JPH10291526A - Wrap film-cutting blade and wrap film carton with cutting blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain good sharpness and durability which can stand cutting of numerous sheets even if a base material is paper by forming a center position of a peak in a wrap film cutting blade made of paper to be positioned at a tooth bottom. SOLUTION: The cutting blade 1 is of a sawtooth shape comprising teeth points 2 and teeth bottoms 3 alternately connected, wherein a virtual line connecting between summits of the respective points 2 draws an approximately symmetric peak. A center position 4 of the peak (a lengthwise center) is positioned at the tooth bottom 3. That is, no tooth point 2 exists at the center position 4, while the tooth point 2 exists at constant distances from the center position 4 on right and left. Thus constituted, when cutting is started, two teeth points 2 laterally adjacent to the center position 4 are to be stuck through a wrap film. That is, force applied at the time of starting cutting can be received dispersively by the two teeth points 2 laterally adjacent to the center position, thereby preventing the points 2 from degrading.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cutting blade for cutting a wrap film mainly used for food packaging and a wrap film carton having the cutting blade. More specifically, a cutting blade having a saw blade shape in which blade ridges and blade valleys are alternately connected, and a virtual line connecting the vertices of each blade ridge is formed in a substantially symmetrical mountain shape, and a wrap film carton having the cutting blade. About.

[0002]

2. Description of the Related Art As a cutting blade for a wrap film, there are used a blade in which the imaginary line has a mountain shape and a blade in which the imaginary line is a flat straight line. All of them are mainly made of metal, and are used by being integrally attached to a paper wrap film carton.

In the meantime, in the case of the above-mentioned metal cutting blade, it must be separated from the paper wrap film carton and disposed of, and it is troublesome to dispose of it. (JP-A-6-1338). It has also been proposed that the cutting blade is made of vulcanized fiber, and that one cutting edge at the center or one cutting edge on each side is made high, and that this portion is used as a cutting start point to improve sharpness. Yes (7-3
No. 8130).

[0004]

However, there is a problem that a sufficient cutting force cannot be obtained simply by forming a saw blade-like cutting blade similar to a conventional metal cutting blade using paper. In addition, if the position of the high cutting edge is set as the cutting start point, although a certain degree of sharpness can be obtained, since the force is concentrated at the start of cutting, it is easy to cause settling of the high cutting edge which is the cutting start point,
There is a problem that it is difficult to maintain good sharpness. This means
In the case where the cutting line in which the imaginary line forms a chevron is attached downward to the tip of the cover piece on the front of the lid that covers the opening on the upper surface of the wrap film carton, the cutting in which the imaginary line forms a straight line The problem is more severe as the stronger forces are concentrated on the peaks of the chevron than with a blade.
As a means for solving such a problem, a method of impregnating and hardening a resin with a paper cutting blade has been proposed,
Satisfactory results have not always been obtained.

The present invention has been made in view of such a problem. In particular, a virtual line connecting the vertices of each of the ridges is formed into a saw blade shape in which the ridges and valleys are alternately connected. An object of the present invention is to provide a cutting blade having a symmetrical chevron shape made of paper, and to maintain good sharpness even after cutting a large number of sheets.

[0006]

According to the present invention, there is provided:
In the cutting blade for paper wrap film, which has a saw blade shape in which blade ridges and valleys are alternately connected, and a virtual line connecting the vertices of each blade ridge is formed in a substantially symmetrical mountain shape, the center position of the mountain shape Are formed so as to be located at the blade valleys.

In a preferred aspect of the present invention, the distance between the vertices of the ridges provided in the substantially central region of the angled cutting blade is set to be equal to the ridge of the ridges provided in the other side regions. This includes being formed wider than the interval between them.

[0008] Still other preferred embodiments of the present invention will be clarified in the following description.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of a cutting blade 1 according to the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the main cutting blade 1 has a saw blade shape in which blade ridges 2 and blade valleys 3 are alternately arranged, and an imaginary line connecting the vertices of each blade ridge 2 is substantially formed. The shape is symmetrical.

[0011] Center position 4 of the above-mentioned chevron (center in the length direction)
Is located in the blade valley 3. That is, the edge 2 does not exist at the center position 4, and the edge 2 exists at a position left and right from the center position 4 by a certain interval.

By the way, the cutting of the lap film by the cutting blade 1 in which the imaginary line connecting the vertices of the blade ridges 2 forms a mountain shape is such that the blade ridges 2 near the center position 4 first pierce the wrap film, and It takes a cutting form that propagates a cut from the part to the left and right. If the cutting edge 2 exists at the center position 4, the cutting edge 2 at the center position 4 pierces the wrap film at the start of cutting, and the force at the start of cutting is mainly received by one cutting edge. In other words, since the force applied at the start of cutting tends to concentrate on one edge 2 at the center position 4, the edge 2 is easily set, and good sharpness cannot be maintained many times.

On the other hand, as in the case of the main cutting blade 1, the blade tip 2 does not exist at the center position 4, and the blade tip 2 exists at a position left and right at a fixed interval from the center position 4. At the start of cutting, two blade ridges 2 adjacent to the left and right of the center position 4 pierce the wrap film. In other words, the force applied at the start of cutting can be distributed and received by the two blade ridges 2 adjacent to the left and right of the center position 4, and the settling of the blade ridges 2 can be prevented.

However, if the force applied at the start of cutting is distributed and received by the plurality of blades 2 as described above, the top of each blade 2 is less likely to pierce the wrap film, and the sharpness is reduced. The problem arises.
Therefore, in order to solve this problem, the present inventor has proposed that the blade tip 2 located in the central area 5 within a certain width from the center position 4 to the left and right
It has been found that this problem can be solved by forming the interval between the vertices of the edge portion 2 wider than the interval between the vertices of the cutting edge 2 of the other side region 6. The reason why the distance between the vertices of the blade ridges 2 located in the central region 5 is wider than the distance between the blade ridges 2 located in the other side regions 6 is that once the cutting of the wrap film is started, The top of each of the blade ridges 2 is in contact with the wrap film, and the top of each of the blade ridges 2 does not easily penetrate the wrap film, thereby preventing the sharpness from being reduced. Further, when the wrap film starts to be cut once, the cuts are successively propagated and cut, so that it is easy to guide the propagation of the cut in a predetermined direction. Are preferably formed relatively narrow.

The distance between the vertices of the blade ridges 2 in the central area 5 is preferably 4.0 to 5.0 mm. If the interval is too wide or too narrow, the sharpness tends to decrease.
The intervals between the vertices of the blade ridges 2 in the central region 5 are usually all the same, but the intervals may be different in the above range. If this interval is wider than 5.0 mm, although the piercing property with respect to the wrap film is good, there is a possibility that the cut formed in the wrap film may be shifted in an unspecified direction when propagating, or the set of the cutting edge 2 may be set. If it is narrower than 4.0 mm,
The piercing property to the wrap film is reduced.

The distance between the vertices of the blade ridges 2 in the side region 6 is preferably 2.5 to 3.8 mm in relation to the height of the blade ridges 2. If the interval is too wide, the direction of propagation of the cut is easily deviated. Conversely, if the interval is too narrow, the height of the cutting edge 2 becomes too low or the cutting edge 2 projects at a steep angle. 2 is difficult to maintain. The height of the cutting edge 2 is preferably 1.5 to 2.0 mm. If it is too high, it is difficult to maintain the strength of the cutting edge 2, and if it is too low, it becomes difficult to obtain good sharpness. Further, the intervals between the vertices of the blade ridges 2 in the side region 6 may be all the same, but the intervals between the vertices of the blade ridges 2 located closest to the center region 5 in the side region 6 are side by side. It is preferable that the distance betWeen the vertices of the other edge ridges 2 in the partial region 6 be larger than the interval betWeen vertices. By doing so, the propagation of the break from the central region 5 to the side region 6 can be made smooth.

The overall length of the main cutting blade 1, the length of the central region 5, and the length of one side region 6 along an imaginary line connecting the vertices of the blade ridges 2 are represented by L ₀ , L _1, and L ₂ , respectively. L ₁
/ L ₀ = 2/15 to 1/6, 2L ₂ / L ₀ = 13/15
５5/6 (however, L ₁ / L ₀ + 2L ₂ / L ₀ = 1). Total length sharpness even after even short too long length L ₂ of the length L ₁ and the side region 6 of the central area 5 for L ₀ tends to decrease. That is, if the length L ₁ of the central region 5 is too long, the propagation of the break of the wrap film from the central region 5 to the side region 6 will not be smooth, and conversely, the length L ₂ of the side region 6 will be long. If it is too long, the initial cuttability of the wrap film is reduced, and the sharpness is reduced.

The shape of each blade 2 is basically an isosceles triangle. The apex angle is preferably 75 to 85 degrees. If the apex angle is too small, it is difficult to maintain the strength of the blade tip 2, and if the apex angle is too large, the sharpness tends to be reduced. Further, in order to keep the sharpness uniform over the entire cutting blade 1, it is preferable that the apex angles of the blade ridges 2 be the same.

Each of the blade ridges 2 may have the same isosceles triangular shape, but the blade ridges 2 located in the center region 5 and the blade ridges 2 near the center position 4 are clearly shown in FIG. An isosceles trapezoidal base 2a and an isosceles triangle having a hypotenuse with an inclination angle equal to the hypotenuse of the base 2a and a lower side shorter than the upper base of the base 2a (the apex angle is preferably 75 to 85 degrees) ) Is preferably formed in two steps from the top 2b. With such a shape of the blade crest 2, the top 2b receives while keeping the top 2b in a shape that is easy to stab into the wrap film.
The wide base 2a can support the outward force that works with the cutting of the wrap film, and the blade tip 2 is bent by the force that pulls the wrap film outward (the direction in which the wrap film is pulled out) when the wrap film is cut. By preventing this, the strength of the blade ridge 2 can be improved while maintaining sharpness. In particular, since the first and second blade ridges 2 on the left and right from the center position 4 are apt to be subjected to force at the start of cutting, it is preferable to use the blade ridges 2 formed in the above-mentioned two steps. Preferably, it is formed to be about 0.1 to 0.5 mm lower than 2.

The cutting blade 1 is made of paper as a base material. As this paper, ordinary paperboard can be used. In order to maintain the strength of the blade ridge 2 and obtain good sharpness, it is preferable that the blade ridge 2 portion (at least the top) is impregnated and cured with a resin. It is preferably impregnated and cured.

The impregnation and curing of the resin into the paper can be performed by immersing the paper in a resin solution, removing the paper and drying and curing the paper, or immersing the paper in an ultraviolet-curable resin liquid, removing the paper and irradiating the paper with ultraviolet rays. It can be performed by a curing method or the like. As the resin, a hard resin such as a melamine resin, a polyester resin, and an acrylic resin is preferable, and among these, an acrylic resin is preferable.

Next, a wrap film carton having the main cutting blade 1 will be described with reference to FIG.

This wrap film carton is made of paper, as is well known, and includes a main body 8 for storing a roll of wrap film 7 and a lid 9 covering an opening on the upper surface of the main body 8. The cover 9 is connected to the back of the main body 8, and the main cutting blade 1 is provided inside the cover piece 10 on the front of the cover 9.
Is attached downward, and the blade tip 2 is seen from the tip edge of the cover piece 10.

The wrap film 7 is cut by pulling out the required amount of the wrap film 7, pressing the central portion of the cover piece 10 with a finger, pressing the wrap film 7 from above the cover piece 10, and cutting the wrap film 7. The cutting is performed by pressing the main cutting blade 1 against the wrap film 7 so that the carton is inclined toward the wrap film 7 from which the carton has been pulled out.

In this way, the two blade ridges 2 located on both sides of the central position 4 (see FIGS. 1 and 2) of the main cutting blade 1
Is mainly pierced into the wrap film 7, and the cut formed by this spreads right and left along the pressed main cutting blade 1 to be cut.

[0026]

The cutting blade 1 of the present invention has good sharpness and durability to withstand cutting a large number of sheets in spite of the fact that it is made of paper as a base material. Can be discarded without removing the cutting blade 1 each time.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a cutting blade according to the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view of a portion B in FIG.

FIG. 4 is a perspective view showing an example of a wrap film carton according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cutting blade 2 Crest 2a Base 2b Top 3 Cutter 4 Center position 5 Central region 6 Side region 7 Wrap film 8 Main body 9 Lid 10 Cover piece

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tamotsu Kiwa 1-9-11, Nihonbashi-Horidome-cho, Chuo-ku, Tokyo Inside Kureha Chemical Industry Co., Ltd. (72) Takashi Nakamura 1-9, Nihonbashi-Horidome-cho, Chuo-ku, Tokyo No. 11 Kureha Chemical Industry Co., Ltd.

Claims (8)

[Claims] 1. A paper wrap film cutting blade having a saw blade shape in which blade ridges and blade valleys are alternately connected, and a virtual line connecting the vertices of each blade ridge is formed in a substantially symmetrical mountain shape.
A cutting blade for a wrap film, wherein the central position of the chevron is formed so as to be located at a blade valley. 2. An interval between vertices of each of the ridges provided in a substantially central region of the mountain-shaped cutting blade is formed to be wider than an interval between vertices of each of the ridges provided in other side regions. The cutting blade for a wrap film according to claim 1, wherein: 3. The distance between the vertices of the respective ridges provided in the substantially central region is 4.0 to 5.0 mm, and the distance between the vertices of the respective ridges provided in the other side regions is 2.5. The cutting blade for a wrap film according to claim 1 or 2, wherein the cutting blade has a length of 3.8 mm. 4. The lapping film cutting blade according to claim 1, wherein the height of each blade peak is 1.5 to 2.0 mm. 5. When the total length along the imaginary line connecting the vertices of the blade ridges, the length of the substantially central region, and the length of one side region are L ₀ , L _1, and L ₂ , respectively, L ₁ / L ₀ = 2
_{/ 15~1 / 6,2L 2 / L 0} = 13 / 15~5 / 6 wrap film cutting blade according to any one of claims 1 to 4, characterized in that a. 6. In the substantially central region, each of the blade ridges located adjacent to at least the left and right sides of the center position is formed by a base having an isosceles trapezoid shape and a triangular top having a lower side shorter than the upper base of the base. The cutting blade for a wrap film according to any one of claims 1 to 5, characterized in that: 7. The cutting blade for a wrap film according to claim 1, wherein a resin is impregnated and hardened on at least a top portion of each of the blade ridges. 8. A wrapping film carton with a cutting blade, wherein the cutting blade for wrapping film according to any one of claims 1 to 7 is attached downward to a tip of a cover piece on a front surface of a lid.