JPH0348136Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a winding core made of a paper tube for winding yarn, synthetic resin film, etc.

<Prior Art> Various improvements have been made to winding cores for winding threads, synthetic resin films, etc. in order to guarantee the quality of the wound products. One of the improvements was to make the outer peripheral surface of the member smooth.

In the conventional winding core made of a paper tube, as shown in FIG. As a result of overlapping and bonding the longitudinal edges 64, 64', a step was created on the outer circumferential surface of the winding member due to the overlapping portion.

Also, paper tubes have been proposed, such as the high-speed spinning paper tube described in Utility Model Application Publication No. 54-24510, in which the surface materials are wound spirally so that they do not overlap each other and the interval between the meeting parts is 1 mm or less. was. However, this paper tube still has the problem that the integrity of the bonding of the surface layer material cannot be guaranteed.

Therefore, the applicant of the present application has made the longitudinal edges of the surface material slightly protrude beyond the longitudinal edges of the inner surface material constituting the inner layer, so that the longitudinal edges of the inner surface material do not overlap each other and are slightly separated. We proposed a paper tube characterized by forming a 〓, positioning the longitudinal edge of the surface material inside the 〓, and bending it toward the paper tube main body (Utility Model Publication No. 129262/1983). I tried to solve the above problem.

<Problem to be solved by the invention> However, in the above invention, only one longitudinal edge of the surface material is positioned within the gap, and the other longitudinal edge is positioned above it. It stops when it is pasted on. Therefore, it cannot be said that the problem of curling up the ears at the other longitudinal edge has been completely solved. Furthermore, if the selvage curls up, the end of the other longitudinal edge has a sharp cut surface, so there is a high risk of damaging the wound object.
Furthermore, since the cut surface is exposed, moisture is allowed to enter from this area, leaving a problem in moisture resistance and causing delamination from this area.

In addition, in the above idea, for a while,
The width is equivalent to or slightly longer than the thickness of the inner surface material, and is only an extremely small width. the result,
In this invention, the following various problems remain unsolved.

Firstly, there is a problem in that the longitudinal edges of the surface material located in the gap are insufficiently bonded.

In order to achieve sufficient adhesion, the longitudinal edge of the surface material must be inserted into the inside of the inner surface material from the above-mentioned gap and bonded. However, in this case,
This portion becomes thicker by the thickness of the longitudinal edge of the inserted inner material. As a result, a protrusion that swells by the thickness is formed on the outer circumferential surface of the paper tube, resulting in a problem that a completely smooth outer circumferential surface cannot be formed.

In order to eliminate these protrusions, it is necessary to simply drop the longitudinal edge of the surface material into the above-mentioned space, and not insert it inside the inner surface material. However, it is extremely difficult to wind the thin surface material while dropping the longitudinal edge of the material in an extremely small space, and it goes without saying that sufficient bonding cannot be achieved. This makes it impossible to bury the whole family. As a result, 〓
A gap is created, and this gap appears as a recess on the outer peripheral surface of the paper tube. Furthermore, if the thickness of the surface layer material and the inner surface material are different, this groove becomes even more noticeable.

As described above, the above-mentioned device still has the problem that convex or grooved lines appear on the outer circumferential surface of the paper tube, making it impossible to form a completely smooth outer circumferential surface.

Furthermore, the above interval 〓 is extremely small,
During this time, it is difficult to keep the width constant during winding of the paper tube. Management of the width of the gap is
The smaller the width, the more difficult it is and the more likely errors will occur, and the larger the errors will be. If the error becomes large, it becomes difficult to correctly position the edges of the surface material within the gap, resulting in the problem that the above-mentioned ridges and grooves become even larger.

<Means for Solving the Problems> Therefore, the present invention provides a paper tube having an inner surface layer and a surface layer formed by pasting and rolling a surface layer material around the outer periphery of the inner surface layer, and having grooves formed in this inner layer. In a winding core made of aluminum, one longitudinal edge of the facing surface material is glued to the bottom of the groove, the other longitudinal edge is double folded inward, and this folded edge is The groove is bonded onto the edge within the groove, and the depth of the groove is approximately equal to the sum of the thickness of one longitudinal edge and the other folded longitudinal edge, and By setting the width of the groove to be approximately equal to the sum of the thickness of one longitudinal edge and the folded width of the other folded longitudinal edge, both edges are positioned within the groove. The above-mentioned problem is solved by providing a winding core made of a paper tube, which is characterized by the following.

Note that the manner of winding the inner layer and the surface layer may be freely selected such as flat winding, spiral winding, etc.

<Function> In the present invention, one longitudinal edge of the facing surface material is adhered to the bottom of the groove, the other longitudinal edge is double folded inward, and this folded Since the edges are bonded onto the edges within the groove, the opposing longitudinal edges will not warp upwards, and no raised edges will occur. In addition, even if a situation similar to raised ears should occur, the longitudinal edges of the surface tape are folded back twice, and the ends are accommodated in the grooves of the inner layer.

Therefore, the raised portions are not sharp edges of the surface tape, but are bent portions, and therefore do not have sharp corners but are rounded.
Since the cut surface of this edge is not exposed, moisture will not enter from this portion, improving the moisture resistance effect and preventing delamination of the surface layer.

Moreover, the depth of the groove is approximately equal to the sum of the thickness of one longitudinal edge and the thickness of the other folded longitudinal edge, and the width of the groove is set to be approximately equal to the thickness of one longitudinal edge. By setting the thickness to be approximately equal to the sum of the folded width of the other folded longitudinal edge, both edges are positioned within the groove and are reliably bonded while filling the groove. At the same time, the surface material is joined flush.

<Example> The embodiment will be explained below with reference to the figures.

FIG. 1 is a partially cutaway front view of the paper tube winding core of the present invention, and FIG. 2 is an enlarged view of the main part of the cutout in FIG. 1.

In this winding core, an inner layer 3 is formed by spirally winding an inner layer tape 2 made of high-quality paper with a thickness of about 0.2 mm around the outer periphery of a main layer 1 which is made by winding cardboard in a 15 mm layer using a conventional method. , Furthermore, on the outer periphery, there is a surface layer tape 4, which is a surface layer material made of high-quality paper with a thickness of about 0.1 mm.
The surface layer 5 is formed by spirally winding. Each layer is bonded as necessary.

The inner layer tape 2 is rolled up with a certain space between them, and the space between the tapes 2 becomes a spiral groove 6. One longitudinal edge 7 of the opposing surface tapes 4, 4 is adhered to the bottom of the groove 6. The other longitudinal edge 7' is folded inward to form a double layer. This folded edge 7' is glued onto the edge 7 glued to the bottom in the groove 6. As a result, the groove 6 formed in the inner surface layer 3 is filled with both edges 7, 7'.
and the edges 7, 7', especially the ends 8, 8', are provided with grooves 6.
It is located inside and does not appear on the outer periphery of this winding core.
The thickness of the surface tape 4 is approximately 0.1 mm.
The inner layer tape 2 only needs to be about twice as thick as this. As a result, the depth of the groove 6 becomes approximately equal to the sum of the thickness of one longitudinal edge 7 and the other folded longitudinal edge 7'. and,
The width of this groove 6 is set approximately equal to the sum of the thickness of one longitudinal edge 7 and the folded width of the other folded longitudinal edge 7'. Thereby, the surface tapes 4, 4 can be joined flush.
The adhesive may be applied to all joints of each tape. It is also desirable to adhere the folded inner side of the other longitudinal edge 7' to the inner surface of the surface tape 4. 9 in the figure indicates this adhesive location.

FIG. 3 shows a second embodiment, in which 11 is a main body layer. The outer periphery of this main body layer 11 has a thickness of 0.3 mm.
An inner layer 13 is formed by spirally rolling an inner layer tape 12 made of paperboard with a thickness of approximately 1.5 mm. The upper corner of one longitudinal edge 14 of the opposing inner layer tapes 12, 12 is ground off with a grinder or pressed with a press, and the longitudinal edge 1 of the other inner layer tape 12 is
A concave groove 15 is formed by 4'. The surface tape 16 is wound in the same configuration as in the first embodiment, with one of the opposing longitudinal edges 17 being adhered to the bottom of the groove 15, and the other edge 1
7' is folded back and glued in a double layer to form the concave groove 15.
is met. The depth of the groove 15 is set approximately equal to the sum of the thickness of one longitudinal edge 17 and the other folded longitudinal edge 17', and the width of the groove 15 is , is set approximately equal to the sum of the thickness of one longitudinal edge 17 and the folded width of the other folded longitudinal edge 17'. Thereby, the surface tapes 16, 16 are joined flush.

FIG. 4 shows the structure of the surface layer in still another embodiment, in which a groove 32 is formed in the center of the tape constituting the inner layer 31 by cutting or pressing. And the structure of the second embodiment can be freely selected. The surface tape 34 forming the surface layer 33 is made by laminating a special tape 36 such as a synthetic resin film, aluminum foil, or oil-proof paper on a paper tape 35. This special tape 36 is used to improve the moisture resistance of the paper tube, and can be made of various materials depending on the purpose, and may be made of multiple layers.

The bending structure of the surface tape 34 is the same as that of the first embodiment.

FIG. 5 shows another embodiment in which a surface tape 43 having a multilayer structure similar to the above embodiment is used, in which 41 is an inner surface layer and 42 is a groove thereof. In this embodiment, the surface tape 43 is constructed by laminating a paper tape 44 and a special tape 45, but the width of the special tape 45 is made wider than the width of the paper tape 44, and one of the opposing special tapes 45 is The longitudinal edge 46 of is glued to the bottom of the groove 42, and the other edge 46' is folded back and glued to the lower part of the special tape 44, and also glued onto the edge 46, so that both edges 46, 46' fills the groove 42.

In addition to these embodiments, oil-proof paper, water-proof wet paper, synthetic resin-impregnated paper, etc. may be used for the surface tape. In addition, the inner layer does not necessarily have to be a separate layer from the main body layer, and the main body layer made by wrapping cardboard etc. is understood as the inner layer, and grooves are formed on the surface of the main body layer, and the outer periphery of the outer layer is You can also wrap it with tape.

In the above examples, a spirally wound paper tube was used, but
A similar bonding structure can be adopted for a flat-wound paper tube, and this bonding structure makes it possible to flatten the winding surface while ensuring the integrity of the bonding of the surface layer material.

It is also possible to perform further processing, such as impregnating the winding core with resin, cutting the entire core with a grinder, and then molding.

<Effects of the invention> As described above, the paper tube winding core of the present invention positions both longitudinal edges of the surface material inside the concave grooves, allows the surface material to be joined flush, and prevents peeling of the surface material. can be prevented. In particular, the opposing longitudinal edges do not warp upward, and no raised ears occur. Furthermore, even if a situation similar to raised ears should occur, the longitudinal edges of the surface layer material are folded back twice, and the ends are accommodated in the grooves of the inner layer. Therefore, the ridged portion is not an end portion of the surface material with a sharp corner, but is a bent portion, and therefore does not have a sharp corner, but is rounded. Therefore, the wrapped material such as tape, thread, etc. will not be damaged by the sharp edges, and the shape of the corner will not remain on the wrapped material. Furthermore, since the cut surface at the edge is not exposed, moisture resistance and the like can be improved, and delamination phenomenon from this portion can be prevented.

Therefore, the present invention has been able to provide a winding core made of a paper tube that can be used for a long time as a winding core for various adhesives without deteriorating the quality thereof.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of the paper tube winding core of the present invention, Fig. 2 shows the first embodiment, an enlarged view of the main part of the notch in Fig. 1, and Figs. FIG. 5 is an enlarged view of main parts showing other embodiments, and FIG. 6 is an enlarged view of main parts showing a conventional example. 2, 12...Inner layer tape, 3, 13, 31, 41
...inner layer, 4, 16, 34, 43... surface tape,
5, 33... Surface layer, 6, 15, 32, 42... Concave groove, 7, 7', 17, 17', 46, 46'... Longitudinal edge of surface tape.

Claims (1)

[Scope of utility model registration request] In a winding core made of a paper tube, which has an inner layer and a surface layer formed by adhering and winding a surface material around the outer periphery of the inner layer, and has grooves formed in this inner layer, one of the facing surface materials A longitudinal edge is glued to the bottom of the groove, the other longitudinal edge is folded back inward, and this folded edge is glued onto the edge of the groove, and the The depth of the groove is approximately equal to the sum of the thickness of one longitudinal edge and the thickness of the other folded longitudinal edge, and the width of the groove is equal to the thickness of one longitudinal edge. A winding core made of a paper tube, characterized in that both edges are positioned within the groove by setting the width to be approximately equal to the sum of the folding width of the other folded longitudinal edge.