JP7071865B2 - Polymer powder and how to use it - Google Patents

Description

Mutual reference to related applications This application is for US provisional patent application No. 62 / 446,470 filed January 15, 2017, and US provisional patent application No. 62 / 446,460 filed January 15, 2017. No., Demands the Benefits of US Provisional Patent Application No. 62 / 446,462 filed January 15, 2017, and US Provisional Patent Application No. 62 / 446,464 filed January 15, 2017. do. The contents of these prior applications are incorporated herein by reference in their entirety.

Technical Fields The present disclosure relates generally to adaptive manufacturing techniques and methods, and more specifically to polyethers for use in selective laser sintering (“SLS” or “LS”). A method for preparing an ether ketone (“PEKK”) copolymer powder, a PEKK copolymer powder (hereinafter, “PEKK powder”), and a method for additionally (laminating) producing a target product using PEKK powder. Regarding.

It is known to use additive manufacturing techniques and methods with polymer powders to produce high performance products for use in various industries (eg, aerospace, industry, medicine, etc.).

SLS is an additive manufacturing method that selectively dissolves a powder material into a desired three-dimensional object using electromagnetic radiation from a laser. The laser selectively melts the powder material by scanning the cross-sectional layer generated from the 3D digital description of the desired object onto the top layer of the bed of the powder material. After scanning the cross-sectional layer, the powder bed is lowered by one layer in the z-axis direction, a new top layer of powder material is applied to the powder bed, and the powder bed is rescanned. This process is repeated until the object is completed. When completed, the object is formed in a "cake" of undissolved powder material. The formed object is pulled out of the cake. The powder material from the cake can be recovered, sieved, combined with the unused powder material and used in subsequent SLS processes.

PEKK powders are of particular interest in SLS processes because objects made from PEKK powders are characterized by flame retardancy, good biocompatibility, and high resistance to hydrolysis and radiation. PEKK powder is distinguished from ordinary plastic powder by its heat resistance and chemical resistance at increased temperatures.

The SLS machine generally preheats the PEKK powder placed on the powder bed to a temperature close to the melting point of the powder. Preheating the PEKK powder makes it easier for the laser to raise the temperature of the PEKK powder to its melting point and suppresses unwanted distortion of the object formed during cooling. A method for preheating PEKK powder is considered, for example, in US Patent Application No. 14 / 472,817, filed August 29, 2014.

U.S. Patent Application No. 14 / 472,817

PEKK with improved strength (eg, improved tensile strength along the z-axis), improved shape accuracy, and less or no structural defects (eg, defects due to improperly dissolved layers). There is an increasing need to manufacture objects with SLS using powders.

Aspects of the invention cover these and other issues.

In aspects of the present invention, one or more of the above tasks is to use a raw material PEKK copolymer material (hereinafter "raw material PEKK") rather than preheating the PEKK powder as is normally done in the art. Regarding the discovery that it can be overcome by heat treatment. The heat-treated raw material PEKK copolymer material is subsequently pulverized to form PEKK powder. The particles of the PEKK powder have an irregular shape as compared with the spherical particles of the PEKK powder of the prior art preheated as described above.

The irregularly shaped PEKK powder particles fill more tightly than the conventional spherical PEKK powder particles. It is believed that the higher stability of the bed filling will generally lead to better shape accuracy and, in some cases, greater resistance to machine transients that would otherwise distort the manufactured object. The shape of the voids (eg, size, shape distribution) created by the irregularly shaped PEKK powder particles provides a different form of connection compared to that of the spherical PEKK powder particles, increasing performance consistency and optionally. It is also considered to bring about an improvement in performance.

According to one aspect of the present invention, the method for preparing PEKK powder for use in SLS includes a step of providing (preparing) a raw material non-powder PEKK material and heat-treating the raw material PEKK at least substantially in the raw material PEKK. A step of evaporating all liquid solvents to form at least substantially all of the raw material PEKK in the form of irregularly shaped particles, a step of cooling the raw material PEKK, and a step of crushing the raw material PEKK to form PEKK powder. Including the process of

According to another aspect of the present invention, after the step of providing the raw material non-powder PEKK material and after the providing step, the raw material PEKK is heat-treated to evaporate at least substantially all the liquid solvent in the raw material PEKK to evaporate the raw material. A step of forming at least substantially all of PEKK into irregularly shaped particles, a step of cooling the raw material PEKK after the heat treatment step, and a step of crushing the raw material PEKK to form PEKK powder after the cooling step. A PEKK powder produced according to a method comprising the above is provided.

According to another aspect of the invention, the method of preparing PAEK powder for use in LS comprises the step of providing the raw material non-powder PAEK material and the heat treatment of the raw material PAEK at least substantially in the raw material PAEK. A step of evaporating all liquid solvents to form at least substantially all of the raw material PAEK in the form of irregularly shaped particles, a step of cooling the raw material PAEK, and a step of crushing the raw material PAEK to form PAEK powder. Including the process.

In addition to, or in lieu of, one or more of the features described above, further embodiments of the invention may include one or more of the following features individually or in combination:
The method further comprises the step of sieving the PEKK powder to remove particles having a size outside the range of 30-150 μm;
-The irregularly shaped particles of the raw material PEKK have a particle size several orders of magnitude larger than 150 μm;
-Before the heat treatment process, the raw material PEKK is in the form of a gel or gel;
-The temperature of the raw material PEKK does not exceed 250 ° C during the heat treatment process:
The heat treatment step (i) raises the temperature of the raw material PEKK from room temperature to about 200 ° C. for a first heating period having a duration of at least 1 hour, and (ii) the temperature of the raw material PEKK to a temperature of about 200 ° C. Includes a second heating period with a duration of several hours retained;
The heat treatment step is (i) a third heating period in which the temperature of the raw material PEKK is raised from about 200 ° C. to about 225 ° C., and (ii) at least one hour in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C. Further includes a fourth heating period having a duration of;
The heat treatment step is (i) a fifth heating period in which the temperature of the raw material PEKK is raised from about 225 ° C. to about 250 ° C., and (ii) at least one hour in which the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C. Further includes a sixth heating period having a duration of;
The heat treatment step (i) keeps the temperature of the raw material PEKK at about 200 ° C. for the first heating period having a duration of 1 hour to raise the temperature of the raw material PEKK from room temperature to about 200 ° C. A second heating period with a duration of 7 hours and a third heating period with a duration of 0.5 hours that raises the temperature of (iii) raw material PEKK from about 200 ° C to about 225 ° C. (Ii) A fourth heating period with a duration of 1.5 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) an increase in the temperature of the raw material PEKK from about 225 ° C. to about 250 ° C. Includes a fifth heating period with a duration of 0.5 hours to allow and (ii) a sixth heating period with a duration of 2 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C.;
The first heating period in which the heat treatment step has a duration of 0.5 hours for (i) raising the temperature of the raw material PEKK from room temperature to about 200 ° C. and (ii) the temperature of the raw material PEKK at about 200 ° C. A second heating period with a duration of 4 hours held in, and a third heating period with a duration of 0.5 hours that raises the temperature of (iii) raw material PEKK from about 200 ° C to about 225 ° C. And (ii) a fourth heating period having a duration of 4 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) raising the temperature of the raw material PEKK from about 225 ° C. to about 250 ° C. Includes a fifth heating period with a duration of 0.5 hours to allow and (ii) a sixth heating period with a duration of 5 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C.;
The heat treatment process involves placing the raw material PEKK in an evaporating dish (pan) and heating both the raw material PEKK and the evaporating dish in a convection oven;
-The cooling process is performed by cooling the raw material PEKK only naturally;
-The heating process causes coalescence of irregularly shaped particles in the raw material PEKK:
-At least substantially all particles of PEKK powder are at least several orders of magnitude smaller than at least substantially all particles of raw material PEKK.

These and other aspects of the invention will become apparent in the light of the drawings and detailed description set forth below.

FIG. 1 shows an SLS machine. FIG. 2 is an image showing an enlarged view of the raw material PEKK flakes. FIG. 3 plots the temperature during the heating and cooling steps of one embodiment of the method as a function of time. FIG. 4 plots the temperature during the heating and cooling steps of another embodiment of the method as a function of time. FIG. 5 is an enlarged view of a plurality of PEKK particles after the pulverization step of this method. FIG. 6 is a table showing data of PEKK powder composition excluding carbon fibers. FIG. 7 is a table showing data of a PEKK powder composition containing carbon fibers.

One aspect of the invention comprises the method of preparing a polymer powder for SLS or LS.

One type of polymer powder is a polyaryletherketone (“PAEK”) polymer. PAEK is interesting in the SLS process because parts made from PAEK powder or PAEK granules are characterized by flame retardancy, good biocompatibility, and high resistance to hydrolysis and radiation. PAEK powders are distinguished from ordinary plastic powders by their heat resistance and chemical resistance at elevated temperatures. PAEK polymer powder can be polyetheretherketone (“PEEK”), polyetherketoneketone (“PEKK”), polyetherketone (“PEK”), polyetheretherketoneketone (“PEEK”), or polyetherketoneether. It can be a powder from the group consisting of ketone ketone (“PEKEKK”).

More specifically, the method is useful for preparing PEKK polymer powders for use in LS. PEKK is known in the art and can be prepared using any suitable polymerization method, including the methods described in the following patents, where each patent is cited in its entirety for all purposes. Incorporated herein. US Pat. No. 3,065,205, US Pat. No. 3,441,538, US Pat. No. 3,442,857, US Pat. No. 3,516,966, US Pat. No. 4, , 704,448, US Pat. No. 4,816,556, and US Pat. No. 6,177,518. PEKK polymers differ from the general classification of PAEK polymers in that they often contain two different isomers of the ketone-ketone type as repeating units. These repeating units can be represented by the following formulas I and II,
-AC (= O) -BC (= O) -I
-AC (= O) -DC (= O) -II
Here, A is a p, p'-Ph-O-Ph group, Ph is a phenylene group, B is p-phenylene, and D is m-phenylene. The ratio of Formula I: Formula II isomers, commonly referred to as the T: I ratio in PEKK, is chosen to alter the overall crystallinity of the polymer. The T: I ratio generally varies from 50:50 to 90:10 and, in some embodiments, from 60:40 to 80:20. Compared with a small T: I ratio such as 60:40, a larger T: I ratio such as 80:20 gives a higher crystallinity.

The crystal structure, polymorphism, and homopolymeric forms of PEKK are described, for example, in Cheng, Z. et al. D. Et al., "Polymorphism and crystal structure in poly (aryl ether ketone ketone) s (identification of homologous images and crystal structures in poly (aryl ether ketone ketone))" Macromol. Chem. Phys. Researched and reported on pages 197, 185-213 (1996), the entire disclosure of which is incorporated herein by reference. In this paper, all paraphenylene bonds [PEKK (T)], one metaphenylene bond [PEKK (I)], or alternating T and I isomers [PEKK (T / I)]. PEKK homopolymers with are being studied. PEKK (T) and PEKK (T / I) show crystalline polymorphisms depending on the crystallization conditions and methods.

In PEKK (T), two crystal morphologies, morphology I and II, are observed. Form I can be produced when the sample crystallizes from melting at low supercooling, while Form II is generally cold crystallized from the glass state by solvent-induced crystallization or at relatively high supercooling. Seen by. PEKK (I) has only one crystal unit cell belonging to the same classification as the form I structure of PEKK (T). The c-axis dimension of the unit cell is determined as three phenylenes with a zigzag structure, with meta-phenylene on the backbone plane. PEKK (T / I) exhibits crystal forms I and II (as in the case of PEKK (T)) and, under certain conditions, exhibits form III.

Suitable PEKKs can be obtained from multiple commercial sources under various trade names. For example, polyetherketone ketones are OXPEKK®-C Polymers, OXPEKK®-CE Polymers, OXPEKK®-D Polymers and OXPEKK®-SP Polymers, OXPEKK®-. Sold under the brand name OXPEKK® polymer by Oxford Performance Materials, South Windsor, South Windsor, USA, including N Polymer, OXPEKK®-ESD Polymer. Polyetherketone Ketone polymers are also manufactured and supplied by Arkema. In addition to using polymers with a particular T: I ratio, a mixture of polyetherketone ketones can be used.

The present disclosure is presented with reference to PAEK polymers, and in particular PEKK polymers, but the present disclosure is not limited thereto. Those skilled in the art familiar with the present disclosure will appreciate that the invention can be used with other forms of polymers useful in LS, and with other materials useful in LS, including but not limited to metals and ceramics. You will understand.

Referring to FIG. 1, an example of the LS system 10 is exemplified, the LS system 10 includes a first chamber 20 having an actuable piston 24 disposed internally. The bed 22 is arranged at the end of the piston 24. It should be understood that the term "bed" means a physical structure supported on a piston, or the top layer of powder placed on a piston. The temperature of the bed 22 can be variably controlled by a controller 60 that communicates with a heating element (not shown) in and / or around the bed 22. The second chamber 30 is adjacent to the first chamber 20. The second chamber 30 includes a table surface 32 disposed on the end of an internally disposed piston 34. The powder 36 used in the LS system 10 is stored in a second chamber 30 prior to the sintering step.

During operation of the LS system 10, the spreader 40 translates across the top surface of the first chamber 20 and uniformly disperses the layer of powder 36 over the top surface of the bed 22 or the material previously placed on the bed 22. Let me. The LS system 10 preheats the powder material 36 placed on the bed 22 to a temperature close to the melting point of the powder. Generally, the powder layer is dispersed to have a thickness of 125 μm, but the thickness of the powder layer can be increased or decreased depending on the particular LS process and within the limits of the LS system.

The laser 50 and the scanning device 54 are arranged above the bed 22. The laser 50 sends the beam 52 to the scanning device 54, which then distributes the laser beam 56 across the layer of powder 36 placed on the bed 22 according to the modeling data. The laser is a powder material (eg, PEKK powder prepared according to the methods of the present disclosure) by scanning a cross section generated from a three-dimensional digital description of the part on the surface of the bed on which the powder material layer is placed. Is selectively melted. The laser 50 and the scanning device 54 communicate with the controller 60. After scanning the cross section, the bed 22 descends by the thickness of one layer (indicated by the down arrow), a new layer of powder material is placed on the bed 22 by the spreader 40, and the bed 22 is rescanned by the laser. To. This process is repeated until the model 28 is completed. During this process, the piston 34 in the second chamber is progressively elevated (indicated by an upward arrow) to ensure a sufficient supply of powder 36.

Next, the process of this method for preparing PAEK powder (for example, PEKK powder) for use in SLS will be described.

First, the raw material PEKK is provided. Raw material PEKK is commercially available from companies such as Arkema of King of Prussia, Pennsylvania, USA and Cytec Industries Inc. of Woodland Park, NJ, USA. ing. The raw material PEKK is generally flushed from a chemical reactor and then washed. The raw material PEKK is a non-powder material. That is, the raw material PEKK is not in the form of powder. As shown in FIG. 2, the raw material PEKK200 is in the form of irregularly shaped particles 202 (eg, slightly rounded, elongated, flat particles, etc.) and has a similar appearance to Rice Krispies® cereals. .. The irregularly shaped particles of the raw material PEKK have, for example, a particle size several orders of magnitude larger than 150 μm. The rest of the raw material PEKK can be in the form of a gel or gel caused by a certain amount of liquid solvent (eg, orthodichlorobenzene (ODCB)) remaining from the process of producing the raw material PEKK, other solvents and volatiles. ..

After the step of providing the raw material PEKK, a heat treatment step is performed which includes placing the raw material PEKK in a shallow evaporating dish and heating both in a convection oven. Raise the temperature to 200 ° C over 1 hour. The temperature is maintained at 200 ° C. for several hours (eg, 5 or 6 hours). The temperature is raised to 225 ° C for the second time. The temperature is maintained at 225 ° C. for at least 1 hour, preferably 1 to 4 hours. The temperature is then raised to 250 ° C. for the third time. The temperature is kept at 250 ° C. for at least 1 hour, preferably 1 to 4 hours. The temperature of the raw material PEKK does not exceed 250 ° C. during the heat treatment step and therefore remains below the melting temperature of the raw material PEKK.

The heat treatment step evaporates the remaining liquid solvent and other impurities, resulting in at least substantially all of the raw material PEKK in the form of irregularly shaped particles. The heat treatment process also causes the coalescence of irregularly shaped particles. However, even after the heat treatment step, the bulk density of the raw material PEKK remains low.

The duration and temperature of each heating period during the heat treatment step can be selected based on the expected amount of impurities in the raw material PEKK. The total duration of the heat treatment step directly correlates with the amount (or expected amount) of impurities (eg, liquid solvent) in the raw material PEKK.

Referring to FIG. 3, in one embodiment where the raw material PEKK was determined to be about 99.75% pure by the ASTM E1868 dry weight loss test method, the heat treatment step was a first heating period having a duration of 1 hour. A first heating period 310 in which the temperature of the raw material PEKK is raised from room temperature to about 200 ° C. 310, and (ii) a duration of 7 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 200 ° C. A second heating period 312 with time, a third heating period 314 with a duration of 0.5 hours that raises the temperature of (iii) raw material PEKK from about 200 ° C to about 225 ° C, and (ii) raw material. A fourth heating period 316 with a duration of 1.5 hours in which the temperature of PEKK is maintained at a temperature of about 225 ° C. and (i) raising the temperature of the raw material PEKK from about 225 ° C. to about 250 ° C. It comprises a fifth heating period 318 having a duration of 5 hours and (ii) a sixth heating period 320 having a duration of 2 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C.

Referring to FIG. 4, in another embodiment where the raw material PEKK was determined to have a purity of about 99.5% by the ASTM E1868 dry weight loss test method, the heat treatment step (i) raises the temperature of the raw material PEKK from room temperature to about 200. A first heating period 410 having a duration of 0.5 hours to raise to ° C. and a second heating period having a duration of 4 hours (ii) keeping the temperature of the raw material PEKK at a temperature of about 200 ° C. 412, a third heating time 414 having a duration of 0.5 hours to raise the temperature of the (iii) raw material PEKK from about 200 ° C to about 225 ° C, and (ii) the temperature of the raw material PEKK of about 225 ° C. A fourth heating period 416 with a duration of 4 hours held at temperature and (i) a fifth with a duration of 0.5 hours raising the temperature of the raw material PEKK from about 225 ° C to about 250 ° C. Includes a heating period 418 and (ii) a sixth heating period 420 having a duration of 5 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C.

After the heat treatment step, a cooling step is performed in which the power of the convection oven heater is turned off and the raw material PEKK is naturally cooled. In some embodiments as shown in FIGS. 3 and 4, the cooling step comprises a cooling period 22, during which the temperature of the oven heater is lowered from about 250 ° C. to 75 ° C. over 0.5 hours. After that, the raw material PEKK is naturally cooled.

After the cooling step, a pulverization step is performed, and the pulverization step includes pulverizing the raw material PEKK to form what is hereinafter referred to as “PEKK powder”. The crushing step can be performed using a known crushing method performed by a company such as Aveka, Inc. of Woodbury, Minnesota, USA. When the grinding step is complete, the particles of the PEKK powder are significantly smaller (ie, orders of magnitude smaller) than the particles of the raw material PEKK. The particles of the PEKK powder are more consistent and regular in shape compared to the particles of the raw material PEKK. However, the PEKK powder particles are still irregularly shaped as compared to the prior art PEKK powder spherical particles preheated as described above. Referring to FIG. 3, a magnified image of the irregularly shaped particles 500 produced by the above process is shown.

After the pulverization step, any treatment step is performed, including sieving the PEKK powder or other treatment to remove particles having a size outside the range suitable for SLS (eg, 30-150 μm). In some embodiments, the LS composition is formed from PEKK powder and carbon fiber.

The above-mentioned grinding process and powder preparation process were filed by Hexcel Corporation on January 16, 2018, and are co-pending the name "Polymer Powder and Method of Preparing the Same" (polymer powder and its preparation method). It is the subject of the US patent application Nos. XX / XXX, XXX. The disclosure of that reference is incorporated herein by reference.

Another aspect of the present invention is a PEKK powder produced according to the above method.

In some embodiments, the method can be performed using a German SLS machine such as the EOSINT P 800 from Germany's EOS GmbH Electrorecto Optical Systems of Krailling. In such an embodiment, the PEKK powder is placed in an overhead gravity feed hopper and then cascaded down (ie, flowed down) into several tiered shelves to make the PEKK powder completely unfilled or unpacked. The PEKK powder is then supplied by a recorder so that the PEKK powder is provided in a flat horizontal layer. It is not necessary to intentionally heat the PEKK powder before it reaches the workspace. The components of an SLS machine that supplies and administers PEKK powder before it reaches the workspace (eg, hopper, recoater, etc.) can become warm, but this is unintentional and of such heating. Do not monitor.

With reference to the tables shown in FIGS. 6 and 7, a first composition substantially consisting of PEKK powder and a second composition substantially consisting of PEKK powder and carbon fiber prepared according to the method of the present disclosure. A comparison of the parts formed from and is shown. This powder is sold under the names OXPEKK®-N and OXPEKK®-ESD, where N comprises PEKK powder and ESD comprises PEKK powder blended with carbon fibers. In both cases, the LS cycle affects the physical and chemical properties of the powder, and the tensile properties of the parts formed from the powder improve with each subsequent production. This comparison confirms that the parts made including the carbon fibers according to the invention of the present disclosure are clearly stronger than the parts made from pure PEKK powder. In both cases, the raw PEKK flakes were processed according to the proposed heat treatment and grinding steps.

Referring to FIG. 6, 600 in Table 1 shows the properties of PEKK powder sold under the brand name OXPEKK®-N by Oxford Performance Materials. Inc. The cake level (Cake Level) in the left column indicates the number of LS cycles received by the OXPEKK®-N powder. Untreated refers to a powder that has not undergone the LS process, cake A undergoes the 1LS process, cake B undergoes the 2LS process, and so on. Each cake level underwent an LS shaping process to produce a test rod in the x-plane. Tensile properties were measured according to ASTM D638. The test rod was manufactured on an EOS P 800 sintering machine. The bed temperature was measured according to the method described in International Patent Application WO 2015301758, Measurement for Analytically Determining SLS Bed Temperature.

Referring to FIG. 7, 700 in Table 2 shows the properties of ESD PEKK powder sold under the brand name OXPEKK®-ESD by Oxford Performance Materials. Inc. This powder was produced according to the above method. Specifically, it is essentially made of PEKK powder and carbon fiber at a weight ratio of 85/15. The D50 of the powder was between 60 μm and 70 μm, and the L50 of the powder was between 70 μm and 80 μm. The particles were substantially non-spherical and the carbon fibers were mixed with the PEKK powder by high-strength mixing to partially embed the fibers in the particles.

The cake level in the left column indicates the number of LS cycles received by the OXPEKK®-ESD powder. Untreated refers to the powder that has not undergone the LS process, cake A has undergone the 1LS process and cake B has undergone the 2LS process. Each ESD cake level underwent an LS shaping process to produce a test rod in the x-plane. Tensile properties were measured according to ASTM D638.

The method offers significant advantages over prior art methods for preparing PEKK powders. In contrast to preheating the PEKK powder, which is typically done in the prior art, the method is performed by heat treating the raw material PEKK and then performing a grinding step to form the PEKK powder. Achieves a PEKK powder with irregularly shaped particles as compared to the spherical particles of the PEKK powder. In contrast to conventional wisdom, irregularly shaped PEKK powder particles provide better consistency and better performance than prior art spherical particles. The irregularly shaped PEKK powder particles integrate more tightly, providing greater floor (bed) stability and generally allowing for better shape accuracy. It is also believed that the irregularly shaped PEKK powder particles provide higher resistance to machine transients that cause strain in the manufactured object if it is not irregularly shaped. The shape of the voids (eg, size, shape distribution) created by the irregularly shaped PEKK powder particles results in a different form of consolidation (linkage) compared to that of the spherical PEKK powder particles, providing performance consistency. It is also considered to increase and in some cases bring about an improvement in performance.

The present disclosure describes embodiments of the invention with reference to exemplary embodiments shown in the drawings, but embodiments of the invention are not limited to the exemplary embodiments shown in the drawings. It will be apparent to those skilled in the art that aspects of the invention include more embodiments. Therefore, aspects of the invention should not be limited in the light of the exemplary embodiments shown in the drawings. It will also be apparent to those skilled in the art that changes and amendments can be made without departing from the true scope of this disclosure. For example, in some examples, one or more features disclosed in connection with one embodiment may be used alone or in combination with one or more features of one or more other embodiments. Can be used.
The embodiments or embodiments that may be included in the present invention are summarized as follows.
[1].
A method of preparing PEKK powder for use in SLS.
The process of providing raw material non-powder PEKK material and
After the providing step, the raw material PEKK is heat-treated to evaporate at least substantially all the liquid solvent in the raw material PEKK, and at least substantially all of the raw material PEKK is formed into irregularly shaped particles. Process and
After the heat treatment step, a step of cooling the raw material PEKK and a step of cooling the raw material PEKK.
A method comprising the step of pulverizing the raw material PEKK to form PEKK powder after the cooling step.
[2].
The method according to item 1 above, further comprising a step of sieving the PEKK powder to remove particles having a size outside the range of 30 to 150 μm.
[3].
The method according to item 1 above, wherein the irregularly shaped particles of the raw material PEKK have a particle size several orders of magnitude larger than 150 μm.
[4].
The method according to item 1 above, wherein the raw material PEKK is in the form of a gel or gel before the heat treatment step.
[5].
The method according to item 1 above, wherein the temperature of the raw material PEKK does not exceed 250 ° C. during the heat treatment step.
[6].
The heat treatment step has (i) a first heating period having a duration of at least 1 hour that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) the temperature of the raw material PEKK is about 200 ° C. The method of item 1 above, comprising a second heating period having a duration of several hours held at temperature.
[7].
The heat treatment step is (i) a third heating period in which the temperature of the raw material PEKK is raised from about 200 ° C. to about 225 ° C., and (ii) at least the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C. 6. The method of item 6 above, further comprising a fourth heating period having a duration of 1 hour.
[8].
The heat treatment step is (i) a fifth heating period in which the temperature of the raw material PEKK is raised from about 225 ° C. to about 250 ° C., and (ii) at least the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C. 7. The method of item 7 above, further comprising a sixth heating period having a duration of 1 hour.
[9].
The heat treatment step has (i) a first heating period having a duration of 1 hour that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) a temperature at which the temperature of the raw material PEKK is about 200 ° C. A second heating period having a duration of 7 hours and (iii) a third heating having a duration of 0.5 hours to raise the temperature of the raw material PEKK from about 200 ° C to about 225 ° C. A period, (ii) a fourth heating period having a duration of 1.5 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) a temperature of the raw material PEKK from about 225 ° C. A fifth heating period having a duration of 0.5 hours to raise to about 250 ° C. and (ii) a sixth having a duration of 2 hours keeping the temperature of the raw material PEKK at a temperature of about 250 ° C. The method according to item 1 above, which includes a heating period.
[10].
The heat treatment step has (i) a first heating period having a duration of 0.5 hours that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) the temperature of the raw material PEKK is about 200 ° C. A second heating period having a duration of 4 hours maintained at the temperature of (iii) and a third having a duration of 0.5 hours raising the temperature of the raw material PEKK from about 200 ° C to about 225 ° C. And (ii) a fourth heating period having a duration of 4 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) a temperature of the raw material PEKK from about 225 ° C. A fifth heating period having a duration of 0.5 hours to raise to about 250 ° C. and (ii) a sixth having a duration of 5 hours keeping the temperature of the raw material PEKK at a temperature of about 250 ° C. The method according to item 1 above, which includes a heating period.
[11].
The method according to item 1, wherein the heat treatment step comprises placing the raw material PEKK in an evaporating dish and heating both the raw material PEKK and the evaporating dish in a convection oven.
[12].
The method according to item 1, wherein the cooling step is performed by cooling the raw material PEKK only naturally.
[13].
The method according to item 1, wherein the heating step causes coalescence of irregularly shaped particles of the raw material PEKK.
[14].
The method according to item 1, wherein at least substantially all the particles of the PEKK powder are at least several orders of magnitude smaller than at least substantially all the particles of the raw material PEKK.
[15].
The process of providing raw material non-powder PEKK material and
After the providing step, the raw material PEKK is heat-treated to evaporate at least substantially all of the liquid solvent in the raw material PEKK into irregularly shaped particles of at least substantially all of the raw material PEKK. And the process to do
After the heat treatment step, a step of cooling the raw material PEKK and a step of cooling the raw material PEKK.
A PEKK powder produced according to a method including a step of pulverizing the raw material PEKK to form a PEKK powder after the cooling step.
[16].
A method of preparing PAEK powder for use in LS.
The process of providing raw non-powder PAEK materials and
After the providing step, the raw material PAEK is heat treated to evaporate at least substantially all of the liquid solvent in the raw material PAEK into irregularly shaped particles of at least substantially all of the raw material PAEK. And the process to do
After the heat treatment step, a step of cooling the raw material PAEK and a step of cooling the raw material PAEK.
A method comprising the step of pulverizing the raw material PAEK to form PAEK powder after the cooling step.

Claims (13)

A method of preparing PEKK powder for use in SLS.
The process of providing raw material non-powder PEKK material and
After the providing step, the raw material PEKK is heat-treated to evaporate at least substantially all the liquid solvent in the raw material PEKK, and at least substantially all of the raw material PEKK is formed into irregularly shaped particles. Process and
After the heat treatment step, a step of cooling the raw material PEKK and a step of cooling the raw material PEKK.
After the cooling step, the step of crushing the raw material PEKK to form PEKK powder is included.
A method in which no heat treatment is performed after this grinding step . The method according to claim 1, further comprising a step of sieving the PEKK powder to remove particles having a size outside the range of 30 to 150 μm. The method according to claim 1, wherein the raw material PEKK is in the form of a gel or a gel before the heat treatment step. The method of claim 1, wherein the temperature of the raw material PEKK does not exceed 250 ° C. during the heat treatment step. The heat treatment step has (i) a first heating period having a duration of at least 1 hour that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) the temperature of the raw material PEKK is about 200 ° C. The method of claim 1, comprising a second heating period having a duration of several hours held at temperature. The heat treatment step is (i) a third heating period in which the temperature of the raw material PEKK is raised from about 200 ° C. to about 225 ° C., and (ii) at least the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C. The method of claim 5 , further comprising a fourth heating period having a duration of 1 hour. The heat treatment step is (i) a fifth heating period in which the temperature of the raw material PEKK is raised from about 225 ° C. to about 250 ° C., and (ii) at least the temperature of the raw material PEKK is maintained at a temperature of about 250 ° C. The method of claim 6 , further comprising a sixth heating period having a duration of 1 hour. The heat treatment step has (i) a first heating period having a duration of 1 hour that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) a temperature at which the temperature of the raw material PEKK is about 200 ° C. A second heating period having a duration of 7 hours and (iii) a third heating having a duration of 0.5 hours to raise the temperature of the raw material PEKK from about 200 ° C to about 225 ° C. A period, (ii) a fourth heating period having a duration of 1.5 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) a temperature of the raw material PEKK from about 225 ° C. A fifth heating period having a duration of 0.5 hours to raise to about 250 ° C. and (ii) a sixth having a duration of 2 hours keeping the temperature of the raw material PEKK at a temperature of about 250 ° C. The method of claim 1, comprising a heating period. The heat treatment step has (i) a first heating period having a duration of 0.5 hours that raises the temperature of the raw material PEKK from room temperature to about 200 ° C., and (ii) the temperature of the raw material PEKK is about 200 ° C. A second heating period having a duration of 4 hours maintained at the temperature of (iii) and a third having a duration of 0.5 hours raising the temperature of the raw material PEKK from about 200 ° C to about 225 ° C. And (ii) a fourth heating period having a duration of 4 hours in which the temperature of the raw material PEKK is maintained at a temperature of about 225 ° C., and (i) a temperature of the raw material PEKK from about 225 ° C. A fifth heating period having a duration of 0.5 hours to raise to about 250 ° C. and (ii) a sixth having a duration of 5 hours keeping the temperature of the raw material PEKK at a temperature of about 250 ° C. The method of claim 1, comprising a heating period. The method of claim 1, wherein the heat treatment step comprises placing the raw material PEKK in an evaporating dish and heating both the raw material PEKK and the evaporating dish in a convection oven. The method according to claim 1, wherein the cooling step is performed by cooling the raw material PEKK only naturally. The method according to claim 1, wherein the heating step causes coalescence of irregularly shaped particles of the raw material PEKK. A method of preparing PAEK powder for use in LS.
The process of providing raw non-powder PAEK materials and
After the providing step, the raw material PAEK is heat treated to evaporate at least substantially all of the liquid solvent in the raw material PAEK into irregularly shaped particles of at least substantially all of the raw material PAEK. And the process to do
After the heat treatment step, the step of cooling the raw material PAEK and the step of cooling the raw material PAEK,
After the cooling step, the step of crushing the raw material PAEK to form PAEK powder is included.
A method in which no heat treatment is performed after this grinding step .

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