Patent classifications
B29B13/021
METHOD AND APPARATUS FOR PRODUCING OBJECTS MADE OF POLYMERIC MATERIAL
An apparatus for producing an object from a polymeric material having a melting temperature comprises: a melting device for melting the polymeric material, a heat exchanger for cooling the polymeric material melted by the melting device below the melting temperature, a mould arranged downstream of the heat exchanger for forming the object from the polymeric material, while the polymeric material has a temperature lower than said melting temperature, a heat recovery device associated with the heat exchanger, the heat recovery device being configured to recover at least part of the heat released by the polymeric material to the heat exchanger.
Method for solid freeform fabrication
The present invention provides methods, processes, and systems for the manufacture of three-dimensional articles made of polymers using 3D printing. A layer of prepolymer is deposited on a build plate to form a powder bed. The deposited powder bed is heated to about 50 C. to about 170 C. Then, a solution of activating agent is printed on the powder bed in a predetermined pattern, and a stimulus is applied converting the prepolymer to the final polymer. After a predetermined period of time, sequential layers are printed to provide the three-dimensional article. The three-dimensional object can be cured to produce the three-dimensional article composed of the final polymers.
PROCESSES FOR PRODUCING POLYMER POWDERS
The present disclosure is directed to improved poly(arylene ether ketone) powders for use in laser sintering.
HEAT TREATED POLYMER POWDERS
The invention relates to heat treatment of polymorphic semicrystalline or crystallizable polymers to increase the content of the highest melting crystalline form. Such heat treatment results in a polymer powder that has a consistent, uniform melting range, improved flow and improved durability of the powder particle size for applications that require powder flow at elevated temperatures. In addition to improved powder properties, the articles produced from the powders also exhibit better physical properties in both appearance and in mechanical properties. Thus the invention also includes polymer powders and articles produced by the described processes.
Heat treated polymer powders
The invention relates to heat treatment of polymorphic semicrystalline or crystallizable polymers to increase the content of the highest melting crystalline form. Such heat treatment results in a polymer powder that has a consistent, uniform melting range, improved flow and improved durability of the powder particle size for applications that require powder flow at elevated temperatures. In addition to improved powder properties, the articles produced from the powders also exhibit better physical properties in both appearance and in mechanical properties. Thus the invention also includes polymer powders and articles produced by the described processes.
INTEGRATED TOWER FOR REMOVING VOC FROM POLYPROPYLENE PARTICLES
In a tower integrated by the heating and drying section and the cooling section, both sides of the heating and drying section housing are provided with an air inlet box and an air outlet box; the air inlet box is communicating with a heat exchanger and distribution pipes in the heating and drying section housing, the air outlet box is communicating with distribution pipes in the heating and drying section housing and a dust remover; both sides of the cooling section housing are provided with an air inlet box and an air outlet box; the air inlet box is communicating with a heat exchanger and distribution pipes in the cooling section housing; the air outlet box is communicating with distribution pipes in the cooling section housing and a dust remover. The integral device improves the heat exchange effect and preventing the polypropylene particles from aging.
POLYKETONE POWDER FOR LASER SINTERING
In one instance a semicrystalline polyketone powder useful for additive manufacturing is comprised of a bimodal melt peak determined by an initial differential scanning calorimetry (DSC) scan at 20? C./min and a D.sub.90 particle size of at most 300 micrometers and average particle size of 1 micrometer to 150 micrometers equivalent spherical diameter. In another instance, A composition is comprised of a semicrystalline polyketone powder having a melt peak and a recrystallization peak, wherein the melt peak and recrystallization peak fail to overlap.
MANUFACTURE AND USE OF ANNEALED POLYMER POWDERS SUITABLE FOR SELECTIVE LASER SINTERING
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.
POLYKETONE POWDER FOR LASER SINTERING
A semicrystalline poly ketone powder useful for additive manufacturing may be made by dissolving a polyketone having differential scanning calorimetry (DSC) monomodal melt peak, at a temperature above 50? C. to below the melt temperature of the polyketone, precipitating the dissolved polyketone by cooling, addition of a nonsolvent or combination thereof. The method may be used to form polyketones having a DSC melt peak with an enthalpy greater than the starting polyketone.
Particulates for additive manufacturing techniques
A globule for an additive manufacturing process includes a plurality of additive manufacturing stock particles respectively having a submicron size. A binder fixes the plurality of submicron size additive manufacturing stock particles to one another such that the particles form a globule having a size of less than fifty microns.