B29C48/36

PROCESS FOR RECYCLING PROPYLENE-ETHYLENE COPOLYMERS

The present invention provides a process for recycling propylene-ethylene copolymers to obtain polymers having good optical and mechanical properties, as well as good processability. The invention further provides propylene-ethylene copolymer pellets obtained from the process, articles comprising or consisting of such pellets and the use of the propylene-ethylene copolymer pellets for injection molding applications. The process comprising the steps of (a) polymerizing propylene and ethylene in the presence of a single site catalyst in a continuous polymerization reactor under dynamic conditions, (b) collecting the resulting propylene-ethylene copolymer powders from step (a) to obtain a mixture (M) of propylene-ethylene copolymer powders having a MFR.sub.2 (ISO 1133, 230 C., 2.16 kg) in a raffle of from 1.5 to 80.0 g/ 10 min and an ethylene content in a range of from 1.0 to 4.0 wt. % based on the total weight of the mixture (M), (c) compounding said mixture (M) in an extruder in the presence of a radical initiator, and a clarifying agent in an amount of from 0.01 to 1.0 wt. %, based on the total weight of the mixture of propylene-ethylene copolymer powders, and (d) extruding the above mixture into pellets; wherein, in step a), the dynamic conditions are such that the ethylene content and the melt flow rate (MFR.sub.2) of the resulting copolymer gradually changes from a first predetermined ethylene content, E1, to a second predetermined ethylene content, E2, and from a first predetermined melt flow rate, MFR.sub.2-1, to a second predetermined melt flow rate, MFR.sub.2-2; wherein collecting the copolymer powders in step b) is started when the polymer produced in step a) has a first ethylene content, E1, and a melt flow rate MFR.sub.2-1, and collecting the copolymer powders in step b) is stopped when the polymer produced in step a) has a second ethylene content, E2, and a melt flow rate MFR.sub.2-2; and wherein said pellets obtained in step d) have (i) a MFR.sub.2 (ISO 1133, 230 C., 2.16 kg) in the range of from 20 to 120 g/10 in, (ii) a ratio of MFR.sub.2 pellets/MFR.sub.2 powder>1, (iii) an ethylene content in a range of from 1.0 to 4.0 wt %, (iv) a crystallization temperature Tc, determined by DSC according to ISO 11357-3:1999 in the range of from 100 to 125 C., and (v) a flexural modulus, determined in a 3-point-bending according to ISO 178 on injection molded specimens of 80104 mm, prepared in accordance with EN ISO 1873-2, of 850 MPa or more.

FILAMENT HEATERS CONFIGURED TO FACILITATE THERMAL TREATMENT OF FILAMENTS FOR EXTRUDER HEADS IN THREE-DIMENSIONAL OBJECT PRINTERS

An additive manufacturing system includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

FILAMENT HEATERS CONFIGURED TO FACILITATE THERMAL TREATMENT OF FILAMENTS FOR EXTRUDER HEADS IN THREE-DIMENSIONAL OBJECT PRINTERS

An additive manufacturing system includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

Mixer structure for a film die and a film die

A mixer structure for a film die for a polymer melt includes multiple web elements. The web elements include a first web element and a second web element. The first web element and the second web element include at least an end, which is connected to a base. A film die includes a first tool element, a second tool element, and a flow channel for the polymer melt extending between the first tool element and the second tool element. The mixer structure is arranged in the flow channel. The mixer structure is held in at least one of the tool elements by a holding element.

Process and system for fabricating a colored powder coating composition from solid filaments
10836077 · 2020-11-17 ·

A process and system for rapidly fabricating small batches of powder coating compositions having desired colors from one or more solid input filaments. An additive manufacturing filament fabricator feeds one or more single-color solid polymer input filaments into a heated mixer in accordance with an input formulation to be liquefied and mixed to produce a homogenous extrudate mixture. The extrudate mixture is solidified on an extrudate receiving platform and is then comminuted by an extrudate mill into a finished powder coating composition having a desired color.

Filament heaters configured to facilitate thermal treatment of filaments for extruder heads in three-dimensional object printers

An apparatus includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

Filament heaters configured to facilitate thermal treatment of filaments for extruder heads in three-dimensional object printers

An apparatus includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

Overturning device for overturning molten material and purging method

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least a melt guidance means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) at the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) in the centre (32) of the melt outlet (30).

Device for reducing microbiological contaminants of container products

A device for reducing the microbiological contaminants of container products made predominantly of plastics materials feeds a plastics granulate to an extruder assembly (19) that melts the granulate. The granulate is subsequently supplied to a form-fill-seal machine for producing a container product. A guide assembly (35) guides the plasticated plastic material from the extruder assembly (19) to the machine. At least one guide assembly (35) has at least one flow or channel guide (41) for the melted plastics material, so that microbiological contaminants are guided predominantly into the interior of the wall of the polymeric tube that interior is enclosed by regions of the plastic material that are less contaminated.

Polyethylene terephthalate coloring systems and methods
10751915 · 2020-08-25 · ·

A method of manufacturing a plurality of colors of bulked continuous carpet filament from a single multi-screw extruder which, in various embodiments, comprises: (A) passing PET through an extruder that melts the PET and purifies the resulting PET polymer melt; (B) splitting the extruded polymer melt into a plurality of melt streams and adding a colorant to each of the plurality of melt streams; (C) using one or more static mixers (e.g., thirty six static mixers) to substantially uniformly mix (e.g., homogeneously mix) each of the plurality of melt streams with its respective added colorant; and (D) feed each of the uniformly mixed and colored plurality of melt streams into a respective spinning machines that turns the polymer into filament for use in manufacturing carpet, rugs, and other products.