Abstract: This invention relates to a check valve (19) for use in an ink supply line (13) of an ink jet printing system (1) between an ink reservoir (11) and an inkjet printhead (3) so as to prevent de-priming of the printhead upon the latter being subjected to impact loads or the like. Specifically, the improvement of this invention comprises a one-piece check valve (37) of an elastomeric material having a flapper valve (43) movable between a closed position in which the flapper valve blocks the backflow of ink and an open position in which ink is free to flow past the check valve member to the printhead. The flapper valve (43) is defined by a slot (49) separating the flapper valve from the outer margin (41) of the check valve (37) and the flapper valve is integrally joined to the outer margin by a hinge portion (45) so as to enable movement of the flapper valve between its open and closed positions.

Abstract: A droplet generator for a continuous stream ink jet print head has a cavity (3, 23) for containing the ink; nozzle orifices (17, 27) in a wall (9) of the cavity (3, 23) for passing the ink from the cavity (3, 23) to form jets; and first (11, 21) and a second (13, 25) actuator device for establishing in combined operation a travelling wave. The travelling wave travels from the fist actuator device (11, 21) through the ink to the second actuator device (13, 25) and passes in a direction substantially parallel to the wall (9) containing the nozzle orifices (17, 27).

Abstract: The present invention provides a jet ink composition suitable for application onto a substrate comprising an ink carrier, a colorant, a polyol, an aldehyde-based cross-linking agent, and a catalyst that promotes a reaction between the cross-linking agent, the polyol, and the substrate. The present invention further provides a process of jet ink printing onto a substrate comprising projecting a stream of ink droplets to said substrate, controlling the direction of the droplets so that the droplets form the desired printed image on the substrate, and heating the image to obtain a cured printed image. Examples of preferred cross-linking agents are modified melamine formaldehyde resin and modified urea formaldehyde resin. The substrates preferably possess carboxyl, hydroxyl, amide, or sulfhydryl groups. An example of a preferred substrate is cellulose. The cross-linking reaction is carried out at relatively moderate temperatures and at high speeds.

Abstract: The present invention provides a laser markable coating composition comprising a colorant and a polymeric material whose opacity changes substantially irreversibly when exposed to heat. The composition may further include a carrier, an adhesion promoter, an energy transfer agent, an opaque polymeric material, and one or more binder resins. The present invention further provides a heat responsive colorant particle comprising a colorant and a polymeric material whose opacity changes substantially irreversibly when exposed to heat. A laser beam can be used to provide the heat. An example of a suitable polymeric material that irreversibly changes in opacity is a styrene/acrylic microsphere. An example of a suitable colorant is carbon black pigment. An example of an energy transfer agent is fumed silica. An example of an adhesion promoter is an oxidized polyethylene. An example of a suitable carrier is water.

Abstract: Surface treated pigment particles made by contacting a dispersion of pigment particles with a halosilane or organohalosilane, elevating the temperature to form a siloxane on the surface of the particles and recovering the surface treated particles as a presscake or as dry particles.

Abstract: A stroke based method for printing for use in a continuous ink jet printer. A set number of drops are assigned to a stroke, but the number of positions which can be printed on a stroke is greater than the number of drops on the stroke. This allows improved fonts at the same print speed.

Abstract: Dry, coated pigment particles are obtained by first suspending uncoated pigment particles in an appropriate medium and then coating the particles while in suspension, with a polymer that is at or above the softening point for that polymer. Coating of the pigment particles is achieved by allowing the suspension to cool to a temperature below the solidification temperature for the polymer. The coated pigment particles are then recovered.

Abstract: An ink jet printing ink containing a polymeric colorant and a substantially non-aqueous vehicle and a method for binary array continuous ink jet printing using the ink.

Abstract: This invention relates to a replaceable ink container or bottle (1) for an ink jet printing apparatus in which the mouth of the bottled is closed by a puncturable diaphragm (19). A puncturing member (35) carried by the ink reservoir (21) of the ink jet printing apparatus pierces through the diaphragm upon the container being installed in the ink jet printing apparatus. Upon the puncturing member (35) puncturing through the diaphragm (19), the diaphragm sealingly engages the sides of the puncturing tube so as to substantially prevent the ink from leaking therepast, and the puncturing tube opens communication between the ink within the container and the ink reservoir thereby permitting ink to flow from the bottle into the ink reservoir via the puncturing member.

Abstract: A method for making coated pigment particles by forming a suspension of the desired pigment particles in a medium that also comprises a polymer characterized by having hydrophobic moieties on the polymer backbone and ionic moieties that are present on, or can be formed on a polymer side chain or at the polymer terminals; allowing the suspension of pigment particles to contact said polymer at a temperature above the softening point of the polymer, allowing the resultant suspension to cool to a temperature below the solidification temperature for the polymer while maintaining the pigment particles in suspension, and, if required, forming the ionic moieties.