A molded part including a first member having a plurality of openings and a second member contacting with a peripheral edge of each of the plurality of openings so as to cover the openings, and having a hollow portion formed by sealing the contact portion with a sealing material, wherein: the second member defines a flow channel for filling the sealing material between the first member and the second member; the second member has a branched shape in which sections corresponding to positions covering the plurality of openings are branched from each other, and portions near a gate of the flow channel are connected as a common section; and the branched shape has a bridge structure for connecting the respective branched sections.

A problem exists of prohibitively high costs associated with molds for small run, legacy, or prototype injection molded parts. Further, the lead time on molds is currently on the order of about two weeks. A mold is provided that is formed from three-dimensional printing. The mold includes a series of air and/or water cooling channels to limit thermal stresses to the mold. Additionally, a series of coatings is added to the surface of a 3D printed mold to extend the lifetime of the mold and increase the performance of the mold. The coatings perform a function other than to define a shape of an injection cavity, such as improving thermal conductivity, providing a thermal barrier between the injection material and the mold body, or improving the detachment of the final mold product from the mold body.

In an aspect, a mold stack may comprise two adjacent components, one at least partially defining a vent adjustable between a molding configuration and a cleaning configuration. A junction of the components may be adjustable between a molding configuration, wherein mating faces contact one another to define a parting line, and a cleaning configuration, wherein mating faces are separated to create a molding cavity extension therebetween and an auxiliary melt barrier prevents uncontrolled flashing from the extension. In another aspect, a mold shut height adjustment mechanism may include a mold component movable along an operational axis of the mold, a stop member, movable along the axis relative to the mold component, having first and second stops for providing first and second gaps on the front and back sides, respectively, of the mold component when the stop member is deployed, and a spacer for use in selectively deploying the stop member.

An apparatus for simultaneously manufacturing a plurality of plastic molds comprises:an injection molding tool comprising a first and second molding tool halves anda gripper tool comprising a plurality of gripper members to which suction can be applied. The first and second molding tool halves are movable into the closed position and into an open position.

A front surface of the first molding members comprises recesses to allow the formation of pins projecting from the rear surface the plastic mold into the recesses to make the plastic molds adhere to the first molding members. The gripper tool is movably arranged only in a direction parallel to the first surface into the space formed between the first and second surfaces for transferring the plastic molds to the gripper members and out of this space again.

A writing utensil adapted for promoting the development of a tripod writing grip includes an elongate body having a substantially polygonal cross section, and having three faces extending between a proximal end and a distal end thereof, and a boss member extending from an intermediate portion of the elongate body, the boss member being adapted for impeding a user's fingers from sliding along a longitudinal axis of the elongate body.

In an aspect, a mold stack may comprise two adjacent components, one at least partially defining a vent adjustable between a molding configuration and a cleaning configuration. A junction of the components may be adjustable between a molding configuration, wherein mating faces contact one another to define a parting line, and a cleaning configuration, wherein mating faces are separated to create a molding cavity extension therebetween and an auxiliary melt barrier prevents uncontrolled flashing from the extension. In another aspect, a mold shut height adjustment mechanism may include a mold component movable along an operational axis of the mold, a stop member, movable along the axis relative to the mold component, having first and second stops for providing first and second gaps on the front and back sides, respectively, of the mold component when the stop member is deployed, and a spacer for use in selectively deploying the stop member.

An apparatus includes a stem connector configured to connect a movable piston with a valve stem, in which the movable piston is slidably receivable in a cylinder, and in which the cylinder is mountable to a distribution manifold of a molding system. The stem connector maintains connection between the movable piston and the valve stem while the valve stem is moved to selectively open or close a mold gate of a mold assembly installed in the molding system. The stem connector urges the movable piston to tilt at a tilt angle while the movable piston is moved along an interior of the cylinder, and in which the tilt angle is formed between a central piston axis extending through the movable piston and a central stem axis extends through the valve stem.

A method of forming an orthodontic aligner from an aligner digital model, the method comprising the steps of: three-dimensionally printing an intermediate structure comprising fused filaments from a biocompatible thermoplastic according to the aligner digital model via fused deposition modelling; coating the intermediate structure with a biocompatible translucent photopolymer; and irradiating the coating with ultraviolet light to cure the coating on the intermediate structure, thereby forming the orthodontic aligner.

A writing utensil adapted for promoting the development of a tripod writing grip includes an elongate body having a substantially polygonal cross section, and having three faces extending between a proximal end and a distal end thereof, and a boss member extending from an intermediate portion of the elongate body, the boss member being adapted for impeding a user's fingers from sliding along a longitudinal axis of the elongate body.

An apparatus usable with an injection molder for producing articles includes a first mold support including a first mold, and a second mold support including a second mold and a first die. The first mold support is movable relative to the second mold support between a first and a second position. In the first position, the first mold and the second mold being brought together to form an injection molded article having at least one protrusion extending outwardly from the body and facing the second mold. In the second position, the first mold and the first die being brought together to subsequently form the article, the first die selectively subsequently forming an altered cross sectional region in the protrusion, forming an undercut in the altered cross sectional region or between the altered cross sectional region of the subsequently formed protrusion and the body, each article being separate and non-interlocking.