阅读说明：本技术 剃刀刀片及其制造方法 (Razor blade and method of making same ) 是由 桑德拉·贝克尔 斯文·维尔茨 于 2019-10-17 设计创作，主要内容包括：在用润滑材料涂布剃刀刀片的方法中,提供了一种剃刀刀片,该剃刀刀片具有主体部分和尖端端部,该尖端端部由至少一个尖端表面和切割刃限定。将润滑材料喷涂在剃刀刀片的尖端端部上,其中,喷涂润滑材料是在蒸气辅助下执行的,其中将润滑材料引入到指向剃刀刀片的尖端端部的过热水蒸气中。此外,提供了一种通过使用前述的用润滑材料涂布剃刀刀片的方法来制造剃刀刀片的方法。最后,还描述了一种根据这些方法涂布的剃刀刀片,以及设置有这种剃刀刀片的剃须刀。(In a method of coating a razor blade with a lubricious material, a razor blade is provided having a body portion and a tip end defined by at least one tip surface and a cutting edge. Spraying a lubricating material on the tip end of the razor blade, wherein the spraying of the lubricating material is performed with the aid of steam, wherein the lubricating material is introduced into superheated water vapour directed towards the tip end of the razor blade. Further, a method of manufacturing a razor blade by using the aforementioned method of coating a razor blade with a lubricating material is provided. Finally, a razor blade coated according to these methods, and a shaver provided with such a razor blade, are also described.)

1. A method of coating a razor blade with a lubricious material comprising the steps of:

-providing a razor blade (16) having a body portion (14) and at least one tip end (38) defined by at least one tip surface (52, 54) and a cutting edge (22), and

-spraying a lubricating material on the tip end (38) of the razor blade (16),

-wherein spraying the lubricating material is performed with the aid of steam, wherein the lubricating material is introduced into superheated water vapor (67) directed towards the tip end (38) of the razor blade (16).

2. The method of claim 1, wherein the razor blade (16) is preheated.

3. Method according to claim 1 or 2, wherein superheated steam (67) is heated to between about 105 ℃ and about 200 ℃, preferably between about 120 ℃ and about 190 ℃, preferably between about 130 ℃ and about 170 ℃, and/or wherein superheated steam (67) is pressurized to a value between about 1.2bar and about 2.5bar, preferably between about 1.5bar and about 2 bar.

4. The method of any of claims 1 to 3, wherein the razor blade (16) is preheated to between about 90 ℃ and about 180 ℃, preferably between about 110 ℃ and about 140 ℃.

5. The method according to any one of claims 1 to 4, wherein several razor blades (16) are arranged side by side in a stack (86) with tip ends (38) facing in the same direction, or wherein a plurality of razor blades (16) are arranged as an integral razor blade strip (88), wherein the razor blade strip (88) is coiled.

6. The method according to any one of claims 1 to 5, wherein the lubricating material is provided in the form of a dispersion (73) of lubricating material particles (63) in a liquid, in particular comprising water, wherein the dispersion (73) is introduced into the water vapour (67).

7. The method according to claim 6, wherein the dispersion (73) is sprayed into the water vapor (67) and/or the dispersion (73) is sucked into the water vapor (67) due to the flow of water vapor (67).

8. The method of claim 6, wherein the dispersion (73) is maintained at a temperature of between about 20 ℃ and about 50 ℃, and/or the dispersion (73) comprises particles of lubricating material in an amount of between about 1% by weight of dispersion and about 5% by weight of dispersion, preferably 1.5% by weight of dispersion and about 2.5% by weight of dispersion, and at least about 95% by weight of dispersion and about 99% by weight of liquid, in particular water, preferably about 97.5% by weight of dispersion, wherein the liquid comprises between about 99% and about 99.8% by weight of liquid, preferably 99.5% by weight of liquid, and about 1% by weight of liquid and about 0.2% by weight of liquid of a stabilizer, preferably about 0.5% by weight of liquid, wherein the stabilizer is preferably a surfactant.

9. The method according to any one of claims 1 to 8, wherein water vapour (67) is provided by a vapour generator (55) and is led through a heated conduit to a sprayer (66) where a lubricating material is incorporated into the water vapour (67) and both are sprayed together by the sprayer onto the tip end (38) of the razor blade (16).

10. The method of any of claims 1 to 9, further comprising sintering the lubricating material sprayed onto the tip end (38) of the razor blade (16) to form a coating (65) of lubricating material on the tip end (38) of the razor blade (16).

11. The method of any of claims 1 to 10, wherein the thickness of the coating of lubricating material (65) on the razor blade (16) is less than about 1.5 μ ι η, preferably between about 0.1 μ ι η to about 1 μ ι η, most preferably between about 0.25 μ ι η to about 0.75 μ ι η.

12. The method of any of claims 1-11, wherein providing a razor blade (16) includes providing a substrate having a body portion (48, 50) and a tip end (38) defined by at least one tip surface (52, 54) and a cutting edge (22).

13. The method according to claim 12, wherein at least one area of the cutting edge (22) and the at least one tip surface (52, 54) adjacent to the cutting edge (22) is coated with an intermediate layer, a hard coating applied onto the intermediate layer, and optionally an outer coating applied onto the hard coating, or with a hard coating applied onto at least one area of the cutting edge and the at least one tip surface (52, 54) adjacent to the cutting edge (22), and optionally an outer coating applied onto the hard coating.

14. The method of any one of claims 1 to 13, wherein providing a razor blade (16) comprises providing a substrate having a body portion (34) and a tip end (38) defined by at least one tip surface (52, 54) and a cutting edge (22), wherein at least a region of the cutting edge (22) and the at least one tip surface (52, 54) adjacent the cutting edge (22) is coated with an intermediate layer comprising niobium, chromium, titanium, silver, zirconium, a mixture of different metals such as chromium and titanium or silver, or nitrides or carbides of these metals and alloys, or other ceramics, a hard coating comprising diamond, a diamond-like material or a ceramic coating such as chromium nitride, chromium carbide, titanium nitride, or other ceramics, a hard coating applied to the intermediate layer, and optionally an outer coating applied to the hard coating, Titanium carbide, zirconium oxide, zirconium nitride, tungsten carbide, tungsten nitride, or other ceramics, and the outer coating comprises a metal or metal alloy, such as chromium, titanium, silver, gold, niobium, zirconium, tungsten, or mixtures of the foregoing metals.

15. The method of any one of claims 1 to 14, wherein the spraying step is performed in a natural environment.

16. A method of manufacturing a razor blade comprising:

-providing an uncoated or pre-coated substrate having a body portion (34) and a tip end (38) defined by at least one tip surface (52, 54) and a cutting edge (22),

-spraying a lubricating material onto the tip end (38) of the substrate according to the method of any one of the preceding claims, and

-sintering the sprayed lubricating material to provide a coating (65) of lubricating material.

17. A razor blade comprising:

-an uncoated or pre-coated substrate having a body portion (34) and at least one tip end (38) defined by at least one tip surface (52, 54) and a cutting edge (22), and

-an outer coating of a lubricating material (65),

-wherein the razor blade (16) is obtainable by the method of claim 16.

18. The razor blade of claim 17 wherein the thickness of the coating of external lubricious material (65) is less than about 1.5 μ ι η, preferably between about 0.1 μ ι η to about 1 μ ι η, most preferably between about 0.25 μ ι η to about 0.75 μ ι η.

19. The razor blade according to claim 18, wherein the cutting edge (22) is completely covered by a lubricating material, and wherein at least 70% of the at least one tip surface (52, 54) or each tip surface (52, 54) is covered by a lubricating material to a distance of 100 μ ι η, preferably 70 μ ι η, from the cutting edge (22).

20. A shaver comprising a handle (12), a housing (13) and at least one shaver blade (16) made according to claim 16 and/or according to any of claims 17 to 19, the at least one shaver blade (16) being mounted in the housing (13).

Technical Field

The present disclosure relates to razor blades and methods of making the same.

Background

Modern razor blades use a multi-layer coating that allows for very close and comfortable shaving. For shaving comfort, the last layer of lubricating material, such as PTFE (polytetrafluoroethylene), on the tip of the blade became the industry standard in the early 60's of the 20 th century (see, for example, GB-A-966084 and US-A-2007/0124944). Such PTFE coatings are henceforth an element of razor blades (see, for example, WO-A-2010/081118, WO-A-2010/081119, WO-A-2011/047727 and US-B-9393588). PTFE is typically applied from a liquid dispersion by a spray process and the liquid carrier partially evaporates, leaving the PTFE particles adhered to the tip of the blade. To increase the adhesion of the PTFE, the powder is heated above the melting point of the polymer and a continuous layer of PTFE is created along the blade edge. This process is known in the industry as sintering.

Such a PTFE coating provides excellent glide when the cutting edge is moved over the skin and it reduces the cutting forces during shaving.

These low cutting forces and slip forces result in a high comfort level during shaving. Today, blades without a PTFE coating would be considered unsuitable for shaving.

In PTFE applications, a balance needs to be found with respect to the thickness of the applied PTFE layer. If the PTFE layer is too thin, or if the amount of PTFE sprayed is too small, voids between particles may result, which voids are not smoothed out during sintering. This will result in improper coverage and suboptimal shaving. There is therefore a trend to increase the amount and thickness of PTFE to avoid the risk of voids.

On the other hand, a too thick PTFE layer may result in a sub-optimal first shave, since the PTFE needs to be pushed back from the tip to allow the hairs to be penetrated in the desired manner by the very sharp tip of the razor blade itself. Too much PTFE layer makes the tip appear somewhat blunt. The cohesive strength of PTFE is relatively low due to its chemical nature and during shaving activities, excess PTFE is removed and only an ultra-thin "monolayer" needs to be left on the tip to provide the desired comfort of shaving. This effect has long been known as peeling or push back, but as the PTFE material is changed and the number of cutting edges (i.e., blades) increases in modern shaving systems, the time to create a single layer becomes longer and results in a somewhat less comfortable first shave. This phenomenon is summarized as the "first shave effect".

Internal and external shaving tests have shown that the blade edge is (negatively) affected by the first shave effect, the elimination of which will significantly improve the shaving performance. It is well known that when a consumer uses a new cartridge (cartridge), the first shave with the new blade should be the best shave to meet the consumer's expectations.

One option for achieving A desired comfortable first shave is to remove excess PTFE material mechanically (see for example WO-A-2016/057302, WO-A-2016/057473 and US-A-2016/0096282) or chemically (see for example US-A-5985459 and US-B-7247249). These processes are material intensive and energy intensive, and in particular chemical removal is a very expensive process, both in terms of equipment investment and in terms of operating costs for removing the chemicals. It is significant to have only a small amount of PTFE particles on the blade tip to produce almost a single layer of PTFE and the resulting cutting edge does not require a "break-in" period, resulting in excellent shaving comfort from the first shave.

Water vapor-assisted painting processes are described in WO-A-2005/087387, DE-A-102006019365, WO-A-2007/122093, GB-A-660233 and GB-A-00608.

It is also well known that razor blades may be coated with other materials, such as those disclosed in US-A-3743551, US-A-3838512, US-A-5488774, US-A-2007/0186424, WO-A-87/04471 and EP-B-2731760, prior to the PTFE coating of the razor blade.

Disclosure of Invention

The present disclosure provides a method of coating a razor blade with a lubricating material comprising the steps of:

-providing a razor blade having a body portion and a tip end, the tip end being defined by at least one tip surface and a cutting edge, an

-spraying a lubricating material on the tip end of the razor blade,

-wherein spraying the lubricating material is performed with the aid of steam, wherein the lubricating material is introduced into superheated water vapour directed towards the tip end of the razor blade.

According to the invention, a lubricating material, in particular in the form of particles having a particle size of preferably 0.5 μm or less, more preferably 0.2 μm or less, is provided on the tip end of the razor blade, which tip end is defined by at least one tip surface and a cutting edge, and preferably by a cutting edge and two tip surfaces, which are provided adjacent to the cutting edge on opposite sides of the razor blade. The step of depositing particles of a lubricating material is performed with the aid of steam, wherein the particles are introduced into superheated water vapour which is directed towards and impinges onto the tip end of the razor blade. The spraying of the superheated steam or steam together with the lubricating material is performed by means of a sprayer, which preferably comprises at least one nozzle for discharging superheated steam. A lubricant discharge nozzle is disposed adjacent to and in proximity to the at least one nozzle, the lubricant discharge nozzle introducing lubricant into the discharge vapor. The vapor nozzle may have an annular slit-shaped opening surrounding the lubricant nozzle. Further steam nozzles may be provided downstream of the discharge streams of superheated steam and lubricating material in order to discharge superheated steam for forming the streams of superheated water steam and lubricating material. These embodiments are alternative and/or preferred variations for carrying out the method of the present invention.

The spray coating process of the present invention may be used for the coating of lubricating material of single-edged or double-edged or multi-edged blades of razors or similar cutting blade devices for purposes other than wet or dry shaving.

The spray coating process is adjusted so that the particles of the lubricating material are smoothly deposited on the tip end of the razor blade. The superheated water vapor smoothly contacts the razor blade causing particles of the lubricating material to deposit or wet (bedew) on the tip end of the razor blade. The parameters of the spraying process adjusted to obtain such a spraying result are in particular:

the pressure of the water vapour as it leaves its outlet nozzle,

the pressure at which the lubricating material or dispersion leaves its outlet nozzle, and

-the distance of the razor blade from the outlet nozzle.

In a preferred embodiment, the razor blade to be treated by spraying the lubricating material on its tip end is preheated.

The lubricating material in an almost (or quasi-) dry state is deposited on the tip end of the razor blade due to the superheated water vapor carrying the lubricating material. After the spraying process, there is no residual water on the tip end of the razor blade. To further ensure that water does not condense on the razor blades, the razor blades are preheated. Thus, there is no or at least little loss of thermal energy in the mixture of vapour and lubricating material when impinging on the razor blade, which is advantageous for preventing or reducing condensation of water. The razor blades are preheated to between about 90 ℃ and about 180 ℃, preferably between 110 ℃ and 140 ℃.

In another preferred embodiment of the invention, the superheated steam is heated at the one or more outlet nozzles to a temperature of between about 105 ℃ and about 200 ℃, preferably between about 120 ℃ and about 190 ℃, most preferably between about 130 ℃ and about 170 ℃, and/or the pressure of the superheated steam in the steam generator is between about 1.5bar and about 2 bar.

In another embodiment of the invention, in order to spray the lubricating material on the tips of the razor blades, several razor blades are arranged side by side in a stack with the tip ends facing in the same direction, or a plurality of razor blades are arranged as an integral razor blade strip, wherein the razor blade strip is coiled. In both cases, the sprayer and blade material (stack or roll) are moved relative to each other in order to coat the tip ends of all the blades or rolls of the stack. In the case of stacking, the relative movement may be a back and forth movement with a lateral displacement between strokes. As the blade material is wound, the applicator may move helically from the center of the roll to its periphery (or vice versa), or the roll is rotated and the applicator moves radially relative to and above the roll. In these cases, the rotational speed of the roll is adjusted so that the amount of lubricating material sprayed onto the tip end of the wound razor blade tape is the same per unit length of razor blade tape. This means that the more the applicator is moved radially outwards the rotational speed of the roll is reduced, or the more the applicator is moved radially inwards the rotational speed of the roll is increased. Alternatively, the relative movement of the razor blade roll and the sprayer is performed in concentric circles, with radially inward or radially outward displacement after completion of, for example, each of a plurality of circles. If the razor blade roll is stationary and the sprayer is moved in concentric circles or spirally, the speed of the sprayer can be kept constant. However, it is also possible to treat the razor blades individually, wherein a plurality of separate razor blades are treated one after the other, or wherein a plurality of razor blades are arranged as an integral razor blade strip which runs along the spraying station or sprayer and passes through the superheated water vapour which is discharged from the sprayer or spraying station.

In another embodiment of the invention, the lubricating material is provided in the form of a dispersion of particles of the lubricating material in a liquid (including in particular water), wherein the dispersion is introduced into water vapour. Furthermore, in this preferred embodiment, it is further preferred that the dispersion is maintained at a temperature of between about 20 ℃ and about 50 ℃ and/or that the dispersion comprises from about 1% by weight of the dispersion to about 5% by weight of the dispersion, preferably from 1.5% by weight of the dispersion to about 2.5% by weight of the dispersion of particles of the lubricating material, and at least from about 95% by weight of the dispersion to about 99% by weight of the dispersion of a liquid, in particular water, preferably from about 97.5% by weight of the dispersion of liquid, wherein the liquid comprises from about 99% to about 99.8% by weight of the liquid, preferably 99.5% by weight of the liquid, of water, and from about 1% by weight of the liquid to about 0.2% by weight of the liquid of a stabilizer, preferably about 0.5% by weight of the liquid, wherein the stabilizer is preferably a surfactant. An advantage of the stabilizer is that the mixture (i.e., dispersion) of the lubricating material particles and the liquid is more uniform.

Furthermore, the dispersion may be preheated to support maintaining a dry condition of the mixture of water vapor and dispersion with a relatively low weight percentage of liquid compared to the volume of vapor.

The step of introducing the dispersion into the water vapour or steam may be performed by spraying the dispersion into the water vapour and/or by sucking the dispersion into the water vapour according to the venturi effect and due to the velocity of the water vapour flow.

In another preferred embodiment of the invention, water vapor is provided by a vapor generator and is directed through a heated conduit to a sprayer where a lubricating material is incorporated into the water vapor and both are sprayed together by the sprayer onto the tip end of the razor blade. This provides that the water vapor remains at the superheated temperature as it exits the sprayer.

With the razor blade of the invention and the method of the invention it is surprisingly possible that a very thin layer of particles of the lubricating material can be deposited on the tip end of the razor blade. Ideally, the layer comprises only particles of lubricating material arranged side by side on the tip end of the razor blade. Particles of a lubricating material adhere to the surface of the tip end to mechanically stabilize such a desired monolayer of particles of the lubricating material, and the razor blade having the particles of the lubricating material on its tip end is treated by sintering the lubricating material to form a coating of the lubricating material on the tip end. According to a test performed in connection with the present invention, the thickness of the coating of the lubricating material on the razor blade is less than about 1.5 μm, preferably between about 0.1 μm and about 1 μm, most preferably between about 0.25 μm and about 0.75 μm, and wherein the cutting edge is almost completely covered by the lubricating material, and wherein at least 70% of at least one tip surface or each tip surface is covered by the lubricating material to a distance of 100 μm, preferably 70 μm, from the cutting edge.

Generally, according to the present invention, all known kinds of lubricating materials for improving the gliding of razor blades on the skin to be shaved may be employed. Most preferably, the lubricating material comprises a fluoropolymer, Polytetrafluoroethylene (PTFE), Polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-perfluoro-methyl vinyl ether (MFA), poly [ tetrafluoroethylene-perfluoro (alkoxy vinyl ether) ] PFA, ethylene-tetrafluoroethylene-hexafluoropropylene-terpolymer EFEP, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorobutyl ethylene, perfluorohexyl ethylene, ethylene-tetrafluoroethylene-copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene-copolymer (FEP), and copolymers of perfluoroethylene and perfluoropropylene.

In razor blades, multilayer coatings allowing a very compact and comfortable shaving are basically known, as already mentioned above. Thus, those multi-layer coatings and corresponding coating techniques may be used to prepare razor blades to be coated with a lubricating material (typically as a final coating step) in accordance with the present invention. Accordingly, in a preferred embodiment of the present invention, providing a razor blade comprises providing a substrate (typically made of metal) having a body portion and a tip end defined by at least one tip surface and a cutting edge, wherein the cutting edge and at least one area of the at least one tip surface adjacent the cutting edge are coated with an intermediate layer, a hard coating on the intermediate layer, and optionally a top coating on the hard coating, or a hard coating applied to the cutting edge and at least one area of the at least one tip surface adjacent the cutting edge, and optionally a top coating applied to the hard coating.

Thus, the following coating variants are possible:

-matrix-lubricating material

Matrix-hard coat-lubricating material

Matrix-intermediate layer-hard coat-lubricating material

-substrate-intermediate layer-hard coating-outer coating-lubricating material

More particularly, in accordance with the present invention, it may be provided that providing a razor blade includes providing a substrate having a body portion and a tip end defined by at least one tip surface and a cutting edge, wherein the cutting edge and at least a region of the at least one tip surface adjacent the cutting edge are coated with an intermediate layer (including niobium, chromium, titanium, silver, zirconium, a mixture of different metals such as chromium and titanium or silver, or nitrides or carbides of these metals and alloys, or other ceramics), a hardcoat layer on the intermediate layer (wherein the hardcoat layer includes diamond, diamond-like materials, or ceramic coatings such as chromium nitride, chromium carbide, titanium nitride, titanium carbide, zirconium oxide, zirconium nitride, tungsten carbide, tungsten nitride, or other ceramics), and optionally an overcoat layer on the hardcoat layer (wherein the overcoat layer includes a metal or metal alloy such as chromium, silver, or other ceramics), and, Titanium, silver, gold, niobium, zirconium, tungsten or mixtures of the foregoing metals). However, the invention may also be used for coating of a lubricating material on a non-pre-coated substrate, i.e. on a bare substrate (usually metal).

In addition to the aforementioned advantages of the present invention, it should be noted that the step of spraying the mixture of water vapor and particles of the lubricating material may be performed in a natural environment. No specific gaseous environment, such as a protective environment, is required for the step of depositing the particles of lubricating material onto the tip end of the razor blade.

In another variation of the invention, a method of manufacturing a razor blade is provided, comprising the steps of:

-providing an uncoated or pre-coated substrate having a body portion and a tip end defined by at least one tip surface and a cutting edge,

-spraying a lubricating material onto the tip end of the substrate according to the method described above, and

-sintering the sprayed lubricating material to provide a coating of lubricating material.

Further, the present invention provides a razor blade comprising:

-an uncoated or pre-coated substrate having a body portion and a tip end defined by at least one tip surface and a cutting edge, and

-a coating of an external lubricating material,

-wherein the razor blade is obtainable by the aforementioned manufacturing method.

In a preferred embodiment, the razor blade comprises at least one of an intermediate layer, a metal or hard coating, and optionally an outer coating, wherein the one or more layers are disposed between the substrate and the outer coating.

In another preferred embodiment, the thickness of the coating of the external lubricating material is less than about 1.5 μm, preferably between about 0.1 μm and about 1 μm, and most preferably between about 0.25 μm and about 0.75 μm.

Furthermore, in another preferred embodiment, the cutting edge is almost completely covered by the lubricating material, and wherein at least 70% of the at least one tip surface or each tip surface is covered by the lubricating material to a distance of 100 μm, preferably 70 μm, from the cutting edge.

In another preferred embodiment, the hard coating comprises diamond, diamond-like materials, or ceramic coatings, such as chromium nitride, chromium carbide, titanium nitride, titanium carbide, zirconium oxide, zirconium nitride, tungsten carbide, tungsten nitride, or other ceramics.

In a further preferred embodiment, the order of the layers on the substrate is an intermediate layer, a hard coating layer and an outer coating layer of a lubricating material, or the order of the layers on the substrate is an intermediate layer, a hard coating layer, an outer coating layer and an outer coating layer of a lubricating material.

Finally, the invention provides a shaver comprising a handle, a housing and at least one razor blade manufactured according to the aforementioned method and/or having the aforementioned characteristics. The razor may include a housing in the form of a replaceable or non-replaceable cartridge having a frame with at least one and preferably more than one razor blade mounted in the frame of plastic or other known material, preferably manufactured by injection molding techniques. Further, the razor may have a housing that may contain at least one replaceable double-edged razor blade.

In another preferred embodiment, the housing comprises at least two to ten razor blades arranged parallel to each other.

In a preferred embodiment, a plurality of blade segments are disposed within the housing.

According to the invention, the particles of lubricating material are carried by the flow of superheated water vapour and only melt upon or after contacting the preferably preheated blades, so that the water vapour does not change its state of aggregation and therefore does not condense, which means that little water is deposited on the blades or the layer of particles of lubricating material. The various parameters (such as the temperature of the superheated water vapour, the temperature of the preheating blade, the flow rate of the water vapour flow, the size of the lubricating material particles, the density of the particles per unit surface and/or unit volume, the amount of lubricating material particles per water vapour volume, the distance between the outlet opening of the applicator and the blade to be coated, and the speed of the relative movement between the applicator and the blade band or blade length to be coated) have to be determined experimentally in order to obtain a lubricating coating of the blade with the desired properties defined by the blade manufacturer.

Drawings

The invention will be explained in more detail with reference to the drawings, in which

FIG. 1 is a front plan view of a razor assembly including a razor cartridge and a handle;

FIG. 2 is a top plan view of the razor cartridge shown in FIG. 1;

FIG. 3 is a perspective view of a razor cartridge;

FIG. 4 is a top plan view of an exemplary razor blade that may be used with the present method;

FIG. 5 is a planar side view of an exemplary razor blade that may be used with the present method;

FIG. 6 is a schematic view of a razor blade tip end having a layer of initial particles of lubricating material sprayed by a sprayer;

FIG. 6A is an enlarged view of a nozzle portion of the sprayer of FIG. 6;

FIG. 7 is a schematic view of a razor blade tip end having a surface coating of a lubricious material after sintering a layer of particles as shown in FIG. 6;

FIG. 8 is a schematic view of a stack of razor blades disposed within an embodiment of a fixture, wherein the relative movement of the fixture and sprayer is illustrated; and

fig. 9 is a schematic view of a coiled razor blade strip showing the relative movement of the clamp and sprayer.

Detailed Description

The present disclosure includes methods for manufacturing razor blades with a surface coating and embodiments thereof, and more particularly, methods for applying a surface coating disposed on a surface of a razor blade.

Referring to fig. 1-3, an exemplary razor cartridge 10 having a housing 13 is shown to facilitate the description provided herein. The present disclosure is not limited to this particular razor cartridge embodiment and may also be used with razor housings having at least one replaceable or non-replaceable double-edged razor blade. The term "housing" shall include replaceable and non-replaceable housings that may or may not be pivotally connected to the handle. The razor, razor handle and housing, and razor blade may be of any design and may be made of any suitable material and may be manufactured by any technique known in the wet and dry shaving razor art.

The exemplary razor cartridge 10 is pivotally or rigidly mounted on a handle 12 (shown in phantom in fig. 1). In some applications, razor cartridge 10 is a disposable part of razor assembly 11, intended to be detachable from reusable handle 12. In other applications, razor cartridge 10 and handle 12 are incorporated into an integral disposable razor assembly 11. In the latter form, the handle 12 and cartridge 10 are not intended to be detached from one another during normal use. The cartridge may have any type of housing 13 made of any material and by any technique known primarily in the art of dry and wet shavers.

The razor cartridge 10 includes a body 14 and one or more razor blades 16, and has a length 18 and a width 20. Each of the one or more razor blades 16 has a longitudinally extending cutting edge 22. However, the present disclosure is not limited to any particular cutting edge and/or razor blade configuration; for example, the present disclosure may be applicable to linear cutting edges, non-linear cutting edges, cutting edges extending around the perimeter of an aperture, integrally curved razor blades, razor blades mounted on a curved or non-curved blade holder, and the like. Razor cartridge 10 preferably also includes guard 24. For clarity, the terms "front" and "rear" are used herein in terms of the orientation of the blade as it is conventionally used against the skin of a user; for example, when the razor blade 16 is used in a conventional manner, the blade will move in a forward to rearward direction relative to a point on the user's skin that the front blade element will encounter before the rear blade element. The body 14 includes a front 26, a rear 28, a first side 30 and a second side 32. The front portion 26 is disposed between the guard 24 and the one or more razor blades 16. A rear portion 28 (sometimes referred to as a "cap") is disposed behind one or more of the razor blades 16. First and second side portions 30, 32 are disposed on opposite sides of one or more razor blades 16 and both extend between the front and rear portions 26, 28. The cartridge or housing 13 may also be provided with an inter-blade guard and a plurality of razor blades, all facing in the same direction, or comprising sets facing in different directions (where there are also opposite directions).

Razor blades 16 according to the present disclosure may take on a variety of configurations, each including a body 34 having a width 36 extending between a tip end 38 and a rear end 40, and a length 42 extending between a first lateral edge 44 and a second lateral edge 46. The body 34 further includes an upper body surface 48 and a lower body surface 50, the body surfaces 48, 50 extending transversely between the tip end 38 and the rear end 40 and longitudinally between the first lateral edge 44 and the second lateral edge 46. The razor blade descriptions provided herein and shown in the drawings are included to facilitate an understanding of the present disclosure. The present disclosure is not limited to this particular razor blade embodiment.

Referring to fig. 4 and 5, the tip end 38 is generally defined by a first tip surface 52, a second tip surface 54, and the cutting edge 22. The first and second tip surfaces 52, 54 converge at the cutting edge 22, each extending rearwardly to the respective body surfaces 48, 50 of the razor blade 16. Strictly speaking, in many cases, there may be a small radius surface (sometimes referred to as a "tip radius") at the convergence of the first tip surface 52 and the second tip surface 54. The tip end 38 may alternatively be configured with a single tip surface extending between the cutting edge 22 and the body surface of the razor blade 16. The present disclosure is not limited to any particular blade tip configuration. The razor blade 16 shown in fig. 4 includes a plurality of apertures extending through the blade between the body surfaces of the blade. Some of the apertures 56 may be used to position/secure the blades 16 within the razor cartridge, while other apertures 58 are rinse ports to facilitate removal of shaving debris. The razor blade 16 may also be described as having a transversely extending centerline 60 that is generally parallel to the body surfaces 48, 50 at least in the region proximate the tip end 38. The razor blades 16 are typically, but not always, made of stainless steel material and, as noted above, may include a coating comprising one or more materials, such as diamond, amorphous diamond, diamond-like carbon (DLC) material, nitrides, carbides, oxides, ceramics, etc., to improve strength, corrosion resistance, and shaving ability. The present methods for manufacturing razor blades 16 having a surface coating, including methods for forming a surface coating that adheres to the surface of the razor blade 16, are not limited to practice on any particular razor blade configuration, nor to practice on any particular razor blade tip configuration or cutting edge geometry or blade material.

Referring to fig. 6 and 6A, an embodiment of a spray coating process according to the present invention is shown. The result of the spray coating process is an initial surface coating 62 of lubricating material particles 63 that form an almost single layer or only a few layers of lubricating material particles 63 arranged side by side and covering the tip end 38 or at least a portion of the tip end 38 of the razor blade 16. The particles 63 of lubricating material are carried by a stream 64 of water vapour 67 sprayed by a sprayer 66 having a body 68 with at least two nozzles 70, 72 in a nozzle plate 71, for example screwed to the body 68. Superheated steam within the steam generator 55 is heated to between about 105 ℃ and about 200 ℃, or between about 120 ℃ and about 190 ℃, preferably between 130 ℃ and 170 ℃, flows through a flow meter 57 (or flow regulator) or directly into an internal annular passage or similar manifold 59 of the sprayer 66 and further through a passage 61 to a nozzle 70 preferably shaped like an annular slit. Arranged around the nozzle 70 is a nozzle 72 for discharging a dispersion 73 of water, stabilizer and particles of lubricating material. The dispersion is fed from reservoir 51 to sprayer 66 by means of pump 53 (or a flow meter or pressure regulator if dispersion 73 in reservoir 51 is under pressure) through passage 49 in sprayer 66. Both the superheated vapor and the dispersion are fed to the sprayer 66 (not shown). The dispersion is stored in a tank (not shown) and fed to the body 68 of the sprayer by means of a pump or similar feeding device. Superheated steam is generated in the steam generator and fed to the body 68 via tubes, which are heated in order to maintain the superheated steam at a desired temperature. Alternatively, the dispersion may also be permanently under pressure and the amount of dispersion per unit time (i.e. flow rate) leaving the nozzle may be controlled by a flow meter or the like through a flow regulator or regulating device. The same is true for controlling the flow of superheated steam out of the steam nozzles.

The initial lubricating material particle surface coating 62 according to the present disclosure may comprise a variety of different materials. Useful surface coating materials include, but are not limited to, fluoropolymers. A particularly useful fluoropolymer surface coating material is polytetrafluoroethylene ("PTFE"). Specific examples of the fluoropolymer includeMP1100, MP1200, MP1600 andLW1200 and Dry manufactured by E.I. DuPont de Nemours and Company, now Chemours, Inc., of EI Dupont, USALW2120 brand polytetrafluoroethylene powder. Other non-limiting examples of surface coating materials include silicon,Organosiloxane gels, and the like. The present method is not limited to the use of any particular type of surface coating material, so long as the material can be processed in the manner described below. For ease of describing the method, the surface coating material will be discussed in terms of PTFE. However, as mentioned above, the present method is not limited to the use of PTFE-type surface coating materials.

The present method uses a spray process and, as noted above, includes a superheated vapor stream 64 comprising a dispersion injected into the vapor stream. However, the present invention is not limited to the introduction of the lubricating material particles into the vapor stream 64 by injecting the dispersion into the vapor stream. However, a particularly useful application process is to initially dispose the surface coating material (e.g., PTFE particles) in dispersion form. The dispersion is deposited on the tip end 38 in almost a single layer or several layers of particles 63 of the lubricating material.

In further accordance with the present disclosure, the blade 16 or blades 16 having the deposited surface coating 62 of the initial lubricating material particles are subjected to a thermal sintering process that includes heating the blade and deposited surface material coating to a predetermined temperature for a period of time sufficient to fuse the PTFE particles together and adhere to the razor blade 16 and, in some cases, to drive off the dispersion medium, thereby forming a sintered form of the aforementioned surface coating 62 of the initial lubricating material particles. During the sintering process, the thickness of the surface coating may be reduced from the thickness of the initial lubricating material particle surface coating 62.

Fig. 7 shows the final surface coating 65 after the sintering process and with a certain thickness (see reference numeral 74).

In fig. 6 and 7, reference numeral 69 denotes one or more (e.g. hard) base coats or intermediate layers as described above, which are covered by a top coat 65. However, such additional primer layer(s) or intermediate layer(s) are optional, and thus, the surface coating 65 may also be applied directly onto the material of the blade (e.g., steel or stainless steel or other metal or ceramic).

The superheated vapor stream 64 directed toward the blade tip end 38 may be configured as a single defined stream impinging on substantially all of the longitudinally extending blade tip end 38, or as a plurality of streams 64 oriented to collectively impinge on substantially all of the longitudinally extending blade tip end 38, or as a stream 64 having a geometry (e.g., diameter) that is less than the length of the blade 16 and moves relative to the blade 16 (or vice versa), or any combination thereof. Vapor stream 64 may be applied continuously or intermittently; such as a pulse. The vapor flow 64 is typically generated by one or more nozzle stamps (nozzle stamps) having nozzle exit orifices positioned a predetermined distance from the blade tip end 38 being processed. The geometry of the vapor stream 64 exiting the nozzle orifice is a function of the fluid and flow parameters, as well as the geometry of the nozzle orifice. The nozzle orifice geometry is selected to be consistent with the fluid and flow parameters sufficient for the selected vapor stream 64 to deposit the initial lubricant particle surface coating 62 at the tip end 38. Additional fluid outlet nozzles (not shown) at the sprayer or downstream of the vapor stream may be used to create the vapor stream, and the size of the vapor stream may be varied and adapted to the surface to be covered with the lubricating material.

Referring to fig. 8, a method for producing a surface coating of lubricious material on a razor blade 16, in accordance with an aspect of the present disclosure, includes mounting a plurality of razor blades 16 (i.e., "stacks 86" of blades) within a fixture 82 that allows the blades 16 to be stacked in the same orientation with the blade tip ends 38 exposed. In one embodiment, the clamp 82 may include one or more blade retaining members; such as at least two rods extending through holes in the blade 16 (e.g., through the positioning/mounting holes 56, or through the flushing port 58). The clips 82 may provide spacers (not shown) disposed between each razor blade 16, or the razor blades 16 may be arranged such that respective adjacent blades contact each other. In this method, the vapor stream 64 is directed at the blade tip end 38 disposed in the fixture 82 in a manner such that the particles 63 form an initial lubricating material particle surface coating 62 at the tip end 38. The fixture 82 described above is a non-limiting example of a fixture that may be used to process multiple blades 16 in a single process (as opposed to a single blade surfacing process).

The fixture 82 may be selectively mounted relative to a device operable to preheat the razor blade 16 within the fixture 82 to a temperature, particularly up to between about 90 c to about 180 c, preferably between 110 c to 140 c, to prevent condensation of the superheated vapor stream 64. Further, for example, the fixture 82 holding the stack 86 of blades 16 may be selectively installed in a furnace operable to heat the stack 86 of razor blades 16 having the surface coating material so as to sinter the initial lubricating material particle surface coating 62. After sintering, the sintered lubricant particle surface coating 65 may have a thickness 76 of less than about 1.5 μm, preferably between about 0.1 μm and about 1 μm, most preferably between about 0.25 μm and about 0.75 μm, and preferably completely cover the tip end 38, wherein the cutting edge is almost completely covered by the lubricant, and wherein at least 70% of at least one tip surface or each tip surface is covered by the lubricant to a distance of 100 μm, preferably 70 μm, from the cutting edge. The thickness 76 may be determined by a suitable method, such as Atomic Force Microscopy (AFM).

In fig. 8, arrows 84, 85 show relative back and forth movement of the sprayer 66 and the clamp 82 with lateral displacement after each front and/or back movement path. However, relative back and forth movement may also occur, for example, perpendicular to arrows 84, 85.

Fig. 9 schematically illustrates a spray coating process according to another embodiment of the invention, wherein a sprayer 66 is used to apply particles of lubricating material in a deposit-like manner onto the tip end of a wound razor blade strip 88. The roll 90 and the applicator 66 are moved relative to each other so that all of the tip end length of the tape can be covered by particles of lubricating material. For example, the roll 90 may rotate in the direction of arrow 92 (or in the opposite direction) under the sprayer 66. As the applicator 66 moves radially (see arrow 94), the rotational speed needs to be adapted according to the position of the applicator 66 above the radius of the coil. This helps to keep the amount of spray constant per unit time and/or per unit tip end length from the outside to the inside of the roll without the need to adjust the flow/amount of sprayed medium. Alternatively, the sprayers 66 may move in concentric circles (e.g., with a radial displacement after each circle) or in a spiral pattern over the roll.

While the invention has been described and illustrated with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to these illustrative embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the true scope of the invention as defined by the appended claims. Accordingly, it is intended that the present invention embrace all such alternatives and modifications as fall within the scope of the appended claims and their equivalents.

List of reference numerals

10 razor cartridge

11 Assembly

12 handle

13 casing

14 main body

16 blade

18 length

20 width

22 cutting edge

24 guard

26 front part

28 rear part

30 side part

32 side part

34 main body

36 width

38 tip end

40 rear end portion

42 length

44 lateral edge

46 lateral edge

48 surface of the body

49 channel

50 surface of the body

51 reservoir

52 tip surface

53 pump

54 tip surface

55 steam generator

56 holes

57 flow meter

58 holes

59 annular channel (manifold)

60 center line

61 channel

62 initial lubricant particle surface coating

63 particles

64 stream

65 sintered coating

66 spray painting device

67 steam

68 sprayer body

69 base coat and/or intermediate layer

70 nozzle

71 nozzle plate

72 nozzle

73 Dispersion

74 thickness of sintered coating

76 thickness of surface coating of primary particles of lubricating material

82 clamp for razor blade stacking

84 moving arrow

85 moving arrow

86 stack

88 wrap razor blade band

90 roll

92 moving arrow

94 moving arrow