In the manufacture of carpet tiles an inverted strip of carpet has a scrim laid thereover and a base layer of pasty PVC is deposited on the scrim and doctored before being partially cured. Further pasty PVC is then deposited on the base layer and, as the carpet passes beneath a doctor blade, is doctored to a finish layer by the blade. The doctor blade comprises a combination of a downstream straight edged chamfered member with a narrow underface and an upstream comb like member with teeth with rounded undersides and with the width of the teeth not exceeding 25% of the tooth pitch.

An apparatus and method for the automatic and controlled application of smooth, even, controlled thickness coatings of viscous fluids such as photographic emulsions to taut, flexible, suspended layers of materials such as silk printing screens. The apparatus employs an adjustable frame for supporting various sizes of materials to be coated in unique cooperation with special spreading means for evenly spreading viscous fluids on the screen as motive power means moves the spreading means at a controlled, predetermined rate. Preferably, curing means is supplied for drying or baking the fluid on the screen. The spreading means includes a tray for holding and spreading the fluid and a base for movably supporting the tray over the screen to be coated without direct, physical contact therewith. The tray moves in unison with the base by a unique arrangement employing magnetic attraction. This invention relates to apparatus for automatic and controlled application of an even coating of a viscous fluid to a suspended layer of material and, more particularly, to apparatus for the application of emulsions and the like to printing screens and other taut, flexible, suspended layers of material in an automatic and controlled manner. BACKGROUND OF THE INVENTION It is well known that the preparation of photo-stencils for the printing industry requires a prepared light sensitive printing screen. Typically, the preparation of such screens requires the spreading of a photographic emulsion in the form of a viscous fluid over the surface of a printing screen stretched and suspended on one face of a supporting framework. After the screen is coated with the emulsion, the coating may be cured or dried. The screen is then ready for exposure to light while adjacent the desired negative such that the photostencil with a selected printing pattern results. In the past, spreading the emulsion on the printing screen was done manually. The manual method generally utilized a channel or trough having a V-shaped cross section filled with the emulsion and manually drawn vertically upwardly over the surface of a printing screen that was in an upright position. The emulsion was allowed to flow over one edge of the V-shaped channel, and that same edge was used to wipe or spread the emulsion over the surface of the screen as the channel was drawn vertically upwardly. It is known that this manual method of coating printing screens is not fully satisfactory. Specifically, it is difficult to control the rate at which the fluid or emulsion runs out of the channel or trough. Additionally, it is difficult to control the pressure uniformly between the entire length of the trough and the screen to cause the emulsion to be evenly applied across the entire length of the channel. Finally, it is difficult if not impossible to maintain uniform emulsion thickness, especially the precise thickness required for high quality photostencils. In fact, only after a considerable time does a person acquire the skill necessary to effect a reasonable emulsion coating by the conventional technique. Even then, it is practically impossible to get the same thickness coating repeatedly. SUMMARY OF THE INVENTION Accordingly, it is an object and feature of the present invention to provide an apparatus for the application of smooth, even coatings of viscous fluids, such as photographic emulsions and the like in controlled and predetermined thicknesses to suspended, taut, flexible layers of material such as a printing screen. It is another object and feature of the present invention to provide an apparatus to apply controlled and predetermined thicknesses of viscous fluid on varying sizes of suspended, taut, flexible layers of material without requiring special manual dexterity and skill. It is a further object and feature of the present invention to provide an apparatus for the application of viscous fluids to suspended, taut, flexible layers of printing screen and adaptable to apply these coatings to either side of the screen, i.e., whether the support frame is upright or inverted. It is yet another object and feature of the present invention to provide an apparatus for the application of controlled coatings of viscous fluid to suspended layers of material in combination with adjacent facilities for curing the coating. It is still another object and feature of the present invention to provide a method for coating suspended, taut, flexible layers of material such as a printing screen with viscous fluid such as photographic emulsion in an automatic and controlled manner. These and other objects and features of the present invention are accomplished by a unique coating apparatus and method having in combination an adjustable support means for supporting a suspended layer of material such as a printing screen to be coated, an adjustable spreading means for holding a quantity of viscous fluid and automatically spreading controlled amounts of viscous fluid evenly on the layer of material, and special cooperative means for moving the spreading means along the layer. The adjustable spreading means incorporates an elongated tray for the viscous fluid and a base for movably supporting the tray. The tray has apertures through which the viscous fluid flows and an adjustable closure means for controlling the rate of flow through the apertures. The base has two adjustable tray supports supporting an alignment rod for aligning the layer of material with the tray and two pairs of support wheels. The tray also has two pairs of wheels which cooperate with the alignment rod and the support wheels of the base to support the tray over the screen which is positioned between the tray and base. The base and tray have cooperative magnetic retention means therebetween. Motive power means automatically and controllably moves the spreading means. Additionally, the apparatus may include a curing means for supporting the coating apparatus and for heating or drying the fluids applied with the coating apparatus to the layers of material. These and other objects, advantages and features of the invention will become apparent from a study of the following description taken in conjunction with the drawings.

A device for so maintaining a roll of tape and a quantity of an adhesive that tends to harden when exposed to the ambient atmosphere, that substantially all of the tape and adhesive are out of contact with the atmosphere when the device is not in use. The device when in use, permits a desired length of the tape to be withdrawn therefrom and severed from the balance of the tape remaining on the roll. The withdrawn length of tape is enveloped in a continuous film of the adhesive, which film due to the structure of the device is of a desired thickness.

A dry wall tape dispenser is utilizable with a bucket-type container of dry wall taping compound of the kind used for bulk shipment and storage. The dispenser includes a support structure for interengagement with portions of the container and includes an arrangement for supporting and positioning a roll of uncoated dry wall tape above the container for unrolling of tape into the compound. The structure includes an extension which protrudes into the container, the extension including a guide for guiding the unrolled tape so that the tape passes into the compound to a point proximate the bottom of the container for thorough coating. The apparatus is provided also with a scraper proximate the opening having an edge for scraping one face of the coated tape to wipe the compound from such face so that only one face of the tape remains coated as the tape is pulled from the opening. Various arrangements utilizing electric motor-driven pinch rolls are disclosed for pulling the coated tape from the opening, or such pulling may be manually effected.

An apparatus for applying wallpaper which moistens prepasted wallpaper or applies paste to unpasted wallpaper and guides the paper as it is withdrawn from the roll and applied to the wall. The apparatus includes a base for rotatably supporting a roll of wallpaper and a frame attached to the base for supporting at least one pair of rollers for guiding the wallpaper through a trough partly filled with a liquid such as water or paste. The apparatus for use with paste has one roll in the trough of paste and a further roll for transfering paste from the roll to the paper.