Pressure and temperature behavior of thermoplastic polymer melts during high-pressure expansion injection molding

2008 ◽  
Vol 48 (9) ◽  
pp. 1815-1823 ◽  
Author(s):  
Sašo Rogelj ◽  
Matjaž Krajnc
Keyword(s):  
High Pressure ◽  
Injection Molding ◽  
Polymer Melts ◽  
Temperature Behavior ◽  
Thermoplastic Polymer

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.

Injection Molding: High Pressure Process

1986 ◽  
pp. 59-70
Author(s):  
Fjodor A. Shutov ◽  
G. Henrici-Olivé ◽  
S. Olivé
Keyword(s):  
High Pressure ◽  
Injection Molding ◽  
High Pressure Process

Process comparison on the microstructure and mechanical properties of fiber-reinforced polyphenylene sulfide using MuCell technology

2018 ◽  
Vol 37 (15) ◽  
pp. 1020-1034 ◽  
Author(s):  
Christoph Lohr ◽  
Björn Beck ◽  
Frank Henning ◽  
Kay André Weidenmann ◽  
Peter Elsner
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Injection Molding ◽  
Fiber Orientation ◽  
Polyphenylene Sulfide ◽  
Injection Molding Process ◽  
Fiber Reinforced ◽  
Molding Process ◽  
Glass Fiber Reinforced ◽  
Foam Injection Molding

The MuCell process is a special injection molding process which utilizes supercritical gas (nitrogen) to create integral foam sandwiches. The advantages are lower weight, higher specific properties and shorter cycle times. In this study, a series of glass fiber-reinforced polyphenylene sulfide foam blanks are manufactured using the MuCell injection molding process. The different variations of the process (low-pressure also known as structural foam injection molding) and high-pressure foam injection molding (also known as “core back expansion,” “breathing mold,” “precision opening,” decompression molding) are used. The sandwich structure and mechanical properties (tensile strength, bending strength, and impact behavior) of the microcellular and glass fiber-reinforced polyphenylene sulfide foams are systematically investigated and compared to compact material. The results showed that the injection parameters (injection speed, foaming mechanism) played an important role in the relative density of microcellular polyphenylene sulfide foams and the mechanical properties. It could be shown that the specific tensile strength decreased while increasing the degree of foaming which can be explained by the increased number of cells and the resulting cell size. This leads to stress peaks which lower the mechanical properties. The Charpy impact strength shows a significant dependence on the fiber orientation. The specific bending modulus of the high-pressure foaming process, however, surpasses the values of the other two processes showing the potential of this manufacturing variation especially with regard to bending loads. Furthermore, a high dependence of the mechanical properties on the fiber orientation of the tested specimens can be found.

scholarly journals High-Temperature Behavior of High-Pressure Diecast Alloys Based on the Al-Si-Cu System: The Role Played by Chemical Composition

Metals ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 348 ◽  
Author(s):  
Elisabetta Gariboldi ◽  
Jannis Lemke ◽  
Ludovica Rovatti ◽  
Oksana Baer ◽  
Giulio Timelli ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Chemical Composition ◽  
Temperature Behavior ◽  
High Temperature Behavior
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