A method of forming a three-dimensional object, wherein said three-dimensional object is an insert for use between a helmet and a human body, is described. The method may use a polymerizable liquid, or resin, useful for the production by additive manufacturing of a three-dimensional object, comprising a mixture of (i) a light polymerizable liquid first component, and (ii) a second solidifiable component that is different from said first component.

A method of forming a three-dimensional object, wherein said three-dimensional object is an insert for use between a helmet and a human body, is described. The method may use a polymerizable liquid, or resin, useful for the production by additive manufacturing of a three-dimensional object, comprising a mixture of (i) a light polymerizable liquid first component, and (ii) a second solidifiable component that is different from said first component.

In one example, an additive manufacturing process includes: making an object slice by slice, including dispensing a first quantity of each of multiple liquid functional agents on to a layer of fusable build material and then irradiating the layer of build material; while making the object, identifying a deviant region in a slice; and dispensing a second quantity different from the first quantity of at least one of the functional agents into a location corresponding to the deviant region.

In one example, an additive manufacturing process includes: making an object slice by slice, including dispensing a first quantity of each of multiple liquid functional agents on to a layer of fusable build material and then irradiating the layer of build material; while making the object, identifying a deviant region in a slice; and dispensing a second quantity different from the first quantity of at least one of the functional agents into a location corresponding to the deviant region.

In one example, a 3D printing system includes a support structure generator to identify a breakaway support to temporarily support part of the object, to design a wedge shaped groove between a portion of the object and the support, the groove ending at a line along which the support intersects the object, and to generate a digital object model that includes the support and the groove. The system also includes a 3D printer to print the object, support and groove based on the object model.

A method of forming a three-dimensional object is carried out by: (a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween; (b) filling the build region with a polymerizable liquid, the polymerizable liquid including a mixture of (i) a light polymerizable liquid first component, and (ii) a second solidifiable component that is different from the first component; (c) irradiating the build region with light through the optically transparent member to form a solid polymer scaffold from the first component and also advancing the carrier away from the build surface to form a three-dimensional intermediate having the same shape as, or a shape to be imparted to, the three-dimensional object, and containing the second solidifiable component carried in the scaffold in unsolidified and/or uncured form; and (d) concurrently with or subsequent to the irradiating step, solidifying and/or curing the second solidifiable component in the three-dimensional intermediate to form the three-dimensional object.

A method of forming a three-dimensional object is carried out by: (a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween; (b) filling the build region with a polymerizable liquid, the polymerizable liquid including a mixture of (i) a light polymerizable liquid first component, and (ii) a second solidifiable component that is different from the first component; (c) irradiating the build region with light through the optically transparent member to form a solid polymer scaffold from the first component and also advancing the carrier away from the build surface to form a three-dimensional intermediate having the same shape as, or a shape to be imparted to, the three-dimensional object, and containing the second solidifiable component carried in the scaffold in unsolidified and/or uncured form; and (d) concurrently with or subsequent to the irradiating step, solidifying and/or curing the second solidifiable component in the three-dimensional intermediate to form the three-dimensional object.

An apparatus (1) for manufacturing a three-dimensional object from particulate material, the apparatus comprising: a work space (100) bounded by a first side wall (100A) on a first side of the work space, and a second side wall (100B) on a second side of the work space, the first side wall opposing the second side wall; a build bed (170) having a build bed surface (160), the build bed surface being comprised in the floor of the work space and having a first edge (160′) on the first side of the work space, towards the first side wall, and a second edge (160″) on the second side of the work space, towards the second side wall; a first gas inlet (101A) at or near the first side wall; a second gas inlet (101B) at or near the second side wall; a first gas outlet (102A) above the floor (100C) of the work space, the position of the first gas outlet being coincident with the first edge of the build bed surface, or between the first edge of the build bed surface and the first gas inlet; and a second gas outlet (102B) above the floor of the work space, the position of the second gas outlet being coincident with the second edge of the build bed surface, or between the second edge of the build bed surface and the second gas inlet; wherein the first gas outlet is positioned higher in the work space than the first gas inlet, and the second gas outlet is positioned higher in the work space than the second gas inlet; and wherein one or more flow devices (210, 211, 212) are operable to create first and second gas flows between the first gas inlet and the first gas outlet, and between the second gas inlet and the second gas outlet, respectively, such as to create respective first and second gas curtains on the first and second sides of the work space in use.

An apparatus (1) for manufacturing a three-dimensional object from particulate material, the apparatus comprising: a work space (100) bounded by a first side wall (100A) on a first side of the work space, and a second side wall (100B) on a second side of the work space, the first side wall opposing the second side wall; a build bed (170) having a build bed surface (160), the build bed surface being comprised in the floor of the work space and having a first edge (160′) on the first side of the work space, towards the first side wall, and a second edge (160″) on the second side of the work space, towards the second side wall; a first gas inlet (101A) at or near the first side wall; a second gas inlet (101B) at or near the second side wall; a first gas outlet (102A) above the floor (100C) of the work space, the position of the first gas outlet being coincident with the first edge of the build bed surface, or between the first edge of the build bed surface and the first gas inlet; and a second gas outlet (102B) above the floor of the work space, the position of the second gas outlet being coincident with the second edge of the build bed surface, or between the second edge of the build bed surface and the second gas inlet; wherein the first gas outlet is positioned higher in the work space than the first gas inlet, and the second gas outlet is positioned higher in the work space than the second gas inlet; and wherein one or more flow devices (210, 211, 212) are operable to create first and second gas flows between the first gas inlet and the first gas outlet, and between the second gas inlet and the second gas outlet, respectively, such as to create respective first and second gas curtains on the first and second sides of the work space in use.

An example of a three-dimensional (3D) build material composition includes from about 70 wt % to about 95 wt % of polyamide particles, based upon a total weight of the build material composition; and from about 5 wt % to about 30 wt % of biodegradable polyester filler particles, based upon the total weight of the build material composition. The biodegradable polyester filler particles are present in the build material composition without any additional filler particles.