JP2003190670A - Cutting tool with fluoropolymer film at cutting edge and method of adjusting characteristic of cutting edge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change and adjust characteristics of a cutting edge of a cutting tool with a fluoropolymer film at the cutting edge. <P>SOLUTION: The cutting tool with the fluoropolymer film at the cutting edge has the fluoropolymer film with an increased cutting resistance by irradiating the fluoropolymer film with ultraviolet light. The cutting tool with the fluoropolymer film at the cutting edge has the fluoropolymer film with an increased cutting resistance by irradiating the fluoropolymer film with ultraviolet light, and the characteristics of the cutting edge are adjusted. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool having a fluororesin coating on the cutting edge and a method for adjusting the cutting edge characteristics.

[0002]

2. Description of the Related Art Fluororesin has non-combustibility, chemical resistance, electrical characteristics, weather resistance, and low friction coefficient.
Some industrial, consumer, medical and other blades including spare blades are coated with a high molecular fluorine resin (hereinafter referred to as "fluorine resin") coating to reduce cutting resistance when cutting. ing. . For example, there is a blade of a razor coated with polytetrafluoroethylene (PTFE) which is a fluororesin, but PTFE has a relatively small friction coefficient and a small cutting resistance when cutting shaving.
It is effective in eliminating discomfort when shaving. In general, a fluororesin having a large molecular weight (for example, exceeding 1,000,000) has a small friction coefficient, but a small molecular weight has a large friction coefficient. To coat the fluororesin, for example, a stirring solution of the fluororesin is sprayed on the blade edge and sintered in a furnace. In this case, the molecular weight of the fluororesin is determined at the time of manufacture, and the friction coefficient does not change even if the sintering conditions are changed.

On the other hand, blades have various uses, and therefore, it is necessary to impart characteristics (for example, the degree of sharpness) suitable for each use to the cutting edge. This is the adjustment of so-called cutting edge characteristics. For example, when shaving a dark beard and shaving a thin beard such as downy hair, it is easy to understand that favorable results cannot be obtained if the cutting edge characteristics are the same. To adjust the blade edge characteristics, there is a method of adjusting the blade angle at the tip of the blade edge by cutting and thereby imparting the blade edge with a characteristic according to the application.
To adjust the blade angle, set the precise blade angle such that the cutting angle at the tip of the cutting edge is as simple as 10 degrees or 13 degrees, and a geometric cutting shape with a vertical cross section of several microns from the tip is formed. The blade angle is adjusted by making full use of the blade edge molding technology, and the blade edge has the specified characteristics (cutting performance, etc.)
Try to give.

However, it cannot be said that the method of adjusting the blade edge characteristics by changing the blade angle by cutting the blade edge, especially the tip thereof has been sufficiently successful. The reason is that in the case of a fluororesin, the resin characteristics are strong, and therefore the cutting edge characteristics that should be obtained by changing the blade angle tend to be hidden by the fluororesin coating. So, as an alternative method,
It is conceivable to prepare various kinds of fluororesins (fluororesins having different molecular weights) for various purposes and adjust the cutting edge characteristics with the most suitable fluororesin according to the purposes. However, preparing a large amount of fluororesin (stock solution) for coating a small amount of versatile cutting edge is a problem from the viewpoint of cost and management. For this reason, it is unavoidable to use the fluorocarbon resin that has already been purchased and has been hand-held, while on the other hand, the blade angle is carefully adjusted to obtain a predetermined blade edge characteristic.

[0005]

Generally, a resin causes changes such as cracking and discoloration when exposed to sunlight for a long time. It is said that this is because the energy of an extremely short wavelength such as ultraviolet rays contained in the sun's rays breaks the bonds of the resin molecules, resulting in a decrease in the bond strength. It is generally known to irradiate an object with a wavelength in a very short wave range from ultraviolet rays to gamma rays, thereby modifying the characteristics of the object. However, regarding fluoropolymers, "Fluoropolymers are stable to all ultraviolet rays, and even if they are left outdoors for several years in the subtropical region, their physical properties are hardly changed." (Plastic Book, p. 118, author) , Eiichi Asayama, published May 10, 1971), and there has not been much research on the relationship between ultraviolet rays and fluororesins. The present invention has focused on polymer fluororesins, which are generally said to have a small modifying effect, and has conducted repeated studies on the relationship between ultraviolet rays and fluororesins, and in particular the changes in their properties. As a result, by irradiating the fluororesin coating film coated on the cutting edge with ultraviolet rays, the cutting edge characteristics were successfully changed, and the present invention was completed for changing and adjusting the cutting edge characteristics.

[0006]

Means for Solving the Problems In the present invention, a means for solving the above problems is to provide a knife having a fluororesin coating on the cutting edge, wherein the fluororesin coating is irradiated with ultraviolet rays to cut resistance of the fluororesin coating. Was made larger. Further, the method of adjusting the blade edge characteristics, in a blade having a fluororesin coating on the blade edge, by irradiating the fluororesin coating with ultraviolet rays, the cutting resistance of the fluororesin coating is increased to adjust the blade edge characteristics. is there.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION To explain the embodiments of the present invention, some blades (cutting blades including spare blades for industrial use, consumer use, medical use, etc.) reduce cutting resistance at the time of cutting, A resin coating of high molecular fluororesin (hereinafter referred to as "fluororesin") is formed on the cutting edge. To provide the fluororesin coating on the blade, for example, the fluororesin stirring liquid is sprayed onto the blade and sintered in a furnace, and the fluororesin is coated on the blade. However, there is no particular limitation on the fluororesin coating method or the fluororesin coating forming means. Before coating the fluororesin, for example, pretreatment such as coating the blade edge with chrome by a sputtering method may be performed, and the blade angle of the blade tip may be cut to obtain a blade angle close to ideal. In any case, the properties of the cutting edge not coated with the fluororesin are determined by various conditions such as the structure, shape, material of the cutting edge, the blade angle of the tip, and the presence or absence of pretreatment.

The fluororesin to be coated is preferably polytetrafluoroethylene (PTFE), and usually polytetrafluoroethylene having a molecular weight of more than 1,000,000 is used. Polytetrafluoroethylene has a low coefficient of friction and is therefore effective in reducing the cutting resistance of the cutting edge. However, the molecular weight may be 1,000,000 or less, and when the molecular weight is small, the friction coefficient of polytetrafluoroethylene becomes large, so that the cutting resistance of the cutting edge becomes relatively larger than when the molecular weight is large.

The fluororesin coating is usually formed on both the front and back surfaces of the cutting edge. The thickness of the fluororesin coating is usually 1 to 3 microns. The fluororesin film on the cutting edge is irradiated with ultraviolet rays. Ultraviolet rays may be irradiated from the surface side of the fluororesin coating. According to the result of the experiment, it was confirmed that the cutting resistance of the cutting edge having the resin coating changes due to the irradiation of ultraviolet rays. That is, as described above, when a coating film of fluororesin (polytetrafluoroethylene) is formed on the cutting edge, the cutting resistance of the cutting edge decreases due to the characteristics of the fluororesin. It was found that when such a fluororesin coating on the cutting edge is irradiated with ultraviolet rays, the cutting resistance (value) of the cutting edge becomes larger than that before irradiation. It was also found that as the irradiation amount increased, the cutting resistance (value) also increased correspondingly (which does not necessarily mean that there is a proportional relationship).

According to this principle, it is possible to impart a predetermined cutting resistance to the cutting edge having the fluororesin coating by irradiation of ultraviolet rays, and change or modify the cutting edge characteristic based on the cutting resistance. The cutting edge characteristic based on the cutting resistance is a property of the cutting edge such as sharpness, which is imparted by a cutting force due to the cutting resistance. In terms of sharpness, generally, as the cutting resistance increases, the sharpness is improved. If the irradiation of ultraviolet rays exceeds a certain amount, the cutting resistance of the cutting edge will be as large as that of a cutting edge without a fluororesin coating, so the cutting resistance is usually within a range that does not become larger than before the formation of the fluororesin coating on the cutting edge. Irradiate with ultraviolet rays.

Further, by utilizing this principle, it is possible to adjust the cutting edge characteristics having a fluororesin coating. That is, since the cutting resistance of the cutting edge having a fluororesin coating increases depending on the irradiation amount of ultraviolet rays, the change in cutting resistance value corresponding to the irradiation amount of ultraviolet rays is grasped in advance by experiments, while the cutting resistance value that changes in this way. Therefore, it is possible to adjust the cutting edge characteristics (such as sharpness) based on the cutting resistance. There are various specific methods for adjusting the blade edge characteristics. For example, first, polytetrafluoroethylene having an average molecular weight of 1,000,000 is irradiated with a certain amount of ultraviolet rays. Regarding the irradiation amount of ultraviolet rays, it is only necessary to be able to make a relative comparison with each other, and therefore conditions such as irradiation time that can specify the irradiation amount may be set appropriately. For example, when irradiating the same ultraviolet ray, the fluororesin film corresponding to such an ultraviolet ray irradiation amount is based on the ultraviolet ray irradiation amount in units of time (one minute, 2 minutes, 3 minutes, respectively). The cutting resistance value of the blade edge is measured by an experiment. If the cutting resistance value per unit time, for example, the cutting resistance value when irradiated with ultraviolet rays for 3 minutes is 1000 g, a cutting resistance value of 1000 g is given to the cutting edge having the fluororesin coating (polytetrafluoroethylene coating). The same cutting edge of the same molecular weight of 1,000,000 polytetrafluoroethylene fluororesin coating film is irradiated with the same ultraviolet rays under the same conditions (for example, 3 minutes), and a desired cutting resistance value of 1000 g is obtained. It is possible to change or modify the cutting edge characteristics. In this case, even if a slight error occurs in the cutting resistance value or the like, there is practically no problem.

When the average molecular weight of polytetrafluoroethylene is unknown (the average molecular weight is not confirmed), first, as a sample, a plurality of blades having the same polytetrafluoroethylene fluororesin coating film formed on the blade edge under the same conditions are used. Prepare (for example, 3 pieces). In this case,
The original characteristics of the cutting edge before forming the fluororesin coating are all the same. Such a fluororesin film is irradiated with ultraviolet rays under the same conditions, and the cutting resistance value per unit time (for example, 1 minute, 2 minutes, 3 minutes) is measured. Among them, the one that was irradiated for 2 minutes had a desired cutting resistance value (for example, 10
00g) was obtained, thereafter, the cutting edge having the same fluorocarbon resin coating of polytetrafluoroethylene was irradiated with ultraviolet rays under the same conditions (for example, irradiation for 2 minutes).
The desired cutting resistance value (for example, 1000
It is possible to obtain a cutting edge (cutting tool) having g). this is,
For a certain object, while grasping the change in the cutting resistance value of the fluororesin film depending on the irradiation amount of ultraviolet rays, after confirming the irradiation amount of ultraviolet rays corresponding to the cutting resistance value, this time, the irradiation amount is the same object. Irradiation is performed to give a desired cutting resistance value to the object. Thus, a desired cutting resistance is imparted to the cutting edge of the fluororesin film, and the cutting edge characteristics are adjusted based on the cutting resistance.

As described above, paying attention to the relationship between the irradiation amount of ultraviolet rays and the change in the cutting resistance of the fluororesin coating, the desired cutting resistance is imparted to the cutting edge having the fluororesin coating, and the cutting resistance such as sharpness is also obtained. Change or modify the cutting edge characteristics. Further, this makes it possible to adjust the cutting edge characteristics.
The present invention is applicable to all blade edges including industrial, consumer, medical, and pathological (for example, microtome) spare blades.

[0014]

EXAMPLES Examples will be described below. First, the fluororesin coating film formed by coating polytetrafluoroethylene having an average molecular weight of about 50,000 on both surfaces of the blade edge (blade angle 35 degrees) of the sputtered blade is irradiated with ultraviolet rays and is irradiated every unit time. Experiments were conducted on the change in cutting resistance of the cutting edge due to the ultraviolet rays (ultraviolet ray irradiation amount). The UV irradiation time is 1 minute, 2 minutes, 3 minutes, 5 minutes, 7 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes,
The cutting resistance value corresponding to these irradiation times was measured. The measuring method is to set a stainless steel blade (replacement blade) having a fluororesin coating in a metal container, and place a 1.5 Kw ultraviolet lamp (wavelength is 200 to 500 nanometers (nm)) about 100 mm away. Irradiate, and the cutting resistance value of the blades (3 pieces each) of them is measured by a cutting load tester (long narrow felt felt is picked up on the left and right, while the blade is lowered from above,
It was measured with a device for measuring the resistance value when the wool felt is cut. The cutting resistance values of the three blades (Samples 1, 2, 3) irradiated with ultraviolet rays per unit time are as follows. In the following, "resistance value" is "cutting resistance value", and the unit of cutting resistance value is gram (g).

[0015]

The average cutting resistance of the three blades (Samples 1, 2, 3) is as follows.

According to the measured cutting resistance value, the cutting resistance value is the largest at 5000 g or more in the state of "no coating" in which the cutting edge has no fluororesin coating. When a fluororesin film is formed on the cutting edge, the cutting resistance value is 20 on average.
It will be 10g, which is a significant decrease. It can be seen that when the irradiation time of the ultraviolet rays becomes long, and thus the irradiation amount of the ultraviolet rays becomes large, the cutting resistance value increases accordingly.

[0018]

As described above, the cutting resistance value is changed (increased) by the irradiation of ultraviolet rays, whereby the characteristics of the cutting edge having the fluororesin coating are changed. Further, it is possible to adjust the blade edge characteristic by utilizing such a change in the cutting resistance value.

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[Procedure amendment]

[Submission date] March 20, 2002 (2002.3.2)
0)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

By this principle, a predetermined cutting resistance is imparted to the cutting edge having a fluororesin coating by irradiation with ultraviolet rays,
The cutting edge characteristics can be changed or modified based on the cutting resistance. The cutting edge characteristic based on the cutting resistance is a property of the cutting edge such as sharpness that is imparted by the cutting force due to the cutting resistance. Generally speaking, as the cutting resistance increases, the sharpness decreases. If the irradiation of ultraviolet rays exceeds a certain amount, the cutting resistance of the cutting edge will be as large as that of a cutting edge without a fluororesin coating, so the cutting resistance is usually within a range that does not become larger than before the formation of the fluororesin coating on the cutting edge. Irradiate with ultraviolet rays.

Claims (2)

[Claims] 1. A blade having a fluororesin coating on its cutting edge, wherein the cutting resistance of the fluororesin coating is increased by irradiating the fluororesin coating with ultraviolet rays. 2. A blade having a fluororesin coating on its cutting edge, wherein the cutting resistance of the fluororesin coating is increased by irradiating the fluororesin coating with ultraviolet rays to adjust the cutting edge characteristics.