JPS603499B2 - How to make an electric razor net blade - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method of manufacturing a net blade for an electric shaver.

BACKGROUND OF THE INVENTION The shaving head of an electric razor typically has an outer stationary mesh blade and an internal movable blade that contacts the inner surface of the silk blade.

The movable blade can be made of multiple independent blades, or it can itself be made from perforated sheet metal. Mochigan Showa 5
No. 1-80311 (Tsubaki Kaisho No. 52-9550) discloses a silk blade for an electric shaver made from a thin plate of metal or alloy, which has holes penetrating the thin plate, and a bar is inserted between these holes. The cross-sectional profile of these bars is dish-shaped;
This dish-shaped bottom has a substantially flat and uniform thickness t, the treads of the dish-shaped profile extending at an obtuse angle to the bottom and terminating in a coplanar plane parallel to the bottom, and A silk blade of an electric shaver is disclosed in which the lateral width W is no greater than the thickness t.

Various types of silk blades have been proposed and actually used.

For example, GB 845,832' discloses a silk blade in which the thickness immediately adjacent to the hole (from the front side to the back side) is greater than the thickness in the middle of the hole. Various methods of making silk blades have been proposed.

For example, “U.S. Patent No. 3,498,891”3
655528, 3655529 ``No. 3,695,927 discloses a hazing technique. United States Patent No. 3
No. 216286 discloses ``a punching technique.
British Patent No. 1,056,038 states, ``A flat stainless steel plate is coated with photoresist, the photoresist is exposed through a mask having the desired holes, and the unhardened portions of the photoresist are removed to expose the stainless steel. A method is disclosed in which a stainless steel plate is bent into a desired shape, a stainless steel plate is etched, and the hardened portion of the photoresist is burned off to produce a net blade.
It is preferable to heat the material to a temperature of 0.000, then rapidly cool it in air or liquid, and then harden it at a temperature of 20,000. British Patent Specification No. 845832! A method is disclosed for chemically or electrochemically etching a thin plate to form a hole surrounded by a rim projecting from a thin beveled inner surface that is contacted by a movable blade.

The holes in the outer resist are grouped together and the inner resist forms an island pattern corresponding to each such group. Etch until less than half the thickness of the metal is removed, then apply photoresist to all interior surfaces, including the etched recesses, and etch so that each hole is etched through the hole from the outside. The group continues to be etched until it becomes a single hole surrounded on the inside by a chain-toothed rim. However, research continues in search of new ways to make silk blades. .

[Summary of the invention]

The object of the present invention is to provide a new method for manufacturing silk blades of electric shavers from sheet metal.

According to the present invention, there is provided a method for manufacturing a net blade for an electric shaver from a thin metal plate, wherein the net blade has a front surface and a back surface.
A plurality of holes pass through from the front side to the back side, and the holes form bars between the holes, and the cross-sectional profile of these bars is dish-shaped. The green portion of the generally planar dish-shaped profile extends at an angle to the bottom and terminates in a coplanar plane parallel to the bottom, with a photosensitive material on each side of the sheet metal. depositing the layers and irradiating the surface with light through a mask having a pattern of holes corresponding to the desired holes of the net blade and irradiating the back surface with light through a mask having a pattern corresponding to the concave bottom of the dish-shaped profile; a step of developing a photosensitive material to generate a pattern of unprotected areas on each side of the metal sheet, respectively; and etching the unprotected areas on the back side and recessed areas at the bottom of the metal sheet. A step of forming a photosensitive material layer, a step of etching the protected area of the surface to such an extent that no holes penetrate through it, and a step of removing the photosensitive material layer from the surface, all of which remove a predetermined amount of metal. A method for producing a silk blade for an electric shaver is provided, comprising the steps of further etching only the surface until the ridges of the bar are smoothly rounded to form the holes of the silk blade, and finally removing the remaining masking material. The present invention will be explained in detail in the following examples with reference to the drawings.

First, referring to Figure 1, the silk blade has holes 1 passing through from the front side to the back side, and bars 2 between the holes.

The cross-sectional profile of the bar 2 is dish-shaped, the bottom 3 of this dish is substantially flat and has a thickness t, with an edge 4 extending at an angle Q with respect to the bottom 3; 4 terminates in a coplanar surface 5 parallel to the bottom 3, the width of which is W. Therefore, the bar 2 has a recessed portion 6.
According to the net blade of No.-80311 (Japanese Unexamined Patent Publication No. 52-1955), the width W is not larger than the thickness t.

In other words, the width W can be approximately the same as or smaller than the thickness t. Silk blades can be made from a single metal (such as steel) or an alloy.

The use of a single material makes it possible to use the advantageous etching technique of the present invention, which will be explained with reference to FIGS. The metal strip 10 is cleaned to remove oil and other contaminants, and a suitable negative or positive photoresist layer 1, 12 is applied to both sides by a bonding method.

A preferred negative photoresist is Philip A. Hunt. Chemical company (Philip AH plate tChemica)
Wa sold by lCorporation)
It is ycoat-450 (product name). Another suitable negative photoresist is Kodak's KMER
(product name). Also, a suitable positive photoresist is “
Shipley Chemical Company
lsLtd. )'s side 111 (product name). The photoresist layers 11 and 12 are hardened by heat treatment. The metal strip 10 at this stage is shown in FIG. Then, a mask such as a photographic film, which has been exposed and developed to have transparent and opaque parts, is placed over the layers 11 and 12, and then exposed to ultraviolet light. In the case of a negative photoresist, the mask placed over the front side layer 11 has an opaque area that corresponds to the desired location of the holes 1, and the mask placed over the back side layer 12 has an opaque area that corresponds to the recessed area 6. have a part. Care must be taken to align the mask so that the positions of the holes 1 and the recessed portions 6 of the completed net blade are accurate. After exposure, development and heat treatment are performed. Then, a masking layer 11 is formed on the surface of the metal strip 10.
a is formed, and a masking layer 12a is formed on the back surface (FIG. 3). Next, the surface having the masking layer 12a (
This surface is spray etched to form a recessed portion 6 (this surface will become the inner surface of the net blade).

After etching to the desired depth, cleaning and drying are performed. This newly etched surface is protected with a protective film 13 such as adhesive tape. Then, the surface having the masking layer 11a (this surface becomes the outer surface of the net blade) is spray-etched.

Etching is stopped when the hole 1 reaches a position 14 just before it is completely opened. After cleaning, the masking layer 11a is removed, leaving the masking layer 12a and the protective film 13.

Or masking layers 11a and 12a and protective film 13
is removed, and then another protective film, such as a shellac layer, is deposited over the entire surface having the recessed portions 6. The unprotected side or surface is then etched to further remove metal and the edges of the bars 2 are rounded off, resulting in a sheet with holes 1 and bars 2. Finally, the protective film is removed by chemical polishing, followed by cleaning and drying. However, this protective film removal may not be necessary in some cases. Next, a specific example of a method for manufacturing a net blade for an electric shaver according to the present invention will be described.

Example A ribbon steel is subjected to an intensive cleaning including ultrasonic cleaning at room temperature with a chlorinated solvent such as trichloroethylene, or preferably trichloroethane.
Blow dry.

Next, it is washed with alkaline in a degreasing salt solution, and then washed with water. A suitable defatting salt for this purpose is Metex TS40A from MacDermjd.
(product name). It is useful for use at temperatures of about 4000°C. Then, for example, OxyMetaIFinishing Co., Ltd.
Co. )'s ○xyprep285 (product name),
Electrolytically clean in a cyanide-free alkaline solution at room temperature and then wash with water. It is then neutralized with 18% desired acid, washed with deionized water with inpropyl alcohol, and dried in the vapors of a chlorinated solvent such as trichloroethane. Next, the wa
The strip is immersed in a YCOAT 450 (trade name) photoresist solution to form a Waycoa 50 (trade name) photoresist layer on both sides.

After air drying, in a convection oven at a temperature of 95-100 do
Heat treat the sheet for 0 minutes. This heat treatment can also be carried out using an infrared device at 350° C. for 2 minutes. next,
A developed photographic film mask with transparent and opaque areas is placed over the photoresist, and the mask is exposed to ultraviolet light. On the surface to which the photoresist layer 11 is attached, which will eventually become the outer surface of the net blade, the transparent portion corresponds to the portion 11a, and on the surface that will eventually become the inner surface of the silk blade, the transparent portion corresponds to the portion 11a. It corresponds to part 12a. The optimal exposure is Sneusen R21 level sensitivity guide or K
6-7 after exposure via odak #2 step guide
This is achieved by holding the steps. After exposure, development is performed by spraying or dipping. This development step requires Waycoat PE developer and Waycoat PE developer.
This includes contacting the exposed photoresist layer with a mixture of tPE thinner and water and rinsing. The developed photoresist is subjected to a heat treatment operation of 120 qo for 10 minutes in a convection oven or 35000 for 2 minutes using an infrared device. Next, for example, Chemcut Co.
Etching is performed using a double-sided spray etching device such as that sold by Rporabn.

Etching can be performed using Waycoa Hana E etchant (trade name), but it is
. It is advantageous to use a Beayama solution. First, the back surface is etched in 20 to 4 steps to form the recessed portion 6, and then washed with deionized water and dried with nitrogen spray.

A protective layer 13, such as adhesive cellulose acetate tape, is then applied. The surface is then etched to remove metal up to location 14. This etching is 100
After the etching was completed, it was washed with deionized water and dried with nitrogen spray. Then, the masking layer 11a is removed using a Komisaki CP stripper (trade name).

At this time, the recessed portion 6 and the masking layer 12a are protected by the protective film 13. Next, use the same etchant as before,
Approximately 4 in-between sand etches are performed on the surface using the same conditions. Then, it is washed with deionized water and dried with nitrogen spray. Next, the material of the thin plate 10 is subjected to chemical polishing using a suitable polishing solution.

Suitable solutions for this are, for example, Dettner (Dettn).
er), “Plating Technology Handbook” edited by Ebe (Handbuch der Galvano chn.
ik)'' Volumes 1 and 2, (Carl Hauser Publishers (Car)
Published by IHauser Verlag (based in Munich)
It is described in. Finally, the protective film 13 is removed, the remaining masking layer 12a is peeled off using a Kosen kLS 13 stripper (trade name), and the fabrication of the silk blade is completed by washing with water and drying with nitrogen spray.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of the net blade disclosed in the above-mentioned Tokubuta No. 51-80311 (Japanese Unexamined Patent Publication No. 52-9550), and FIGS. 2 and 3 show two methods of the present invention. It is a sectional view showing a state in a process. 1...hole, 2...bar, 3...bottom, 4...
... Edge, 6 ... Recessed part, 10 ...
...Thin metal plate, 11,12...Photoresist layer, 11
a, 12a...masking layer, 13...protective film. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. It has a front surface and a back surface, and a plurality of holes pass through from the front surface to the back surface, and bars are formed between the holes, and the cross-sectional profile of the bars is dish-shaped. The net blade of an electric shaver is constructed such that the bottom is of uniform thickness and substantially flat, and the edge of the dish-shaped profile extends at an angle to the bottom and terminates coplanarly parallel to the bottom. A method of manufacturing from a thin metal sheet, comprising the steps of depositing a layer of photosensitive material on each side of the sheet metal, and irradiating the surface with light through a mask having a pattern of holes corresponding to the desired holes of the net blade.
irradiating the back side with light through a mask having a pattern corresponding to the concave bottom of the dish-shaped profile; and developing a photosensitive material to generate a pattern of unprotected areas on each side of the sheet metal respectively. etching the unprotected area on the back side to form the recessed bottom part; etching the unprotected area on the front side to an extent that the hole does not penetrate;
removing the photosensitive material layer from the surface; further etching only the surface until a predetermined amount of metal is removed and the bar ridges are smoothly rounded to form the holes of the net blade;
A method for producing a net blade for an electric razor, comprising the step of finally removing remaining masking material.