US3794933A

US3794933A - Hair populated material

Info

Publication number: US3794933A
Application number: US00339044A
Authority: US
Inventors: T Moorhead
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-03-08
Filing date: 1973-03-08
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26

Abstract

The invention relates to a process for the manufacture of hairpopulated material, more particularly hair-pieces, by the embedment of natural or synthetic hair in a fluid base material and the solidification of the base material to anchor the hairs therein. Prior to embedment the hairs in a bundle are separated from each other by electrically charging the hairs in a bundle resulting in the mutual repulsion of the hairs from each other.

Description

United States Patent [191 Moorhead Q [451 Feb. 26, 1974 HAIR POPULATED MATERIAL 12/1959 Trissellu... 132/5 Primary ExaminerLouis G. Mancene Assistant Examiner-Greg0ry E. McNeil] Attorney, Agent, or FirmArmstrong & Wegner [5 7 ABSTRACT The invention relates to a process for the manufacture of hair-populated material, more particularly hairpieces, by the embedment of natural or synthetic hair in a fluid base material and the solidification of the base material to anchor the hairs therein. Prior to embedment the hairs in a bundle are separated from each other by electrically charging the hairs in a bundle resulting in the mutual repulsion of the hairs from each other.

24 Claims, 3 Drawing Figures HAIR POPULATED MATERIAL BACKGROUND OF THE INVENTION 1. Field of the Invention v This invention relates to the manufacture of hairpopulated material and is particularly concerned with the manufactureof hair-pieces.

2. Description of the Prior Art Hair pieces available hitherto conventionally incorporate, as an essential base component or part thereof, a fibrous sheet material, usually of reticulate structure, to which the ends of hair tufts or individual hairsare mechanically anchored in various ways in the course of manufacture. The production of such hair pieces, and particularly the step therein of fastening the hair to the base layer, involves complicated operations and also necessitates the employment of mechanical means of temporary retention, spacing, and control for the hair, also of considerable complexity. Even the best hair pieces produced by such methods are usually fairly complex multi-component structures, which may imitate to some extent, but do not closely resemble, the hair/skin combination of the natural scalp. It has also been proposed to clamp hair between a plurality of mechanical dividers to expose the ends 'of the hair and to dip the exposed ends into a liquid which is subsequently solidified. Such a procedure. is complex and involves a large manual content and skill in use.

SUMMARY OF THE INVENTION The objects of the present invention are two-fold. First to provide improved hair pieces whose structure can be made more closely to resemble that of the skin/- hair combination of the human scalp; second, to provide improved methods for the production of such hair pieces, which methods are convenient and simple to operate.

The main advantage of the invention include simplicity of the method and a product in which the spacing of the hair in the base can be very even whilst devoid of any sense of being located in rows, that is, the product has a very natural appearance. Further the product can be manufactured initially with a flat base, and later moulded to the shape of a scalp. This facility for postmanufacture moulding allows mass-produced hairpiece material to be readily and accurately formed to individual head shapes and requirements. The process of the invention requires no individual hair or hair-tuft threading or anchoring operations and a reticulate component in the base layer is not necessary (although one may be used, if desired, e.g. as a reinforcement for the base layer). There is excellent control over the spacing between individual hairs in the course of production without need for mechanical spacers, clamps or holding means, no adhesives are used to secure the hair in the base layer. The production operations are simple and rapid and the process may be carried out either with simple apparatus by an individual on a oneoff basis, or it may be adapted to mass production.

The present invention provides a method of producing hair-populated material comprising the steps of:

a. Electrically charging at least one bundle of hairs to cause exposed ends of hairs in the bundle to take up mutually repelled positions,

b. Embedding the exposed ends of the hairs in a base layer material which is in a softened or fluid state, and

c. solidifying the base layer material to secure the hairs therein.

The hairs in the bundle can be all natural hair, or natural hair blended with fibres of synthetic material or wholly fibres of synthetic material. A possible synthetic material is a modacrylic fibre of dernier, thickness and appearance appropriate for imitation hair.

The bundle of hair, prior to being electrically charged, is prepared in the way usual in the preliminaries to production of hair pieces and the like such as by combing to make the hairs roughly parallel and cutting to ensure that the hair ends to be mounted in the base layer material are approximately in the same plane at the end of the bundle. The bundle may contain the total amount of hair to be contained within the area of the base layer material to be populated. It is a feature and content of the hair bundle in conjunction with, and inrelation to, means limiting the repulsion of the hairs. It will be understood that whilst the preferred embodiment of the invention is concerned with, and particularly well adapted to, the embedding a number of hairs simultaneously and separate from each other, tufts of hair may also be mounted in a similar way, providing that they are kept discreet within the hair bundle and that they are capable of separately acquiring electrical charge as do the individual hairs in the preferred embodiment of the invention.

The bundle of hair may conveniently be connected to the source of electrical potential by firmly attaching an electrode of the source to that end of the bundle remote from that having the exposed hair ends. It is desirable that any method of electrode attachment should ensure good contact. The hair bundle may hang suspended from the electrode or separate means of sus- I pension may be employed. In any case the exposed hair ends will be substantially level and free from embedding in the base layer material. Whilst one bundle of hair may be used in the production of a hair piece in the method of the invention, for part-wigs or generally hair-populated base layers of considerable area, it may be more convenient to use a number of separate hair bundles all connected to the source of potential and disposed in a suitable pattern within an area defined by means limiting the repulsion of the hairs, especially those outermost in the bundle.

The source of electric charge may range from a simple apparatus, such as a Van de Graaff apparatus operated manually or by a small motor to generate the charge as required, to a permanent source of high voltage such as a suitable transformer operating off the mains within a rectified output. The magnitude of the optimum charge will vary with the type of set-up used, the resistivity of the hair (which in turn will be influenced by its chemical nature, i.e. whether natural or synthetic, and by its moisture content), with the atmospheric humidity, and other relevant extraneous factors. By way of illustration the potential of about 40,000 volts (as measured with a scalamp electrostatic voltmeter manufactured by W.G. Pye & Co. Ltd. of Cambridge) has been found suitable when produced by a small, hand-operated generator in the production of hair-piece material involving a bundle of natural hair approximately /2 inch diameter when compressed.

It is the main function of said means limiting the repulsion of the hairs, conveniently referred to as a peripheral guide means, to define in approximate shape and extent the area of the base layer material to be populated with hair from the bundles, and this function may be fulfilled without physical contact between the guide means and the hair. In this connection the guide means need not, although they may, enclose the bundle fully along the whole length of the bundle. The guide means may consist of a thin ring positioned around the bundle near its exposed end. The peripheral guide means may be shaped to impart a particular shape to the ultimate hair-populated area. The guide means may also be of non-physical form such as a magnetic or electrical force field. Peripheral guide means of physical form consisting for example of a ring or tube surrounding the hair bundle, may be of metal or non-metal material. The guide means will normally be connected to the same source of electrical potential as the charging electrode so, that the hairs of the bundle and/or their ends subsequently to be embedded, which are themselves maintained when charged in a substantially randomly spaced array, are also peripherally confined by repulsion at a distance from the charged guide means. The guide means may be modified to additionally control the hair within the bundle to impart special distribution characteristics to the hair-piece material being produced. Thus, for example, if the guide means consist of a ring, the ring may be suitably bridged, such as by a rid, if a hair-free line (to imitate a parting) is formed in the hair-piece material. It will be understood that the hair ends at the exposed end of the bundle will normally protrude below the lower boundary of the peripheral guide means so those ends may be embedded in the base layer material without contact between the peripheral guide means and the base layer material.

The base layer material should preferably be thermoplastic so that a hair piece may be made with an initially flat base and subsequently be moulded to a curved shape. However, the invention also extends to the implantation of the hair in pre-shaped base layer material. The base layer material may be temporarily softened by heat for receiving the hair end enabling them to penetrate through the layer. Softening may also be achieved by suitable solvent treatment (e.g. soaking in a swelling agent). Special compositions may also be used, for example a polyvinyl chloride plastisol. This is particularly useful in the process of the invention in that it is normally liquid (with consistency and viscosity variable within wide limits) and may be gelled to a homogeneous solid (which, however, remains thermoplastic) by application of heat followed by cooling. The composition of plastisols (which basically consist of a mixture of polyvinyl chloride resin particles and plasticisers with other comparatively minor additives if required) and methods of gelation are well known to those familiar with the appropriate art. The base layer material in its temporarily soft state will normally be presented on a suitable support to the hair ends maintained in randomly but substantially equally spaced disposition at the exposed end of the charged bundle, the actual spacing being very similar to hair spacing on the human scalp. The combination of the temporary rigidity im parted to the hair ends by mutual repulsion with the requisite degree of softness of the base layer material should be such as to enable the hair ends to penetrate readily through the base layer material to the desired depth. The penetration may be assisted by the pressure of a charge induced in or on the base layer material and its supporting tray by the proximity of the ends of the hair of the charged bundle. Normally the base layer will be comparatively thin about 0.7 1.3 mm and it may be advantageous to allow the hair ends to penetrate to the underside where their progress is stopped and protrusion prevented by the support for the base layer material. Such penetration affords a high degree of anchorage for the individual hairs. When the hair ends have been embedded in the way described, the base layer material is solidified either by cooling in the case of a temporarily heat softened thermoplastic or by removal of solvent (e.g. by heating) if originally solvent-softened, or by gelation through heating and cooling in the case of a polyvinyl chloride plastisol. In the plastisol case it is possible so to arrange the viscosity and surface tension that the hair after insertion into the base layer material and solidification of the latter is surrounded by a miniature depression resembling in this respect the corresponding feature of the natural scalp. It will be understood that the base layer material, can be suitably coloured (e.g. to imitate the colour of the skin) by the incorporation therein of colourants and that it may also incorporate fillers to modify the physical properties or to induce microporosity. In the case of polyvinyl chloride, such colourants and fillers may be conveniently mixed into the plastisol. The material of the base layer may incorporate a continuous reinforcement such as fabric, fibrous scrim, mesh or the like. In this embodiment such reinforcements are envisaged primarily as means of strengthening the base layer of the hair piece in which layer they may be totally occluded. However, the hair ends being inserted into the temporarily softened base layer material may, of course, pass through the reinforcement and/or come in intimate contact with it in the base layer. In another embodiment of the invention the reinforcement is largely coated, but not completely occluded, by the material of the base layer. Whilst the latter still serves as the embedding medium for the hair, the resulting structure is lighter, albeit not necessarily weaker, and can be characterised by inbuilt porosity governed largely by the degree of occlusion of the reinforcement and the method of application.

BRIEF DESCRIPTION OF THE DRAWINGS Some embodiments of the invention are illustrated by the following examples which are in no way limitative and which are described with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of a reinforced base layer material.

FIG. 2 is a plan view of a reinforced base layer material using a reticulated reinforcement the aperture of which are partially occluded.

FIG. 3 is a diagrammatic representation of an apparatus for carrying out the method of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, there is shown a base layer material with a fibrous scrim reinforcement 11. The material can have a variety of shapes. Frequently a circular shape is used. The material 10 can be made using any of the methods referred to above. As shown in FIG. 1 the reinforcement is wholly occluded.

FIG. 2 is similar to FIG. I with the exception that the reinforcement 11 is only partially occluded thereby leaving irregular apertures for ventilation l2 and a body 13 for the embedment of hairs.

In FIG. 3 there is provided a Van de Graaff generator comprising a charge generating belt 14, pick up brush l5 and bow shaped electrode 16. Below the electrode 16 and spaced from it there is a hot plate 17 and a tray 18 having a rim l9 curved in section to reduce charge dissipation from the rim. The tray is shown containing base layer material 20 in a softened form.

Depending from the electrode there is support 21 terminating at a peripheral guide means in the form of a ring 22. The ring 22 could be made of cardboard and the support 21 could be threads. The ring 22 could be split and pivoted, rather in the manner of calipers, so that it can easily be located round a bundle 23 of hairs having one end 24 of the bundle connected with the electrode 16 and the exposed end 25 of the bundle terminating above the tray 18. The generator has an earthing electrode 26. The bundle 23 can be attached to the electrode in a number of ways. In an elementary way the bundle end 24 is held against the electrode by an adhesive tape. In another way the electrode is perforated and the bundle carries a wire which can be passed through the perforations and bent over to support the weight of the bundle. In yet another way the electrode can have a comb like surface in which the bundle is pressed.

Electrical potential could be imparted to the base layer opposite in sign to that of the hair ends, so that the potential difference betweenthe hair end and the base layer with its tray is increased beyond the difference available with the same magnitude of charge on the hair if the tray is merely earthed. The separate charging of the tray and the base layer which may be effected e.g. by a suitable generator, could, if controllably variable, provide further means of final adjustment of the disposition of the hair ends, as well as increasing ease of penetration due to the increased potential difference.

The invention will now be further described with reference to the following examples:

EXAMPLE I A bundle of natural hairs was combed to make the hairs roughly parallel, and tied at one end. The other end of the bundle, that is the exposed hair ends, was trimmed to make the exposed hair ends level. The number of hairs in the bundle 23 so formed was such as to give a hair population density of approximately 250 hairs per square centimetre when secured in the base layer material with the total hair-populated area in the fonn of a circle of about 6 cm. diameter. The hair bundle 23 was attached at the tied end 24 to the electrode in the form of a bowl 16 of the generator. The exposed end of the free-hanging bundle was surrounded by the cardboard ring 22, 7 cm in diameter suspended from the electrode bowl 16 by threads 21. The tray 18 of metal and I5 cm in diameter held a layer 20 approximately 0.1 cm thick ofa pvc plastisol and positioned on the hot plate 17 (initially switched off), directly under the ring 22 coaxially with it. The generator was operated manually for a short time generating on the electrode bowl a potential of approximately 35,000 volts (as measured by the voltmeter previously mentioned). The hairs in the bundle and the ring 22 acquire charges, causing the hair portions within the free end of the bundle to straighten and become spaced within the area defined by the ring. The tray and hot-plate were then raised the requisite distance for the hair ends to penetrate the plastisol layer. The hot-plate was switched on causing the tray and plastisol to heat and the latter to set in the manner usual in the initial stages of gelation of plastisols. The bowl 16 was then discharged by means of earthing electrode 26, the hair bundle was detached from it and removed with the tray into an oven to complete the gellation of the pvc by heating for 20 minutes at C. The resulting product consisted of a flexible, thin thermoplastic pvc base layer populated over a circular area with randomly and substantially equally spaced hairs firmly embedded in the pvc layer and penetrating the layer almost to the inner side, the ends being visible on that side near the surface owing to the partial transparency of the base layer material.

Where, because of the nature or condition of the hair, it may be desirable to take special precautions against possible degredation through heating in the oven, the gelation of the pvc base layer may be completed by heating that layer in situ in the tray, either on a hot-plate or by exposing the underside to radiant heat, or by any other convenient method.

EXAMPLE 2 A hair piece was prepared as in Example 1 up to and including the initial set of the plastisol after insertion of the hair ends therein. At this stage the base layer material 20 was carefully removed from the tray 18 (with the hair in position) and fastened around the periphery to a positive casting of the area of the scalp ultimately to be fitted with the hair piece. The surface of the casting had been treated with a thin layer of a siliconebased parting agent. The assembly was placed in an oven, with the hair loosely supported in a partly stretched condition, and heated at C for 25 minutes. This treatment fully gelled the base material of the hair piece which also partly collapsed in its hot thermoplastic state to conform to the contours of the positive casting. The hair piece was removed and finally trimmed after cooling.

Thecasting was prepared, in the known way, by first taking an impression with a composition-type dental material, of the bald spot on the scalp. As is known, an alginate impression compound or plaster of Paris may also be used. A positive cast in plaster of Paris was then made from the impression in the usual way.

Certain modifications can be adopted. For example, instead of cutting the hair in a bundle to length, the hair can be scorched to length with a hot plate. However, in general this is not preferred as it tends to form crumbly ends to the hair which should be removed by brush ing or other means.

Natural hair tends to have an overall taper and it is preferred that the widest end is embedded.

The base layer material may be a powder or fine granules and the term fluid state is intended to include material in such a form. The powder or granules could be partly fluidised by known fluidising means.

It is envisaged that a charge could be induced on a bundle of hair by applying a charge only to the base layer material and its supporting tray. This would simplify the support of the hair which could be a simple insulated clamp at the top end of the bundle. It is seen that there are at least three possible charge and potential applying zones, namely, the zone of the held end" of the hair bundle, the zone of the peripheral guide means and the zone of the base layer material and its tray and regulation of said charge and potential can be effected in a number of ways to create exposed hair ends in mutually repelled positions for embedding in a base layer.

1 claim:

1. A method of producing hair-populated material comprising the steps of:

a. Electrically charging at least one bundle of hairs to cause exposed ends of hairs in the bundle to take up mutually repelled positions;

b. softening or liquifying a base layer material;

c. Embedding the exposed ends of the hairs in the base layer material which is in the softened or fluid state; and,

d. Solidifying the base layer material to secure the hairs therein.

2. The method of claim 1 further including limiting the mutual repulsion of the hairs in the bundle.

3. The method of claim 2 wherein limiting the mutual repulsion includes surrounding the bundle at the exposed ends of the hair with a charged body, the body having a charge of the same polarity as the hairs.

4. The method of claim 1 wherein the charged hairs in the bundle of hairs are subjected to a charged body such that the density of population of the hairs in the bundle is non-uniform at the exposed ends of the hairs.

5. The method of claim 1 wherein the base layer ma terial is solidified flat and further including subsequently shaping the base layer to conform to a non-flat surface.

6. The method of claim 5 wherein the base layer material is thermoplastic which can be subsequently shaped by heating.

7. The method of claim 1 further including charging the base layer material when in the softened or fluid state, such that the exposed ends of the hairs are attracted to the base layer material in the course of embedding the exposed ends in the material.

8. The method of claim 1 wherein a reinforcement is included in the base layer material.

9. The method of claim 1 wherein the hairs in the bundle are all natural hair.

10. The method of claim 1 wherein the hairs in the bundle are natural hair blended with fibres of synthetic material.

11. The method of claim 1 wherein the hairs in the bundle are wholly of fibres of synthetic material.

12. The method of claim 11 wherein the fibres of the synthetic material are a modacrylic.

13. The method of claim 1 wherein a. The base layer material is softened for receiving the exposed ends of the ahir by heating; and

b. The base layer is cooled to create the solid state.

14. The method of claim 1 wherein a. The base layer material is softened for receiving the exposed ends of the hair by application of a solvent; and

b. The solvent is expelled to create the solid state.

15. The method of claim 1 wherein the base layer material is a liquid polyvinyl chloride plastisol and wherein solidification includes heating and then cooling the plastisol.

16. The method of claim 15 wherein the viscosity and surface tension of the plastisol is selected so that, on solidification, the individual hairs are surrounded by a depression.

17. The method of claim 1 wherein the base layer material has a thickness in the range of 0.7 to 1.3 mm.

18. The method of claim 1 including penetrating the exposed ends of the hairs to the underside of the base layer material.

19. The method of claim 1 including coloring the base layer material.

20. The method of claim 1 including adding fillers to the base layer material.

21. The method of claim 20 including selecting the fillers to introduce microporosity.

22. The method of claim 8 wherein the reinforcement is meshlike and the base layer material occludes the reinforcement at the region of intersections in the mesh to leave openings through the base layer material remote from said intersections.

23. An apparatus for producing a hair populated material comprising an electrostatic generator having electrode means for securing a bundle of hairs by one end so that the hairs in the bundle hang downwardly and for charging the bundle of hairs; and chargeable peripheral guide means below the electrode for surrounding the unsecured ends of the bundle of hairs wherein the area populated by the exposed ends of the hair is controlled by charging the hairs and the guide means.

24. Apparatus as claimed in claim 23 further including tray means to support a base layer material, the tray means having a rim curved in section to reduce charge dissipation tendencies from the rim.

Claims

1. A method of producing hair-populated material comprising the steps of: a. Electrically charging at least one bundle of hairs to cause exposed ends of hairs in the bundle to take up mutually repelled positions; b. softening or liquifying a base layer material; c. Embedding the exposed ends of the hairs in the base layer material which is in the softened or fluid state; and, d. Solidifying the base layer material to secure the hairs therein.

5. The method of claim 1 wherein the base layer material is solidified flat and further including subsequently shaping the base layer to conform to a non-flat surface.

9. The method of claim 1 wherein the hairs in the bundle are all natural hair.

13. The method of claim 1 wherein a. The base layer material is softened for receiving the exposed ends of the ahir by heating; and b. The base layer is cooled to create the solid state.

14. The method of claim 1 wherein a. The base layer material is softened for receiving the exposed ends of the hair by application of a solvent; and b. The solvent is expelled to create the solid state.

19. The method of claim 1 including coloring the base layer material.

20. The method of claim 1 including adding fillers to the base layer material.