US1676362A - Waterproof fabric - Google Patents

Description

Patented i July 10,

UNITED' srAras' PATENT orrrca.

l LE ROY SEIDELL AND GEORGE :Bl JACK, JR., yOF NEW YORK, N. Y., ASSIGNORS v'.IIO JATON MANUFACTURING CORPORATION, 0F BROOKLYN, NEW YORK, A. CORPORATION OF NEW YORK.

Application led February l y This invention relates to Water proof fabrics and involves the provision of improved therefor and a' non-drying or semi-drying vegetable oil. The improved Water proof fabric of the invention comprises a fabric havingthe individual fibres thereof impregnated throughout and coated with a thin flexible film ofan ether-soluble cellulose ester together wit-h a latent solvent or a non-drying or semi-drying vegetable oil.

The Water proof fabric of this invention retains the desirable characteristics of the untreated fabric and has, in addition, several -further advantages. The water proof fabric of the invention retains the identity and substantially all of the iiexibiflity of the untreated fabric, and is free from adhering layers separate from the fabric itself Which tend to crack or break on flexure. -The treated fabric is usually stronger than the same fabric untreated and the protective act-ion of the Water proofing materialvdistributed throughout the fabric lprolongs the life and preserves the strength of the fabric. s

The treatedfabric will also' preserve and protect materialddeleteriously affected bythe air or external moisture and is also adapted'v to retain, Without- `undesirable effect, materials lwhich act upon or are acted upon by the untreated fabric.4 The water proof fabric of the invention is comparatively light Ain weight althoughv water proof and/substantially impervious, and is sanitary and can be washed in the ordinary' way Withoutndetrif ment. i

Cellulose nitrate or cellulose acetate may be'employed, either separatelyor in admix-v ture, inthe Water proofing composition of the invention in conjunction with a latent solvent therefor such as camphor. Such compositions 'are flexible. without brittleness.

WATERPROOF FABRIC.

25, 1924.- Serial No. 695,039.

Non-drying, or semi-drying vegetable oils such as castor oil, rapeseed oll-or cocoanut 011 may be used raw or blown, that 1s, partly oxidized. The use of blown oil sometimes causes discoloration and-it should be used with care where color is important. Castor oil dissolves readily in solvents such as ethyl alcohol with the production of thin solutions of low viscosity and is particularly advantageous in the prepartion'of the water proof fabric of the present invention. lts use also enables the production of a product of excellent and permanent qualities. Methyl, ethyl, amyl or butyl acetates, or acetone, or ether, o-r various mixtures thereof, for example, may be employed as solvents for the cellulose esters and the latent solvent employed in the practice of the'present invention. These solvents may be employed in admiXture with alcohols such as methyl ethyl, amyl or butyl alcohol. Solvent naph- -tha, or benzol, toluol, or xylol may be used as diluents of the cellulose ester solutions.

The Water proofing composition of the present invention may comprise, for example, 12 ozs. of cellulose nitrate or cellulose acetate, 8 ozs. of camphor, andabout 35` ozs. of raw or blown castor oil, in solution in one gallon of equal proportions. A compositionof these proportions is particularl adapted for the treatment of canvas and eavy fabrics.

The viscosity of the inipregnating solution is regulated in accordance with the character of the fabric, the temperature of impregnation and 'the volatility of the solvent employed. If the solution is'too viscous, a surface coating forms on the fabric which stii'-, ens it and destroysv the original properties and the identity of the fabrlc. If the solution is too thin,.the water proofing may be imperfect or discontinuous, although solutions too thin to secureV a satisfactory. result ina single application may be'satisfactory `Wherethe impregnation is repeated -one or more. times. The viscosity of the solution can be decreased by increasing theamount of solvent or diluent employed and vice versa, but the proportion of solvent employed must at all times besuficient to maintain the water proofing composition .in solution.

The fabrics which may be treated in accordance with the present invention include textiles such as canvas, linen, satin, silk and burlap, and rope, cord and twine, and unwoven fabrics such asfelt.- The term fabric is used herein to include woven, felted or knitted material. As noted above, different fabrics require the use of impregnating solutions of different viscosity for best results. More viscous solutions are used with open mesh fabrics than for close mesh fabrics and verythin solutions are used for the treatment ofl paper and the like. The increase in weight per unit of area differs with different materials and different thicknesses of the i sam-c material but advantageously roughly approximates 20% of the weight of the fabric, or less.

`A treatment of a fabric-in accordance with the methodof the present invention is diagrammatically represented in the accompanying drawing. The fabric from the. roll 1 is` drawn successively through the conditioning chamber 2, the impregnating chamber 3 and the drying chamber 4 by the traction drum 5. In the conditioning chamber 2 the fabric passes over a. hollowdrum 6 which is heated by steam supplied through pipe 7 condensed water being removedfrom thev drum 4 by means of the spiral vane 8. Steam munder a pressure of from 20 to 30 lbs. per

square inch may'- be employed to maintain the drum at the `proper temperature. In the impregnating chamber 3, tl'efabric first passes between a'pair of felt rollers 9,`internal1y supplied with a solvent-throughconnection 10, preferably that used in the impregnating solution, where it is thoroughly impregnated with the solvent. The fabric then passes through a trough ,formed by the members 11 which arel held' against the fabric. rllhe impregnating solution is supplied to depressions in the upper surfaces of the members 11 from the tanks 12, and overflows from the puddles formed in these depressions into the lower 4part of the trough Wherefit thoroughly impregnates the fabric. \"'l`he doctors 13, which may be of glass are adjusted to remove excess solution from the fabric. The tem erature of the impregnating bath is pre erably maintained at about 80 to 100 F.'

Leavingl the impregnating chamber 8, the impregnated fabric passes through the drying chamber 4 where it is brought in contact with a stream `of heated air flowing counter current to the motion of the fabric.' A series of vanes 14 serve to redirect fresh portions of the' heated air against the fabric.l The tem- I perature of the heated air may be' maintained at about 175 F., at which tempera'- ture blistering of the treated fabric is avoided. The 'air passed through the drying Lenses and then passes over the steam coils in ythe air heater 16 being directed into the upper part of the drying chamber through connecmaintained by the exhaust fan 21, which may also serve to remove moist air from the conditioning chamber 2. A series of baffles 22 are provided about the fabric between the conditioning chamber, .the impregnating chamber and the drying chamber, ,and at the top of the drying chamber, to` 'inhibit as much as possible theescape of the vapors and/gases from any of-tliese chambers. A connection 23 serves to remove vapors formed in the impregnating chamber and to pass "them to the solvent recovery apparatus where any solvents and diluents vaporized in the impregnating 'chamber are collectedtogether with those recovered fromthe drying air. By arranging vthe traction drum 5 at the upper end of the drying chamber 4, any contact with the surfaces of the treated fabric is avoided until the fabric is thoroughly dry.

Many fabrics are loaded or filled with substances such as clay or metallic oxides or starch. This'invention is applicable directly to the treatment of'such loaded or filled materials, but more"- advantageously the fabric is treated before the loading or filling is carried out, or such loading or filling sub` stances are removed in any appropriate manner before treatment 5in accordance with the The finished fabric is revycund on the roll present invention. In the case of many fillers,

this cari be accomplished by prolonged washmg' f The water content of various fabrics, par# ticularly cotton textiles, is frequently high and usually variable. Before treatment lwith -thelmpregnating solution ofA the prese-nt invention, it advantageous to remove any water present, or reduce it to a` low and constant amount, by adryingzoperation. This `drylng operation can be carried out by passing the untreated fabric through a chamber maintained at a temperature of about 225 E? ,250 F. immediately before impregna 1on. f

vImpregnation with the water proofing solution c an be facilitated by previously im pregnating thefabric with a solvent for the cel1ulose ester employed in the impregnatlng solutlon. Advantageously, the same solvent or solvent mixture is employed in this preliminary impregnation as in treatment with the water proofing composition of the invention. After impregnation with the wa.- ter proofing Isolution, the treated fabric can be dried by the removal of the excess solvent and diluent in any suitable manner. If necessary or desirable, impregnation with the water proofing composition followed by the drying operation can be repeated one or more times.l In thetreatment of very dense fabrics, it is sometimes useful to employ a thinner impregnating solution and to repeat the operation if necessary to secure a completely water proof fabric. Repeated preliminary limpregnation with the. solvent can also bey employed Where the impregnation with the water proofing composition is repeated. v.

The Water proof fabric of the invention is .'i'adapted to resist the attackof Wind and salt i Water and can be used advantageously for sails Vand hatch covers and the like. It is particularly useful as sail material in coning a heavy fabricimpregnated throughout with a mixture containing approximately 12 parts of an ether-soluble cellulose ester, 8 parts of comphor and 35 parts of castor oil, andretaining the identity Land substantially Vthe o1iginalflexibility of the untreated fabric. v

2. A process of .making a flexible water proof fabric, comprising impre'gnating the fabric with a solvent for cellulose esters and then while still impregnated with the solvent impregnating it wlth a dilute `vsolution v containing an ether-soluble cellulose ester, a latent solvent therefor and a non-drying or semi-drying vegetable oil2 said solution being' of sufficiently -low viscoslt to coat and impregnate the individual fi res of the fabric Without the formation of a thick relatively inflexible surface layer on the fabric and s`o that the impregnated fabric is substantially homogeneous with respect to the impregnating composition. y

3.' A process of making a flexible water proof fabric, comprising -impregnating the fabric with a solvent and then while still impregnated with the solvent impregnating it with a dilute solution in the same solvent containing an ether-soluble cellulose ester, a

latent solvent therefor and a non-drying or semi-drying vegetable oil, said solution be ing of sufliciently low viscosity to coat and impregnatethe individual fibres of the fabric without the formation of a thick relatively inflexible surface layer on the fabric and so that the impregnated fabric li's substantially homogeneous with respect to the impregnating composition.

4. A process of making a flexible waterl proof fabric, comprising impre nating the fabric base with a solvent for ce ulose esters and then while still impregnated with the solvent impregnating it Withoa dilute solution contaming an ether-soluble cellulose viscosity to coat and impregnate the indi-v vidual fibres -of the fabric base without the formation of a thick relatively inflexible surface layer on the fabric base and so that the impregnated fabric `is substantially homogeneous with respect to the impregnatin composition. I c

ln testimony whereof we Vaffix our signatures. Y

LE ROY SEIDELL. GEO. B. JACK, Jn.

'80 ester, said solution being of suiiciently lowv

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