scholarly journals Impact of Bimodal Particle Size Distribution Ratio of Functional Calcium Carbonate Filler on Thermal and Flowability Properties of Polyamide 12

2021 ◽  
Vol 11 (2) ◽  
pp. 641
Author(s):  
Fabio Ippolito ◽  
Gunter Hübner ◽  
Tim Claypole ◽  
Patrick Gane
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Crystallization Behavior ◽  
Filler Particle ◽  
Melt Flow ◽  
Polyamide 12 ◽  
Carbonate Filler

In previous investigations, it was shown that the melting, as well as crystallization behavior of polyamide 12, could be manipulated by adjusting the particle size distribution of calcium carbonate as a functional filler. It was demonstrated that the melt properties of this compound show a significant dependency on the filler volume-based particle size. As finer and narrower the calcium carbonate particles in the polymer matrix become, the less influence the filler has on the melting properties, influencing the melt flow less significantly than the same surface amount of broad size distribution coarse calcium carbonate filler particles. However, due to increased nucleation, the crystallization behavior on cooling showed a markedly more rapid onset in the case of fine sub-micrometer filler particle size. To control further and optimize the thermal response properties of a filling compound for improved properties in additive manufacturing processing through selective laser sintering, the possibility to combine precisely defined particle size distributions has been studied, thereby combining the benefits of each particle size range within the chosen material size distribution contributes to the matrix. The melt flow at 190 °C, the melting speed, melting and crystallization point as well as crystallization time at 170 °C were analyzed. The thermal and flow properties of a polyamide 12 matrix can potentially be optimized with a combination of a precise amount of coarse and fine calcium carbonate filler. The improvements were exemplified using a twin-screw extruder for compounding, indicating the potential for optimizing functionally filled polymer in additive manufacturing.

WITHIN-PEDON VARIABILITY IN SOIL PROPERTIES

1982 ◽  
Vol 62 (4) ◽  
pp. 631-639 ◽  
Author(s):  
G. T. PATTERSON ◽  
G. J. WALL
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Soil Properties ◽  
Size Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Drainage ◽  
Soil Material

Replicate soil samples (2–20) from the A, B and C horizons of 41 pedons were collected to measure within-pedon variability of particle size distribution, organic matter content, calcium carbonate equivalent and pH. Variability in soil properties was examined in relation to the mode of origin of the soil material, soil horizonation and soil drainage. Variance in particle size distribution was significantly influenced by mode of deposition as well as by soil horizons, while soil drainage had no significant influence on the variation in particle size distribution. Variance in calcium carbonate equivalent and organic matter content was not influenced by soil drainage or mode of deposition. The number of replicate samples required for statistically reliable evaluation of a pedon at given confidence limits was determined for the soil properties studied. The results of these calculations indicate the need for up to five replicate samples to achieve satisfactory levels of accuracy at the 95% confidence level for some of the soil properties studied.

scholarly journals Plasma Spheroidisation of Irregular Ti6Al4V Powder for Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1763
Author(s):  
Nthateng Nkhasi ◽  
Willie du Preez ◽  
Hertzog Bissett
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Metal Powder ◽  
Weight Ratio ◽  
High Strength ◽  
Powder Bed Fusion ◽  
Metal Powders ◽  
Powder Bed

Metal powders suitable for use in powder bed additive manufacturing processes should ideally be spherical, dense, chemically pure and of a specified particle size distribution. Ti6Al4V is commonly used in the aerospace, medical and automotive industries due to its high strength-to-weight ratio and excellent corrosion resistance properties. Interstitial impurities in titanium alloys have an impact upon mechanical properties, particularly oxygen, nitrogen, hydrogen and carbon. The plasma spheroidisation process can be used to spheroidise metal powder consisting of irregularly shaped particles. In this study, the plasma spheroidisation of metal powder was performed on Ti6Al4V powder consisting of irregularly shaped particles. The properties of the powder relevant for powder bed fusion that were determined included the particle size distribution, morphology, particle porosity and chemical composition. Conclusions were drawn regarding the viability of using this process to produce powder suitable for additive manufacturing.

Change of Formation Yield and Characterization of PCC Particle Synthesized with Impurity Ions Contents by Carbonation Process

2006 ◽  
Vol 510-511 ◽  
pp. 1026-1029
Author(s):  
Jin Sang Cho ◽  
Sung Min Joo ◽  
Sang Hwan Cho ◽  
Young Hwan Yu ◽  
Im Ho Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Precipitated Calcium Carbonate ◽  
Carbonation Process ◽  
Crystal Properties ◽  
Impurity Ions

The effect of the impurity ions Al3+, Fe3+ and Mg2+ on the formation yield and crystal properties of precipitated calcium carbonate(PCC) produced by the carbonation process was investigated in Ca(OH)2-H2O-CO2 system. The effect of the impurity ions Al3+, Fe3+ and Mg2+ on the formation yield using particle size distribution and morphology of PCC were discussed. The particle size distribution of PCC was increased with increase of impurity ions. The morphology was transformed in order of spheroidal, scalenohedral, rhombohedral calcite for Al3+, Fe3+ and rhombospheroidal, spherical, scalenohedral for Mg2+ with increase of impurity ions.

Investigating the Sensitivity of Particle Size Distribution on Part Geometry in Additive Manufacturing

2021 ◽  
Author(s):  
Vaishak Ramesh Sagar ◽  
Samuel Lorin ◽  
Johan G\xf6hl ◽  
Johannes Quist ◽  
Klas Jareteg ◽  
...  
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Part Geometry

Filler Pigments Designed for Recyclability

1992 ◽  
Vol 266 ◽  
Author(s):  
June D. Passaretti ◽  
Trudy D. Young ◽  
Mick J. Herman ◽  
D. Bruce Evans
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Size Distribution ◽  
Paper Industry ◽  
Precipitated Calcium Carbonate ◽  
Recycled Paper ◽  
New Material ◽  
The Cost

AbstractThis paper discusses the use of a new rhombohedral precipitated calcium carbonate (PCC) morphology and existing PCC morphologies in wood free, wood containing, and recycled paper. The new material has properties that mimic TiO2 with respect to morphology, particle size, particle size distribution, and surface area. TiO2 is widely used by the paper industry as a functional filler for opacity and brightness. The new PCC rhombohedral morphology can be used in place of TiO2 for many applications greatly reducing the cost of production.The physical properties of the new PCC morphology as well as application as a paper filling pigment will be discussed.

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