Abstract: This invention relates to a process for forming a single-layer, durably wettable polymeric web having a plurality of apertures. This process comprises melting a mixture of at least one thermoplastic polymer and at least one migratable surfactant and extruding the mixture to form a single-layer, substantially continuous polymeric film. The film is then apertured using high pressure fluid flows. Aperture formation is conducted when the single-layer polymeric film has a contact angle of at least about 30.degree., to minimize wash-off of the surfactant impregnated in the polymer web. The invention also relates to durably-wettable apertured webs.

Abstract: This invention relates to a process for forming a single-layer, durably wettable polymeric web having a plurality of apertures. This process comprises melting a mixture of at least one thermoplastic polymer and at least one migratable surfactant and extruding the mixture to form a single-layer, substantially continuous polymeric film. The film is then apertured using high pressure fluid flows. Aperture formation is conducted when the single-layer polymeric film has a contact angle of at least about 30.degree., to minimize wash-off of the surfactant impregnated in the polymer web. The invention also relates to durably-wettable apertured webs.

Abstract: In a method of manufacturing material suitable for use as a top sheet in an absorbent disposable article, such as a sanitary napkin, an incontinence guard or a diaper, a laminate (1) comprised of a plastic film (2) and a layer of non-woven material (3) on at least one side of the plastic film is applied to a perforated supportive device (6) with one layer of non-woven material facing towards the supportive device. The plastic film is heated to a temperature above its softening temperature and there is generated between the two mutually opposing sides of the laminate a pressure difference of such magnitude that the plastic film will rupture within the regions of the holes in the supportive device so as to form openings (10) which lead to the associated non-woven material. A soft and smooth, liquid-permeable top sheet material is achieved.

Abstract: A screen cylinder is made up of a plurality of identical ceramic elements in arcuate form having screen openings, and opposite longitudinally extending edges carrying a tongue and groove, respectively. The elements are joined one to the other along their edges by inserting the tongues into the grooves to form a complete cylinder. Different diameter and lengths of screen cylinders may be formed by varying the number of elements in each closed arrangement of elements, and the closed arrangements may be disposed end-to-end with an intermediate connecting ring between them. End rings are provided to maintain the elements in a generally cylindrical configuration. Cinch rods connected between the end rings and under tension subject the elements in assembly to axial compression.

Abstract: This invention relates to a process for making a tubular structure formed by a film of extruded synthetic matter whose walls are at least partially perforated, including the steps of extruding from an annular die a tubular film having gaps or voids obtained in manner known per se by teeth which temporarily obturate the outlet of said die, and extruding and forming the film on leaving the die after flow of matter in the plastic state, upstream of the die, in a ring-shaped passage of which the outlet constitutes the die, this passage being of constant thickness equal to the width of the extrusion slot and consequently to the final thickness of the film, the flow of plastic material in this ring-shaped passage causing an effect of lamination of the matter ensuring dimensional stability, particularly the thickness of the film obtained at the outlet of the die, and in particular avoiding the formation of excess thickness or surface roughness on the film thus extruded.

Abstract: A unitary injection molded filter is disclosed which includes a rigid frame of resin material to provide a rigid shape to the filter, and at least one screen of non-woven sheet resin material suspended on the frame and having formed therethrough a plurality of holes extending between the opposed side surfaces of the screen so as to form fluid passages therethrough. Each screen is integrally molded simultaneously with the frame.

Abstract: A method of making apertured films including the step of perforating films of thermoplastic materials with embossing rolls engraved with patterns which form small slits or incipient slits in the sheet. The patterns are such that the design on the roll includes lands, or raised areas, which cross lands of the opposing roll at an acute angle. The perforated or partially perforated film formed may then be further processed by orientation, uniaxial or biaxial, simultaneous or sequential; by heat treatment; or both to modify the porosity, hole size, or other properties as desired.

Abstract: A vapor permeable and liquid impermeable microporous film suitable for diaper back sheets and other disposable applications is produced by abrading a filled, unoriented film by passing it through at least one set of at least two cooperating nip rollers, each having an abrasive grit surface.

Abstract: A process to obtain molecular orientations in perforated plates made of extruded plastic material includes a first heating of the plastic material at an extrusion temperature, the extruding of the plastic material in the form of a perforated plate, a first cooling of said plate, a second heating of the plate at the longitudinal orientation temperature, the longitudinal stretching of the plate, a second cooling of the plate at a temperature approaching room temperature, a third heating of the plate at the longitudinal stabilization temperature, a third cooling of the plate, a fourth heating of the plate at the transverse orientation temperature, the transverse stretching of the plate, a fourth cooling of the plate at the transverse stabilization temperature, and the final cooling of the plate.

Abstract: The microfilter foil is made of an inorganic substance such as metal with opened pores. Each pore is formed with a channel which increases in cross-section from the crest so as to obviate clogging. The foil is produced by exposure of a photosensitive layer of paint or lacquer with the use of an interference pattern produced by monochromatic and coherent light. A skin of inorganic material is produced on the photosensitive layer and portions of the skin are thereafter removed from the coated teeth in order to produce the pores in the subsequently formed foil.

Abstract: A process is disclosed for the continuous manufacture of a perforated plastic film, where the plastic film is extruded directly from the extrusion unit either onto one roller of a pair of rollers or directly into the gap between a pair of rollers (a perforating/texturing roller and a back-up roller). The hot plastic film is perforated on a roller under the influence of a vacuum and shock cooling by the flow of cold air and the coolness of the back-up roller is carried out during the perforating step, and immediately thereafter. The film is preferably textured at the same time that it is perforated, the immediate cooling setting the texture in the film.

Abstract: The present invention provides for a process for transforming a substantially continuous web of substantially planar, deformable material having an indefinite length, a first surface, and a second surface into a formed material. The material has a transformation temperature range. The process comprises the following steps:(a) The web of material is provided on a forming structure with the first surface of the web of material proximate a forming surface of the forming structure. The forming surface moves in a direction of the length of the web of material and carries the web of material in that direction.(b) A liquid stream is applied to the second surface of the web of material. The liquid stream has sufficient force and mass flux to cause the web of material to be deformed toward the forming surface, such that the material acquires a substantial three-dimensional conformation.

Abstract: There is disclosed an ink roller and method of making same. The ink roller includes a tube having a plurality of holes. A porous ink-receptive sleeve is received about the tube. The end portions of the tube are coupled to bearing rolls and the bearing rolls are closed off to provide space for holding ink. At least one bearing roll is a separate part and is sealed to the tube and closures are sealed to both bearing rolls. Means are provided to keep the separate bearing roll from becoming uncoupled from the tube. The holes converge outwardly toward the surface of the roll to conduct ink to the sleeve. Also disclosed is method of making the roll.

Abstract: A process for the manufacture of thermoplastic sheet having elliptical perforations including a rotatable molding element having a series of hexagonal-shaped depressions having centered therein elliptical holes, the elliptical holes having a major axis and a minor axis, the major axis being oriented parallel to the direction in which the molding element is rotated, a means for applying a fluid pressure differential to a surface of the thermoplastic sheet to force the sheet against the molding element to effect rupturing of the sheet and the formation of elliptical holes in the sheet.

Abstract: The present invention relates to a process for extruding a thermoplastic sheath in the form of a tubular film provided with perforations and to a device for carrying out the process, according to which the extruded film passes over a skirt through which are blown jets of hot air provoking the perforation and formation of openings in the film; in the areas where the film is not to be perforated, air jets are also blown through channels of smaller width, therefore with a reduced pressure, so that the jets do not provoke the perforation of the film but form an air-cushion facilitating the flow of the film on the skirt; the channels are supplied from a pneumatic chamber with interposition of a rotary distributor formed by a ring made of graphite or self-lubricating material. The invention is applicable to the manufacture of partially perforated tubular films with a view to making packings.

Abstract: In the process of embossing film by continuously passing the film through a nip formed by cooperating pattern and backup rolls, the improvement of passing the embossed pattern while in registration with the pattern roll through a second nip to improve the pattern detail. The apparatus includes a second backup roll in pressurized contact with the pattern roll forming the second nip. The surface configuration of the rolls may be such as to locally perforate the film within the pattern.

Abstract: The invention relates to a method of manufacturing a sieve which is composed of several planar sieve sheet sections, which are lying adjacent each other and are separated by a plurality of slots and are communicating with one another at a common point. The sieve sheet sections when so arranged are placed into a mold, and thereafter plastics material is introduced into the mold to form ribs that are covering the slots and that are holding in place and stiffening the rims of the sections that form a slot. The sieve sheet may be formed as an integral part or alternatively may be made of several sieve sheet sections that are held together at the peripheral region by connecting means. The plastics ribs covering the slots may be integrally formed with a container holding the sieve sheet.

Abstract: The invention is a process for forming a reticulated web net oriented from a perforated film wherein the perforated film is produced by thermoforming projections or pips on an endless perforated surface and subsequently skiving the pips off flush with the film, said thermoforming, skiving and orientation all taking place in a continuous fashion.

Abstract: An element for use in forming a deck for a grading or dewatering screen is formed by casting an elastomeric material such as polyurethane into a mould so that a smooth sheet of the material is formed in a liquid state in the mould, lowering into the liquid elastomeric material a substantially rigid open-work reinforcement, such as a perforated metal plate, and an array of studs for forming apertures in the screen element, the studs extending through the openings of the reinforcement and through the elastomeric material substantially to the bottom of the mould, allowing the elastomeric material to set, and then withdrawing the studs from the set sheet of elastomeric material. This provides a screen element comprising a sheet of elastomeric material having a rigid reinforcement embedded therein and a plurality of grading or dewatering apertures extending through the elastomeric sheet, the apertures being aligned with the openings in the reinforcement.

Abstract: A perforate screening member having a substrate with an upper surface and perforation sidewalls covered with elastomer to protect against abrasion is formed by casting elastomer into place adhered to the substrate at locations to be protected.