Polymer compositions containing polyethylene particles having a multi-modal molecular weight distribution are disclosed. The polymer compositions are well suited to producing porous substrates through a sintering process. Formulations made according to the present disclosure can produce porous substrates having improved flexibility demonstrated by an increased flexural strength while still retaining excellent pressure drop characteristics.

A method for the manufacture of a component comprises the following steps, in sequence using an additive layer manufacturing process to build a three-dimensional net shape of the component; performing a first abrasive blasting operation on a region of a surface of the component; and performing a second abrasive blasting operation on the region. The angle of incidence of the abrasive on the surface in the first abrasive blasting operation is less than the angle of incidence of the abrasive on the surface in the second abrasive blasting operation.

A method for the manufacture of a component comprises the following steps, in sequence using an additive layer manufacturing process to build a three-dimensional net shape of the component; performing a first abrasive blasting operation on a region of a surface of the component; and performing a second abrasive blasting operation on the region. The angle of incidence of the abrasive on the surface in the first abrasive blasting operation is less than the angle of incidence of the abrasive on the surface in the second abrasive blasting operation.

A three-dimensional object may be produced with improved dimensional control by laser sintering a polymer powder having a melting point and melting onset temperature, which has been annealed prior to sintering. The initial melting onset temperature of the polymer is between 50 C. and 170 C. The polymer powder is first annealed at a temperature which is below the polymer melting point, and from 5 C. above the melting onset temperature of the polymer powder to 10 C. below the melting onset temperature. Annealing may be carried out for a period of between 2 hours and 48 hours. A layer of the annealed polymer powder is applied to a carrier; and the layer is irradiated with a laser beam in areas of the layer which correspond to the three-dimensional object to be produced. The steps of applying the annealed polymer powder and irradiating the powder are repeated sequentially until the complete three-dimensional object is prepared. The irradiating step sinters the annealed polymer powder in areas of the layer which correspond to the three-dimensional object, without sintering the annealed polymer powder in other areas.

A three-dimensional object may be produced with improved dimensional control by laser sintering a polymer powder having a melting point and melting onset temperature, which has been annealed prior to sintering. The initial melting onset temperature of the polymer is between 50 C. and 170 C. The polymer powder is first annealed at a temperature which is below the polymer melting point, and from 5 C. above the melting onset temperature of the polymer powder to 10 C. below the melting onset temperature. Annealing may be carried out for a period of between 2 hours and 48 hours. A layer of the annealed polymer powder is applied to a carrier; and the layer is irradiated with a laser beam in areas of the layer which correspond to the three-dimensional object to be produced. The steps of applying the annealed polymer powder and irradiating the powder are repeated sequentially until the complete three-dimensional object is prepared. The irradiating step sinters the annealed polymer powder in areas of the layer which correspond to the three-dimensional object, without sintering the annealed polymer powder in other areas.

The present invention relates to a method for reducing the crystallization temperature an the melting temperature of a polyamide powder resulting from the polymerization of at least one predominant monomer, in which the reduction in the crystallization temperature is greater than the reduction in the melting temperature, said method comprising a step of polymerization of said at least one predominant monomer with at least one different minor comonomer polymerized according to the same polymerization process as said at least one predominant monomer, said at least one minor comonomer being chosen from aminocarboxylic acids, diamine/diacid pairs, lactams and/or lactones, and said at least one minor comonomer representing from 0.1% to 20% by weight of the total blend of said monomers(s) and comonomer(s), preferably from 0.5% to 15% by weight of said total blend, preferably from 1% to 10% by weight of said total blend.

The present invention relates to a method for reducing the crystallization temperature an the melting temperature of a polyamide powder resulting from the polymerization of at least one predominant monomer, in which the reduction in the crystallization temperature is greater than the reduction in the melting temperature, said method comprising a step of polymerization of said at least one predominant monomer with at least one different minor comonomer polymerized according to the same polymerization process as said at least one predominant monomer, said at least one minor comonomer being chosen from aminocarboxylic acids, diamine/diacid pairs, lactams and/or lactones, and said at least one minor comonomer representing from 0.1% to 20% by weight of the total blend of said monomers(s) and comonomer(s), preferably from 0.5% to 15% by weight of said total blend, preferably from 1% to 10% by weight of said total blend.

Methods, systems, and apparatus for multi-scale stereolithography. The apparatus includes a light source for providing a laser beam having a first shape and a first size. The apparatus includes a dynamic aperture having multiple apertures that are of the same or different sizes or shapes. The dynamic aperture is configured to receive the laser beam and modify at least one of the shape or the size of the laser beam. The apparatus includes a platform for holding an object to be printed. The apparatus includes a processor connected to at least one of the light source, the dynamic aperture or the platform. The processor is configured to move the platform to direct the laser beam or direct the laser beam to cure resin onto the object to be printed using a first aperture of the multiple apertures to form the object.

Methods, systems, and apparatus for multi-scale stereolithography. The apparatus includes a light source for providing a laser beam having a first shape and a first size. The apparatus includes a dynamic aperture having multiple apertures that are of the same or different sizes or shapes. The dynamic aperture is configured to receive the laser beam and modify at least one of the shape or the size of the laser beam. The apparatus includes a platform for holding an object to be printed. The apparatus includes a processor connected to at least one of the light source, the dynamic aperture or the platform. The processor is configured to move the platform to direct the laser beam or direct the laser beam to cure resin onto the object to be printed using a first aperture of the multiple apertures to form the object.

A method and a control device for deflection of a laser beam for laser-based additive manufacturing processes includes first and second orthogonally rotatable mirrors designed to reflect the laser beam and guide the laser beam to an irradiation field. The first mirror and the second mirror are secured on respective first and second shafts, with the first mirror performing a continuous first vibration with a first frequency, and the second mirror performing a continuous second vibration with a second frequency different from the first frequency and/or with a phase difference with respect to the first vibration. Each of the two shafts has a known position such that the first vibration is synchronous with the second vibration. The laser is activated/deactivated upon reaching/leaving an irradiation point. The generated vibrations of the mirrors describe a continuous Lissajous curve.