Apparatus for applying liquid to a running web

[57] ABSTRACT

One or more liquids may be applied to a running textile web in flat tubular or open width form by three different cooperative and integrated systems. A drying chamber is associated with the apparatus for recovering solvent which may be included in certain liquid chemicals. The chemical applicating apparatus includes spray nozzles spaced transversely adjacent the path of travel of the web for spraying chemicals on the moving web. Guiding means are provided for selectively positioning the web with respect to the nozzles for optimum spraying position. A padding tank is also provided for passing the web directly through a bath of the chemical and a metering system including an applicator roll and an adjustable blade in different configurations is provided for applying precisely controlled amounts of chemicals to the web.

Claim, 5 Drawing Figures

<img file="US3800569A_D0001.tif" />

PATENTED*™ 21974 3,800,569

SHEET 1 OF 2

<img file="US3800569A_D0002.tif" />

PATENTED APR 21974

SHEET 2 OF 2

3,800,569

<img file="US3800569A_D0003.tif" />

3,800,569

APPARATUS FOR APPLYING LIQUID TO A RUNNING WEB

This is a division of application Ser. No. 141,304, filed May 7, 1971 now U.S. Pat. No. 3,701,269.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to textile machinery and more particularly is directed towards a new and improved apparatus for applying various liquid chemicals to a running textile web and subsequently removing solvents therefrom.

2. Description of the Prior Art

In the production of many types of textiles it is common practive to treat the fabric with certain types of chemicals. For example, some fabrics will be treated with water repellent coatings, others may be treated with anti-shrinking chemicals while still others may be treated with dyes or scouring solvents. In some cases the same material will be subjected to a combination of chemical treatments depending upon the end product desired. Heretofore, separate pieces of equipment have been used to carry out specific operations. It is an object of the present invention to provide in a single piece of equipment the capability of carrying out multiple chemical treatment techniques on a running web.

Some of the chemicals used to treat fabrics often are quite expensive and the amount of the chemical applied to the fabric should be closely controlled, not only from the standpoint of cost but also to provide an end product of uniformly high quality. It is another object of this invention to provide precise means for metering liquid chemicals onto a running web.

SUMMARY OF THE INVENTION

This invention features an apparatus for treating a running web, comprising a housing,guide means within the housing for directing the web through different treatment stations. One station includes a plurality of nozzles mounted for spraying a liquid chemical across the width of the web, and means for controlling the distance between the web and the nozzles. A second station includes a tank adapted to hold a quantity of liquid chemical for bathing the web passing therethrough. A third station is comprised of an applicator roll and a metering blade disposed in closely spaced relation thereto defining a trough therewith adapted to meter a film of liquid chemical onto a web moving into contact with the roll. A drying and condensing section is provided in the housing for drying the web continuously and to drive off solvents that may be present in the chemicals. Condensing means recover the solvents for reuse.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view in side elevation, somewhat schematic, showing an apparatus made according to the invention for carrying out different chemical treatments on a running web,

FIG. 2 is a detailed plan view of the spray station of FIG. 1,

FIG. 3 is a detailed sectional view in side elevation showing the metering mechanism of FIG. 1,

FIG. 4 is a view similar to FIG. 3 portraying a modification thereof, and,

FIG. 5 is a view similar to FIG. 3 portraying a further modification of the metering device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1 of the drawings, the refer5 ence character 10 generally indicates a housing, preferably closed except for inlet and outlet ports 12 and 14 respectively, through which a running web 16 is fed normally in an open width or flat tubular form. Each port preferably is surrounded by a water cooled duct 18 10 and 20 which serve to condense any vapors tending to escape through the ports. The housing 10 is generally divided into two functional sections, the first section, generally indicated by reference character 22, serving as a fabric treatment section, and the reference charac15 ter 24 generally indicating a drying and condensing section, the two sections being connected by a crossover duct 26. The crossover duct is joined to the top walls of the sections 22 and 24 through water seals 28, with a removable cover 30 connected to the duct also by 20 means of a water seal 32.

Condenser trays 34 are employed in the upper portions of the sections 24 to collect condensation formed on the top walls and prevent it from dripping onto the web 16 which is carried about a series of rotating 25 heated drying cylinders 36 which serve to dry the web and drive off any solvents in the web so that they may be condensed and recovered. One or more condensers 38 may be provided in the lower portion of the section 24 to introduce the cooling action for condensing the ³⁰ vapor driven off by the drying cylinders. The lower walls of the section 24 are inclined to funnel the condensate to a drain line 40 at the base of the unit.

The fabric treatment section 22 includes three functional stations providing means for applying one or more liquids to the running web 16. The stations, in sequence, include a spray station 42, a padding station 44 and a metering station 46. The spray station 42 is comprised of spray nozzles 48, preferably arranged in two vertically spaced horizontal rows in position to direct a spray of liquid against the vertical reach of the web 16 passing in .front of the nozzles. The nozzles 48 are pressure fed by means of a conduit 50 connected to a spray pumping tank 52 charged by means of a pump 54 taking suction on a receiving tank 56. The tank 56 receives the drains from the fabric treatment section 22 via conduit 58. The pump 54 is also connected by a conduit 60 to a mixture tank 62 communicating with a mixing tank 64 in which various chemicals may be combined before introduction to the fabric treatment section. The liquid supply system also includes a conduit 66 provided with a flow meter 68 for delivering a controlled amount of liquid selectively from the mixture tank 62 or the spray pumping tank 52 to the metering station 56 or the padding station 44.

As best shown in FIG. 2, each horizontal row of nozzles 48 is connected to a common manifold 70 fed by the conduit 50 and the nozzle tips are in alignment /hereby, the discharged liquid forms a cone 72 with adjacent cones intersecting one another at points indicated by reference character 74 closely spaced from the nozzle tips. With the nozzles properly adjusted, the intersecting points 74 should be in alignment.

In order to prevent formation of longitudinal streaks on the web 16 which may result if the web is not properly spaced from the nozzles, an adjustable web guiding apparatus is provided whereby the vertical reach of the web passing in front of the nozzles 48 may be moved

3,800,569 to and away from the nozzles. In this fashion the web may be selectively spaced from the nozzles so that adjacent conical discharges 72 will impinge on the web 16 at a distance where the line of intersection points 74 lie in the plane of the web to just slightly overlap with no 5 spacing. The web thus will be uniformly treated by the spray without the formation of longitudinal lines of double treated or untreated areas. If the web were too close to the nozzles, as indicated by dotted line 16' in FIG. 2,the web would be within the intersection points 10 74 and the conical discharges would not form a continuous line of impingement the entire width of the fabric, but rather would produce longitudinal stripes of alternately treated and untreated areas. By the same token, if the web 16 is too far away from the nozzles,as indi- 15 cated by reference character 16 in FIG. 2, the spray discharges will overlap and would form differently coated stripes, the web portions directly opposite the nozzles receiving the effect of one nozzle while portions opposite the junction points 74 would receive the 20 effects of two nozzles. By being able to selectively control the spacing between the nozzles and the web the optimum position may be obtained to spray the web in a uniform pattern. By employing two banks of nozzles, one bank may be used while the other is being serviced ²⁵or, in certain cases, both banks may be used simultaneously. Each nozzle 48 is provided with its own valve 76 whereby certain nozzles may be turned off when processing webs which are narrower than the width of the spray stations. 30

The web spacing apparatus includes a vertical carriage frame 78 threaded to and supported by upper and lower horizontal lead screws 80 and 82, respectively, mounted within the housing 10. The lead screws are suitably supported in bearing blocks 84 and the ³⁵lead screws are disposed not only at the top and bottom of the frame but also on either side thereof. Each lead screw is drivingly connected to a sprocket gear 86 engaged to a chain 88. A handwheel 90 is provided exterior to the housing, and it will be understood that by ro- ⁴⁰tating the handwheel 90 lead screw 80 will be turned as well as all other lead screws by virtue of the common chain connection. Rotation of the lead screw will, of course, move the frame 78 horizontally to and away from the nozzles 48. Idler guide rollers 92 and 94 are ⁴⁵supported by the frame 78 and engage the web as it travels downwardly past the spray station.

A backing plate 96 is mounted on the frame 78 opposite the spray station to hold the web in position against the force of the spray discharge from the nozzles. ⁵⁰

From the spray station 42 the web 16 is guided down to a padding station 44 comprised of a pad tank 98 in the form of an open trough preferably disposed within a water jacket 100. The trough is supplied with liquid such as a dye, etc., from an outlet 102 in the conduit ⁵⁵66. The trough is normally filled with the liquid and a roller 104 is located in the bottom of the trough about which the web is wrapped to carry the web in and out of the liquid. Another roller 108 is located above the padding tank to guide the web out of the tank and, where the padding station is to be by-passed, the web may be fed directly from the roller 94 onto the roller 108.

From the padding station 44 the web is guided to the ₆₅metering station 46 where an accurately controlled film of liquid is applied to the web. The metering station is comprised of an applicator roll 110 preferably fabricated with a stainless steel outer cylindrical surface, a squeeze roll 112 and a metering blade 114 cooperatively positioned with respect to the applicator roll 110. A liquid to be applied to the web is delivered as by a split tube conduit 116 above the blade in position to deposit a controlled amount of liquid into a trough formed by the rotating applicator roll 110, the angularly disposed metering blade 114 and opposing end walls 118 which prevent the liquid from flowing out the ends of the trough.

The metering blade 114 is mounted to a pivot shaft 120 for selective adjustment of the edge of the blade with respect to the applicator roll. In practice the edge of the blade does not touch the surface of the applicator roll but rather defines a uniform gap therewith serving to meter out in a closely controlled fashion a film of liquid onto the roll surface which is then carried against the web and is squeezed into intimate contact with the web by virtue of the bite between the applicator roll 110 and the squeeze roll 112. Adjustment of the gap permits an increase or decrease in the weight percentage of liquid that is picked up by the web. The clearance is preset by the operator and it may be selectively adjusted to increase or decrease the amount and rate of liquid application depending upon various factors such as the liquid involved, the type of material being processed, the speed of operation, etc.

The metering blade 114 as best shown in FIG. 3 is an elongated member rectangular in outline and mounted on a holder 122 which is positioned by means of adjustment screws 124 and 126 extending through the holder and engaging the blade 114. The adjustment screws are mutually perpendicular to permit different adjustments of the blade. The screw 122 serves to set the edge of the blade into a perfect parallellism with the surface of the roll 110 to insure a uniform gap and a film of constant thickness while the screw 126 serves to clamp the blade in position once set.

The holder 122 is mounted on the end of a bracket arm 128 carried by the pivot shaft 120. The arm 128 together with its holder is angularly adjustable about the axis of the shaft 120 in order to adjust the gap between the edge of the blade and the applicator roll. The adjustment mechanism is best shown in FIG. 4 and is comprised of a lever 130 which is rigidly connected to the bracket arm 128 or 128' and extends between the opposing ends of aligned adjustment screws 132 and 134. The adjustment screws are threaded to a fixed bracket 136 and by manipulating the two adjustment screws the lever 130 may be biased about the pivot shaft to move the metering blade to and away from the surface of the roller 110.

In the preferred form of the invention, as best shown in FIG. 3, the squeeze roll 112 is offset to the right or discharge side of the applicator roll 110 and the metering blade is located to the left or feed side of the applicator roll. This arrangement prevents the formation of a pocket of liquid at the inlet side of the bite. The film is applied to the roll prior to contact between the web and the roll perhaps by a lead angle of 45°. After the film on the roll is transferred to the web the aqueeze roll 112 serves to ensure intimate contact between the liquid and the web and to squeeze off any excess.

Referring now more particularly to FIG. 4, there is an illustrated modification of the metering apparatus and in this embodiment a metering blade 114' is mounted to apply the liquid to the upper right hand quadrant of

3,800, 5 an applicator roll 110' and, in this instance, the web 16' does not wrap about the applicator roll but rather is carried about a squeeze roll 112' disposed in horizontal parallel relation with the applicator roll. This arrangement has a disadvantage in that excess of liquid will 5 tend to accumulate in the pocket at the upper inlet side of the bite of the rollers.

Referring now to FIG. 5 of the drawings there is illustrated a further modification of the metering apparatus and in this embodiment the blade is mounted in a fash- 10 ion similar to the FIG. 1 embodiment but a squeeze roller 112” is located directly below an applicator roller 110 .

It is desirable that the amount of liquid delivered into the trough and the metering station be carefully con- 15 trolled and to this end the flow meter 68 is supplied. While various flow meters may be utilized the device of FIG. 1 has been found to be particularly satisfactory.

The flow meter is comprised of a transparent frustroconical chamber with an inlet at its lower end and an 20 outlet at its upper end and containing a weighted float 140. The walls of the chamber are marked with graduations and the flow rate is set by controlling valves on the inlet and discharge sides of the meter whereby the pressure of the liquid flowing through the meter will 25 cause the float 140 to rise to a particular height, the height being indicative of the flow rate.

The apparatus may be used to treat the web with a variety of chemicals such as dyes, shrinkage stabilizers, waterproofing materials and the like. Many such chem- 30 icals will be dispersed in solvents which must be removed from the cloth after treatment since the solvents are relatively expensive it is desirable to recover them for reuse from the drying and the condenser stage.

569

Some chemicals such as, “Scotchguard” sold by 3M Company, Will be mixed in a chlorinated hydro-carbon solvent and the fabric treated with the chemical will pick up approximately 40 percent by weight of which only 4 percent will represent the Scotchguard material while the 36 percent will be a solvent. Chemicals of this nature are quite expensive and it is desirable to control closely the amount applied to the web not only to maintain cost controls but also to achieve an end product of uniform quality, meeting certain required specification. The use of the metering station provides all of the precise control needed to govern the application of chemicals of this nature.