JPH0455835B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for cutting paper tubes, and more specifically, a paper tube main layer made of paper or the like and a surface treatment layer of synthetic resin or the like formed on the surface of the paper tube main layer. This invention relates to improvements in cutting methods for paper tubes.

<Prior art> Conventionally, paper tubes are cut by inserting a paper tube 1 into a cutting shaft 2, holding it by a rotary chuck part 3, and rotating it with a round knife or the like, as shown in FIG. A method is used in which a cutting knife (4) is used to press the paper tube from the surface to the inner surface.

<Problems to be Solved by the Invention> However, when conventional cutting methods are used for paper tubes that have undergone surface treatment such as the formation of a resin layer, cracks or damage occur in the surface treatment such as the resin layer. Post-processing such as grinding was required. The inventor investigated the cause of this cracking and damage and found that the cause was that the surface treatment layer hardened by synthetic resin was cut with a cutting knife that was originally most suitable for paper tubes. .

<Means for Solving the Problems> Therefore, the present invention provides a method for cutting a paper tube consisting of a paper tube main layer made of paper or the like and a surface treated layer of synthetic resin formed on the surface. A first step in which the surface of the paper tube including the surface of the paper tube is separated from the paper tube after being ground with a grinding knife; a first step in which the post-grinding knife is separated from the paper tube; and a main body of the paper tube exposed in the first step. A paper tube cutting method is provided, which includes a second step of cutting the layers with a cutting knife. In this method, the blade angle of the grinding blade in the first step is the same as that in the second step.
The blade angle is larger than the blade angle of the cutting tool in the process, and the first
The blade width of the grinding knife in the step is larger than the blade width of the cutting knife in the second step, and in addition, the grinding knife in the first step has an abrasive on its surface.
In this first step, the surface treatment layer of the paper tube is scraped off, and the cut end surface is rounded.

<Function> In the present invention, after the surface treatment layer is scraped off with a knife most suitable for cutting off the surface treatment layer of synthetic resin, etc., the exposed paper tube main layer is cut with a cutting knife, so there is no possibility of cracks or The paper tube can be cut without causing damage to the surface treated layer. By making the blade angle of the grinding blade larger than the blade angle of the cutting blade, it is possible to perform rounding on the end face of the surface treatment layer at the same time as cutting.

<Examples> Examples of the present invention will be described below based on the drawings.
FIG. 1 is an explanatory diagram of the cutting preparation state, FIG. 2 is an explanatory diagram of the first cutting step, FIG. 3 is an explanatory diagram of the second cutting step, and FIG. 4 is a sectional view of the paper tube after cutting.

Description of paper tube The paper tube 1 to be cut according to the present invention is
As shown in the figure, it consists of a paper tube main layer 11 formed by winding paper tape, and a synthetic resin layer 12 formed on the surface thereof. This synthetic resin layer 12 is formed to increase the water resistance and hardness of the surface of the paper tube, using a conventional processing method in which the surface of the paper tube main layer 11 is coated and impregnated with a synthetic resin, and then heated and pressurized. It is formed of.

Cutting Preparation State The paper tube 1 is inserted into the cutting shaft 2 and is held by the rotary chuck section 3. Then, a rotatable disc-shaped cutting blade 4 such as a round knife is provided at the cutting part.
A disk-shaped and freely rotatable grinding knife 5 of the surface treatment layer is arranged. In this embodiment, one double-edged knife 4, 5 is used, and they are arranged at the top and bottom of the paper tube, respectively.

First Step The paper tube 1 is rotated by the rotary chuck section 3, and the synthetic resin layer 12 is scraped off by pressing the grinding knife 5 against the paper tube 1. The blade angle α of this grinding knife 5 is larger than the blade angle β of the cutting knife 4. This blade angle α determines the radius of the end face 13 shown in FIG. 4, and the blade angle α can be changed depending on the size of this radius. Further, the blade width of the grinding knife 5 is larger than the blade width of the cutting knife 4. In addition, the grinding knife 5 has an abrasive material on its surface, and the synthetic resin layer 12 is ground by the action of this abrasive material, thereby preventing cracking or damage. Although not shown, a sharp cutting blade may be formed at the tip of the grinding blade 5.

Second Step After the synthetic resin layer 12 has been cut off, the grinding knife 5 is moved back, and the cutting knife 4 is pressed against the exposed main layer 11 and cuts the paper tube in a way that pushes it through. As this cutting edge 4, a round knife may be used as in the conventional case. For convenience of illustration, the cut end surface of the main layer 11 is not perpendicular to the axial direction in FIG. 3, but in reality, it is cut substantially perpendicularly to the axial direction, as in the conventional case. It is also desirable to automate the approach and retreat of the grinding knife 5 and the cutting knife 4 through timer control or control based on the moving distances of the two knives 4 and 5.

<Effects of the Invention> As described above, in the present invention, after the surface treatment layer is scraped off with the grinding knife 5 most suitable for cutting off the surface treatment layer 12 of synthetic resin, etc., the exposed paper tube main layer 11 is removed with the cutting knife 4. Since the paper tube 1 is cut by the cutting edge, the paper tube 1 can be cut without causing cracks or damage to the surface treated layer 12. In addition, the blade angle α of the grinding tool
By making the blade angle larger than β of the cutting blade, it is possible to simultaneously process the radius 13 on the end face of the surface treated layer at the same time as cutting. Therefore, the present invention enables cutting without causing cracks or damage to the surface treated layer, eliminates the need for post-processing that was conventionally necessary, and furthermore enables the rounding of the end surface to be performed at the same time. This provides an efficient and good method for cutting paper tubes.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the cutting preparation state, Fig. 2 is an explanatory diagram of the first cutting process, Fig. 3 is an explanatory diagram of the second cutting process, Fig. 4 is a cross-sectional view of the paper tube after cutting, and Fig. 5 is an explanatory diagram of the cutting preparation state. The figure is an explanatory diagram of a conventional cutting method. DESCRIPTION OF SYMBOLS 1... Paper tube, 2... Cutting shaft, 3... Rotating chuck part, 4... Cutting knife, 5... Grinding knife, 11... Paper tube main layer, 12... Surface treatment layer (synthetic resin layer), 13... end surface.

Claims (1)

[Claims] 1 In a method for cutting a paper tube consisting of a paper tube main layer made of paper or the like and a surface treatment layer such as a synthetic resin formed on the surface thereof, after the surface of the paper tube including the surface treatment layer is scraped off with a grinding knife. It consists of a first step in which the grinding knife is separated from the paper tube, and a second step in which the main layer of the paper tube exposed in the first step is cut with a cutting knife. The blade angle of the cutting blade in the second process is larger, and the blade width of the grinding blade in the first process is larger than the blade width of the cutting blade in the second process. It has an abrasive material on its surface, and in this first step, the surface treatment layer of the paper tube is scraped off, and
A method for cutting a paper tube, characterized in that the cut end surface is rounded.