applying heat and pressure. However, the inside bags known from these documents have the problems that the sealing folds and side seams by means of an adhesive cannot easily be performed in such a way that the formation of small crevices is prevented. By using these known packages it is therefore difficult to avoid leaking of the content, especially in the case of a viscous, semisolid material. 2. SUMMARY OF THE INVENTION An object of the present invention is to provide a packing inside bag for a viscous semisolid material. With regard to the inside bags according to the present invention, the viscous semisolid material will not leak through its seams, a sealing state is perfect enough to prevent the contamination with foreign matters, a cutter or the like is not necessary for opening them, the materials which are in the state of a semisolid when heated and which have a relatively low viscosity can easily be received therein, and a space volumetric efficiency is excellent. In short, according to the present invention, there can be provided packages in which drawbacks of the conventional known packages are overcome. The above mentioned object of the present invention can be achieved by providing a packing inside bag for a semisolid viscous material which is constructed by folding one laminated rectangular blank sheet whose inner surface has release properties, comprising a rectangular bottom surface (1) formed so as to fit to an outside box, and a front wall (3), a rear wall (3a) and pairs of side walls (8, 8a and 9, 9a) which are uprightly raised along the four side edges of said bottom surface (1), said inside bag being constructed by folding said blank sheet so that first lugs (A, A') extending uprightly along the center of said side walls may be put on said opposite side walls, and so that second lugs (B, B') are formed which are composed of irregular quadrilaterals extending outwardly via folds (4, 5) parallel to said bottom surface from the opposite side edges thereof, said irregular quadrilaterals being formed by putting triangle portions (D, D') on extensions (c, c') of said first lugs (A, A'), characterized in that said laminated sheet has a thickness of 50 to 300 µm and comprises a glassine paper or a semiglassine paper and a polyethylene terephthalate film, the inner surface thereof being treated with silicone. 3. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an expanded plan view of a packing inside bag for a viscous material according to the present invention; and Figs. 2 and 3 are partial perspective views illustrating constractive states of the inside bag. 4. DESCRIPTION OF THE PREFERRED EMBODIMENT The glassine paper used in the present invention can be optionally selected from commercially available articles, as long as they have a standard weight of 25 to 30 g/m², are free from pinholes, and are good in transparency. Additionally, commercial semiglassine papers having a lower transparency may also be employed. The glassine and semiglassine papers both have heat resistance, so that their quality will scarcely be deteriorated, even when heated in the step of packing the contents. In the present invention, a release agent baking treatment by applying silicone to the sheets can be carried out in accordance with a known optional procedure such as a release agent baking treatment of the surface of the sheet by thermal crosslinking after the application of a commercially available siloxane prepolymer.The thickness of the prepolymer membrane may not be always uniform, but it is important that any coating unevenness of the prepolymer is avoided. A laminated film consisting of the above mentioned PET film and glassine paper or semiglassine paper is one of preferable embodiments of the sheet for constituting the inside bag of the present invention, but other sheets can be used, as long as they are foldable and flexible within the range of the object of the present invention, and as long as their inner surfaces have release properties. These sheets include a polyethylene fluoride resin such as Teflon (trade name) and ultra-high-molecular-weight polyethylene sheets, and in the cases of such sheets, the specific release agent baking treatment is unnecessary. EXAMPLE Now, the present invention will be described in detail in reference to an example. Fig. 1 is an expanded plan view of a packing inside bag for a viscous material according to the present invention, and Figs. 2 and 3 are partial perspective views illustrating constructive states of the inside bag. In Fig. 1, a bottom surface 1 having a rectangular shape is connected to a front wall 3 and a rear wall 3a with the interposition of folds 2, 2a. The front wall 3 is provided, on the opposite side edges thereof, with side walls 8, 9 via folds 6, 7, and the rear wall 3a is likewise provided, on the opposite side edges thereof, with side walls 8a, 9a via folds 6a, 7a. Further, first lug flaps 12, 13 and 12a, 13a are provided along outer edges of the side walls 8, 9 and 8a, 9a via folds 10, 11 and 10a, 11a. Flaps c, c'' constituting substantial extensions of the flaps 12, 13 are provided along upper edges of the latter 12, 13 via folds 18, 19, and in like manner, flaps c', c''' constituting substantial extensions of the flaps 12a, 13a are provided along lower edges of the latter 12a, 13a via folds 18a, 19a. A first lug A (see Fig. 2) is formed by associating the portion consisting of the first lug flap 13 and the flap C'' with the other portion consisting of the first lug flap 13a and the flap c''' along a fold 15, with their inner surfaces faced to each other, and another first lug A' (see Fig. 3) is likewise formed by associating the portion consisting of the first lug flap 12 and the flap c with the other portion consisting of the first lug flap 12a and the flap c' along a fold 14, with their inner surfaces faced to each other. Therefore, the four first lug flaps and the four flaps just described have the same size and the same rectangular shape. Fold flaps a, a', b, b', b'' and b''' having a top angle of 90° and oblique sides of folds are provided along the opposite side edges of the bottom surface 1 via the folds 4, 5, and other folds 14, 15 are formed so as to extend horizontally from the top points 24, 25.The length of the folds 14, 15 is not limited in particular, but at least about 5 cm is necessary from the viewpoints of the prevention of the cold flow of contents through a crevice of the logs A, A' and the easiness of fitting the inside bag having the lugs into an outside box. More preferably, the length of the folds 14, 15 is half of a length of the side wall plus the lug flap in a horizontal direction in Fig. 1. Next, reference will be made to a procedure of constructing the thus constituted unfolding sheet so as to manufacture the packing inside bag of the present invention in accordance with the respective drawings. In the first place, the front wall 3 and the rear wall 3a are upwardly raised along the folds 2, 2a on the upper and lower sides of the bottom surface 1 in Fig. 1 in order to construct the front wall and the rear wall. At this time, the first lug flaps 12, 12a, 13, 13a and the flaps c, c' c'' c''' are simultaneously raised, and by the use of these sections, the first lugs A and A' are constructed. That is to say, the first lug A (Fig. 2) is formed by associating the portion consisting of the first lug flap 13 and the flap c'' with the other portion consisting of the first lug flap 13a and the flap c''' along a fold 15, with their inner surfaces faced to each other, and the other first lug A' (Fig. 3) is, in like manner, formed by associating the portion consisting of the first lug flap 12 and the flap c with the other portion consisting of the first lug flap 12a and the flap c' along a fold 14, with their inner surfaces facing each others. The thus formed first lugs A, A' are fixed on the side edges thereof by a heat resistant adhesive tape or the like, if necessary. By means of the above described procedure, a bag (Figs. 2 and 3) can be prepared which has an opened upper end portion and a shape adapted to an outside box (not shown). Afterward, the fold flaps b'', b''' are folded inward along oblique folds 17, 17a via the folds 7, 11 and 7a, 11a so that the folds 21, 21a may be put on the base 5 of the flap a', in order to form side wall 9, 9a (Fig. 2) of the inside bag. In this case, the fold flaps b'', b''' are put on the inner surface of the flap a', so that a new triangle portion D (Fig. 2) is formed. In like manner, also at the other side wall, a new triange portion D' (Fig. 3) is formed. The first lug A' is then folded along the folds 10, 10a, 22, 22a so as to join face to face with either of the side walls 8 and 8a. As a result, the flaps c, c' constituting the substantial extensions of the first lug A' are put on a part of the triangle portion D' in order to form a second lug B' (Fig. 3) having an irregular quadrilateral. In like manner, at the other side wall, another second lug B (not shown) is formed which extends outward in parallel with the bottom surface via the fold 5. The thus prepared inside bag having the opened upper end portion is received by the outside box, but at this time, each of the second lugs B, B' is folded so as to join face to face with each side wall or the bottom surface connected thereto. After having been fitted in the outside box, the inside bag is then charged with a suitably heated and thereby fluidized semisolid viscous material, and the upper portions alone of the side walls 8, 8a are then folded inward along the upper portions of the folds 10, 10a (Fig. 3) and the upper portions of the front wall and the rear wall are joined face to face with each other. Afterwards, the joined portions are fixed by the use of an adhesive tape or like so as to airtightly seal the inside bag. The outside box preferably has an upper lid and is rectangular.

Claims: A packing inside bag for a semisolid viscous material which is constructed by folding one laminated rectangular blank sheet whose inner surface has release properties, comprising a rectangular bottom surface (1) formed so as to fit to an outside box, and a front wall (3), a rear wall (3a) and pairs of side walls (8, 8a and 9, 9a) which are uprightly raised along the four side edges of said bottom surface (1), said inside bag being constructed by folding said blank sheet so that first lugs (A, A') extending uprightly along the center of said side walls may be put on said opposite side walls, and so that second lugs (B, B') are formed which are composed of irregular quadrilaterals extending outwardly via folds (4, 5) parallel to said bottom surface from the opposite side edges thereof, said irregular quadrilaterals being formed by putting triangle portions (D, D') on extensions (c, c') of said first lugs (A, A'), characterized in that said laminated sheet has a thickness of 50 to 300 µm and comprises a glassine paper or a semiglassine paper and a polyethylene therephthalate film, the inner surface therof being treated with silicone.

Inventors: KATASE, HARUHISA, ROKUSHIMA, YASUO, YANAGI, TOSIO
Applicants: NIPPON PETROCHEMICALS COMPANY, LIMITED
Application year: 1986
Main classification: B65D5
IPC codes: B32B27, B65D30, B65D5, B65D77