scholarly journals Fatigue Fracture Properties and Morphology of Polyoxymethylene (POM) Plates Produced under Moderate Processing Conditions

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
M. Berer ◽  
M. Halb ◽  
M. Feuchter ◽  
G. Pacher ◽  
G. Pinter
Keyword(s):  
Injection Molding ◽  
Residual Stresses ◽  
Fatigue Fracture ◽  
Hierarchical Structure ◽  
Strong Dependence ◽  
Combined Effect ◽  
The Other ◽  
Processing Conditions ◽  
Fracture Properties ◽  
Fracture Performance

The present study was inspired by different industry projects in which a strong dependence of the fatigue fracture performance of POM on the processing conditions was observed. To examine the relationships under more reproducible conditions, plates of two different POM homopolymer resins (one significantly nucleated) were produced by compression molding and by injection molding under moderate conditions. For the injection molding, three different mold temperatures were used. At specific locations, the plates were analyzed concerning their hierarchical structure on the micro- and nanolevel and concerning their fatigue fracture performance. For the fatigue fracture performance, the dependence on the processing conditions was rather small for the nucleated resin but much more significant for the other resins. This dependence could not be related to morphological effects only, and thus, a combined effect of morphology and residual stresses was assumed.

scholarly journals Fatigue Fracture Properties of Wood Plastic Composites

2015 ◽  
Vol 71 (12) ◽  
pp. 339-344 ◽  
Author(s):  
Nordin M. N. A. ◽  
Yuta Makino ◽  
Koichi Goda ◽  
Hirokazu Ito
Keyword(s):  
Fatigue Fracture ◽  
Wood Plastic Composites ◽  
Fracture Properties ◽  
Plastic Composites

Effect of Weld Line Formation on Morphology and Mechanical Properties for 3D-MID Technology

2015 ◽  
Vol 659 ◽  
pp. 659-665
Author(s):  
Supakit Chuaping ◽  
Thomas Mann ◽  
Rapeephun Dangtungee ◽  
Suchart Siengchin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Injection Molding ◽  
Filler Content ◽  
Research Work ◽  
Weld Line ◽  
Processing Conditions ◽  
High Reduction ◽  
Flexural Tests

The topic of this research work was to demonstrate the feasibility of a 3D-MID concept using injection molding technique and investigate the effects of two weld line types on the structure and mechanical properties such as tensile, flexural strength and morphology. In order to obtain more understanding of the bonds between polymer and metals, two different polymer bases of polyphthalamide (PPA) with the same type and amount of filler content were produced by injection molding at the different processing conditions. A mold was designed in such a way that weld and meld line can be produced with different angles by changing as insert inside of the mold. The mechanical properties such as stiffness, tensile strength and flexural strength were determined in tensile and flexural tests, respectively. The results showed in line with the expectation of high reduction on mechanical properties in area where weld/meld lines occurred. The result of tensile test was clearly seen that weld and meld line showed a considerable influence on mechanical properties. The reduction in tensile strength was approximately 58% according to weld line types, whereas in flexural strength was approximately 62%. On the other hand, the effect of the injection times and mold temperatures on the tensile strength were marginal.

Mechanical Properties of Jute/PLA Injection Molded Products-All Natural Composites

2011 ◽  
Author(s):  
Masuo Murakami ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Density Measurement ◽  
The Other ◽  
Jute Fiber ◽  
Poly Lactic Acid ◽  
Thermoplastic Polymer ◽  
Environmental Friendly ◽  
Molding Condition ◽  
Natural Composites

Natural composites have been important materials system due to preservation of earth environments. Natural fibers such as jute, hemp, bagasse and so on are very good candidate of natural composites as reinforcements. On the other hand regarding matrix parts thermosetting polymer and thermoplastic polymer deriver form petrochemical products are not environmental friendly material, even if thermoplastic polymer can be recycled. In order to create fully environmental friendly material (FEFM) biodegradable polymer which can be deriver from natural resources is needed. Therefore poly(lactic acid) (PLA) polymer is very good material for the FEFM. However, PLA is very brittle polymer, so that polymer chemists have been made the efforts to make tough PLA. In this paper Jute/PLA composites was fabricated by injection moldings and mechanical properties were measured. It is believable that industries will have much attention to FEFM, so that injection molding was adopted to fabricate the composites. Long fiber pellet pultrusion technique was adopted to prepare jute fiber-PLA pellet (Jute/PLA). Because it is a new method which is able to fabricate composite pellets with relative long length fibers for injection molding process, where, jute yarns were continuously pulled and coated with PLA resin. Here two kinds of PLA materials were used including the one with mold releasing agent and the other is without it. After pass through a heated die whereby PLA resin impregnates into the jute yarns and sufficient cooling, the impregnated jute yarns were cut into pellets. Then Jute/PLA pellets were fed into injection machine to make dumbbell shape specimens. In current study, the effects of temperature of heat die i.e. impregnation temperature and the kind of PLA were focused to get optimum molding condition. The volume fractions of jute fiber in pellet were measured by several measuring method including image analyzing, density measurement and dissolution methods. And the mechanical property were investigated by tensile and Izod testing. It is found that 250 degree is much suitable for Jute/PLA long fiber pultrusion process. Additionally the jute fibers seem much effective to increase the tensile modulus and the Izod strength. That is to say, the addition of Jute fiber in PLA, the brittle property can be improved.

scholarly journals Angolan vegetable crops have unique genotypes of potential value for future breeding programmes

2016 ◽  
Vol Volume 112 (Number 3/4) ◽  
Author(s):  
José P. Domingos ◽  
Ana M. Fita ◽  
María B. Picó ◽  
Alicia Sifres ◽  
Isabel H. Daniel ◽  
...  
Keyword(s):  
Strong Dependence ◽  
The Other ◽  
Vegetable Crops ◽  
Cucurbita Maxima ◽  
Capsicum Chinense ◽  
Local Markets ◽  
Potential Value ◽  
Wide Range ◽  
Different Types ◽  
Breeding Programmes

Abstract A survey was carried out in Angola with the aim of collecting vegetable crops. Collecting expeditions were conducted in Kwanza-Sul, Benguela, Huíla and Namibe Provinces and a total of 80 accessions belonging to 22 species was collected from farmers and local markets. Species belonging to the Solanaceae (37 accessions) and Cucurbitaceae (36 accessions) families were the most frequently found with pepper and eggplant being the predominant solanaceous crops collected. Peppers were sold in local markets as a mixture of different types, even different species: Capsicum chinense, C. baccatum, C. frutescens and C. pubescens. Most of the eggplant accessions collected belonged to Solanum aethiopicum L. Gilo Group, the so-called ‘scarlet eggplant’. Cucurbita genus was better represented than the other cucurbit crops. A high morphological variation was present in the Cucurbita maxima and C. moschata accessions. A set of 22 Cucurbita accessions from Angola, along with 32 Cucurbita controls from a wide range of origins, was cultivated in Valencia, Spain and characterised based on morphology and molecularity using a set of 15 microsatellite markers. A strong dependence on latitude was found in most of the accessions and as a result, many accessions did not set fruit. The molecular analysis showed high molecular variability and uniqueness in the collected accessions, as shown by their segregation from the set of global controls. In summary, the material collected is quite valuable because of its uniqueness and the potential of the breeding characteristics it possesses.

scholarly journals Hydrothermal treatment of sprout-damaged grain: I. Effects on the technological quality of wheat

1978 ◽  
Vol 50 (3) ◽  
pp. 240-253
Author(s):  
Christina Westermarck-Rosendahl ◽  
Hannu Salovaara
Keyword(s):  
Amylase Activity ◽  
The Other ◽  
Processing Conditions ◽  
Falling Number ◽  
Gluten Quality ◽  
Heat Treated ◽  
Technological Quality ◽  
The One ◽  
Increasing Temperature

Two sprout-damaged wheat lots with the falling number values of 91 and 65 were heat-treated by immersing the grain in water of temperatures of 80, 85, 90 and 100°C, followed by rapid chilling in water. The purpose of the treatment was to suppress the excess a-amylase activity in the outer layers of the kernels. The a-amylase activity following the treatment was measured by the falling number test. The increase in the falling number value was the greater the longer the treatment lasted and the higher the water temperature was. Processing lasting 30 sec at 80, 85, 90 and 100°C increased the falling number value of the one lot from 91 to 105, 117, 133 and 238 and of the other lot from 65 to 69, 70, 98, 163, respectively. As the falling numbers increased the wet gluten content of the samples decreased. These changes had a negative correlation. The gluten quality showed heat damage when the amount of gluten had dropped by about 5 and 2 precentage units in the lots with the falling numbers 91 and 65, respectively. This occurred at processing of the lot of better quality for 70, 20, 13 and 6 sec in the order of increasing temperature. The corresponding durations for the other lot were above 60, 30, 20 and 6 sec. During these treatments the falling number values rose from 91 to 104—129 and from 65 to 70—71. These results were confirmed by farinogram and extensigram determinations and by baking tests. The same processing conditions affected more severely the lot having the better initial quality than the lot with greater sprout damages.

An Experimental Evaluation of Vibration-Assisted Injection Molding During Manufacturing

1999 ◽  
Author(s):  
Alan M. Tom ◽  
Akihisa Kikuchi ◽  
John P. Coulter
Keyword(s):  
Experimental Study ◽  
Injection Molding ◽  
Scientific Explanation ◽  
Molecular Level ◽  
Injection Molding Process ◽  
Processing Conditions ◽  
Vibrational Motion ◽  
Current Investigation ◽  
Molding Process ◽  
Polymer Properties

Abstract The current investigation focused on contributing to the development of a novel injection molding process by attempting to understand the scientific relationship that exist between the applied vibrational parameters involved in this process and the effect it has on final product polymeric characterization. Although previous and current attempts at understanding the connection between applied oscillatory or vibrational motion to an injection molding process has shown positive quantitative advantages to final product properties, there still exists a void in the scientific explanation on a molecular level linking these effects. This experimental study, in particular, involved an evaluation on a range of processing conditions applied to Polystyrene and the effects it produced on resultant product quality and polymer properties. Optimal control and mechanical vibrational molding conditions were obtained for Polystyrene. As a result of this, optimal opportunities for initial commercial utilization of the technology can be proposed.

Study of the Effect of Boundary Conditions on Residual Stresses in Welding Using Element Birth and Element Movement Techniques

2003 ◽  
Author(s):  
Ihab F. Z. Fanous ◽  
Maher Y. A. Younan ◽  
Abdalla S. Wifi
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Boundary Conditions ◽  
Welding Process ◽  
Computation Time ◽  
3D Models ◽  
The Other ◽  
3D Analysis ◽  
The Media ◽  
Element Movement

The structure in which the welding process is performed highly affects the residual stresses generated in the welding. This effect is simulated by choosing the appropriate boundary conditions in modeling the welding process. The major parameters of the boundary conditions are the method by which the base metal is being fixed and the amount of heat being applied through the torch. Other parameters may include the coefficients of thermal heat loss from the plate which may simulate the media in which the welding is taking place. In modeling the welding process, 2D forms of approximation were developed in analyzing most of the models of such problem. 3D models analyzing the welding process were developed in limited applications due to its high computation time and cost. With the development of new finite element tools, namely the element movement technique developed by the authors, full 3D analysis of the welding process is becoming in hand. In the present work, three different boundary conditions shall be modeled companng their effect on the welding. These boundary conditions shall be applied to two models of the welding process: one using the element birth technique and the other using the element movement technique showing the similarity in their responses verifying the effectiveness of the latter being accomplished in a shorter time.

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