[0001] The present invention relates to metal scissors used in a barber shop, a beauty salon
and a shop for caring pets such as a dog and a cat and to a production process of
the metal scissors.
DESCRIPTION OF THE RELATED ART
[0002] For example, the grips of metal scissors used in a barber shop and a beauty salon
are subjected to a variety of surface treatments such as glossing, a hair line finish
and plating. Further, recently, metal scissors with plastic insert molded grips or
ion plated grips are commercially available.
[0003] However, the grips of all these products feel cold and hard when held in a hand and
lack a good fit. Further, they also have a problem that they are liable to be slippery
when used by a wet hand.
[0004] To solve these problems, several metal scissors with devised grips have been proposed.
However, since all of these metal scissors require separately molded synthetic resin
or rubber parts to be attached thereto, they are not suitable for use in a barber
shop and a beauty salon where metal scissors with a structurally complicated design
are required. Particularly, for an article of this type which is required to make
a user feel as if the article were a part of the user's hand, a fit is an important
factor which cannot be overlooked, and such an article must be used freely by a user.
Further, since a mold is required to form the synthetic resin or rubber molded parts,
production of a variety of such metal scissors in small quantities results in relatively
high costs and lacks practicability.
[0005] To solve the problems, a first object of the present invention is to provide metal
scissors having grips which give a good touch, are not liable to be slippery even
when used by a wet hand and are free from the possibility that the surface of a base
material is not exposed even when the surface of the grip is abraded or scratched.
A second object of the present invention is to provide metal scissors having grips
which give an exquisite fit. A third object of the present invention is to provide
metal scissors having grips which give a good touch, are not liable to be slippery
even when used by a wet hand, are free from the possibility that the surface of a
base material is not exposed even when the surface of the grip is abraded or scratched,
and are coated with a protective coating film which does not come off easily. A fourth
object of the present invention is to provide metal scissors having grips which give
an exquisite fit. A fifth object of the present invention is to provide a process
capable of mass-producing the above scissors efficiently at low costs.
[0006] WO 99/07527 discloses metal scissors according to the preamble of claim 1, and a
process according to the preamble of claim 5.
3. SUMMARY OF THE INVENTION
[0007] To achieve the above objects of the present invention, metal scissors of the present
invention have grips each having a titanium coating layer formed on the surface of
a base material and a polymer compound coating layer formed on the titanium coating
layer, the polymer compound coating layer having excellent abrasion resistance and
scratch resistance.
[0008] Further, in the metal scissors of the present invention, the base material in the
grip preferably has moderate surface roughness with fine pits and projections on the
surface, and the titanium coating layer and the polymer compound coating layer are
laminated to such a thickness that does not impair the surface roughness of the base
material so as to form fine pits and projections comparable to the surface roughness
of the base material, on the surface of the polymer compound coating layer.
[0009] Further, the metal scissors of the present invention preferably comprise a polymer
compound foundation layer formed on the titanium coating layer, the foundation layer
having excellent adhesion to the titanium coating layer; and said polymer compound
coating layer formed on the polymer compound foundation layer.
[0010] In this case, the base material in the grip may have moderate surface roughness with
fine pits and projections on the surface, and the titanium coating layer, the polymer
compound foundation layer and the polymer compound coating layer are laminated to
such a thickness that does not impair the surface roughness of the base material so
as to form fine pits and projections comparable to the surface roughness of the base
material, on the surface of the polymer compound coating layer.
[0011] Further, a process for producing metal scissors according to the present invention
comprises:
a first step of blast-treating the surfaces of base materials in the grips of a pair
of scissors parts so as to cause them to have moderate surface roughness with fine
pits and projections formed on the surfaces,
a second step of titanium-coating the whole scissors part so as to form a titanium
coating layer whose thickness, together with the thicknesses of all other layers to
which the titanium coating layer is laminated, does not impair the surface roughness
of the base material,
a third step of forming a polymer compound foundation layer on the titanium coating
layer in the grip by baking coating, the foundation layer having a thickness which
together with the
thicknesses of all other layers to which the foundation layer is laminated does not
impair the surface roughness of the base material and also having excellent adhesion
to the titanium coating layer,
a fourth step of forming a polymer compound coating layer on the polymer compound
foundation layer in the grip by baking coating, the coating layer having a thickness
which together with the thicknesses of all other layers to which the coating layer
is laminated does not impair the surface roughness of the base material and also having
excellent abrasion resistance and scratch resistance, and
a fifth step of joining the pair of scissors parts together.
[0012] The pair of scissors parts in the present invention are made of stainless steel or
other known metals. The surface roughness of the base material in the grip is arbitrary.
However, in consideration of sense of touch, slipperiness, a fit to a hand, and the
like, its lower limit Ry is 12.5, and its upper limit Ry is 50. When the surface roughness
is lower than the lower limit, pits and projections are so small that the grip is
liable to be slippery, while when it is higher than the upper limit, the pits and
projections are so large that the grip irritates skin excessively upon contact and
causes pain in a hand. This surface roughness is set at an optimum value according
to application purposes as in a barber shop and a beauty salon, individual differences,
and other factors.
[0013] The thickness of the titanium coating layer is about 0.8 to 1.2 µm. The color of
the titanium coating layer may be any appropriate color in addition to blue, gray,
black, gold and a rainbow color.
[0014] The polymer compound foundation layer comprises clear paint such as a polyurethane
for a base coat and may be any polymer compound member having excellent adhesion to
the titanium coating layer. The thickness of the foundation layer is about 3 to 7
µm, desirably about 5 µm.
[0015] The polymer compound coating layer comprises a synthetic resin material such as a
polyurethane resin or an acrylic resin or synthetic rubber and may be any polymer
compound having excellent abrasion resistance and scratch resistance. The thickness
of the coating layer is about 15 to 25 µm, desirably about 20 µm. The total thickness
of the titanium coating layer, the foundation layer and the coating layer when they
are laminated together is such a thickness that does not impair the surface roughness
of the finely uneven surface of the base material in the grip and allows the surface
roughness of the base material to be reflected directly on the surface of the coating
layer, i.e., about 19 to 33 µm, desirably about 25 µm.
4. BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Fig. 1 is a front view of an embodiment of metal scissors of the present invention,
Fig. 2 is an enlarged cross-sectional diagram of a portion of the embodiment shown
in Fig. 1,
Fig. 3 is an enlarged cross-sectional diagram of a portion of another embodiment of
the metal scissors of the present invention,
Fig. 4 is an enlarged cross-sectional diagram of a portion of another embodiment of
the metal scissors of the present invention,
Fig. 5 is an enlarged cross-sectional diagram of a portion of another embodiment of
the metal scissors of the present invention, and
Figs. 6A-6D are front views of metal scissors in sequential steps in an embodiment
of a production process of metal scissors of the present invention. Fig.6A shows the
metal scissors in a first step, Fig.6B shows the metal scissors in a second step,
Fig. 6C shows the metal scissors in a third step, and Fig.6D shows the metal scissors
in a fourth step.
5. DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Figs. 1 and 2 exemplify one embodiment of metal scissors of claim 1 of the present
invention. Scissors 1 for use in a barber shop and a beauty salon comprise a pair
of stainless steel scissors parts 2 and a shaft 3 which joins the stainless steel
scissors parts 2 together.
[0018] The pair of scissors parts 2 are wholly coated with a titanium coating layer 6. Grips
4 each comprise the titanium coating layer 6 which is formed on the smooth surface
of a base material 5 and a polyurethane coating layer 7 which is formed on the layer
6 and has excellent abrasion resistance and scratch resistance.
[0019] Fig. 3 exemplifies one embodiment of metal scissors of claim 2 of the present invention.
Since its constitution is basically the same as that of the above embodiment of Fig.
1, descriptions on constituents common between them will be omitted, using the same
reference numerals, and only constituents different between them will be described.
[0020] Grips 4 each comprise a titanium coating layer 6 which is formed on the surface of
a base material 5, a polyurethane foundation layer 8 for a base coat which is formed
on the layer 6 and has excellent adhesion to the layer 6, and a polyurethane coating
layer 7 which is formed on the layer 8 and has excellent abrasion resistance and scratch
resistance.
[0021] Fig. 4 exemplifies one embodiment of metal scissors of claim 3 of the present invention.
Since its constitution is basically the same as that of the above embodiment of Fig.
1, descriptions on constituents common between them will be omitted, using the same
reference numerals, and only constituents different between them will be described.
[0022] Grips 4 each comprise a base material 5 with a surface 5a which has fine pits and
projections thereon with a surface roughness Ry of 12.5 to 50, a titanium coating
layer 6 which is formed on the surface of the base material 5, and a polyurethane
coating layer 7 which is formed on the layer 6 and has excellent abrasion resistance
and scratch resistance. The total thickness of the titanium coating layer 6 and the
polyurethane coating layer 7 when they are laminated together is such a thickness
that does not impair the surface roughness of the finely uneven surface 5a of the
base material 5 so as to form a finely uneven surface 7a of the polyurethane coating
layer 7 which is comparable to the surface roughness of the base material surface
5a.
[0023] Fig. 5 exemplifies one embodiment of the metal scissors of claim 3 of the present
invention. Since its constitution is basically the same as that of the above embodiment
of Fig. 1, descriptions on constituents common between them will be omitted, using
the same reference numerals, and only constituents different between them will be
described.
[0024] Grips 4 each comprise a base material 5 with a surface 5a which has fine pits and
projections thereon with a surface roughness Ry of 12.5 to 50, a titanium coating
layer 6 which is formed on the surface of the base material 5, a polyurethane foundation
layer 8 for a base coat which is formed on the layer 6 and has excellent adhesion
to the layer 6, and a polyurethane coating layer 7 which is formed on the layer 8
and has excellent abrasion resistance and scratch resistance. The total thickness
of the titanium coating layer 6, the polyurethane foundation layer 8 for a base coat
and the polyurethane coating layer 7 when they are laminated together is such a thickness
that does not impair the surface roughness of the finely uneven surface 5a of the
base material 5 so as to form a finely uneven surface 7a of the polyurethane coating
layer 7 which is comparable to the surface roughness of the base material surface
5a.
[0025] Figs. 6A to 6D show a production example of the above scissors of Fig. 5 as one embodiment
of the production process of metal scissors of the present invention. Scissors 1 are
prepared in accordance with the following steps.
First Step (refer to Fig.6A )
[0026] The surfaces of base materials 5 in grips 4 of a pair of scissors parts 2 are blast-treated
so as to form a finely uneven base material surface 5a with a surface roughness Ry
of 12.5 to 50.
Second Step (refer to Fig.6B )
[0027] The scissors part 2 is wholly coated with titanium so as to form a titanium coating
layer 6 whose thickness together with the thicknesses of all other layers 7 and 8
to which the layer 6 is laminated does not impair the surface roughness of the base
material surface 5a.
Third Step (refer to Fig.6C )
[0028] On the titanium coating layer 6 in the grip 4, the polyurethane foundation layer
8 for a base coat which has excellent adhesion to the layer 6 is formed by baking
coating such that the layer 8 has such a thickness that together with the thicknesses
of all other layers 6 and 7 to which the layer 8 is laminated does not impair the
surface roughness of the base material surface 5a.
Fourth Step (refer to Fig. 6D)
[0029] On the polyurethane foundation layer 8 for a base coat in the grip 4, the polyurethane
coating layer 7 which has excellent abrasion resistance and scratch resistance is
baking-coated to such a thickness that together with the thicknesses of all other
layers 6 and 8 to which the layer 7 is laminated does not impair the surface roughness
of the base material surface 5a, thereby forming a finely uneven surface 7a of the
polyurethane coating layer 7 which is comparable to the surface roughness of the base
material surface 5a.
Fifth Step
[0030] The pair of scissors parts 2 are joined together by means of a shaft 3, thereby producing
the scissors 1 with the grips 4 that each comprise the finely uneven base material
5 which has a surface roughness Ry of 12.5 to 50, the titanium coating layer 6 which
is formed on the finely uneven base material surface 5a, the polyurethane foundation
layer 8 for a base coat which is formed on the layer 6 and has excellent adhesion
to the layer 6, and the polyurethane coating layer 7 which is formed on the layer
8 and has excellent abrasion resistance and scratch resistance. The titanium coating
layer 6, the foundation layer 8 and the polyurethane coating layer 7 are formed in
such a total thickness that does not impair the surface roughness of the finely uneven
base material surface 5a of the base material 5 so as to form the finely uneven surface
7a of the polyurethane coating layer 7 which is comparable to the surface roughness
of the base material surface 5a.
A. According to claim 1, metal scissors of the present invention provide a unique,
favorable touch, are not liable to be slippery even when used by a wet hand and are
highly useful in practical use. Further, even when the surface of a grip is abraded
or scratched, the surface of a base material is not exposed since it is protected
by a titanium coating layer. In addition, the surfaces of the grips have a unique
color ascribable to the titanium coating layer and a polymer compound coating layer.
Further, allergy to metals can be prevented completely due to the presence of the
polymer compound coating layer.
B. According to claim 2, since a foundation layer serves as a medium for joining the
titanium coating layer and the coating layer together, the protective coating on the
surface of the grip does not come off easily, resulting in high usefulness in practical
use. Further, the metal scissors of the present invention have a two-tone color ascribable
to the foundation layer and the coating layer and are therefore excellent in design
as well.
C. According to claim 3, metal scissors of the present invention provide a good touch,
are not liable to be slippery even when used by a wet hand and provide an exquisite
fit, due to the finely uneven surfaces of grips. Further, even when the surface of
the grip is abraded or scratched, the surface of a base material is not exposed since
it is protected by a titanium coating layer, resulting in high usefulness in practical
use. In addition, the surfaces of the grips show a unique color due to irregular reflection
caused by pits and projections on the surfaces and have a unique color ascribable
to the titanium coating layer and a polymer compound coating layer. Furthermore, allergy
to metals can be prevented completely due to the presence of the polymer compound
coating layer.
D. According to claim 4, since a foundation layer serves as a medium for joining the
titanium coating layer and the coating layer together, the protective coating on the
surface of the grip does not come off easily, resulting in high usefulness in practical
use. Further, the metal scissors of the present invention have a two-tone color ascribable
to the foundation layer and the coating layer and are therefore excellent in design
as well.
E. According to claim 5, scissors having the effects of the invention of claim 4 can
be mass-produced efficiently at low costs. Further, since a polymer compound foundation
layer and a polymer compound coating layer on the surface of a grip are formed by
baking coating, no expensive mold is required. In addition, in general, when blades
are to be coated with titanium, a step of masking grips and then removing masking
materials after titanium coating is necessary. The step is obviated in the present
invention, resulting in high productivity.
[0031] Having described specific preferred embodiments of the invention with reference to
the accompanying drawings, it will be appreciated that the present invention is not
limited to those precise embodiments, and that various changes and modifications can
be effected therein by one of ordinary skill in the art without departing from the
scope of the invention as defined by the appended claims.
1. Metal scissors (1) with grips (4) each having a titanium coating layer (6) formed
on the surface of a base material (5), characterized by a polymer compound coating layer (7) formed on the titanium coating layer (6), the
polymer compound coating layer (7) having excellent abrasion resistance and scratch
resistance.
2. The metal scissors (1) of claim 1, wherein the base material (5) in the grip (4) has
moderate surface roughness with fine pits and projections on the surface, and the
titanium coating layer (6) and the polymer compound coating layer (7) are laminated
to such a thickness that does not impair the surface roughness of the base material
(5) so as to form fine pits and projections comparable to the surface roughness of
the base material (5), on the surface of the polymer compound coating layer (7).
3. The metal scissors (1) of claim 1, further comprising a polymer compound foundation
layer (8) formed on the titanium coating layer (6), the foundation layer having excellent
adhesion to the titanium coating layer (6), said polymer compound coating layer (7)
being formed on the polymer compound foundation layer (8).
4. The metal scissors (1) of claim 3, wherein the base material (5) in the grip (4) has
moderate surface roughness with fine pits and projections on the surface, and the
titanium coating layer (6), the polymer compound foundation layer (8) and the polymer
compound coating layer (7) are laminated to such a thickness that does not impair
the surface roughness of the base material (5) so as to form fine pits and projections
comparable to the surface roughness of the base material (5), on the surface of the
polymer compound coating layer (7).
5. A process for producing metal scissors (1), which is
characterized by:
a first step of blast-treating the surfaces of base materials (5) in the grips (4)
of a pair of scissors parts (2) so as to cause them to have moderate surface roughness
with fine pits and projections formed on the surfaces,
a second step of titanium-coating the whole scissors part (2) so as to form a titanium
coating layer (6) whose thickness, together with the thicknesses of all other layers
to which the titanium coating layer (6) is laminated, does not impair the surface
roughness of the base material (5),
a third step of forming a polymer compound foundation layer (8) on the titanium coating
layer (6) in the grip (4) by baking coating, the foundation layer (8) having a thickness
which together with the thicknesses of all other layers to which the foundation layer
(8) is laminated does not impair the surface roughness of the base material (5) and
also having excellent adhesion to the titanium coating layer (6),
a fourth step of forming a polymer compound coating layer (7) on the polymer compound
foundation layer (8) in the grip (4) by baking coating, the coating layer (7) having
a thickness which together with the thicknesses of all other layers to which the coating
layer (7) is laminated does not impair the surface roughness of the base material
(5) and also having excellent abrasion resistance and scratch resistance, and
a fifth step of joining the pair of scissors parts (2) together.
1. Metallschere (1) mit Griffen (4), die jeder eine auf der Oberfläche eines Basismaterials
(5) ausgebildete Titan-Beschichtung (6) haben,
gekennzeichnet durch eine Polymerverbindungsbeschichtung (7), die auf der Titan-Beschichtung (6) ausgebildet
ist, welche Polymerverbindungsbeschichtung (7) einen exzellenten Abriebwiderstand
und Kratzwiderstand hat.
2. Metallschere (1) nach Anspruch 1, bei welcher das Basismaterial (5) in dem Griff (4)
eine gemäßigte Oberflächenrauhigkeit mit feinen Gruben und Vorsprüngen auf der Oberfläche
hat, und die Titanbeschichtung (6) und die Polymerverbindungsbeschichtung (7) auf
eine solche Dicke laminiert sind, dass sie die Oberflächenrauhigkeit des Basismaterials
(5) nicht beeinträchtigen, um so feine Gruben und Vorsprünge vergleichbar mit der
Oberflächenrauhigkeit des Basismaterials (5) auf der Oberfläche der Polymerverbindungsbeschichtung
(7) auszubilden.
3. Metallschere (1) nach Anspruch 1, weiter mit einer Polymerverbindungsgrundierung (8),
die auf der Titanschicht (6) ausgebildet ist, welche-Grundierung eine exzellente Anhaftung
an der Titanbeschichtung (6) hat, wobei die Polymerverbindungsbeschichtung (7) auf
der Polymerverbindungsgrundierung (8) ausgebildet ist.
4. Metallschere (1) nach Anspruch 3, bei welcher das Basismaterial (5) in dem Griff (4)
eine gemäßigte Oberflächenrauhigkeit mit feinen Gruben und Vorsprüngen auf der Oberfläche
hat, und die Titanbeschichtung (6), die Polymerverbindungsgrundierung (8) und die
Polymerverbindungsbeschichtung (7) auf eine solche Dicke laminiert sind, die die Oberflächenrauhigkeit
des Basismaterials (5) nicht beeinträchtigt, um so feine Gruben und Vorsprünge vergleichbar
mit der Oberflächenrauhigkeit des Basismaterials (5) auf der Oberfläche der Polymerverbindungsbeschichtung
(7) auszubilden.
5. Verfahren zur Herstellung einer Metallschere (1),
gekennzeichnet durch:
einen ersten Schritt zum Blasbehandeln der Oberflächen von Basismaterialien (5) in
den Griffen (4) von zwei Scherenteilen (2) so, dass diese eine gemäßigte Oberflächenrauhigkeit
mit feinen Gruben und Vorsprüngen auf den Oberflächen bekommen,
einen zweiten Schritt zum Beschichten des gesamten Scherenteils (2) mit Titan, um
so eine Titanbeschichtung (6) auszubilden, deren Dicke zusammen mit den Dicken aller
anderen Schichten, mit welchen die Titanbeschichtung (6) laminiert wird, die Oberflächenrauhigkeit
des Basismaterials (5) nicht beeinträchtigt,
einen dritten Schritt zum Ausbilden einer Polymerverbindungsgrundierung (8) auf der
Titanbeschichtung (6) in dem Griff (4) durch Backbeschichten, welche Grundierung (8) eine Dicke hat, die zusammen mit den Dicken
aller anderen Schichten, mit welchen die Grundierung (8) laminiert wird, die Oberflächenrauhigkeit
des Basismaterials (5) nicht beeinträchtigt, und wobei die Grundierung (8) auch eine
exzellente Anhaftung an der Titanbeschichtung (6) hat,
einen vierten Schritt zum Ausbilden einer Polymerverbindungsbeschichtung (7) auf der
Polymerverbindungsgrundierung (8) in dem Griff (4) durch Backbeschichten, wobei die Beschichtung (7) eine Dicke hat, die zusammen mit den
Dicken aller anderen Schichten, mit welchen die Beschichtung (7) laminiert wird, die
Oberflächenrauhigkeit des Basismaterials (5) nicht beeinträchtigt und auch einen exzellenten
Abriebswiderstand und Kratzwiderstand hat, und
einen fünften Schritt zum Verbinden der beiden Scherenteile (2).
1. Ciseaux métalliques (1) avec des poignées (4) ayant chacun une couche de revêtement
en titane (6) formée sur la surface d'un matériau de base (5), caractérisés par une couche de revêtement de composé de polymère (7) formée sur la couche de revêtement
en titane (6), la couche de revêtement de composé de polymère (7) ayant une excellente
résistance à l'abrasion et excellente résistance aux rayures.
2. Ciseaux métalliques (1) selon la revendication 1, dans lesquels le matériau de base
(5) dans la poignée (4) présente une rugosité en surface modérée avec des petits creux
et des petites protubérances sur la surface, et la couche de revêtement en titane
(6) et la couche de revêtement de composé de polymère (7) sont stratifiées à une épaisseur
telle qu'elle ne détériore pas la rugosité en surface du matériau de base (5) de façon
à former des petits creux et des petites protubérances comparables à la rugosité en
surface du matériau de base (5), sur la surface de la couche de revêtement de composé
de polymère (7).
3. Ciseaux métalliques (1) selon la revendication 1, comprenant, en outre, une couche
de fond de composé de polymère (8) formée sur la couche de revêtement en titane (6),
la couche de fond ayant une excellente adhérence à la couche de revêtement en titane
(6), ladite couche de revêtement de composé de polymère (7) étant formée sur la couche
de fond de composé de polymère (8).
4. Ciseaux métalliques (1) selon la revendication 3, dans lesquels le matériau de base
(5) dans la poignée (4) présente une rugosité en surface modérée avec des petits creux
et des petites protubérances sur la surface, et la couche de revêtement en titane
(6), la couche de fondation de composé de polymère (8) et la couche de revêtement
de composé de polymère (7) sont stratifiées à une épaisseur telle qu'elle ne détériore
pas la rugosité en surface du matériau de base (5) de façon à former des petits creux
et des petites protubérances comparables à la rugosité en surface du matériau de base
(5), sur la surface de la couche de revêtement de composé de polymère (7).
5. Procédé pour produire des ciseaux métalliques (1), lequel est
caractérisé par :
une première étape de traitement par grenaillage des surfaces des matériaux de base
(5) dans la poignée (4) d'une paire de parties de ciseaux (2) de façon à les amener
à avoir une rugosité en surface modérée avec des petits creux et des petites protubérances
formés sur les surfaces,
une seconde étape de revêtir en titane la partie des ciseaux complets (2) de façon
à former une couche de revêtement en titane (6) dont l'épaisseur, associée à l'épaisseur
de toutes les autres couches sur lesquelles la couche de revêtement en titane (6)
est stratifiée, ne détériore pas la rugosité en surface du matériau de base (5),
une troisième étape de formation d'une couche de fond de composé de polymère (8) sur
la couche de revêtement en titane (6) dans la poignée (4) par dépôt au recuit, la
couche de fond (8) ayant une épaisseur qui associée aux épaisseurs de toutes les autres
couches sur lesquelles la couche de fond (8) est stratifiée ne détériore pas la rugosité
en surface du matériau de base (5) et présente également une excellente adhérence
à la couche de revêtement en titane (6),
une quatrième étape de formation d'une couche de revêtement de composé de polymère
(7) sur la couche de fond de composé de polymère (8) dans la poignée (4) par dépôt
au recuit, la couche de revêtement (7) ayant une épaisseur qui associée aux épaisseurs
de toutes les autres couches sur lesquelles la couche de revêtement (7) est stratifiée
ne détériore pas la rugosité en surface du matériau de base (5) et présente également
une excellente résistance à l'abrasion et une excellente résistance aux rayures, et
une cinquième étape de joindre la paire de parties de ciseaux (2) ensemble.