A technique for planarizing build surfaces in three-dimensional printing includes the use of a three-dimensional printer having an extruder with a sensor mechanically coupled thereto, where the sensor is operable to sense a contact force between the extruder and a separate structure. In particular, the sensor may be used to measure the contact force at a plurality of locations across a build surface of the separate structure, so that a difference between the measured contact force at two or more locations can be identified. In response to the difference between the measured contact force at these locations, a control signal may be created to reduce the difference for planarizing the build surface, e.g., by fabricating a layer on the build surface that mitigates irregularities therein, by gap filling on the build surface, or by adjusting a parameter of the three-dimensional printer.

According to one aspect, embodiments herein provide a method for in-process inspection of a 3D printed part with a 3D printer, comprising slicing a three dimensional model to define a plurality of shell volumes, for substantially each shell volume, generating a toolpath for depositing a printing material shell corresponding to the shell volume, transmitting, together with an identification, the toolpaths defining the printing material shells for deposition by a 3D printer, receiving, together with the identification, from the 3D printer a scanned surface profile of a printing material shell, and computing a process inspection including, according to the identification, a comparison between a received scanned surface profile and a toolpath defining a printing material shell.

A method of selecting thermoplastic materials for use with an injection molding apparatus that adjusts viscosity of a thermoplastic material based on an interpreted viscosity is provided. The method includes determining a target MFI for an identified plastic article based on performance properties. A thermoplastic material supply chain is analyzed and a first thermoplastic material having a first starting MFI and a first MFI range is identified and a second thermoplastic material having a second starting MFI and a second MFI range that is greater than the first MFI range is identified and is priced less than the first thermoplastic material. The second thermoplastic material is purchased. The second thermoplastic material is tested by providing the second thermoplastic material to the injection molding apparatus for multiple shot molding cycles with the second thermoplastic material in a molten state. The step of testing includes monitoring melt pressure of the molten second thermoplastic material using a sensor and providing a signal to a controller indicative of melt pressure. The controller controls introduction of an additive to the second thermoplastic material thereby changing a viscosity of the molten second thermoplastic material based on the signal. A molded article is formed by reducing a mold temperature of the second thermoplastic material within the at least one mold cavity.

A method of manufacturing bulked continuous carpet filament which, in various embodiments, comprises: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an extrusion system while maintaining the pressure within the extrusion system below about 25 millibars; (F) passing the resulting polymer melt through at least one filter having a micron rating of less than about 50 microns; and (G) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.

A process for manufacturing an article, comprising the step of manufacturing the article via an additive fabrication process from a structural material, is notable in that the structural material comprises a polymer selected from the following group: (co)polycarbonates, polyesters, polyestercarbonates, polyformals, polyamides, polyethers, polyvinyl chloride, polymethyl (meth)acrylate, polystyrene or a combination of at least two thereof and an additive absorbing infrared radiation. The additive absorbing infrared radiation is selected for its chemical structure and its concentration in the structural material such that it reduces transmission by the structural material of light in the wavelength range between 600 nm and 1700 nm, determined on a sample 100 μm thick, by ≥2.5 percentage points relative to a structural material sample with a thickness of 100 μm that does not contain the additive absorbing infrared radiation. During the additive fabrication process the structural material is exposed at least temporarily to infrared radiation in the wavelength range between 600 nm and 1700 nm. An article obtainable by a process as described above is notable for its production from a structural material which comprises a polymer selected from the following group: (co)polycarbonates, polyesters, polyestercarbonates, polyformals, polyamides, polyethers, polyvinyl chloride, polymethyl (meth)acrylate, polystyrene or a combination of at least two thereof and an additive absorbing infrared radiation, where the article, in the direction of its construction in the additive manufacturing process used to make it, has a tensile strength (ISO 527) which is >30% to . . . 100% of the tensile strength (ISO 527) of a specimen injection-moulded from the same structural material.

A method of forming a part includes locating an insert at an angle within a mold cavity, sending a quantity of molten resin through the mold cavity to form a first melt front, and sending another quantity of molten resin through the mold cavity to form a second melt front such that the first melt front meets the second melt front at a weld line and each front flows along opposite sides of the insert. The mold cavity can define opposed internal surfaces and the insert can be disposed at an angle between the internal surfaces at the weld line. Also, one end of the insert can be fixedly located to one of the opposed internal surfaces and another end of the insert can float within the mold cavity.

An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator, a mold and a cooling device, wherein the cooling device comprises: a heat transmitter comprising a distal arm or member and a proximal base or member, the distal arm or member being mounted by a spring loadable interconnection or engagement to or with the proximal base or member, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate.

In in-process inspection or calibration of a print bed or 3D printed part with a 3D printer, toolpaths defining printing material shells for deposition by a 3D printer are compared to surface profile scans from a range scanner to identify differences between the print bed, instructed deposition and the measured result, permitting pausing or alteration of the toolpaths or printing process.

Methods, apparatus, and systems for cutting material used in fused deposition modeling systems are provided, which comprise a ribbon including one or more perforations. Material is passed through at least one perforation and movement of the ribbon cuts the material. A further embodiment comprises a disk including one or more blade structures, each forming at least one cavity. Material is passed through at least one cavity and a rotational movement of the disk cuts the material. A further embodiment comprises a slider-crank mechanism including a slider coupled to a set of parallel rails of a guide shaft. The slider moves along a length of the rails to cut the material. Yet another embodiment comprises one or more rotatable blade structures coupled to at least one rod. The rotation of the blade structures causes the blade structures to intersect and cut extruded material during each rotation.

In the formation of a solid object by progressively adding extruded materials to a workpiece, a mechanism is disclosed for transposing the paths by which two or more extrusion nozzles travel to deposit materials. Paralleling a surface contour of the object being formed, the paths for two or more substantially continuous extruded traces are directed in complementary fashion to cause a first extrusion trace to form the object surface while a second extrusion trace is deposited behind the first trace. At another position along the surface contour, the paths of the extruded traces may cross over one another to allow the second extruded trace to define the object surface. Where the first and second traces have a different color or visual appearance, the disclosed mechanism enables fine graphic features to efficiently be integrated into the surface of the object being formed.