US2648088A - Textile print blanket washing equipment - Google Patents

Description

Aug. 11, 1953 H. H. BAILEY 2,648,088

TEXTILE PRINT BLANKET WASHING EQUIPMENT Filed July 26, 1949 wvg/vron Herman h. Bm/ey Patented Aug. 11, 1953 TEXTILE PRINT BLANKET WASHING. EQUIPMENT Herman H. Bailey, Belmont, Mass, assignor to Dewey and Almy Chemical Company, North Cambridge, Mass., a corporation of Massachusetts Application July 26, 1949, Serial No. 1 06,817

2 Claims. 1

This invention relates to an improvement in the process of printing textiles with the so.-called oil-base colors, in which an endless waterproof blanket is employed as the backing up element in the process.

For years, textiles were printed with colors which were, essentially suspensions of pigments or solutions of dye in water which had been thickened by some water-soluble. gum. The gum ave the necessary body to the color. Back grays.-that is, a cloth usually wider and as long as the piece of goods being printed, were run through the printer just under the goods. The back gray absorbed the excess color which was forced through the porous goods in printing. Later, a continuous. Wash process appeared; no back grays were. used; instead, the goods were printed on an endless, rubberized blanket which was washed free of the surplus color, dried and returned to. the printing station continuously.

Sincethe gum; was water soluble, it was not difficult to remove excess color from the endless waterproof blankets.

The advent of resin emulsion colors has completely changed this situation. Essentially, these such a color is, printed on a textile, the emulsion immediately breaks, and the resin is. deposited on the textile fibres in the form of a solvent solution which is hardened or advanced to permanent colored coating on the fibres by passing the printed goods through a chamber heated to For the a temperature high enough to. polymerize the run, back grays are usually put up, for they reduce the color build-up on the blanket and conserve its life. Their life in this service is so short, however, that some mills show a back gray cost of $40,000 a year for each printing range.

It has been found that if a textile blanket smeared with oil-base color is dampened or sprayed with an oil-base solvent and then run through a blanket washing apparatus which is only a slight modification of the usual washer, the color is broken up, re-emulsified in the Wash Water, and the blanket leaves the washerin a satisfactorily clean condition.

Unfortunately, solvents. which will soften or dissolve the. resin films on the blanket, usually will also dissolve the surface of the blanket, or at least so affect the blanket structure that] its tensile strength is greatly reduced. It has been found, for example, that the tensile strength of a high-grade so-called solvent-resistant," blanket will drop as much as 60%. if the solvent power of the resin remover is high.

One test for solvent power is the so-called Kauri-Butanol 1 test. Twenty grams, of a colorless solution of Kauri gum in butanol at 77 F. is placed in an Erlenmeyer flask. The. flask is placed on a sheet of white paper on which appears a legend printed in 10 point type with black ink. Solvent is then poured into. the flask and the number of cubic centimeters of solvent that will cloud the. solution enough to make. the type illegible through the solution is determined. It has been found that if the Kauri-Butanol figure substantially exceeds 45, a high-grade textile printing blanket will lose tensile strength to such a degree that the use of that particular. solvent is inadvisable. Another widely used test for solvent power is the aniline cloud point test. Equal quantities of the solvent. to be tested and of aniline are placed in a beaker or flask. The highest Fahrenheit temperature at which the aniline and the solvent exist as separate layers is read. The higher the temperature value found, the lower is the solvent power of the solvent. We have also found that if the aniline value is less than 100 F., the deleterious eficct upon a high-grade textile print blanket again makes the practice inadvisable.

It can be seen, therefore, that the use of solvent to dissolve and break up the film of resin on the surface of the blanket is at best undee sirable, but it is forced upon the textile printer by the inherent nature of oil-base colors. It will also be seen that the amount of solvent which is used should be held at the lowest practical limits and that the time during which the sol-.-

1 See Balcleschweiler, Troeller, and Morgan Industrial and Engineering Chemistry, Analytical Ed, page 374, vol. 7, No. 6November 15, 1935.

See Part 2, page 7: Industrial Solvent Naphthas Socony Vacuum Oil Co., 1946.

vent remains in contact with the blanket should be made as short as possible, even when the solvency value is less than 45, Kauri-Butanol test.

These requirements make the application of solvents to the blankets prior to the cleaning and washing operation quite diflicult, for the blanket does not run through the printing machine at any predictable speed. Change in the pattern, variations in the depth of the engraving and changes in the type of goods demand changes in the speed at which goods pass through a textile printer. For example, cotton prints on muslin are often run through the printing station at from 115 to 130 yards a minute. High-grade cretonnes may be run at only 30 or 40 yards a minute. Rayon and acetate crepe will run at even lower speeds, and printing on high-grade natural silks will be conducted at speeds even less than these. In addition, the printer must set his rolls and get the press rolling. To do this, the press is jogged again and again as the rolls are being brought into adjustment. Then, too, a piece of goods is not printed at a uniform rate. The printer runs the press slowly at the beginning of the run; then he gradually increases the speed to the maximum he considers safe when he has become convinced that the color and roll settings are correct. It can easily be seen that no printer can manually adjust a supply of solvent under such variable conditions, and it can also be seen that any device which will automatically adjust a spray gun, for example, to discharge an amount of solvent proportionally to the demands of the blanket would be complicated in the extreme. Yet this is necessary if the blanket is not to be ruined.

The present invention places solvent on a wash textile printing blanket exactly in proportion to the surface area of the blanket which passes the application point in a unit of time. It prevents solvent from lying on the blanket and softening it locally and is capable of misting and spreading such a minute quantity of solvent over the blanket that gallons of solvent is sufficient for 16,000 to 18,000 yards of a 42 inch wide blanket, and it does this uniformly and independently of the speed with which the machine operates. The means used to accomplish this effect is extremely simple.

Figure l is a sectional view through the solvent applying apparatus, blanket and blanket cylinder. The cylinder is partially diagrammized.

Figure 2 is a diagrammatical view indicating the position of the solvent applicator in conjunction with the modified washing and drying apparatus.

The combination is diagrammatically shown in Figure 2. Blanket 10, having left the printing station, enters the cleaning apparatus in a substantially vertical downward direction. It then carries on its face the excess resin-emulsion color from the textile printing operation. It is met by a mist ll of solvent projected onto the blanket from brush [2 at the point shown. Almost immediately thereafter the surface of the blanket comes into contact with the tips of bristles l3 of brush l2. The bristle action at this point is to scrub the color film and mix it with the solvent. Subsequently, the blanket, in looping around the wash cylinder [4, comes into contact with the bristles of washing brushes 15 which are charged with water projected onto the brushes by spray pipes l6 and spray nozzles IT. Wash brushes I 5 rotate counter to the direction of travel of the blanket. In passing out of the cleaning apparatus, the blanket passes through the bite formed between wash cylinder [4 and squeeze roll [8 where the surplus water is squeezed ofi. The blanket is then brushed by one or more rotary brushes [9 and passes through a cloud of powder particles 20 projected onto the blanket by the snapping of the bristles in a powder charged brush 2|.

With specific reference to Figure 1, the brush [2 is mounted transversely to blanket 10 on axle 22 with the tips of the bristles I3 in contact with the surface of blanket ID at point 23. Brush I2 is rotated in the same direction as blanket ID with a tangential velocity proportional to but in excess of the linear velocity of the blanket. Preferably, brush [2 is driven by drive means connected to wash cylinder M which in turn is driven by blanket 10. For example, brush I2 may be driven by crossed drive belt 30 passing over sheaves 3| and 32 attached to brush l2 and wash cylinder I4 respectively. The relative diameters of the sheaves ensures the proportionality of the relative velocities. However, it is possible to use independent power means to drive brush [2 at a velocity proportional to that of the blanket.

Solvent is applied to brush l2 from solvent supply pipe 24 mounted above the brush and parallel to but displaced from the vertical projection of the axis of the brush in the direction away from the surface of the blanket. In this way, any solvent which may be applied to the brush when the brush is not rotating will flow down the side of the brush away from the blanket and cannot therefore wet the surface of the blanket where its static action would weaken the blanket locally. Solvent supply pipe 24 carries a multiplicity of very fine holes such as those made with a drill so that small quantities of solvent may be applied to brush I2, preferably in a dropwise manner. Solvent supply pipe 24 may also be equipped with automatic valves to shut off the solvent supply when the blanket is not in motion and to vary the quantity of solvent applied to the brush roughly in proportion to the amount required.

The bristles l3 of brush l 2 are preferably made of smooth, solvent-resistant monofilaments such as nylon monofilaments so that solvent is not retained on the wet bristles. The non-retention of solvent is especially important in that it permits any color picked up by the bristles when in contact with the blanket to be washed away by the solvent remaining at the base of the bristles as that solvent flows down the bristles under the influence of centrifugal and gravitational force.

Angle bar 25 is mounted on support arms 26 parallel to the axis of brush I2 with the free end of bar 25 extending within the bristle tip circumference of brush 12 at a point between the vertical projection of the axis of the brush and the point of contact of the brush with the blanket. When the bristles come into contact with bar 25 as brush l2 rotates, they are bent from their normal position. After passing under the bar, the bristles snap back to a straightened position, dislodging the solvent contained thereon as a fine mist. The amount of solvent applied per unit area of the blanket may be varied by varying the depth to which the angle bar extends within the bristle tip circumference. Preferably the position of the bar is made adjustable by slotting support arms 26 and by providing a positioning adjusting screw 2'! and a calibrated hand wheel 28. After the position of the bar has been properly set, it is locked in position by setting up holding and clamp bolts 29.

Since it is the snap of the bristles rather than the velocity of the brush which projects the solvent towards the blanket, the amount of solvent projected during each revolution of the brush is largely independent of the speed. The uniformity of the amount of solvent applied to each square foot of blanket passing the solvent station is therefore maintained substantially independent of the speed. The automatic stopping and starting of the solvent mist prevents soaking the blanket, and all this is secured without attention on the part of the operator.

The coaction of the combination may be explained as follows. The solvent mist re-wets and dilutes the resin-color film on the blanket. Contact with the bristles of the solvent brush works the small supply of solvent into the lower layers of the color film and breaks it up. Seemingly, the mechanical action of the bristles of the wet scrubbing brushes acting on the solventswollen, mechanically broken-up film of resincolor in the presence of water is first to reemulsify the resin in the water and later to cause the clumping of the emulsified resin droplets. At any event, a non-adhesive, soft curd is formed which is flushed off the blanket by the water and also is flushed and thrown from the bristles of the revolving wash brushes. Some colors emulsify with such relative ease that the solvent applicator brush may be backed 01? from contact with the blanket and the break-up of the film left to the first wet scrub brush. But contact of the solvent applicator brush with the blanket is recommended.

The simplicity, ease of maintenance and effectiveness of cleaning which this combination secures now make it unnecessary to use back grays with a large majority of patterns printed with resin emulsion colors.

The Words oil-base color appearing in the specification and claims are intended to include resinous emulsion colors of both the water-inoil and oil-in-water types.

I claim:

1. In a textile print blanket cleaning apparatus of the type having a rotating cylinder and rotating wet cleaning brushes adapted to bear on the face of acontinuous textile print blanket passing around said cylinder, means for applying a small quantity of a solvent for the color carried on the blanket to the color film on the face of the blanket in the form of a mist immediately in advance of the wet cleaning brushes at a rate which is uniform per unit area of the blanket surface irrespective of the rate of travel of said blanket, said means comprising a rotary solvent applicator brush having its axis parallel to the axis of the cylinder and located adjacent to the cylinder in advance of the cleaning brushes at a point where the direction of travel of the blanket is essentially vertically downward, a striker bar extending the width of the applicator brush, located parallel to the axis and above the upper inner quadrant of said brush, said striker bar having a longitudinal bristle engaging portion extending into the bristle periphery of said applicator brush, means for adjusting the position of said striker bar relative to the axis of said brush, means for applying a solvent to said applicator brush including a drip pipe to drip solvent on the applicator brush, said drip pipe located above the upper outer quadrant of said brush, and means for rotating said applicator brush at a peripheral speed proportional to and in excess of that of the cylinder and in a direction opposite to that of said cylinder.

2. In a textile print blanket cleaning apparatus of the type having a rotating cylinder and rotating wet cleaning brushes adapted to bear on the face of a continuous textile print blanket passing around said cylinder, means for applying a small quantity of a solvent for the color carried on the blanket to the color film on the face of the blanket in the form of a mist immediately in advance of the wet cleaning brushes at a rate which is uniform per unit area of blanket surface irrespective of the rate of travel 01' said blanket and for working the solvent into this color film, said means comprising a rotary solvent applicator brush having its axis parallel to the axis of the cylinder and located adjacent to the cylinder in advance of the cleaning brushes at a point where the direction of travel of the blanket is essentially vertically downward, said applicator brush so mounted that the tips of the bristles of the brush contact the blanket, a striker bar extending the width of the applicator brush, located parallel to the axis and above the upper inner quadrant of said brush, said striker bar having a longitudinal bristle engaging portion extending into the bristle periphery of said applicator brush, means for adjusting the position of said striker bar relative to the axis of said brush, means for applying the solvent to said applicator brush including a drip pipe to drip solvent on the applicator brush, said drip pipe located above the upper outer quadrant of said brush, and means for rotating said applicator brush at a tangential velocity at the point of contact with the blanket which is proportional to but in excess of the linear velocity of the blanket.

HERMAN H. BAILEY.

References Cited in the file Of this patent UNITED STATES PATENTS Number Name Date 604,504 Simpson May 24, 1898 842,122 Spatz Jan. 22, 1907 1,005,888 Rutler Oct. 17, 1911 1,290,151 Feyes Jan. 7, 1919 1,360,060 Vierling Nov. 23, 1920 1,428,931 Barber Sept. 12, 1922 1,882,439 Murphy Oct. 11, 1932 2,335,782 McMordie Nov. 30, 1942 FOREIGN PATENTS Number Country Date 673,762 France Oct. 14, 1929

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