ABS Material Research Articles

Unstable Fracture Behavior of Rubber Toughened Poly(Styrene-co-Acrylonitrile)

A linear elastic fracture mechanics (LEFM) approach was used to study fracture characteristics of ABS materials. The effects of crack (ligament) length and rubber content on the microscopic deformations taking place at the front of crack tip and in the bulk of the specimens were investigated. The results of fractography studies showed that, in addition to rubber content, the microscopic deformations are influenced by crack length. For some materials this manifests itself as a change in macroscopic response. The ligament length dependent behavior was increased for the samples with higher rubber contents. The results also showed that, although the elastic behavior with unstable crack growth is the dominant micromechanism of deformation, stable crack propagation still occurred in some compositions. All the fracture parameters, including fracture toughness, fracture energy, plastic zone size, and crack tip opening, increased with rubber content. The changes in microscopic and, as a consequence, in the macroscopic deformation behavior of a given specimen with ligament length were attributed to changes in yield stress of the sample and maximum stress on the ligament.

Mold Temperature Influence on Tensile Strength and Fiber Orientation of Plastic Parts in Dynamic Mold Temperature Injection Technology

Dynamic mold temperature injection technology can be used to eliminate many surface defects such as weldline, flow mark that usually appear on the polymer parts. In this paper, fiber reinforced ABS material is employed in order to study the influence of mold temperature on tensile strength and fiber orientation properties in dynamic mold temperature injection technology. By studying the standard specimens obtained in our laboratory, the relationship between the tensile strength and the dynamic mold temperature was demonstrated. The influence of the fiber orientation on the tensile strength was also investigated. Experiment results showed that the fiber orientation in different places of the specimen had a great effect on its tensile strength. Studies presented in this paper are of great help to promote the application of the technology in fiber reinforced polymer material.

Change in Capacitance with Pore Structure of Microcellular Foamed ABS

An experiment was conducted to confirm how changes in characteristics due to the porous structure apply to the electrical characteristics as the pore size decreases in polymer foam. ABS material, whose foaming process is relatively easy to control, was used to control the foaming ratio by adjusting the foaming temperature. A change in capacitance was observed as a result of the experiment. When the foam structure was analyzed and numerically recorded, it was confirmed that the changes in distribution, according to the specific volume and variation in capacitance, showed similar tendencies.

A New Complex Design for Air-Breathing Polymer Electrolyte Membrane Fuel Cells Aided by Rapid Prototyping

One of the most difficult issues to fabricate a fuel cell with a complex design is the manufacturing method. To solve this difficulty, the authors applied an innovative method of fuel cell fabrication, i.e., rapid prototyping technology. The rapid prototyping technology can both fabricate the complex design and shorten the fabrication time. In this paper, the authors used a 3D software (CATIA) on the fuel cell design and utilized the rapid prototyping to accelerate the prototype development of complex stack designs and to verify the practicability of the new fabrication for fuel cells. The honeycomb shape methanol reservoir and cathode structure design of a direct methanol fuel cell (DMFC) and the complex flow distributor design of a monopolar air-breathing proton exchange membrane fuel cell (PEMFC) stack, which were almost impossibly manufactured by traditional manufacturing, were made in this study. The performance of the traditional air-pumping DMFC and that of an air-breathing DMFC were compared in this study. The feasibility of a complex pseudobipolar design DMFC stack was also verified. For the miniature air-breathing PEMFC made by rapid prototyping with ABS material, its performance is close to the state-of-the-art compared to previous published literatures (Hsieh et al. 2006, “Study of Operational Parameters on the Performance of Micro PEMFCs With Different Flow Fields,” Energy Convers. Manage., 47, pp. 1868–1878; Schmitz, A., Wagner, S., Hahn, R., Uzun, H., and Hebling, C., 2004, “Stability of Planar PEMFC in Printed Circuit Board Technology,” J. Power Sources, 127, pp. 197–205; Hottinen, T., Mikkola, M., and Lund, P., 2004, “Evaluation of Planar Free-Breathing Polymer Electrolyte Membrane Fuel Cell Design,” J. Power Sources, 129, pp. 68–72). A new solution to manufacture complex fuel cell design, rapid prototyping, has been first applied to the fabrication of complicated flow channels in ABS materials and directly used in both DMFC and PEMFC in this paper. Its feasibility was verified and its promising performance was also proved.

Photoluminescence study of the carbon antisite-vacancy pair in4H- and6H-SiC

Two sets of prominent photoluminescence (PL) lines, called A and B here, in electron-irradiated and ion-implanted $4H\text{-SiC}$ have been investigated by low-temperature PL microscopy. From their spectral details, temperature dependence, emission energies, introduction, and annealing characteristics it is concluded that they arise from the neutral on-axis and off-axis carbon antisite-vacancy pairs ${({\text{V}}_{\text{C}}{\text{C}}_{\text{Si}})}^{0}$. Photoluminescence excitation spectroscopy has been used to derive an energy-level diagram for the B set of lines of $4H\text{-SiC}$. The creation of these centers is demonstrated as a process that is sensitively dependent not only on the $n$ or $p$ doping of the material, as has been proposed but also on the temperature and the existence of inhomogeneous internal electric and strain fields. Samples of different purities from many different sources have been studied. Relatively impure, highly compensated doped samples exhibit very strong A and B PL and are referred to as AB material. Purer materials, largely uncompensated, called V here, that are $n(\text{N})$ or $p(\text{Al})$ doped, have photoluminescence from Si vacancy related defects but relatively little A or B intensity even after annealing at $900\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$. Similar sets of PL lines have also been observed in ion-implanted $4H\text{-SiC}$ and electron-irradiated $6H\text{-SiC}$ and investigated to a more limited extent. A wide range of different electron-irradiation conditions has been explored.

Infrared assisted polymer forming

In recent years a new technology has been studied for polymer forming. Plastic shaping was performed by means of the combination of IR heating and pellet softening in a semi-transparent mould, which allowed the radiation transmission. In the current work moulding tests were performed on ABS material (acrylonitrile-butadiene-styrene) by using a very low holding force (20 N). Several thin disks 20 mm in diameter were produced in different process conditions and subsequently characterized by dimensional analysis and mechanical tests. The pellet agglomeration was good as well as the aesthetic aspect. Mechanical performances were evaluated by plate bending test. A finite element (FE) model was defined to infer elastic modulus and yield stress. Finally, the best process conditions were identified to minimize the moulding time without affecting the moulded material properties.

English

Three different two wheeler helmets were studied to investigate their dynamic performance.First is helmet with ABS shell, second is helmet with metal foam, and third is helmet with singlegroove in the liner foam for providing ventilation. Front and side impact analyses were carriedout at 10 m/s velocity by using LS-DYNATM. Forces on the helmet and on the head due to impactwere studied with function of time. Pressure and stresses in the brain were investigated andfound not to change significantly due to the presence of groove in the liner foam, which wasprovided to improve the ventilation in helmets. The dynamic performance of a helmet with outershell as metal foam was examined and compared with ABS material.

Rapid manufacturing and rapid tooling of polymer miniaturized parts using Stereolithography

Currently, miniaturization is a major trend in the manufacturing and commercialization of new industrial products. When small-sized objects should be manufactured with dimensions of only a few millimeters or less, many difficulties can appear using traditional processes. An alternative to study these new requirements is through the use of rapid prototyping technologies. Stereolithography (SL) has established itself as one of the most popular and reliable process allowing the rapid manufacturing of complex parts. This paper investigates the SL process, which directly produces small parts by rapid manufacturing, and also indirectly by rapid tooling. The processability of small parts was investigated using two different shapes. The POM and ABS materials were used in the indirect manufacturing. The dimensional accuracy, precision and tolerance of micro parts were evaluated using metrological techniques. Results showed accuracy and precision greater than 97% when small-parts are manufactured directly by Stereolithography.

Deformation and Failure Behaviors of PC/ABS (50/50) Blends under Impact

An instrumented-drop weight impact test carried out at room temperature under a range of loading rates was applied to study the deformation and failure behaviors of PC/ABS (50/50) blends. Actually, these blends have different type of ABS, one grade of the blends is the blend containing small-sized particles of rubber and another grade is the blend containing larger-sized particles of rubber in the ABS systems. Testing results showed that both of the blends generally exhibited similar behaviors but they were totally different under 3 m/sec. A weld line-like formation captured on the fracture surface was found in each of the blends. Preliminary study using scanning electron microscope (SEM) indicated that crack also propagated along the weld line. Fracture of the blends might be initially induced due to fracture of the weld lines. Hence, it has been suspected as a factor affecting behavior of the blends. Since existence of the weld line-like formation has not been found in fractured ABS materials, it is necessary to point out the complex relationship among of the ABS composition, the existence of the weld line and the weld line quality in the blends. A finite element (FE) simulation of the testing was carried in order to determine whether the weld line strength is significant enough affects the behaviors. Although the model was generated using estimated failure criterion for the weld line, the simulation results showed that weld line strength might influence the blends behavior.

Influence of Elastic Deformation on Single-Wall Carbon Nanotube Atomic Force Microscopy Probe Resolution

We have previously reported that 4−6 nm diameter single-wall carbon nanotube (SWNT) probes used for tapping-mode atomic force microscopy (AFM) can exhibit lateral resolution that is significantly better than the probe diameter when prone nanotubes are imaged on a flat SiO2 surface. To further investigate this phenomenon, accurate models for use in atomistic molecular dynamics simulations were constructed on the basis of transmission electron microscopy (TEM) and AFM data. Probe−sample interaction potentials were generated by utilization of force fields derived from ab initio quantum mechanics calculations and material bulk and surface properties, and the resulting force curves were integrated numerically with the AFM cantilever equation of motion. The simulations demonstrate that, under the AFM imaging conditions employed, elastic deformations of both the probe and sample nanotubes result in a decrease of the apparent width of the sample. This behavior provides an explanation for the unexpected resolution improvement and illustrates some of the subtleties involved when imaging is performed with SWNT probes in place of conventional silicon probes. However, the generality of this phenomenon for other AFM imaging applications employing SWNT probes remains to be explored.

PBT/ABS 블렌드의 상용화제에 따른 기계적 물성 연구

Poly-butylene-terephalate(PBT) can be impact-modified by blending with ABS material. The effects of compatibilizers and ABS content on the mechanical properties of PST/ASS blend were examined in this study. EPDM-g-GMA and polycarbonate(PC) were used as a compatibilizer. As the GMA content in EPDM-g-GMA increased, the tensile strength of PST/ASS blend increased and the impact strength decreased. With increasing the EPDM-g-GMA content in PBT/ABS blend, the tensile strength and impact strength decreased. With PC compatibilizer, the particle size of ABS in PBT/ABS blend became smaller than that of the blend without compatibilizer and the particles were more evenly dispersed in matrix. The maximum impact strength of the PBT/ABS blend was observed in the range of 20 ~ 30% ABS content.<br/> <br/>

Influence of Triangular Pattern Infill on 3D Printed Torus Mechanical Behavior

The torus or toroidal surfaces are geometries that can be easily found in various industrial applications, from containers, devices, cartwheels, design objects and even machine parts, being also a geometric primitive often used in solid constructive geometry. For a better understanding of the torus-type surface mechanical behavior, this paper aims to study the toroidal geometry manufactured from ABS material by using the FDM 3D printing method and subjecting each sample to compression tests to identify the influence of the sample filling percentage in the case of triangular pattern.

Effects of rubber content and temperature on ductile tearing stability in ABS materials

The material can fail by tearing instability when the elastic contraction is greater than the plastic extension due to crack growth. Tearing instability (TIS) theory developed by Paris and co-workers is applied to describe the effects of rubber content and temperature on the stability of ductile crack growth in ABS materials under impact test conditions. The increase in slope of the J–Δa (δ-Δa) curve, dJ/d(Δa) (dδ/d(Δa)), tearing modulus, T (TJ or Tδ) and JTJ with increasing rubber concentration indicates that higher rubber content is beneficial in maintaining crack growth stability. dJ/d(Δa), TJ and JTJ increase with increasing temperature until a certain temperature. After that they decrease with further increasing temperature. This is due to the embrittlement of SAN matrix close to its glass transition temperature. Materialversagen durch Tearing-Instabilitat kann eintreten, wenn die elastische Kontraktion groser als die plastische Deformation durch Riswachstum ist. Die von Paris und Mitarbeitern entwickelte Theorie der Tearing-Instabilitat wird zur Beschreibung der Einflusse von Kautschukgehalt und Temperatur auf die Stabilitat des duktilen Riswachstums in ABS unter Schlagbeanspruchung angewendet. Die Zunahme der Steigung der J-Δa(δ–Δa)-Kurve, dJ/d(Δa) (dδ/d(Δa)), des Tearingmoduls, T (TJ or Tδ) und JTJ mit steigender Kautschukkonzentration deutet darauf hin, das ein hoher Kautschukgehalt zum Erhalt der Riswachstumsstabilitat beitragt. dJ/d(Δa), TJ und JTJ nehmen mit steigender Temperatur bis zu einer bestimmten Temperatur zu. Danach nehmen sie mit weiter steigender Temperatur ab. Dies wird durch die Versprodung der SAN-Matrix in der Nahe der Glasubergangstemperatur verursacht.

Effects of rubber content and temperature on ductile tearing stability in ABS materials

Effects of rubber content and temperature on ductile tearing stability in ABS materials

Effect of compatibilization and ABS type on properties of PBT/ABS blends

Toughened blends of poly(butylene terephthalate) (PBT) with appropriate ABS materials can be prepared without a compatibilizer within limited melt processing situations. As illustrated by transmission electron microscopy, coarsening of uncompatibilized blends occurs under certain molding conditions resulting in a deleterious effect on blend properties. Methyl methacrylate, glycidyl methacrylate (GMA), ethyl acrylate (MGE) terpolymers were shown to be effective reactive compatibilizers for PBT/ABS blends that broaden the processing window and provide improved low temperature impact properties, ABS dispersion, and morphological stability. A twin screw extruder is more effective than the single screw extruder used here for processing these reactive blends. Several ABS types with different rubber contents were examined; generally, materials with very high rubber contents were found to be more beneficial for toughening PBT. Among these high rubber content materials, the ABS material having the lowest melt viscosity was found to be superior for optimizing morphology and impact properties. At leat 30% of this material, containing a minimum of 36% rubber, is required for producing toughened blends. Moderate amounts of GMA functionality in the compatibilizer (>5%) and small amounts of compatibilizer in the blend (<5%) significantly improve low temperature impact properties and ABS dispersion. Higher amounts of GMA in the blend increase the room temperature impact strength with little effect on the ductile–brittle transition temperature and increase blend viscosity.

Compatibilization of PBT/ABS blends by methyl methacrylate-glycidyl methacrylate-ethyl acrylate terpolymers

Poly (butylene terephthalate), PBT, can be impact modified by blending with appropriate ABS materials within a limited range of processing conditions. The morphology of these uncompatibilized blends is unstable; the dispersed phase coarsens when the melt is subjected to low shear conditions, e.g. during certain moulding conditions, which has a deleterious effect on the final blend properties. Terpolymers of methyl methacrylate, glycidyl methacrylate (GMA), and ethyl acrylate have been synthesized and shown to be effective reactive compatibilizers for blends of PBT with styrene-acrylonitrile copolymers (SAN) or ABS materials as revealed by improvements in SAN or ABS dispersion and morphological stability. Evidence for reaction between the carboxyl endgroups of PBT and the epoxide groups of GMA during melt processing to form a graft copolymer is presented. The effect of terpolymer composition and content on morphology generation and stabilization of PBT-SAN blends has been examined in depth. Moderate amounts of GMA in the terpolymer (>5%) and small amounts of compatibilizer in the blend (<5%) were found to significantly improve SAN dispersion. Blends of PBT and SAN containing the compatibilizer did not show any coarsening of the dispersed phase particle size due to coalesence under certian conditions of low shear. A preliminary investigation into the effect of this compatibilizer on PBT-ABS morphology and impact properties revealed greatly improved rubber dispersion and low temperature toughness.

Impact modification of poly(butylene terephthalate) by ABS materials

Poly(butylene terephthalate), PBT, can be impact modified by blending with appropriate ABS materials. The effect of ABS type and processing conditions on the notched Izod impact strength of PBT blends is examined in depth. Of three emulsion-made ABS materials containing 38 to 50% rubber, the one with the highest melt viscosity (50% rubber and a broad rubber particle distribution) proved the least effective for improving the impact strength of PBT when processed at high temperatures (260°C). Blends prepared in twin screw vs a single screw extruder have similar impact behavior. Melt temperatures greater than 240°C used during molding have little effect on the crystalline behaviour of PBT; however, they reduce the effectiveness of some ABS grades for impact modification. Blends moulded at higher temperatures show a coarse phase morphology with large, poorly dispersed ABS domains. PBT/ABS blends can have excellent mechanical properties in the absence of any compatibilizer; however, a compatabilizer would no doubt improve the stability of the morphology of the blends and may lessen their dependence on process conditions.

METHODS

ABS in Britain's largest wastewater treatment plant. ABS pipework supplied by Durapipe of Cannock has been used in Britain's largest wastewater treatment plant at Tunnel Refineries in Greenwich, London. The plant, designed by Biomechanics, uses the anaerobic digestion process, and Durapipe's ABS material was chosen for almost all the process pipework in preference to stainless steel because of its superior corrosion resistance under anaerobic conditions.

The Problems of Quantifying Mineral Liberation: A review

AbstractA review is given of recent publications concerning the theory of liberation of component B from AB material as particle size is reduced, with a view to combining models of liberation with models of size reduction. Although a number of approaches are promising, it is concluded that there is no adequate model of liberation of binary systems suitable for incorporation into a mill model.

Dependence of the migration out of mass plastics on the thickness and sampling of the material

The work, the results of which are reported here, was mainly concerned with systematic investigation of the influence of thickness, shape and production of polymeric test specimens on the migration of components into fat‐releasing foodstuffs or adequate test fats. For this purpose several types of LDPE, HDPE, PP, HIPS and ABS, differing in their physical and structural‐chemical properties, were dosed with a defined amount of the 14C‐labelled antioxidant Irganox 1076 and processed into pressed sheets and into extruded or chill‐rolled films, the nominal thicknesses of which were in the range 10–3000 μχη. In addition, small injection‐moulded cups were produced from the HIPS and ABS materials. Rectangular and circular test specimens were obtained from the plastics sheets and films by means of a cutting device and a punch, respectively. These test specimens were placed under defined time and temperature conditions in one‐sided or all‐sided contact with the test fat HB 307; the plastics cups were filled with th...