According to some aspects, water repellent treatments for fabrics. More particularly, systems and methods for water repellant treatment of protective fabrics for ballistic and other applications, and protective fabrics made using such techniques.

According to some aspects, water repellent treatments for fabrics. More particularly, systems and methods for water repellant treatment of protective fabrics for ballistic and other applications, and protective fabrics made using such techniques.

The invention relates to a method and an apparatus for impregnating an item, preferably a garment such as a coat, a jacket, a shirt or a pair of trousers, optionally other fabric-like textile such as tents, tarpaulins, hoods for vehicles or vessels. The apparatus comprises an inner support for supporting the garment or other fabric-like textile. The inner support has an electrically conducting surface and an electrically conducting outer cover for covering the garment or other fabric-like textile when supported by the inner support. The apparatus also comprises means for applying an electrostatic field between the electrically conducting surface of the inner support and the electrically conducting outer cover, and nozzles for providing an impregnating agent between the electrically conducting surface of the inner support and the electrically conducting outer cover, from the outer cover towards the garment or other fabric-like textile.

The invention relates to a method and an apparatus for impregnating an item, preferably a garment such as a coat, a jacket, a shirt or a pair of trousers, optionally other fabric-like textile such as tents, tarpaulins, hoods for vehicles or vessels. The apparatus comprises an inner support for supporting the garment or other fabric-like textile. The inner support has an electrically conducting surface and an electrically conducting outer cover for covering the garment or other fabric-like textile when supported by the inner support. The apparatus also comprises means for applying an electrostatic field between the electrically conducting surface of the inner support and the electrically conducting outer cover, and nozzles for providing an impregnating agent between the electrically conducting surface of the inner support and the electrically conducting outer cover, from the outer cover towards the garment or other fabric-like textile.

A method of preparing an electret by saturating a nonwoven fabric with a liquid, such as water, and removing the liquid via suction to generate charges by friction between the fabric fibers and the liquid is described. The saturating can be carried out, for example, by impinging the bottom side of the fabric with a jet or jets of water while the fabric is being pulled under a solid roller. Excess water can also be applied during a water quenching step of a meltblowing or spunbonding process. An apparatus for preparing an electret according to the presently disclosed methods is also described.

A method of preparing an electret by saturating a nonwoven fabric with a liquid, such as water, and removing the liquid via suction to generate charges by friction between the fabric fibers and the liquid is described. The saturating can be carried out, for example, by impinging the bottom side of the fabric with a jet or jets of water while the fabric is being pulled under a solid roller. Excess water can also be applied during a water quenching step of a meltblowing or spunbonding process. An apparatus for preparing an electret according to the presently disclosed methods is also described.

A suction nozzle (23) for a hollow jet suction box (14) is used for sucking liquid jets (4). The jet suction box has on a box casing (18) at least one slot casing opening (20) to a box interior space (17). The suction nozzle (23, 23) has a nozzle body (24), arrangeable above the casing opening (20), with a slot suction opening (25), which passes through the nozzle body in a flow direction (23). The suction opening extends from an inlet side (26) at a free end to an outlet side (27), arrangeable at the casing opening. The nozzle body has a mobile sealing element (29, 29) adjacent the suction opening and laterally defining the slot-like suction opening and a resilient expansion device (33), which acts on the sealing element (29, 29) and pushes the sealing element outward, away from the outlet side, against the suction flow direction.

A suction nozzle (23) for a hollow jet suction box (14) is used for sucking liquid jets (4). The jet suction box has on a box casing (18) at least one slot casing opening (20) to a box interior space (17). The suction nozzle (23, 23) has a nozzle body (24), arrangeable above the casing opening (20), with a slot suction opening (25), which passes through the nozzle body in a flow direction (23). The suction opening extends from an inlet side (26) at a free end to an outlet side (27), arrangeable at the casing opening. The nozzle body has a mobile sealing element (29, 29) adjacent the suction opening and laterally defining the slot-like suction opening and a resilient expansion device (33), which acts on the sealing element (29, 29) and pushes the sealing element outward, away from the outlet side, against the suction flow direction.