IMPROVED POWDER FOR ADDITIVE MANUFACTURING

Abstract

Disclosed is a composition including at least one polymer, wherein the polymer is in the form of a powder, and wherein the polymer includes at least one thermoplastic polymer. The thermoplastic polymer is selected from at least one polyaryletherketone and/or a copolymer and/or a block-copolymer and/or a polymer blend thereof, wherein the composition has a melt volume rate (MVR) of at least 5 cm.sup.3/10 min and a process of manufacturing and a use thereof. Also disclosed are a process for the manufacture of a construction element and the construction element thereof.

Claims

1. Composition comprising at least one polymer, wherein the polymer is in the form of a powder, and wherein the polymer comprises at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from at least one polyaryletherketone as well as a copolymer and/or block-copolymer and/or a polymer blend thereof, wherein the composition has a melt volume rate (MVR) of at least 5 cm.sup.3/10 min, and/or not more than 55 cm.sup.3/10 min.

2. Composition according claim 1, wherein the at least one polyaryletherketone is selected from the group of polyetherketoneketone (PEKK), from the group of polyetheretherketone (PEEK), from the group of copolymers of PEKK and from the group of copolymers of PEEK.

3. Composition according to claim 1, wherein the polymer comprises at least one semicrystalline polymer, and/or at least one amorphous polymer.

4. Composition according to claim 2, wherein the polyetherketoneketone comprises the following repeat units ##STR00012## wherein the ratio of the repeat unit A to the repeat unit B is between approx. 80:20 to 10:90.

5. Composition according to claim 1, wherein the polyaryletherketone has a melting temperature Tm of at least about 250° C., and/or up to about 320° C., and/or wherein the polyaryletherketone has a glass transition temperature Tg of at least about 120° C., and/or not more than about 200° C.

6. Composition according to claim 2, wherein the polyetherketoneketone (PEKK) has an extrapolated starting temperature of melting T.sub.eim of at least 250° C., and/or up to 285° C.

7. Composition according to claim 2, having a process window.sub.; of at least about 1° C. and/or not more than about 200° C.

8. Composition according to claim 1, wherein the polymer blend comprises a polyaryletherketone-polyetherimide.

9. Composition according to claim 1, wherein the polymer particles of the composition have a particle size distribution as follows: d10=at least 10 μm, d50=at least 25 μm and/or not more than 100 μm, d90=at least 50 μm and/or not more than 150 μm.

10. Composition according to claim 1, wherein the polymer particles of the composition have a particle size distribution as follows: d10=at least 15 μm, and/or not more than 50 μm d50=at least 40 μm and/or not more than 100 μm, d90=at least 70 μm and/or not more than 150 μm, preferably at least 80 μm and/or not more than 120 μm, most preferably not more than 110 μm; wherein the polymer particles are obtained by milling of polymerisation flakes.

11. Composition according to claim 1, wherein the composition has a distribution width (d90-d10)/d50 of not more than 3.

12. Composition according to claim 1, wherein the polymer particles have a sphericity of at least about 0.8.

13. Composition according to claims 1, wherein the composition comprises a primary composition and wherein the content of the primary composition is above 10 wt.% and/or below 60 wt. %, of the total composition.

14. Composition according to claim 1, having a pourability of at least about 1 sec, at and/or not more than about 12 sec.

15. Composition according to claim 1, wherein the composition has a Hausner Factor of at least 1.01 and/or not more than 1.7.

16. Composition according to claims 1, wherein the composition comprises at least one flow agent.

17. Composition according to claim 16, wherein the content of the at least one flow agent in the composition is not more than about 1 wt. %.

18. Composition according to claim 1, wherein the composition has a BET-surface of at least about 0.1 m.sup.2/g and/or not more than about 10 m.sup.2/g.

19. Process for the manufacture of a composition according to claim 1, wherein the process comprises the following steps: (i) providing at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from at least one polyaryletherketone and/or a copolymer and/or block-copolymer and/or a polymer blend thereof, (ii) grinding the polymer, (iii) rounding of the polymer particles, by thermo-mechanical treatment, at a temperature of at least 30° C. and below the melting point Tm of the polymer.

20. Process for the manufacture of a composition according to claim 19, wherein the process further comprises the following step of annealing the composition at a temperature above Tg and below Tm.

21. Process for the manufacture of a construction element, comprising the steps: (i) applying a layer of a composition according to claim 1 onto a production panel, (ii) selectively solidifying the applied layer of the composition at sites representing a cross section of the object to be manufactured, and (iii) lowering the carrier and repeating the steps for applying and solidifying until the construction element, is finished.

22. Process for the manufacture of a construction element, according to claim 21, wherein step i) of applying the layer is applied by at least a double coating, wherein applying of the layer is subdivided into a step of applying a first layer having a first height H1 and a step of applying a second layer having a second height H2, wherein the second layer of height H2 is applied onto the first layer of height H1.

23-25. (canceled)

Description

EXAMPLES

Example 1

[0147] A PEKK with a ratio of terephthalic to isophthalic units of 60:40 was manufactured as follows:

[0148] Ortho-dichlorobenzene (1600 g) and 1,4-(phenoxybenzoyl)benzene (EKKE) (65 g) were placed in a 2 L reactor while stirring under a stream of dry nitrogen. The following acid chlorides were added: terephthaloyl chloride (5.4 g), isophthaloyl chloride (22.2 g) and benzoyl chloride (0.38 g). The reactor was cooled to −5° C. AlCl.sub.3 (115 g) was added while keeping the temperature in the reactor below 5° C. After a homogenization period (about 10 minutes), the reactor temperature was raised by 5° C. per minute up to 90° C. (polymerization started during this temperature increase). The reactor was maintained at 90° C. for 30 minutes and then cooled to 30° C. 400 g of acidic water (3% HCl) was added slowly so as not to exceed a temperature of 90° C. in the reactor. The reactor was stirred for 2 hours and then cooled to 30° C.

[0149] The reaction medium was removed form the reactor and filtration/purification steps are done according the person skilled in the art. After, the purified wet PEKK is dried at 190° C. under vacuum (30mbar) overnight. Flakes were obtained.

Example 2

[0150] The PEKK polymerisation flakes from Example 1 was suitably ground and air classified to a fine powder. The data of the powder is shown in Table A.

TABLE-US-00001 TABLE A PSD Sample <10 bulk density Nr. d10 d50 d90 μm (d90-d10)/d50 [kg/m.sup.3] 1 26.6 65.73 158.3 0.9 2.00 33.6

Example 3

[0151] A polyetherketoneketone (PEKK) was manufactured as to Example 1 and 2.

[0152] The powder was then mixed in a mixer of the type Henschel FML according to Table 1. The mass of the powder is hereinafter referred to as m. Phase 1 refers to the heating phase, i. e., the phase up to the time when the mixture (powder) in the mixer reached the maximum temperature Tmax. Tmax corresponds to the treatment temperature T.sub.B. The speed of the mixer in phase 1 is called D1. The duration of phase 1 is called t.sub.1. Phase 2 is the holding phase, i. e., the phase during which the temperature reached was maintained. The speed of the mixer in phase 2 is called D.sub.2. The duration of phase 2 is called t.sub.2.

[0153] The names m, Tmax, D1, D2, t1, t2 are used as well in the following examples.

[0154] The obtained values for the bulk density S, the BET surface, the fraction of powder particles with a grain size of 10 μm in volume percentage (“% <10 μm”) and the quantiles d10, d50 and d90 of the particle size distribution are given in Table 2.

TABLE-US-00002 TABLE 1 T.sub.max m D.sub.1 D.sub.2 t.sub.1 t.sub.2 t.sub.1 + t.sub.2 Nr. [° C.] [kg] [m/s] [m/s] [min] [min] [min] 1 113 8.5 46.8 46.8 6 14 20

TABLE-US-00003 TABLE 2 PSD Sample <10 bulk density Nr. d10 d50 d90 μm (d90-d10)/d50 [kg/m.sup.3] 1 24.96 59.38 145.4 0.55 2.03 39.8

Example 4

[0155] The powder of Example 3 was annealed at different temperatures (according to Table 3a) in a ventilated furnace (type Nabertherm N250/A) under nitrogen atmosphere for 3 hours. After the annealing, the powder was sieved with a 160 μm sieve on a vibration sieve of the type Perflux 501 (Siebtechnik GmbH, Mühlheim, Germany). The obtained powder values are given in Table 3a.

[0156] On a laser sintering system of type P800 (EOS P800 with Startup-Kit PAEK 3302 CF), test bodies were produced from the resulting three powders (primary powder) with processing parameters given in Table 3b. The layer thickness was 120 μm and was applied by using a double coating process (layer thickness 60 μm). The powders were analysed with respect to processability (process window) and the mechanical characteristics of the laser sintered parts. The values obtained are depicted in Table 3b and 3c.

TABLE-US-00004 TABLE 3a MVR Teim (primary PSD bulk (1st MVR (used Sample Annealing powder) <10 (d90-d10)/ density pourability heat) powder) Nr. [° C.] [cm.sup.3/10 min] d10 d50 d90 μm d50 [kg/m.sup.3] [s] [° C.] [cm.sup.3/10 min] 1 265 52.1 22.7 50.2 105.7 0.6 1.65 39.8 6.3 268.0 47.2 2 270 51.5 23.8 53.2 108.8 0.4 1.60 39.5 6.3 271.4 45.0 3 275 54.3 24.3 54.2 112.4 0.3 1.36 39.2 9.6 276.2 46.3

TABLE-US-00005 TABLE 3b Energy Sample input hatch NCT UBT T.sub.PK Nr. [W * s/mm.sup.3] [° C.] [° C.] [° C.] 1 0,273 274 279 276 2 0,273 275 282 279 3 0,273 278 286 283

[0157] As can be seen, the Non-Curl temperature (NCT) is increased at a higher annealing temperature. Thus, the powders need to be built at a higher process chamber temperature (PK), which increases the ageing of the used powder (stronger drop of MVR value, see table 3a), which results in a worse refresh ratio with increasing heat treat temperature.

TABLE-US-00006 TABLE 3c Young's Tensile Elongation Young's Tensile Elongation Modulus strength at break Modulus strength at break Sample (xy) (xy) (xy) (zx) (zx) (zx) Nr. [MPa] [MPa] [%] [MPa] [MPa] [%] 1 3755 58 1.7 3737 40 1.1 2 3733 58 1.7 3668 41 1.2 3 3802 59 1.7 3883 46 1.2

[0158] The influence of thermal treatment on the mechanical properties are depicted. Tensile strength in z is increased at an annealing temperature of 275° C.

Example 5

[0159] In Example 5, three PEKK types of different melt viscosities were produced in analogy to Example 4. Except, the polymerization time was adjusted (compared to Example 1) to obtain powders with different melt viscosities (MVR). Furthermore, the treatment temperature Tmax of the mixer of Example 5 was between 110-120° C. t2 was adapted for each powder, so that t1+t2 were always kept 25 minutes. The annealing temperature of Example 5 for all three powders was 265° C. The analytical data of the powders are shown in Table 4a.

[0160] Test bodies were produced on a laser sintering system of type P800 (EOS P800 with Startup-Kit PAEK 3302 CF) from the resulting three powders (primary powder) with processing parameters given in Table 4b. The layer thickness was 120 μm and was applied by using a double coating process (layer thickness 60 μm). The powders were analyzed with respect to their processability (process window) and the mechanical characteristics of the laser-sintered parts. The values obtained can be found in Tables 4b and 4c.

TABLE-US-00007 TABLE 4a PSD bulk T.sub.eim Sample MVR (d90-d10)/ density (1.sup.st heat) Nr. [cm.sup.3/10 min] d10 d50 d90 <10 μm d50 [kg/m.sup.3] [° C.] 1 13.3 23.1 52.1 95.9 0.6 1.40 37.7 267.2 2 24.3 25.0 53.4 88.7 0.6 1.19 33.1 267.4 3 58 23.0 54.0 119.1 0.5 1.78 43.3 267.3

TABLE-US-00008 TABLE 4b Energy Sample input hatch NCT UBT TPK Nr. [W * s/mm.sup.3] ier [° C.] [° C.] 1 0,273 269 282 275 2 0,273 271 280 274 3 0,273 275 280 277

[0161] As seen in Tables 4a and 4b, the NCT is increased with increasing MVR value of the powder. This means, that the building temperature (Tpk) is at a higher temperature, which has a negative impact on the ageing and refreshing of the powder. Also, the process window (difference of UBT to NCT) is reduced from 13° C. to only 5° C. with increasing MVR of the powder.

TABLE-US-00009 TABLE 4c Young's Tensile Elongation Young's Tensile Elongation Modulus strength at break Modulus strength at break Sample MVR (xy) (xy) (xy) (zx) (zx) (zx) Nr. [cm.sup.3/10 min] [MPa] [MPa] [%] [MPa] [MPa] [%] 1 13.3 3484 96 3.8 3433 39 1.2 2 24.3 3419 85 3.1 3339 40 1.2 3 55.1 3851 73 2.1 4026 51 1.3

[0162] The influence of the melt viscosity on the mechanical properties is clearly seen in Table 4c. The tensile strength and elongation at break in xy direction strongly increases from 73 to 96 MPa and from 2,1 to 3,8% with a lower MVR, whilst in z-direction the elongation at break is only slightly reduced from 1.3 to 1.2%.

Example 6

[0163] In Example 6, two PEKK types with different particle size distributions were produced in analogy to Example 4. Except, the polymerisation time was adjusted (compared to Example 1) to obtain powders with an MVR of 24 cm.sup.3/10 min after heat treatment. Furthermore, the treatment temperature Tmax of the mixer of Example 6 was between 110-120° C. t2 was adapted for each powder, so that t1+t2 was always kept 25 minutes. The annealing temperature of Example 6 was 265° C. for both powders. The analytical data of the primary powder are shown in Table 5a.

TABLE-US-00010 TABLE 5a PSD bulk Sample MVR (d90-d10)/ density pourability Nr. [cm.sup.3/10 min] d10.sub.dry d50.sub.dry d90.sub.dry <10 μm.sub.dry d50 [kg/m.sup.3] [s] 1 24 25.04 53.35 88.73 0.6 1.19 33.1 8 2 24 21.84 44.98 73.35 0.9 1.15 33.7 15

[0164] The influence of the particle size distribution on the flowability of the powder is clearly visible. The coarse powder shows a better flowability (pourability time is reduced from 15 to 8 seconds).

[0165] Test bodies were produced on a laser sintering system of type P800 (EOS P800 with Startup-Kit PAEK 3302 CF) from the resulting powders (50% refreshed) with processing parameters given in Table 5b. The layer thickness was 120 μm and was applied by using a double coating process (layer thickness 60 μm). The powders were analysed with respect to the mechanical characteristics of the laser-sintered parts. The obtained values are depicted in Table 6.

TABLE-US-00011 TABLE 5b Energy Sample input hatch NCT UBT TPK Nr. [W * s/mm.sup.3] [° C.] [° C.] [° C.] 1 0,273 276 282 278 2 0,273 274 278 276

TABLE-US-00012 TABLE 6 Refresh Young's Tensile Elongation Young's Tensile Elongation ratio of Modulus strength at break Modulus strength at break Sample powder (xy) (xy) (xy) (zx) (zx) (zx) Nr. [%] [MPa] [MPa] [%] [MPa] [MPa] [%] 1 50 3330 83 3.1 3183 50 1.7 2 50 3460 77 2.6 3620 50 1.5

[0166] It can be seen from Table 6, that the powder with the improved pourability of 8 sec shows improved tensile strength and elongation at break in x-y direction,

Example 7

[0167] In Example 7, a PEKK was produced as described in analogy to Example 5. Except, the polymerisation time was adjusted (compared to Example 1) to obtain a powder with an MVR of 22 cm.sup.3/10 min after heat treatment. Furthermore, the treatment temperature Tmax of the mixer from Example 7 was 116° C. t2 was adapted for the powder, so that t1+t2 was kept 25 minutes. The annealing temperature of Example 5 was 265° C.

TABLE-US-00013 TABLE 7a PSD bulk Sample MVR (d90-d10)/ density pourability Nr. [cm.sup.3/10 min] d10 d50 d90 <10 μm d50 [kg/m.sup.3] [s] 1 22.3 24.8 54.0 91.3 0.6 1.23 31.7 —

[0168] Test bodies were produced on a laser sintering system of type P800 (EOS P800 with Startup-Kit PAEK 3302 CF) from the resulting powder (primary powder) with processing parameters given in Table 7b with three different layer thicknesses of 120 μm, 100 μm and 60 μm, by applying a double coating process (layer thickness 60 μm, 50 μm and 30 μm, respectively). The different layer thicknesses were analysed with respect to the mechanical characteristics of the laser sintered parts. The values obtained are depicted in Table 7c.

TABLE-US-00014 TABLE 7b Layer Energy Trial thickness input hatch TPK Nr. [pm] [W * s/mm.sup.3] [° C.] 1 120 0,273 274 2 100 0,273 274 3 60 0,273 274

TABLE-US-00015 TABLE 7c Young's Tensile Elongation Modulus strength at break Density of Trial (zx) (zx) (zx) object Nr. [MPa] [MPa] [%] [g/cm3] 1 3265 39 1,2 1,28 2 3400 49 1,5 1,29 3 3773 48 1,4 1,29

[0169] The influence on the mechanical properties and density of the parts in z-direction is clearly visible. When applying a reduced layer thickness of 100 μm and 60 μm, tensile strength and elongation at break in z-x direction is increased.

Example 8

[0170] In Example 8, a PEKK was produced as described in analogy to Example 4, except, that the polymerization time was adjusted (compared to Example 1) to obtain a powder with an MVR of 23 cm.sup.3/10 min before heat treatment. Furthermore, the treatment temperature Tmax of the mixer of Example 8 was between 110-120° C. t2 was adapted, so that t1+t2 were always kept 25 minutes. Also, the annealing temperature was adjusted. The powder was annealed at different temperatures (according to Table 8a) in a ventilated furnace (type Nabertherm N250/A) under nitrogen atmosphere for 3 hours. After the annealing, the powder was sieved with a 160 μm sieve on a vibration sieve of the type Perflux 501 (Siebtechnik GmbH, Mühlheim, Germany). The obtained powder values are given in Table 8a.

[0171] On a laser sintering system of type P810 test bodies were produced from the resulting three powders (primary powder) with processing parameters given in Table 8b. The layer thickness was 120 μm and was applied by using a double coating process (layer thickness 60 μm). The powders were analysed with respect to processability (process window), the powder bed hardness after the build and the mechanical characteristics of the laser sintered parts. The values obtained are depicted in Table 8b and 8c.

TABLE-US-00016 TABLE 8a MVR bulk bulk (primary density density Teim powder) PSD (primary (used (1st MVR (used Sample Annealing [cm.sup.3/ <10 (d90-d10)/ powder) powder) pourability heat) powder) Nr. [° C.] 10 min] d10 d50 [m.sup.2/g] μm d50 [kg/m.sup.3] [kg/m.sup.3] [s] [° C.] [cm.sup.3/10 min] 1 235 21.8 26.8 57.4 103.9 0.4 1.34 32.1 29.6 7.5 242.2 20.4 2 265 25.7 26.3 57.3 101.8 0.3 1.32 32.9 32.6 4.3 267.8 21.3 3 293 21.1 27.6 56.5 99.0 0.2 1.26 35.4 34.2 5.5 295.0 16.4

TABLE-US-00017 TABLE 8b Energy input Sample hatch NCT UBT T.sub.PK Nr. [W * s/mm.sup.3] [° C.] [° C.] [° C.] 1 0,273 264 278 271 2 0,273 286 288 287 3 0,273 301 305 303

[0172] As can be seen, the Non-Curl temperature (NCT) is increased at a higher annealing temperature. Thus, the powders need to be built at a higher process chamber temperature (PK), which increases the ageing of the used powder (stronger drop of MVR value, see Table 8a), which results in a worse refresh ratio with increasing heat treat temperature. At the lowest annealing temperature, the bulk density of the used powder drops stronger and also the flowability of the powder is poorest.

TABLE-US-00018 TABLE 8c Young's Modulus Tensile Elongation at Sample (xy) strength (xy) break (xy) Nr. [MPa] [MPa] [%] 1 3149 72 2,8 2 3428 85 3,1 3 2907 75 2,7

[0173] The influence of thermal treatment on the mechanical properties are depicted. The highest values are reached at an annealing temperature of 265° C.

Example 9

[0174] In Example 9, a PEKK (sample Nr. 1) was produced in analogy to Example 2 but polymerization time was adjusted to get a viscosity similar to Example 6. It then was mixed as described in Example 3 except the treatment temperature Tmax of the mixer was between 110-120° C. t2 was adapted so that t1+t2 was kept 25 minutes (sample Nr. 2). Afterwards it was annealed (sample Nr. 3) in analogy to Example 4. The annealing temperature of sample 3 was 265° C. A different PEKK was also produced according to Example 9, sample Nr. 3 (sample Nr. 4). The annealing temperature of sample 4 was also 265° C. The data of the powders are shown in Table 9 below. The Hausner ratio was analysed for those powders.

TABLE-US-00019 TABLE 9 Sample Annealing Sphericity Bulk density Hausner ratio Nr. [° C.] [-] [g/cm.sup.3] [ ] 1   0,843 0,258 1,45 2   0,855 0,337 1,47 3 265 0,866 0,331 1,37 4 265 0,865 0,337 1,36

[0175] The obtained values are depicted in Table 9. The influence of thermal treatment on the Hausner ratio is visible. The thermal treatment shows in particular a beneficial effect on flowability as measured by the Hausner ratio. As can be seen, sphericity is influenced by mixing and thermal treatment.

Example 10

[0176] In Example 10, a PEKK was produced in analogy to Example 2 but polymerization time was adjusted to obtain a powder with an MVR of 29 cm.sup.3/10 min before heat treatment (sample Nr. 1). It was then mixed as described in Example 3, except that the treatment temperature Tmax of the mixer was between 110-120° C. t2 was adapted so that t1+t2 was kept 25 minutes (sample Nr. 2). Afterwards sample Nr. 2 was annealed in analogy to Example 4 but the annealing time was adjusted (sample Nr. 3). The annealing temperature of sample 3 was 265° C. The BET analysis was performed with these samples. The obtained data is shown in Table 10.

TABLE-US-00020 TABLE 10 Sample Annealing BET Nr. [° C.] [m.sup.2/g] 1   1,9 2   1,2 3 265 1,0

[0177] The obtained values are depicted in Table 10. The influence of mixing and thermal treatment on the BET surface of particles is visible.

Methods Section

Rounding By Thermo-mechanical Treatment

[0178] Thermo-mechanical treatment of the polymer particles can be carried out preferably in a mixer, at a temperature of at least 30° C. and below the melting point Tm of the polymer. A mixer that can be used is e.g. a Henschel mixer of the type FML, machine size 40 (Zeppelin Systems GmbH, Germany).

Hausner Ratio

[0179] The Hausner ratio H provides information about the compressibility of a bulk material. The bulk density p.sub.bo of the uncompacted bulk material (according to the EN ISO-60) and the tap density p.sub.t (according to DIN EN ISO 787-11) are used for the determination.

[00001]$H=\frac{{\rho }_t}{{\rho }_{b0}}$

Tap Density

[0180] The tap density is determined according to DIN EN ISO 787-11.

Determination of the Mechanical Properties By Means of Tensile Testing

[0181]

TABLE-US-00021 TABLE 11 Dimensions of the specimens mm I.sub.3 overall length 60 I.sub.1 Length of the narrow parallel part 12 r radius 40.5 I.sub.2 Distance between the wide parallel sides 40 b.sub.2 Width at the ends 10 b.sub.1 Width of the narrow part 5 h thickness >2 L.sub.0 measuring length 10 L Initial distance of the terminals I.sub.2 0.sup.+2

[0182] The mechanical properties of the three-dimensional objects according to the invention can be determined on the basis of test specimens as described below.

[0183] The test method and the component dimensions of the test specimens are of the standard DIN EN ISO 527-1: 2012-06 for the tensile test. For this purpose, the material testing machine TC-FR005TN.A50, dossier No.:605922 from Zwick with the software TestExpert II V3.6.

[0184] In the standardized tensile test, test results such as modulus of elasticity [GPa], tensile strength [MPa] and elongation at break with tensile specimens with dimensions from Table 11 were determined. The test speed is 5 mm/min for PEKK components. The E-Modulus is determined at a test speed of 1 m /min.

Determination of the Extrapolated Starting Temperature of the Melting Peak

[0185] The material requires certain properties, which can be determined on the basis of the extrapolated starting temperature T.sub.eim by means of dynamic differential calorimetry, usually referred to DSC (Differential Scanning calorimetry). The corresponding DSC measurements for the determination of T.sub.ei,m are preferably carried out according to the standard ISO 11357. The device is, for example, Mettler Toledo DSC 823. Also melting temperature T.sub.m and crystallization temperature T.sub.c are determined by this method. T.sub.eim and T.sub.m are determined from the first heating curve.

[0186] If the thermoplastic material contains or is a polymer of the class of PEKK, a temperature ramp of 0° C.-360° C.-0° C.-360° C. is deviated from the standard. The initial temperature (0° C.), maximum temperature (360° C.) and minimum temperature (0° C.) are maintained for three minutes, but not at the final temperature (360° C.). Furthermore, the heating or cooling rate is 20K/min and the weight in the measurements 4.5 mg to 5.5 mg.

Optical Methods for the Determination of Particle Sizes and Particle Shape

[0187] The measurement is carried out on the Camsizer XT device and the X-Jet module (Retsch Technology GmbH) with the associated software CamsizerXT64 (Version 6.6.11.1069). The optical methods for the determination of the particle sizes and particle shape are in accordance with standard ISO 13322-2. After determining the speed adjustment, the sample of about 2 g is dispersed with 80 kPa compressed air and passed through a 4 mm wide passage on a calibrated optics unit with two different magnifying cameras (“Basic” and “Zoom”). For evaluation, at least 10000 individual images are recorded. In order to ensure good optical separation of the particles under consideration, images are only used if the areal density of the imaged particles is less than 3% (“Basic” camera) or less than 5% (“Zoom” camera). The particle sizes and shapes are determined by means of defined measurement parameters. The determined size is the equivalent diameter of the coextensive circle of the particle projection x_area=√(4A/π). The meridian or mean of this evaluation method is comparable to laser diffraction (reported as d10, d50, and d90, i.e., 10% quantile, 50% quantile, and 90% quantile of the volumetric particle size distribution). The measurement is repeated several times for statistical measurement formation.

[0188] For powders with high specific density>2 g/cm.sup.3, or powders that are difficult to disperse, it may be necessary to adjust the method in terms of sample volume, dispersing pressure or the addition of 1% of the flow aid Alu C. The method is adapted in such a way that the variation of the sample quantity (up to 8 g) and the dispersion pressure (up to 150 kPa) is varied so that the smallest possible d90 is achieved.

[0189] The calibration and setting of the camera parameters are to be carried out device-specifically and the adjustment and maintenance are carried out according to the manufacturers specifications. The following configuration of the Camsizer XT software (which can also be seen in the original configuration printouts of the software in FIGS. 5, 6 and 7) was used:

TABLE-US-00022 Configuration of the CAMSIZER XT software CAMSIZER XT: 0301 Overlapping areas: x area: 0.080 mm to 0.160 mm xc min: 0.080 mm to 0.160 mm xFe min: 0.080 mm to 0.160 mm xFe max: 0.080 mm to 0.160 mm x area: 0.100 mm to 0.160 mm xc min: 0.100 mm to 0.160 mm xFE min: 0.100 mm to 0.160 mm xFE max: 0.100 mm to 0.160 mm x area: 0.100 mm to 0.160 mm xc min: 0.100 mm to 0.160 mm xFe min: 0.100 mm to 0.160 mm xFe_max: 0.100 mm to 0.160 mm fixed ratio between cameras for calculation: no switch off lighting source: yes CCD—basic CCD—zoom Scale of reproduction 72.2359 Pixel/mm 633.1597 Pixel/mm Vertical distance to gutter 37.0000 mm 35.0000 mm Middle of the calibration range 72.2347 Pixel/mm 633.3091 Pixel/mm Max. Number files of mean value 50 Calculating p2, Q2, q2: no Max. Number files for customisation 10 Calculating p2_Sv: no Editing comments: yes Calculating class-dependent Q(limit): no Adopting parameters of the 2. measuring Unlocking automatic image storage: yes task: no Calculating relative density rD: no Adopting parameters of the 2. measuring Unlocking of a balance for rD: no task: no Calculating chord length distribution: no Q0 and Q2 creation of customisation files: Minimum gutter control value 0 no External control via COM port: no Testing of limit values: yes Unlocking automatic trend analysis: no Multiple x-definitions: yes Accuracy in table, digits: 2 Calculating Mv(x), Sigma(x): yes Zooming of the diagram in y-direction: yes Setting of Q3-size limits: yes Setting of maximum area density: yes Setting of QO-size limits: no Testing direction and segregation: no Setting of Q2-size limits: no Partial images evaluation: no Calculating AFS-number: no Number of directions of mould Calculating CV, MA: no parameters: 32 Calculating SGN, UI: no Smoothing factor for xFE, xMa, xc: 1 Calculating PI: no Smoothing factor for Q [xc min], Calculating Beta for RRSB: no Q [xFe_min], Q [xFe_max]: 1.8000 Rupture break parameter: no Configurating SPHT: yes Calculating Q(V): no Weighting of mould data of CCD-zoom and Calculating Q3_MVH: no CCD-basic: yes Searching xmax[q3], xmax[qO]: no Ellipsoid model for Q [xc min], Q [xFe_min], Unlocking automatic funnel adjustment: no Q [xFe_max]: I, b, b Unlocking of the high positioning of the Making concave particles convex: no funnel: no Max. number of searching steps: 0 Updating of the background during the Search repeats: 0 measurement: no Particle form configuration: choosing in Interval [s]: 0 measuring task Stepped gutter: no xFe, xMa, xc correction: no Deviation [mm]: 10.0 xFe, xMa, xc correction (sphere): no Setting of limits of mould parameters: yes correction of b/l, B/L, ...(sphere): no Presentation mode: no Correction of unsharp edges: yes With exposure compensation: no 40 Extended XLD and XLE export files: yes Binary images: no Enable editing of sample mass: no With contour: no Calculating UI_qkl(Q1, Q2): no CAMSIZER XT image presentation: yes Adjustment configuration Combined parameters: yes Adjustment of Q3(x): yes Ignoring unsharp particles: yes 45 Adjustment of Q0(x): no Copying and exporting of files in Adjustment of Q2(x): no UNICODE: yes A screen class: yes Combining of screening and CAMSIZER A screen class using symmetric Weilbul XT measurement: yes distribution: no Automatic brightness test: yes so A screen class using Weilbul distribution Unlocking of automatic copy of no measuring tasks: yes A screen class and complete distribution Unlocking of calibration within the yes measuring mode: yes Complete distribution using symmetric Unlocking of Creation and Evaluation of 55 Weilbul distribution: yes binary files: no Date format: automatic Unlocking of series measurement: yes Display guide plate and gutter width at Unlocking of calculation of the medium the first start of the fair after software particle size DM-CECA and TG: no start: no Security software 60 Maximum class number: 300 Unlocking file overwrite in administrator Editing comments during measuring mode: no mode: no Logout of WINDOWS after end of Higher precision of x-values: yes program: no Calculating of Mv(x)-values: no Margin error correction: elliptic, Q(x) and 65 Calculating roundness: no form Configurating roundness during Calculating q(x) without smoothing: no parameter mode: no Unlocking particle count: no Configuration of roundness Measurement without CCD-Basic: no Using xc_min: yes Measurement without CCD-Zoom: no 70 Using x_lnner: no Calculating class dependent mean subforRDNS_C 0.1744 values of the mould parameters: yes divforRDNS_C 0.6718 sub for SPHT_K 0.2892 Time between negative pressure and divforSPHT_K 0.6714 dispersion [ms]: 800 Cameras (measuring parameters) CCD-Basic: yes Threshold for particle sizes smaller than [mm]: 0.0023 taller than [mm]: 20 For mould parameters smaller than [mm]: 0.0023 taller than [mm]: 20 CCD-zoom: yes Threshold for particle sizes smaller than [mm]: 0.0023 taller than [mm]: 2 for mould parameters smaller than [mm]: 0.0023 taller than [mm]: 2 image rate: 100 % (1: 1) Warning, if image rate < 0.95: yes Interval of display: 80 Filling of transparent particles: yes

Determination of the Lower Building Temperature (NCT)

[0190] The lower building temperature (also non-curl temperature=NCT) is determined by means of a cross test, e.g. a matrix of cross-shaped test components (4×2 on the smaller construction platform of P800 FIG. 1.) determined. For this purpose, the laser sintering machine is warmed to a temperature of about 10° C. (estimated) below the usual building temperature or alternatively about 5° C. below the expected non-curl temperature. After automatic powder application, a layer of crosses is exposed from a height of z=3 mm. Show these strong process-critical curl, e.g. the edges of the exposed test crosses are significantly upwards, the crosses are removed from the installation space and the temperature is raised by 2° C. After applying 1.2 mm powder layers (P800, 10 layers of 0.12 mm layer thickness or 12 layers at 0.10 mm layer thickness or 20 layers at 0.06 mm layer thickness), the test is repeated. If only little curl can be observed, the temperature is further increased in 1° C. increments until no more process-critical curl is observed in the cross-test. That is, the crosses can be built in full height (1.2 mm height) without being torn out of the powder bed by the coater during the coating process. The temperature at which no process-critical curl is observable is called the non-curl temperature and defines the lowest possible building temperature. FIG. 1 shows the position of the cross-shaped test components and the pyrometer measuring spot (“P”, top right) on the EOS P800 with installation space reduction (left).

[0191] The term “no process-critical curl” means that no curl can be observed or only minimal curl, but which occurs to such a low degree that the coater can no longer tear the exposed crosses out of the powder bed during powder application.

Determination of Upper Building Temperature (UBT)

[0192] The maximum building temperature is the building temperature of the powdery material, in which the powdery material just does not stick, so that form no aggregates of powder particles, and the powdery material for the coating process is still sufficiently flowable and there are no coating defects (e.g. banding by agglomerates). The maximum processing temperature depends in particular on the type of powdery material used.

[0193] However, the maximum building temperature can also be reached if it just does not come to the (local) melt film formation of the powder, which can be seen on a glossy film (e.g. polyamide 12, PA2200) or a local dark colour of the powder (e.g. EOS PEEK-HP3 described in the application manual).

[0194] For determination, the process chamber temperature is gradually increased (1-2° C.) after the determination of the lower building temperature and the powder bed is precisely observed when one of the effects described above occurs. Additionally or alternatively, the upper building temperature can be determined by determining the powder bed hardness by means of a Shore measurement. This can be helpful if one of the effects described above does not yet occur. If the unsintered powder bed is too hard after the end of the building process it is no longer possible to separate exposed components from the unsintered powder. This restricts the accuracy of the components. For this purpose, when the observed or assumed upper building temperature is reached, the process chamber temperature is lowered by 1° C. and another layer of 3 mm powder is applied as a top layer in automatic construction operation. After the construction process, the powder cake is cooled to room temperature. The surface of the cooled powder cake is determined in the interchangeable frame in the machine by means of a suitable Shore hardness measuring device (here: Bareiss HPII) on a matrix on the smaller construction platform of P800 (5×2 in xy, FIG. 2) in the middle of each sector. The value for Shore hardness results as average value from the 50% highest measured values of the matrix. If there is a crack in the powder bed in the region of the point to be measured (due to the loss of powder cake due to the cooling process to room temperature), then the measured value in the respective sector must be detected at a sufficient distance approx.15 mm from the crack. The Shore hardness for the upper building temperature depends in particular on the type of powdery material used. How high this is depends on the respective material and on the requirements of component quality and waste powder recycling. Suitably, the same Shore hardness for the upper building temperature is used as a comparison. That for all equally proportionate refreshments this is always essentially the same. Furthermore, preference should be given to no change in the heating distribution of the laser sintering machine between the powders to be compared, since this can have an effect on the determined Shore hardness value.

[0195] Which Shore hardness measurement is suitable for which powder can be determined. Shore hardness of Shore 00, Shore 000 and Shore 000 S, which is also regulated in ASTM D 2240, have proven to be preferred.

[0196] These and other hardness tests according to Shore are described in the Bareiss HPII Operating Instructions (HPE II Shore [D], Version 26.05.2017) and the corresponding standards are listed. By way of example, for some polymer powders, the Shore hardnesses for the upper building temperature have been determined with the Bareiss HPII Shore Hardness Tester:

[0197] 1) Polyaryletherketone

[0198] Shore-00=85

Working Temperature (T.SUB.PK.)

[0199] The processing temperature, represented by the process chamber temperature T.sub.PK, is preferably chosen such that it is at least 1° C., more preferably at least 2° C. and even more preferably at least 4° C. above the lower building temperature of the powder and/or at most at the top Building temperature, more preferably at most 1° C., even more preferably at most 2° C. and even more preferably at most 4° C. below the upper building temperature. Preferably, the processing temperature is above the lower building temperature and below the upper building temperature of the powder. Sufficient process security (no curling, by the greatest possible distance from the NCT) has to be assured. Furthermore, the temperature has to be as high as possible, without causing a sticking of the powdery material.

[0200] Alternatively or additionally, the processing temperature for each powder can be determined by determining the Shore hardness of the cooled powder cake, according to the method described under Upper Building Temperature Determination (UBT). The Shore hardness value should preferably be 5% and at most 50% below the Shore hardness value of the UBT. Preferably at most 15% below, more preferably at most 10% below.

Production of Components on the Laser Sintering Machine

[0201] If the thermoplastic material contains or is a polymer of the polyaryletherketone (PAEK) class, in particular PEKK, the experiments were carried out on a modified P800 (EOS P800 with start-up kit PAEK 3302 CF) with PSW 3.8. After a warm-up phase, during which the process chamber of the laser sintering machine is warmed from room temperature to the specified building temperature or the start temperature of the temperature search within 120 minutes, 50 layers (with a layer thickness of 120 μm) or 60 layers (with a layer thickness of 100 μm) or 120 layers (with layer thickness of 60 μm) are laid without exposure as the bottom layer (=6 mm). After laying the bottom layer, the 6 tensile specimens (dimensions see table 1) are positioned next to each other in the middle of the construction field, with the parallel length aligned parallel to the x-direction and 4 cuboid test components (dimensions: 20 mm×4 mm×13.56 mm), positioned to the left and right of the tensile specimens. Between the components in the z direction layers are laid without exposure. At z=9,960 mm, the 25 tensile specimens (positioned centrally in the construction field next to each other, aligned with the parallel length parallel to the z-direction) are built. Following the last exposed layer, another 3 mm powder is automatically applied and the machine is cooled to 180° C. within about 8 hours by means of a controlled cooling phase, which is defined in the default job, before the heaters are completely switched off. After reaching room temperature, the components were manually removed, glass bead blasted and measured / tested. FIGS. 3 and 4 show the positions of tensile specimens in the x-direction, z-direction and powder boxes as well as density cubes on the EOS P800.

[0202] The size of the building area is about 350 mm×120 mm (about ⅛ of the full platform size, modified construction space reduction variant 1 for P800 in the xy direction in accordance with the EOS PEEK-HP3 application manual).

[0203] The job height is 72.96 mm.

[0204] The following settings were selected: [0205] Process chamber temperature during construction of the parts is detailed in the Examples section; [0206] Temperature of the removable frame/building platform: 255° C. (for PEKK); [0207] Default job settings: PAEK3302CF; [0208] Exposure parameters: volume energy input as described in the Examples section;

[0209] If the experiments were carried out on a P810 (with PSW 3.8), following parameters were used to run the builds: After a warm-up phase, during which the process chamber of the laser sintering machine is warmed from room temperature to the specified building temperature or the start temperature of the temperature search within 120 minutes, 50 layers (with a layer thickness of 120 μm) or 60 layers (with a layer thickness of 100 μm) or 120 layers (with layer thickness of 60 μm) are laid without exposure as the bottom layer (=6 mm). After laying the bottom layer, the 6 tensile specimens (dimensions see table 1) are positioned next to each other in the middle of the construction field, with the parallel length aligned parallel to the x-direction. Following the last exposed layer, another 3 mm powder is automatically applied and the machine is cooled to 180° C. within about 8 hours by means of a controlled cooling phase, which is defined in the default job, before the heaters are completely switched off. After reaching room temperature, the components were manually removed, glass bead blasted and measured/tested. FIGS. 3 shows the positions of tensile specimens in the x-direction on the EOS P810.

[0210] The size of the building area is about 350 mm×120 mm (about ⅛ of the full platform size, modified construction space reduction variant 1 for P800 in the xy direction in accordance with the EOS PEEK-HP3 application manual).

[0211] The job height is 35.16 mm.

[0212] The following settings were selected: [0213] Process chamber temperature during construction of the parts is detailed in the Examples section; [0214] Temperature of the removable frame is 265° C. and of the building platform 255° C.; [0215] Default job settings: EOS_PAEK3304_120_000; [0216] Exposure parameters: volume energy input as described in the Examples section.