scholarly journals Experimental Determination of Coefficients for the Renner Model of the Thermodynamic Equation of State of the Poly(butylene succinate) and Wheat Bran Biocomposites

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5293
Author(s):  
Emil Sasimowski ◽  
Łukasz Majewski ◽  
Tomasz Jachowicz ◽  
Michał Sąsiadek

This paper presents the assumptions of a thermodynamic equation of state for polymers according to the Renner model. The experiments involved extruding a biocomposite based on poly(butylene succinate) that was filled with ground wheat bran with its size not exceeding 200 μm. The biocomposite was produced in pellet form with three different contents by weight of wheat bran, i.e., 10%, 30% and 50%. All specimens were examined for their thermodynamic p-v-T characteristics. Taking advantage of the SimFit module of Cadmould 3D-F, experimental results were used to determine the coefficients of thermodynamic equation of state for the tested biocomposite according to the Renner model. The coefficients were then used to calculate transition temperature and to create diagrams illustrating the relationship between pressure, temperature and specific volume for the tested biocomposite. The obtained results can serve as a basis for assessing the suitability of the biocomposite for injection molding, selecting technological parameters of this process, as well as for analyzing shrinkage and defects of injection-molded parts.

Author(s):  
Olaf Hellmuth ◽  
Rainer Feistel ◽  
Thomas Foken

AbstractThe differences between one classical and three state-of-the-art formulations of the mass density of humid air were quantified. Here, we present both the calculi for direct determination of the humid-air mass density employing the virial form of the thermodynamic equation of state, and a sufficiently accurate look-up-table for the quick-look determination of the humid-air mass density, which is based on the advanced Thermodynamic Equation of Seawater 2010.


2016 ◽  
Vol 686 ◽  
pp. 131-136 ◽  
Author(s):  
Jiří Čop ◽  
Vladimír Pata ◽  
Ondřej Bílek

In the most cases manufacturing of injection mold and its cavities comprise more than half of the total production time. Very fine finishing operations can increase production time and cost of injection mold. Appropriate choice of finishing operations and injection technological parameters can reduce price of injection mold production, shorten production time and thus lower price of small and thin injection molded parts. Tool material X38CrMoV5-1, used for cavity in injection mold, was finished by fine turning, grinding, lapping and polishing with different technological conditions to achieve various surface roughness. The main aim of this research is to find an influence of surface quality of cavity and injection technological parameters on the surface quality of injection molded parts.


Author(s):  
Zhengchao Gu ◽  
Zhenyong Zhou ◽  
Shuming Gao ◽  
Jiaoying Shi

Abstract Mold parting direction is an important factor to verify the moldability of a molded part. The determination of mold parting direction is the first step to achieve automatic design of an injection mold or a casting die. A method using automatic feature recognition is proposed in this paper to automatically determine parting direction of an injection mold. Parting direction determination of a molded part consists of three steps in our approach. First, all features of a molded part are recognized using a universal hint-based feature recognition algorithm, and all candidate and feasible parting directions of each feature are determined according to the type of the feature. Then, all candidate parting directions of the molded part are automatically generated from all recognized features candidate parting directions. The optimal parting direction is finally chosen based on certain criteria. The case studies on several industrial parts show that the proposed method is effective and efficient in determining the optimal parting direction of injection molded parts.


1983 ◽  
Vol 48 (1) ◽  
pp. 192-198 ◽  
Author(s):  
Tomáš Boublík

The excess entropy of mixing of mixtures of hard spheres and spherocylinders is determined from an equation of state of hard convex bodies. The obtained dependence of excess entropy on composition was used to find the accuracy of determining ΔSE from relations employed for the correlation and prediction of vapour-liquid equilibrium. Simple rules were proposed for establishing the mean parameter of nonsphericity for mixtures of hard bodies of different shapes allowing to describe the P-V-T behaviour of solutions in terms of the equation of state fo pure substance. The determination of ΔSE by means of these rules is discussed.


2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2523
Author(s):  
Franciszek Pawlak ◽  
Miguel Aldas ◽  
Francisco Parres ◽  
Juan López-Martínez ◽  
Marina Patricia Arrieta

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.


2014 ◽  
Vol 37 ◽  
pp. 112-116 ◽  
Author(s):  
L. Zsíros ◽  
A. Suplicz ◽  
G. Romhány ◽  
T. Tábi ◽  
J.G. Kovács

Science ◽  
2002 ◽  
Vol 298 (5598) ◽  
pp. 1592-1596 ◽  
Author(s):  
P.&l. Danielewicz

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