US2468908A - Loom temple - Google Patents

Description

May 3, 1949.

1'. c. WOODMAN 2,468,908

LOOM TEMPLE Q Filed Sept. 16, 1943 FIG. 1

KIN OF FILM- FORMING MATERIAL WITH FIBRES EMBEDDED THEEEIN.

PARTIALLY IMPREGNATED FIBRES.

FRTIALLY IMPREGNATED FIBRES FIG. 3

MA T SURFACE.

PARTIALLY IMPREGNATED FiBPES,

T C -WOODMAN mvsunx film-forming material.-

' mediate neighbourhood the required degree of the body by the dope,

Patented 3, 1 949 UNITED STATES rare LooM TEMPLE Thomas Clifford Woodman,

London, England, as-

signor, by mesne assignments, to Celanese Corporation of America,-a corporation of- Delaware Application September 16, 1943, Serial No.

In Great Britain September 28, 1942 '1 Claim. (01. 139294) This invention relates to artificial materials and is especially concerned with the production of resilient members'that may be used in substitution for rubber in many of the applications of that substance.

According to the present invention, a resilient member comprises a shaped body of fibres that areassociated by being felted or matted together, said body being partially impregnated with a The impregnation is partial in the sense that, except perhaps in the imof the surface, the fibres are only coated to a greater or less degree with the film-forming material, the spaces betweenthe fibres not being. completely filled up so as to embed the fibressolidly on the material; at the surface of the body, however, the film-forming material may form a skin, rendering the-surface of the member impervious The degree of partial impregnation may, and usually will diminish from the surface of the member inwards, and a penetrating into the I duly brittle.

core of fibres may be left within the member that is not impregnated. with the film-forming material. By retaining unfilled within the member the spaces between the fibres forming the shaped body, the member thus constituted retains in a large measure the resilience of the body of fibres from which it ismade, while the partial impregnationof the body, besides itself wear and disintegration. Where an impervious skin is formed and retained on the the member a smooth and impervious rubberlike surface.

The partial impregnation of taining the film-forming material in solution or suspension for a period long enough to bring about and then removing the contributing to' the resilience of the member, protects it against body this gives,

the body may conveniently be effected by, dipping it in a dope conpartial impregnation of volatile constituents of the dope by drying. The

penetration of the body of fibres by the dope may be encouraged by subjecting the'body to a vacuum before immersing it in the dope. Thus the body, or a batch thereof, may be enclosed in a vacuum chamber which is then evacuated, the dope being allowed to run into the evacuated chamber in sufilcient quantity to submerge the body being treated. When a sufiicient quantity has been run in, the vacuum may be released so that atmospheric pressure, or an applied superatmospheric pressure, forces the dope into the body; The excess dope is then run off, and the body removed for drying. On drying, some shrinkage of the body may occur, which mustv impregnation may be of theorder' of 0.2-0.4 gramcloth-engaging parts of loom temples.

be allowed for in calculating the size of the body of fibres employed. I

Ifdesired, the partially impregnated body may,

after drying, be dipped a second'time or as many times as required so as togive added protection; in this case the layer of film-forming material deposited by the first dipping prevents the dope the second dipping. If necessary, having regard to the nature of thefilm-forming material employed,- the dope may contain a plasticiser for the film-forming material to prevent the film or coating on the outside of the member from being un- The resilient members formed in accordance with the present invention may be used in substitution for members made of rubber and the. like and-intended to serve as stops or buffers to absorb shock or pressure. Thus, forexamplathe resilient members may be made in the form of door-stops and like shock-absorbing buflers, re-

silient gaskets, shock-absorbing mountings and Vibration-absorbing,pads. The smooth and impervious nature of the surface of the member is of particular value where resistance to the absorption of moisture is of importance for hygienic or other reasons, e. g. in buffer pads for watercloset seats. Several examples of uses to which members formed in accordance with the present invention may be put occur in textile looms in which, for

vthe resulting smooth matt surface acting, like rubber, to grip the edges of the fabric being woven, and to hold the fabric out to its full width. The fibrous body that is partially impregnated for the purpose of the present invention may con- 'sist of or contain animal fibres, such as'wool,

felted together or of artificial'filaments or fibres matted together to form a shaped body, or it may I be a mixture of animal and artificialor other fibres. The average density of the body before per cc. corresponding in the case of a wool felt,

T OFFICE? body of fibrous material in to a proportion of solid fibre to voids of about 1530%.

The mass may be shaped, to the form required in the resilient member to be produced, by any suitable means, e. g. by cutting a previously formed'slab or block of matted fibres, e. g. felted wool fibres, to the required shape, or by felting the fibres together by beating or hammering in the desired form in the first instance. Where a continuous skin is required on the surface of the fibres should be formed in the desired shape prior to the partial impregnation thereof, since the impregnation and drying of the body fixes the form of the body. Where a continuous skin is not required, however, resilient members may be cut from blocks or thick sheets of felted fibres, partially impregnated in the manner of the invention. I

As the dope with which the shaped body of fibres is partially impregnated, solutions or suspensions having a basis of various film-forming materials may be used. Thus, for example a solution in a volatile solvent of cellulose acetate or some other thermoplastic derivative of cellulose may be employed, e. g. other cellulose esters such as cellulose propionate and cellulose butyrate, mixed esters such as cellulose acetatepropionate, cellulose acetate-butyrate or cellulose acetate-stearate, and cellulose ethers such as ethyl, benzyl and hexyl cellulose. An example of substances of this kind which may, alternatively, be applied in the form of a latex or similar aqueous suspension is a complex of ethyl cellulose with a substantial proportion, say '75 to 100% of its weight, of a plasticiser such as castor oil or tricresyl phosphate. Other film-forming materials that may be applied in the form of a solution in an organic solvent are the polymerised vinyl compounds, e. g. polyvinyl acetate, a copolymer of vinyl acetate and vinyl chloride, or a polyacrylic ester. These substances, like the ethyl cellulose complex mentioned above, have a somewhat rubbery consistency which increases the resilience arising in the product from the partial character of the impregnation. Other rubber-like bodies which may be employed, preferably in the form of an aqueous suspension or latex, are polyvinyl chloride, polyvinylidene and polyisobutylene, suitably plasticised, e. g. with tri-cresyl phosphate, or polymers of dienes including the polymers of halogenated dienes such as butadiene and chloroprene, or co-polymers thereof with mono-olefinic compounds such as styrene, acrylonitrile and isobutylene, or even rubber itself and its derivatives, it being understood that the quantity of rubber involved would be far less than in a resilient member made of solid rubber or of fibrous or other core surrounded by a thick layer of solid rubber.

The proportion of film-forming material dissolved or suspended in the dope should be such as to give a dope fluid enough to penetrate .below the surface of the fibrous body to the desired extent, the body being removed from the dope before excessive impregnation has occurred. Thus the dope, and the time and conditions of its application may be such that a quantity of dope equivalent to 50-95% of the voids in the fibrous body is applied, leaving an unimpregnated core, the weight of film-forming material (including plasticiser) being, for example, from -25% or more of the weight of the fibres according to the density of the felt, and the proportion of the voids filled with the dope.

If desired, efiect materials of various kinds may be added to the dope to produce particular effects on the surface of the members. Thus dyes, pigments, abrasive materials, fire-retardants or the like may be added in this manner. Or again, solid lubricants, such as graphite, e. g. of a particle size of 5'20 microns, or talc, may be added to facilitate internal movement in the resilient member when it is distorted. These materials, or other effect materials in the form of insoluble powders, may be added not only to the dope but, in addition or alternatively, to the body of fibrous material before impregnation. This may be done, for example, by passing a current of air, laden with the powder to be incorporated, through the body so as to carry the particles into the body. In such an operation the fibrous body may become unduly compacted, and it may be necessary to raise or loosen it in a separate subsequent operation.

The following are given by way of example of the manner in which the invention may be carried out.

Example I Shaped blocks of wool felt having a length of 6 and a section A" square having a' density of 0.38 gram per 0. c. are enclosed in a vacuum chamber which is. then evacuated. A quantity of dope sufficient to cover the blocks (which are prevented from floating by suitable means) is then run into the chamber, the dope having the following composition: Cellulose acetate grams 800 Plasticiser (triacetin or diethyl or dimethyl phthalate) grams Acetone ccs 5000 Benzene ccs 2800 Ethyl alcohol ccs 2200 Diacetone alcohol ccs 400 When the blocks are covered, the vacuum is released, so that atmospheric pressure forces the dope into the blocks. The blocks are then re- 0 moved and drained of excess dope, and dried.

The resulting blocks have an increased weight corresponding to an addition of 16% by weight of film-forming material, based on the weight of the original fibres. The blocks so formed are suitable for conversion into the cloth-engaging parts of loom temples, for which purpose they are bored for the reception of a spindle, to which they are attached by means of an adhesive having a nitrocellulose base. The blocks are then turned down to a diameter of about Example 11 Cellulose acetate grams 800 Plasticiser do 160 Acetone ccs. 4900 Benzene ccs. 2230 Ethyl alcohol ccs. 2480 Ethyl lactate ccs. 800

The dope carries the graphite into the interstices of the block, and the resulting product is more resilient in character, apparently by reason of lubrication of the contacts between the fibres in the product.

dicate the depth of partial impregnation of the body of felted fibres, the unimpregnated core, and the formation of an impervious skin on the surface of the article. In the article shown in Fig. 1 this skin is retained, so as to resist the absorption of moisture. In the loom temple roller. shown in Fig. 3, however, a matt, gripping sur-.

face is required, and the skin formed on the block shown in Fig. 2 is cut away during the formation from the block of the cylindrical body shown in Fig. 3. Said roller is provided withv the average density of said core being from 0.2 to 0.4 gram per c. c., said member having a bore for the reception of a spindle and suitable for employment as the cloth-engaging part of a loom temple roller.

moms cur'roan woonmin.

REFERENCES CITED The following references are ofrecord 1n the file of this patent:

UNITED STATES PATENTS Number Name Date 41,073 Johnson Jan. 5, 1864 889,208 Cunniif June 2, 1908 987,629 Ketcheson Mar. 21, 1911 1,331,729 Taylor Feb. 24, 1920 1,379,155 Acheson May 24, 1921 1,562,382 Taylor Nov. 17, 1925 1,573,982 Macadam Feb. 23. 1926 1,941,769 Ward Jan. 2, 19 34 2,096,087 Coolidge Oct. 19, 1937 2,124,330 Pascoe .1.... July 19,1938 2,159,586 Greider May 23, 1939 2308,232 Bmolak July 16, 1940 2,267,316 Thompson Dec, 23, 1941 2,295,070 Allen Sept. 8, 1942 I FOREIGN PATENTS Number Country Date 1,005 Great Britain 1863 3,096

Great Britain 1883

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