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(11) | EP 1 712 145 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method for manufacturing hair prostheses |
| (57) A method (1) for manufacturing hair prostheses (2), which comprises the steps of:
acquiring (5) the coordinates of all the points of the surface of a cast of the skull
of the user (3) and storing them (6); generating (7) a replica of the skull of the
user (3) on which a fringe of hair is placed (8); and spreading (9) onto the replica
a polyurethane cap (10), on which a silicone cap is distributed (11); applying (13)
to the replica a sponge-like layer and fixing (14) the pair of caps onto the sponge-like
layer; implanting (15) a plurality of hairs; separating (16) the pair of caps, with
the implanted hair, from the sponge-like layer and overturning (17) the pair so as
to direct outward the roots of the hair, in order to spread a layer of fixing resin;
removing (19) the silicone cap; applying (20) a lining inside the polyurethane cap;
and polymerizing (21) in an oven the resulting prosthesis (2).
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[0001] The present invention relates to a method for manufacturing hair prostheses constituted by real or synthetic hair implanted on a base which replicates human skin and is placed in contact with the scalp of the user.
[0002] Hair prostheses are currently made of highly sophisticated material and increasingly use only real hair.
[0003] The need to work on these sophisticated materials and on hair with extreme skill entails a generally rather long time between the order from the user and the delivery of the prosthesis.
[0004] The various operations must in fact be performed by different individuals, who often do not even work within a same facility.
[0005] Substantially, in order to produce a high-quality hair prosthesis, each step of production must be followed by a specialized technician, because the processes are complicated.
[0006] The aim of the present invention is to obviate the cited drawbacks and meet the mentioned requirements, by providing a method for manufacturing hair prostheses which is easy to provide in practice and can be performed completely in a relatively short time even by personnel which is not highly specialized.
[0007] Within this aim, an object of the present invention is to minimize the number of operations requiring the presence of the user, which is a great advantage both for the user and for the manufacturer.
[0008] Another object of the present invention is to minimize the number of times that the user has to be subjected to the taking of a cast of his or her skull.
[0009] Another object of the present invention is to provide a method with a sequence of operations which is simple, safe in use, effective in operation, and has a relatively low cost.
[0010] This aim and these and other objects which will become better apparent hereinafter are achieved by the present method for manufacturing hair prostheses, which consists in taking a cast of the skull of the user with the references of the hairless area; acquiring, with a sensor, the coordinates of all the points of the surface of the cast, including the demarcation line between the hairless area and the remaining area, and storing said set of coordinates in a storage unit; generating a replica of the skull of the user, by machining a solid body, according to the respective set of coordinates previously stored in said unit; placing on the replica of the skull, along the entire demarcation line, a fringe of hair and spreading onto said replica a thin layer of polyurethane resin in order to form a polyurethane cap, the extent of which corresponds to the part of the head to be covered with said prosthesis, said area being delimited by said demarcation line; distributing on said polyurethane cap a thin layer of silicone material, which forms a silicone cap; separating the pair of caps from said replica of the skull; applying to said replica of the skull a layer of sponge-like material; fixing the pair of caps onto said layer of sponge-like material; implanting a plurality of hairs in the pair of caps by means of an appropriate microneedle in an oblique direction which corresponds to the direction of the hairline in the various regions of the scalp; separating the pair of caps, with the implanted hair, from said sponge-like layer and overturning said pair so as to direct outward the roots of said hair, oriented in said oblique direction, in order to spread on said oriented roots a layer of fixing resin; lifting from the replica of the skull the pair of caps and removing the silicone cap; applying a suitable lining inside the polyurethane cap; polymerizing in an oven the resulting prosthesis.
[0011] Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of a method for manufacturing hair prostheses, illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1 is a block diagram which is representative of the method according to the invention;
Figure 2 is a block diagram of the use of the prostheses obtained with the method according to the invention;
Figure 3 is a sectional side view, taken along a vertical plane, of a prosthesis obtained with the method according to the invention.
[0012] With reference to the figures, the reference numeral 1 generally designates a method for manufacturing hair prostheses.
[0013] The method 1 for manufacturing hair prostheses 2 is constituted by a sequence of operations, some of which must be performed in the presence of a user 3: the method 1 inherently entails the advantage of minimizing the number of operations requiring the presence of the user 3, which is a great advantage both for the user 3 and for the manufacturer.
[0014] First of all, it is necessary to provide 4 a cast of the skull of the user 3 with the references of the hairless area: the easiest cast to take is made with plaster (although it is conceivable to replace the plaster with rapidly crosslinking polymers which are not toxic upon skin contact). In this case, the user 3 must undergo a series of procedures, during which he will get dirty and will have to remain motionless for a rather long time: the need to minimize the number of times that the user 3 has to undergo this procedure is one of the goals of the method 1, since as will become apparent hereafter, the possibility to store the coordinates of the skull of the user 3 and retrieve them when necessary is employed.
[0015] Once the cast has been taken, step 4, it is necessary to acquire, step 5, the coordinates of all the points of the surface of said cast (by means of an appropriate sensor), including the demarcation line between the area that corresponds to the hairless area on the head of the user 3 and the remaining area. In a preferred embodiment, the coordinates are acquired by using a probe, the acquisition end of which can move on the surface of the cast by being guided so as to trace all the points of the surface of said cast. These coordinates must be stored, step 6, within a single file in an appropriate storage unit: this file which contains the set of coordinates will also comprise a code suitable to associate it uniquely with the user 3 to which it corresponds. Generally, the storage unit is a computer (a personal computer, in a preferred solution) which is connected (with the interposition of at least one suitable interface) to the probe and manages its operation.
[0016] The stored sets of coordinates can be retrieved at any time to send them to a numeric-control milling machine which is functionally associated with the personal computer: by means of this milling machine, it is possible to generate, step 7, a replica of the skull of the user 3 by milling a solid body constituted by a material which is substantially of the polymeric type.
[0017] On the replica of the skull, along the entire demarcation line between the portion that corresponds to the area covered with hair and the hairless area, it is necessary to distribute, step 8, a fringe of hair, which is designed to make less conspicuous the discontinuity between the hair of the user 3 and the hair of the prosthesis being manufactured. On the replica of the skull, taking care to cover the previously distributed fringe, it is necessary to spread, step 9, a thin layer of polyurethane resin in order to form a polyurethane cap 10, the extent of which corresponds to the part of the head to be covered with the prosthesis 2, said area being indeed delimited by said demarcation line. The polyurethane cap 10 must have a maximum thickness at its central region and a minimum thickness along the outside perimeter (as shown in Figure 3) in order to make the presence of the cap 10 undetectable when the user 3 wears the prosthesis 2.
[0018] One proceeds by distributing, step 11, on the polyurethane cap 10a thin layer of silicone material, which forms a silicone cap.
[0019] Once the pair of caps has been separated, step 12, from the replica of the skull, it is necessary to apply, step 13, on the replica of the skull a layer of sponge-like material: this is substantially a thin layer of a material such as sponge rubber which is distributed uniformly.
[0020] The pair of caps must then be fixed, step 14, again onto the layer of sponge-like material, and a plurality of hairs is implanted, step 15, therein by means of an appropriate microneedle: the implantation must be performed in an oblique direction with respect to the surface of the pair of caps, a direction which corresponds to the hairline direction in the various regions of the scalp on the head of the user 3.
[0021] After all the hairs have been implanted, the pair of caps with the implanted hairs must be separated, step 16, from the sponge-like layer and overturned, step 17, so as to direct outward the roots of the hairs (fitting the overturned pair again onto the replica of the skull), in order to spread onto it a layer of fixing resin.
[0022] At this point, the inverted pair of caps is lifted, step 18, from the replica of the skull and the silicone cap is removed, step 19.
[0023] One proceeds by applying, step 20, inside the polyurethane cap 10 a suitable lining and by polymerizing, step 21, in an oven the prosthesis 2 thus formed.
[0024] The method 1 is of particular interest in relation to the fact that it can be repeated easily in order to provide a plurality of prostheses designed to cover areas of the skull of the user having different sizes. When the method is complete, it is in fact sufficient to check, step 22, whether other prostheses 2 are needed and, if they are, arrange again the fringes of hair (as in step 8) on the replica of the skull and repeat the method 1. The purpose of providing a plurality of prostheses 2 is linked to the possibility to have a first prosthesis 23 which comprises a hair-covered area which is smaller than in a second prosthesis 24, and so forth, including a last prosthesis 25 which has the largest hair-covered area.
[0025] In this way, it is possible to provide (A) the user 3 with the first prosthesis 23 for a first period, during which he can become accustomed to seeing his own image altered by the prosthesis 23. Once this first period has ended, it is necessary to replace (B) the first prosthesis 23 with the second prosthesis 24 and leave the second prosthesis to the user 3 for a second period. This process entails several cycles of replacement of the prosthesis in use with the next one among the ones that have been manufactured, once the corresponding period has ended, leaving the next prosthesis to the user 3 for a suitable period.
[0026] Only the last prosthesis 25 (the one with the maximum covering area) is provided (N) indefinitely, so that the user 3 does not see his image change overnight, struggling to accept the change.
[0027] Before arranging the hair on the replica of the skull and on the pair of caps, it is convenient to wash the hair with shampoo and water at a temperature between 25°C and 45°C, eliminating the hair that are defective and dividing them by groups having uniform characteristics: accordingly, locks of hair which are uniform in terms of color and type (straight, curly) are provided, allowing easier use.
[0028] Once the final polymerization has been performed, it is convenient to provide a distributed microperforation on the prosthesis 2, in which the holes 26 are mutually offset: in this way, breathability is allowed and the comfort of the user 3 is improved.
[0029] The polyurethane resin with which the caps 10 are manufactured comprises, within the base mix, suitable colors in order to give the polyurethane cap 10 the same color as the skin of the user 3.
[0030] Of course, the hair on the prosthesis 2 is distributed in accordance to the color distribution and orientation of the hair of the user 3.
[0032] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
[0034] In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.
[0035] Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.
[0036] In practice, the materials used, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.
[0037] The disclosures in Italian Patent Application No. BO2005A000246 from which this application claims priority are incorporated herein by reference.
[0038] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.
taking (4) a cast of the skull of the user (3) with the references of the hairless area;
acquiring (5), with a sensor, the coordinates of all the points of the surface of the cast, including the demarcation line between the hairless area and the remaining area, and storing (6) said set of coordinates in a storage unit;
generating (7) a replica of the skull of the user (3), by machining a solid body, according to the respective set of coordinates previously stored (6) in said unit;
placing (8) on the replica of the skull, along the entire demarcation line, a fringe of hair and spreading (9) onto said replica a thin layer of polyurethane resin in order to form a polyurethane cap (10), the extent of which corresponds to the part of the head to be covered with said prosthesis (2), said area being delimited by said demarcation line;
distributing (11) on said polyurethane cap (10) a thin layer of silicone material, which forms a silicone cap;
separating (12) the pair of caps from said replica of the skull;
applying (13) to said replica of the skull a layer of sponge-like material;
fixing (14) the pair of caps onto said layer of sponge-like material;
implanting (15) a plurality of hairs in the pair of caps by means of a microneedle in an oblique direction which corresponds to the direction of the hairline in the various regions of the scalp;
separating (16) the pair of caps, with the implanted hair, from said sponge-like layer and overturning (17) said pair so as to direct outward the roots of said hair, oriented in said oblique direction, in order to spread on said oriented roots a layer of fixing resin;
lifting (18) from the replica of the skull the pair of caps and removing (19) the silicone cap;
applying (20) a suitable lining inside the polyurethane cap;
polymerizing (21) in an oven the resulting prosthesis (2).
providing (A) to the user (3) the first prosthesis (23) for a first period,
replacing (B) the first prosthesis (23) with the second prosthesis (24), once said first period has ended, and leaving the second prosthesis (24) to the user (3) for a second period,
replacing the prosthesis being used with the next one among the ones that have been manufactured, once the corresponding period has ended, and leaving the next prosthesis to the user (3) for a respective period,
supplying (N) the last prosthesis (25) to the user (3) indefinitely.
before arranging (8) the hair on the replica of the skull and on the pair of caps,
washing the hair with shampoo and water at a temperature between 25°C and 45°C, eliminating the hairs found to be defective,
dividing the hairs by groups having uniform characteristics.
providing said layer of polyurethane resin, arranged on said replica of the skull, with a maximum thickness at its central region and a minimum thickness along the outside perimeter.
performing on said prosthesis (2) a distributed microperforation in which the holes (26) are mutually offset.
mixing, within the polyurethane resin with which said caps (10) are produced, suitable colors in order to give the polyurethane cap (10) the same color as the skin of the user (3).
distributing the hair on the prosthesis (2) in accordance with the color distribution and orientation of the hair of the user (3).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description