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Publication numberUS2697009 A
Publication typeGrant
Publication dateDec 14, 1954
Filing dateApr 15, 1949
Priority dateApr 29, 1948
Publication numberUS 2697009 A, US 2697009A, US-A-2697009, US2697009 A, US2697009A
InventorsIngraito Francesco
Original AssigneeRhodiatoce
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Device for pointing bristles
US 2697009 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Dec. 14, 1954 F. INGRAITO 2,697,009



United States Patent DEVICE FOR POINTING BRISTLES Francesco Ingraito, Verbania-Pallanza, Italy, assignor to Socita Rhodiatoce S. p. A., a corporation of Italy Application April 15, 1949, Serial No. 87,838

Claims priority, application Italy April 29, 1948 2 Claims. (Cl. 300-2) In brush-making, for a large number of applications, in particular for the making of shaving brushes, paint brushes and the like, natural bristles are preferred rather than monofilaments of natural, artificial or synthetic origin, because those bristles are sharp-pointed and split and impart to the articles mentioned, the desired properties, such as softness of contact of the ends of the brushes and better retention of the liquid they serve to convey.

Attempts have been made directly to obtain pointed artificial or synthetic monofilaments, but the processes for attaining this result are very hard to carry out.

it has also been proposed to grind the ends of various bristles of different characters. But this operation, which is ordinarily carried out on manufactured articles (paint brushes, shaving brushes, brushes in general) has the disadvantage of abnormally shortening, by excessive Wear, the peripheral bristles of these articles and of insufficiently affecting those of the central portion.

it has equally been proposed to sharpen natural monofilaments by combing them by means of emery-coated points, but the latter are of extremely diflicult manufacture.

Finally, it has been proposed to split or flower natural monofilaments by attacking them with pointed needles or sharp teeth, which penetrate into the matter and split it up lengthwise: however, those devices get blunt very quickly and it takes an abnormally long tlme to obtain monofilaments with satisfactory flowering, which moreover is rather irregular; whence it is advisable frequently to sharpen the needles and teeth, and even to replace these members, and such operations are costly.

Moreover, even with the last-mentioned process, it is impossible in practice to obtain monofilaments having the appearance and properties of natural bristles.

Now it has been found, as a result of the invention, that it is possible to impart to any monofilament or bristle of whatsoever origin, natural, artificial or synthetic, the desired refining and flowering, particularly with the appliances hereinbefore referred to,

The present invention relates to a method of treating natural, artificial or synthetic bristles, and provides the method and apparatus for subjecting the free ends of said bristles to the action of the needles-of a card wire band moving at high speed, in such a manner that the bristle ends be struck by the points of the needles, and of protracting this action until the bristles get sharpened and flowered at their ends. The invention further provides new natural, artificial or synthetic bristles characterized in that the ends of the individual bristles are sharp-pointed and flowered at the same time.

There are numerous models of cards adapted for the carrying out of the process according to the invention; those of the scratch-card type are the most suitable. The needles used with this typehave the pecularity of being made of sufliciently hard metal and of offering, nevertheless, a certain elasticity owing to their shape and to the manner in which they are fastened to their base at one of their ends; they are of practically constant cross-section and they are arranged parallel to one another. Cards are to be chosen of suitable type as'to their shape, thickness, free length of the needles, density, that is to say number per unit area, kind of base orsupport, etc. and those skilled in the art will be readily able to determine optimum conditions in each individual case as well as the most favourable speed and duration of operation.

The translatory movement of the card striking the ends 2,697,009 Patented Dec. 14, 1954 "ice their ends subjected to sharpening and if needed to flowering; this free length of bristle should in general be greater than the length of the card needles, and it may reach the total length of utilization of the sharpened and flowered bristles, as is the case, for example, if treatment of the bristles is effected while the said bristles are already mounted on the appliance. Following this free length, following the pressure exerted on the bristles during treatment pressure means here the eifort developed to cause the monofilaments to penetrate between the needles of the moving card), following the direction in which the bristles are exposed with respect to the movement of the card, there are obtained different lengths of refining. Flowering appears to get more and more general as the treatment according to the invention is protracted. At any rate, by controlling the different factors, notably the duration of operation, it is possible to obtain bristles either only sharp-pointed in general, or, on the contrary, both sharpened and flowered entirely, or even an assembly with bristles mostly sharpened and partly flowered.

It should be understood that the optimum operating conditions are essentially a function also of the material constituting the monofilaments as well as of their thickness; these conditions, however, can be easily determined by those skilled in the art.

It is easy to provide a supporting member for the bristles being controlled in such a way as to enable one to adjust the penetration of the bristles between the needles as well as to make the treatment according to the invention uniform for the whole of the bristles, by rotating about an axis parallel to their general direction, rotation being imparted to the whole of the bristles tied in bunches or mounted on the appliance.

If desired, the monofilaments may undergo external I cooling during the operation, for example by water or air-cooling but such arrangement proved to be superfluous in the majority of cases.

The treatment may be effected on straight bristles, whether they be cylindrical or frusto-conical, notably such as are obtained with certain manufactures; however, it is also possible to utilize non-rectilinear monofilaments, for example those having undergone previous treatment and permanent deformation, in particular those of undulated shape, which is eminently favorable to expansion if mounted on the appliance, and, moreover, entails better retention of the substances the bristles of the brush are designed to convey.

It is equally possible to utilize monofilaments having undergone previous auxiliary treatments, for example treatment of swelling, dyeing, pigmenting, fireproofing, or rendering water-shedding or insoluble.

Among the kinds of filaments or bristles to which the invention may be specially applied, there may be mentioned:

The hair of certain quadrapeds, for example horse-hair;

The filaments or bristles obtained from regenerated cellulose, possibly treated with phenoplasts or aminoplasts;

The filaments or bristles obtained from cellulose ethers or esters and more particularly from cellulose tri-estcrs;

The filaments or bristles obtained from polyvinyl derivatives, such as polyvinyl chloride pure or superchlorinated, vinyl chloride co-polymers with other vinyl derivatives (vinyl acetate, vinyl cyanide, vinylidene chloride), polyvinyl cyanide, polyvinylidene chloride;

The filaments or bristles from synthetic linear superpolycondensates such as superpolyesters, superpolyurethanes, and particularly superpolyamides, which superpolycondensates may be simple or mixed or treated with foreign substances such as aminoplasts; as to superpolyamides, particularly interesting results have been attained with superpolyhexamethyleneadipamide, superpolyhexa- 3 methylenesebacamide, superpolyamide from 6-aminoexanoic acid or ll-aminoendecanoic acid.

The accompanying drawing shows by way of example a preferred embodiment of a device for carrying out the invention.

In said drawing, 2 indicates a bristle holder carrying bunches of bristles 3 to be treated. This holder 2 is rotatable upon a supporting shaft 1 and longitudinallyadjustable along said shaft to vary the depth to which the bristles 3 are penetrated by the needles 4 of card wire bands mounted on and driven by the rolls 5 in the direction indicated by the arrows and in a plane substantially normal to the plane of rotation of the bristle holder 2. The drive assembly is conventional, and will be sufliciently understood from the more or less diagrammatic representation. Of course, the bristles might be held against a moving card by other means or by'hand, but the arrangement shown is particularly advantageous in that it enables absolutely regular or uniform treatment.

The monofilaments according to the invention find particularly interesting applications, as already stated, in brush-making, notably in the manufacture of paintbrushes, shaving brushes, varnish brushes and certain other domestic, sanitary or industrial brushes.

The invention has been hereinbefore described with particular reference to a moving scratch-card whose needles come to strike the ends of fixedly supported bristles. It is self-evident that recourse may be had to any appropriate device comprising metal needles having features like those of the said scratch-cards, that is to say, notably having constant cross-section, shape of circumflex accent, arrangement parallel to each other and one of their ends secured to a suitable supporting member. Moreover, the card may be fixed and the bristles displaced, or even the card and bristles may be simultaneously displaced in contrary senses.

It is surprising that by carrying out the process according to the invention, monofilaments are obtained which from the first are perfectly finished and free from any deterioration, although it might be expected that intensive processing would be necessary to cause the desired modifications and would entail such increase of temperature as to make the monofilaments melt or soften, viz. be depolymerized.

It is also quite unexpected that the utilization of needles having a constant cross-section, that is to say, having no sharp points at all, are able in particular to cause quick and regular splitting of monofilaments'constituted by such substances. It has even been found that it is possible to split the end of one individual bristle into a large number of parts (up to fifteen such parts could in one case be counted) and there was nothing to lead one to expect, a priori, such a result, which result, incidentally, is of considerable practical interest.

At last, and contrary to expectation too, it has been found that the needles have particular durability, resetting becoming necessary only after a long time of use.

The invention is illustrated, merely by way of indication, by the following examples:

Example 1 On the shaft of a 0.7 H. P. electric motor, adapted to turn at 2800 R. P. M., a wooden disk of 190 mm. diameter and 30 mm. thickness is fitted, which corresponds to a linear peripheral speed of about 1650 metres per minute. On the periphery of said disk a scratch-card is mounted, which is provided with steel needles shaped in the form of a Wide open V (about 130 angle), the two branches of which are each about 3 mm. long; the diameter of the needles is 0 of mm. and their density is 100 a cm. these needles have been clasped onto a soft foundation of about 2 mm. thickness and constituted by the assembly of four layers of a cotton fabric glued to each other and coated with a rubber film. In this way, the needles get a certain flexibility due to both the character of their foundation and their shape.

With bristles of polyhexamethyleneadipamide of 7 of mm. diameter after drawing, which were previously undulated in a manner known in itself, a bunch of 30 mm. diameter is formed. This bunch is mounted in a supporting member adapted to allow for turning the bunch within it about its axis; the bunch is previously adjusted in said support in such a way that the bristles are-arranged radially with respect to the disk, the free lengths of the bristles being '50 mm. and the distance between the free ends of the needles and the fastening points of the bunch nearest to the disk being 30 mm.

The motor is made to'run, while the needles are in contact with the ends of the bristles, and after 2 minutes, operation is stopped. At this time, it can be seen that the bristles have got their ends regularly sharpened over a length of about ten mm. and that almostall of them present at their ends each two, three, four or'even more sprigs of from 0.5 to 1 mm. length. A bunch of this kind is particularly suitable for the manufacturing of shaving brushes. V

Example 2 The operations of Example 1 are carried out with the following variations:

Bristles of polyhexamethylenesebacamide are used;

The said bristles, non-undulated, are 70 mm. long and are of frustoconical shape; large diameter 0 of mm.. small diameter of mm.;

A scratch-card is used provided with needles having square cross-section of of mm. side-length, presenting 200 needles a cmfl;

The motor (1 H. P.) turns at 3,200 R. P. M.;

The bristles are mounted, of courseat their larger ends, in the ferrule of a round paint-brush, which is rotated about its-axis during operation.

In this way, apaint-brush is obtained with sharp-pointed and flowered ends and, therefore, having excellent retention power for paint.

Example 3 Operation is carried out-as in Example 1, except:

Bristles of pure polyvinyl chloride are used, having of mm. diameter after drawing;

The motor turns at 2,500 R. P. M., and operation is made to last four minutes.

An ultimate bunch is obtained which from all points of view is analogous to a product as obtainable from natural bristles.

What is claimed is:

1. A device for pointing and flowering the free ends of monofilaments, comprising in combination a rotary cylindrical needle support, a group of metallic needles of substantially constant cross section and-smooth surfaces projecting radially from the periphery of said support, a discshaped member carrying at its outer perimetral annular portion the bristles to be pointed and flowered, means for adjusting the axial position of said disc-shaped member to bring the bristles to be pointed and flowered into contact with said needles, and means for rotating said needle support in a plane substantially normal to the plane of rotation of said bristle-carrying member.

2. A device for pointing and flowering the free ends of monofilaments, comprising in combination a plurality of rotary cylindrical needle supports equipped with metallic needles of substantially const'ant cross section and smooth surfaces projecting substantially radially from the periphery of said supports, eachof said needle supports being arranged upon'a shaft normal to the axes of rotation of said supports, a disc-shaped member rotatable about said shaft and carrying at its perimetral ring-portion the bristles to be pointed and flowered, means for adjusting the axialpositionof said member on said shaft to bring the bristles to be pointed and flowered into contact with said needles, and means for rotating said supports in a plane substantially normal to the plane of rotation of said bristle-carrying member.

References Citedin the file of this patent UNITED STATES PATENTS Number Name Date 425,044 McKirn Apr. 8, 1890 1,627,704 'Izawa May 10, 1927 2,207,156 Neville July 9, 1940 2,292,905 Smith Aug. 11, 1942 2,353,683 Martines July 18, 1944 FOREIGN PATENTS Number Country Date

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US425044 *Apr 17, 1889Apr 8, 1890Charles Emckim
US1627704 *Dec 29, 1925May 10, 1927Izawa RiichiroBristle-pointing device
US2207156 *Jun 9, 1937Jul 9, 1940Devoe & Raynolds Co IncArtificial bristle and method of making same
US2292905 *Jul 6, 1939Aug 11, 1942Du PontArtificial filament
US2353683 *Aug 30, 1943Jul 18, 1944Martines ReneMethod of sharpening files
DE631924C *Oct 13, 1934Jun 29, 1936Konrad BayerVerfahren zum Schlitzen oder Spalten von Rosshaaren, Pflanzenfasern u. dgl.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4279053 *Sep 24, 1979Jul 21, 1981E. I. Du Pont De Nemours And CompanyTri- or tetra-locular paint brush bristles
US5032456 *Sep 11, 1987Jul 16, 1991Newell Operating CompanyMicrocellular synthetic paintbrush bristles
US5786087 *Feb 22, 1995Jul 28, 1998Specialty Filaments, Inc.Honeycomb brush bristles and brush made therefrom
US6086373 *Nov 10, 1998Jul 11, 2000Schiff; ThomasMethod of cleaning teeth with a toothbrush with improved cleaning and abrasion efficiency
US6138314 *Jul 24, 1997Oct 31, 2000Whitehill Oral Technologies, Inc.Toothbrush with improved cleaning and abrasion efficiency
US6311359May 25, 1999Nov 6, 2001E.I. Du Pont De Nemours And CompanyTapered brush bristles with clay or silica additive and brushes made therefrom
US20100125963 *Nov 16, 2009May 27, 2010E. I. Du Pont De Nemours And CompanyMonofilament comprising hydrophilic agent
DE1168388B *Mar 30, 1961Apr 23, 1964Du PontZahnbuerste
DE3035860A1 *Sep 23, 1980Apr 2, 1981Du PontBorste
U.S. Classification300/2, 451/914, 451/55
International ClassificationA46D1/05
Cooperative ClassificationY10S451/914, A46D1/05
European ClassificationA46D1/05