JPH0811924A - Roll paper core receiving cap - Google Patents

Abstract

PURPOSE:To form a roll paper core receiving cap used for containing roll paper in an exclusive box using an olefinic resin sheet by a vacuum forming method. CONSTITUTION:A cap formed by a vacuum forming method using an olefinic resin sheet with an inorganic filler included comprises a substrate 2, a square frame 3, a roll fitting cylinder 5, and connecting protuberances 6. On the outer peripheral wall of the square frame and the outer periphery of the roll fitting cylinder, reinforcing ribs shaped into U-shaped grooves are provided. Though the cap is formed by a vacuum forming method, the cap formed into a specific shape can have a sufficient strength as a roll-protecting cap. In addition, the cap has a superior profitability and easy incineration properties because of inclusion of an inorganic filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll paper tube receiving cap for rolls packed in boxes.

[0002]

2. Description of the Related Art A roll wound with a paper tube as a core is housed in a rectangular box. When the paper is housed, a paper tube receiving cap 1 is attached to the paper tube at the core of the roll as shown in FIG. The outer surface of the cap is brought into contact with the case 12 of the rectangular storage box 11 to hold the roll immovable in the box and protect it from external impacts. Conventionally, as a paper tube receiving cap, FIG.
A hollow molded product made of rigid polyethylene as shown in (3) is used. However, although this roll has good protection and support action for the roll itself, it itself is uneconomical in terms of distribution cost because of high raw material cost, large bulk volume before and after use, and heavy weight. There is a problem that black smoke is liable to be generated at the time of post-incineration disposal, and there is a problem in terms of environmental protection, and that the incinerator is damaged due to high combustion heat.

[0003]

DISCLOSURE OF THE INVENTION The inventors have investigated a method of forming a roll paper tube receiving cap by forming a sheet by vacuum forming or vacuum pressure forming, and have a suitable shape and composition of the material. The present invention has been completed by repeating the research on.

[0004]

Thus, according to the present invention, a synthetic resin sheet or a composite layer of a synthetic resin sheet and a foamed resin is formed, and the outer periphery of the substrate is bent in a convex shape to form a corner portion. Is formed into an arc-shaped rectangular frame body, a hollow cylindrical base portion is formed in the center of the substrate, and a roll-fitting cylinder is formed on the cylindrical base portion so as to be connected to each other, and a substrate between the rectangular frame body and the cylindrical base portion is formed. Has a shape connected to the rectangular frame by a plurality of connecting ridges radially arranged around the cylindrical base and having an opening in the center of the lower surface, and at least the outer wall of the rectangular frame and the outer wall of the roll fitting cylinder. Provided is a roll paper tube receiving cap, characterized in that groove-shaped reinforcing ribs are provided on each of them. That is, the roll-fitting cylinders of the cap of the present invention are mounted on both sides of the roll core paper tube, and the base surfaces of the caps are brought into contact with the both sides of the box during storage, and the rectangular frame surface and the connecting ridge surface The side surface of the roll is made to face the surface to be formed, and the roll is immovably held in the storage box.

The synthetic resin sheet for molding used in the present invention is
It is obtained by mixing an olefin resin with an inorganic filler. As the olefin resin, polypropylene homopolymer,
Propylene-ethylene copolymer (ethylene content 1 ~
50% by weight), high density polyethylene, or a mixture of these olefinic resins. The thickness is selected within the range of 0.5 to 2.0 mm from the viewpoint of strength and economy. If the thickness is less than 0.5 mm, the rigidity will be insufficient,
If it exceeds 2.0 mm, the shapeability at the time of molding will be poor, and the economy,
Considering both the shapeability, the range of 0.7 to 1.4 mm is preferable. As the inorganic filler, talc, calcium carbonate, mica, titanium oxide, iron oxide, clay, carbon black, white carbon, barium sulfate, aluminum hydroxide, and other inorganic fillers are used. However, the selection is made in consideration of this point. The inorganic filler is added in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the olefin resin. If it is less than 10 parts by weight, the rigidity is insufficiently expressed, and if it exceeds 100 parts by weight, it becomes brittle. Considering the balance of both rigidity and toughness, the range of 20 to 80 parts by weight is preferable.

In the present invention, in addition to the rigid single-layer sheet, a composite sheet of a rigid resin sheet and a foam synthetic resin sheet is used. The impact due to a collision or the like can be mitigated to further enhance the protective action. As the foamed synthetic resin sheet, low density polyethylene and linear low density polyethylene are preferably used in addition to the above-mentioned foamed material of olefin resin containing inorganic filler. The expansion ratio of the foam is 1.1 to 30. When it is lower than 1.1, the effect of the buffering property is poor, and when it exceeds 30, the mechanical strength is poor, and it is preferably 1.3 to 5 times in consideration of the balance between the buffering property and the strength. The thickness is 50 to
Those having a range of 100 μm are used. The composite sheet may have a two-layer structure of a foamed sheet of a buffer layer and a olefin-based rigid sheet containing a filler, or a three-layer structure in which the rigid layer is laminated on both sides with the buffer layer in the middle. It may have a three-layer structure in which a buffer layer is laminated on both sides in the middle. These composite sheets are extrusion-laminated or co-extruded as a two-layer or three-layer composite sheet in an extruder, and then vacuum-molded or vacuum-pressure air-molded by using a cap molding die like a single-layer sheet. Is molded by.

Next, the shape of the roll paper tube receiving cap according to the present invention will be described. 1 (A) is a plan view of an embodiment of the cap of the present invention, and FIG. 1 (B) is a vertical sectional view taken along the line AA in FIG. 1 (A). The outer periphery of the base plate 2 of the cap 1 is formed into a downward-opening rectangular frame body 3, and the center part of the base plate is formed with a cylindrical base portion 4 having an open lower surface, and roll-fitting cylinders 5 are formed continuously with the cylindrical base portion 4. The substrate between the rectangular frame 3 and the cylindrical base 4 is formed in a shape in which the connecting convex strips 6 having a U-shaped cross section with the lower surface opened are provided radially with the cylindrical base 4 as the center. The upper surface of the ridge is continuous with the upper surface of the rectangular frame 3,
The surface facing the side surface of the roll is formed. The facing surface is formed in a conical surface inclined slightly outwardly so as not to come into contact with the side end surface of the roll. The rectangular frame 3 and the connecting ridges 6 have U-shaped, U-shaped, and
Either a trapezoid or a triangle is used, but when rigidity is particularly required, a U-shape or a U-shape is preferably used. The width of the rectangular frame 4 is preferably in the range of 5 to 15 mm from the viewpoint of strength and is selected according to the weight and size of the roll. The cross-sectional shape of the connecting ridge 6 may be the same as that of the rectangular frame, and the number of connecting ridges radially arranged from the cylindrical base to the rectangular frame is preferably 4 to 12 in order to impart rigidity. is there. If the number is 3 or less, the rigidity is insufficient and deformation is likely to occur, and if the number is 13 or more, the molded product may be thinned and the rigidity may be lost. Therefore, the preferable number for maintaining the rigidity homogeneity is 6-10 rolls, depending on the weight and size of the roll.

On the peripheral wall of the roll fitting cylinder 5, a fitting groove rib 7 having a U-shaped cross section and having a vertical groove shape is provided to reinforce the mechanical strength of the fitting cylinder. The number of the fitting cylinder ribs 7 arranged is in the range of 4 to 30, and when the number is 3 or less, the rigidity is insufficient and deformation is likely to occur, and when the number is 31 or more, the molded product may have a thin portion. Stiffness is lost. A suitable range for uniformly expressing rigidity is 8 to 16 and is determined by the weight and size of the roll. Further, on the outer wall of the rectangular frame body, in order to enhance mechanical strength, a frame groove rib 8 having a U-shaped cross section and having a vertical groove shape is formed.
Is provided. The number of the frame ribs 8 arranged is in the range of 8 to 48. If the number of the frame ribs 8 is 7 or less, the rigidity is insufficient and deformation easily occurs. Is lost. A suitable range for uniformly expressing the rigidity is 16 to 36, which is determined by the weight and size of the roll.

FIG. 2A is a plan view of another embodiment of the present invention, and FIG. 2B is a sectional view taken along the line BB of FIG. 2A. In this embodiment, fan-shaped recesses are provided on the upper surface of the roll fitting cylinder 5, and the ridges formed between the fan-shaped recesses are configured as reinforcing ribs, and the inner wall portion surrounded by the rectangular frame and the connecting ridges. Also provided are vertical groove-shaped reinforcing ribs having a U-shaped cross section. It is preferable to provide these reinforcing ribs as needed depending on the size and weight of the roll. Further, in this embodiment, the connecting convex strip 6 and the upper surface of the rectangular frame 3 are formed on the same horizontal plane, and the step portion 9 is provided between the cylindrical base portion 4 and the roll fitting cylinder 5 to form the connecting convex strip. A gap may be formed between the roll facing portion formed by 6 and the rectangular frame 3 and the roll end surface so that they do not come into contact with each other.

[0010]

In the roll paper tube receiving cap according to the present invention, the outer periphery is formed into a rectangular frame body, and the rectangular frame body and the cylindrical base portion are connected by the connecting convex strip, and the outer wall of the rectangular frame body and the roll fitting cylinder are connected. Since groove-shaped reinforcing ribs are provided on the outer wall of each, it has sufficient mechanical strength as a paper tube receiving cap, despite being a vacuum-formed or vacuum-pressurized product with a thickness of 0.7 to 1.4 mm. To do. Further, the corners of the rectangular frame are arcuate in shape to prevent transmission of impact force applied to the corner ridges of the storage box. Furthermore, in a molded product using a composite sheet of a rigid sheet and a foamed sheet, the cushioning effect of the foamed sheet is developed, and the effect of protecting the roll in the box is increased. Further, since a gap is provided between the end surface of the roll and the opposing surface of the cap, and the groove-shaped rib is provided in the hollow cylinder, there is also an effect that the roll can be smoothly rotated when the rolled film or the like is pulled out from the box. . Since the cap is a sheet molded product, it is lightweight, it is possible to stack caps on top of each other, a large amount of caps can be stored and transported, and since it is a molded product of an inorganic filler mixed sheet, it is easy to incinerate after disposal. Is.

[0011]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 Melt index 0.7 g according to JIS K 6758
/ 10 min. 100 parts by weight of propylene-ethylene block copolymer (ethylene content 15% by weight), 60 parts by weight of calcium carbonate, 2 parts by weight of titanium oxide as a coloring agent, phenolic antioxidant, bisphenolic antioxidant , A cap shown in FIG. 1 by a vacuum forming method using a molding die from an extruded sheet having a thickness of 1.2 mm obtained by adding 0.2 part by weight of metal stearate as an amine-based processing aid and a lubricant. Was molded. The planar shape of the rectangular frame in the cap is a square with one side of 130 mm, the corners are rounded into an arc with a radius of 34 mm, the height of the rectangular frame, that is, the thickness of the supporting part is 10 mm, and the number of connecting ridges is 8. The diameter of the central fitting part is 70 mm, the height is 15 mm, 32 groove-shaped reinforcing ribs with a depth of 1 mm are provided on the outer circumference of the rectangular frame, and the groove-shaped reinforcement with a depth of 1.5 mm is provided on the outer wall of the fitting part. 16 ribs are provided. The roll-fitting cylinder of this cap is fitted to the paper tube of the roll, and the in-plane dimension is 130 mm × 130 mm, and the inner dimension is 55 mm.
It is stored in a 0 mm dedicated cardboard box and the compression test is conducted to examine (1) the buckling strength, (2) the amount of strain when the buckling strength is developed, and (3) the appearance of the roll when the buckling strength is reached. It was Here, the buckling means that when the roll paper tube receiving caps are attached to both ends of the roll and housed in a dedicated rectangular cardboard box and a compressive force is applied between the upper surface and the lower surface of the rectangular box, the box and the paper tube receiving caps. Is a phenomenon in which the material cannot withstand the compressive force and is rapidly deformed in the direction perpendicular to the compressive force. The buckling strength is the compression force in kgf when buckling occurs, and the amount of strain is the difference between the distance between the upper and lower surfaces of the rectangular box before compression and the upper and lower surface distance after buckling. It is expressed in% of the bottom surface distance. A rectangular cardboard box placed on the base of the tester was compressed in the direction of gravity at a speed of 12.0 mm / min. By a large-scale Tensilon universal testing machine UTM-10TPL type manufactured by Orientec Co., Ltd. The buckling strength due to compression was 500 kgf and the amount of strain when buckling was 7%. After the test was completed, the film roll was taken out from the box and visually inspected, but there was no dent in the film roll due to buckling. In addition, 60 caps could be stored by stacking the caps on the dedicated cardboard box. Example 2 A composite sheet was produced by co-extruding the mixture of Example 1 and a mixture of this mixture with 2.0 parts by weight of baking soda / citric acid type foaming agent as a foaming agent. The upper rigid sheet had a thickness of 1.2 mm, and the lower foam sheet had a thickness of 100 μm. A cap shown in FIG. 2 was molded from this composite sheet by a vacuum molding method using a molding die and tested. The buckling strength was 650 kgf and the amount of strain when buckling was 5%.

Comparative Example 1 Using a rigid sheet having the same composition and thickness as used in Example 1, the shape shown in the plan view of FIG. 3 (A) and the vertical sectional view taken along the line CC of FIG. 3 (B). A cap was manufactured. The dimensions are the same as those of the cap of the first embodiment, but the connecting ridges and the groove reinforcing ribs are not provided, and the side edges having a height of 10 mm are provided instead of the rectangular frame body. As a result of performing a test in the same manner as in Example 1 using this product, the buckling strength was as low as 350 kgf, the strain amount at the time of buckling occurrence was as large as 15%, and at this time, the depression of the film roll due to buckling was also confirmed. It was Comparative Example 2 Melt index 0.4 g according to JIS K 6758
A high-performance polyethylene of / 10 min. Was used, and the conventional cap shown in FIG. As a result of testing in the same manner as in Example 1, the buckling strength was 750 kgf, the amount of strain when buckling was 4%, and no film roll dent due to buckling was observed, but this cap was the same as that of the sheet of Example 1. The thickness of this cap body is 1.5 against the thickness of 1.2 mm.
mm, and the cap weight is slightly less than 3 times.
There were only 14 rolls in the same dedicated roll storage box.

[0013]

As shown by the results of the above Examples and Comparative Examples, by adopting the shape of the present invention as the shape of the cap, a cap of sufficient strength can be obtained by the vacuum forming method or the vacuum pressure forming method of the sheet, which is light It is possible to greatly reduce the manufacturing cost and the physical distribution cost such as transportation and storage. Further, there are few problems in incineration and discarding after use, and it is very useful as a protective cap for not only film rolls but also paper rolls, fabric rolls and the like.

[Brief description of drawings]

1A is a plan view of an embodiment of a roll paper tube receiving cap of the present invention, and FIG. 1B is a longitudinal sectional view taken along the line AA in FIG.

FIG. 2A is a plan view of another embodiment of the roll paper tube receiving cap of the present invention, and FIG. 2B is a vertical sectional view taken along line BB in FIG. 2B.

3A is a plan view of a paper tube receiving cap of Comparative Example 1, and FIG. 3B is a vertical cross-sectional view taken along the line CC of FIG. 3A.

FIG. 4 is a perspective view of a conventional paper tube receiving cap.

FIG. 5 is an explanatory diagram showing how to use the paper tube receiving cap in the storage box.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Substrate 3 Square frame 4 Cylindrical base 5 Roll fitting cylinder 6 Connecting convex strip 7 Fitting cylinder rib 8 Frame rib 9 Step 11 Storage box 12

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kanji Yuyama 1-2-1 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Zeon Kasei Co., Ltd. Kawasaki Laboratory

Claims (2)

[Claims] 1. A rectangular frame body formed from a synthetic resin sheet, the outer periphery of a substrate being bent in a convex shape and the corners being arcuate, and a hollow cylindrical base portion at the center of the substrate, and A plurality of connecting ridges are formed by connecting roll-fitting cylinders on a cylinder base, and the substrate between the rectangular frame and the cylinder base is radially arranged around the cylinder base and has an opening in the center of the lower surface. A roll paper tube receiving cap having a shape connected to the rectangular frame by means of which groove-shaped reinforcing ribs are provided on at least the outer wall of the rectangular frame and the outer wall of the roll fitting cylinder, respectively. 2. A rectangular frame body formed from a composite layer of a synthetic resin sheet and a foamed resin sheet, the outer periphery of the substrate being bent in a convex shape and the corners being arc-shaped, and the center of the substrate being formed. To form a hollow cylindrical base portion and a roll-fitting cylinder connected to the cylindrical base portion, and form a substrate between the rectangular frame and the cylindrical base portion.
A shape connected to the rectangular frame by a plurality of connecting projections radially arranged around the cylindrical base and having an opening in the center of the lower surface, and at least on the outer wall of the rectangular frame and the outer wall of the roll fitting cylinder, respectively. A roll paper tube receiving cap characterized by having groove-shaped reinforcing ribs.