Influence of Processing Parameters in Reaction Injection Foam Molding for Multi-Layer Parts on Foam Structure and Mechanical Properties

2015 ◽  
Vol 805 ◽  
pp. 131-138
Author(s):  
Martin Löhner ◽  
Dietmar Drummer
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Chemical Reaction ◽  
Reactive Systems ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Foam Structure ◽  
Blowing Agents ◽  
Reaction Injection Molding ◽  
Plastic Processing

Reaction injection molding is a plastic processing method to produce net shape parts using reactive systems. By integrating semi-finished products as inserts, complex multi-layer parts can be generated in highly integrative and energy efficient processes. The material by far mostly used is polyurethane, a polymer which results from the reaction of isocyanate and polyol. By adding blowing agents, like for example water, to the polyol component, foamed parts can be realized. In contrast to thermoplastic injection molding a chemical reaction takes part during molding within the cavity. Therefore the processing parameters have a significant effect on this chemical reaction and on the properties of the finished part.In this work the influences of different processing parameters like for example mold temperature and injection volume on the resulting foam structure are investigated for reaction injection foam molding. Therefore multi-layer parts based on polyurethane materials (thermoplastic and reactive) were molded varying relevant processing parameters. The foaming took place within an open cavity. The resulting foam structures were characterized using scanning electron microscopy (SEM). Additional the multi-layer parts were characterized mechanically to reveal the resulting effects on the mechanical properties of parts containing a foamed reactive polyurethane component.

scholarly journals Mechanical and structural properties of composites made from recycled and virgin polyethylene terephthalate (PET) and metal chip or mesh wire

2019 ◽  
Vol 299 ◽  
pp. 06007
Author(s):  
Mircea Aurelian Antoniu Rusu ◽  
Sever-Adrian Radu ◽  
Catalin Moldovan ◽  
Codruta Sarosi ◽  
Ionela Amalia Mazilu (Moldovan) ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Processing Parameters ◽  
Sem Images ◽  
Major Drawback ◽  
Recycled Pet ◽  
Plastic Processing ◽  
Metal Chip ◽  
Intense Research ◽  
Properties Of Composites

Although polyethylene terephthalate (PET) is a champion of recycling, intense research is being done to find new solutions for using recycled plastic. This study aims to characterize the mechanical andstructural properties (SEM- scanning electron microscopy) of products made from recycled metal swarf or mesh wire with recycled plastic (PET) in comparison with virgin plastic. Samples manufactured from virgin and recycled PET are made by pressing and high temperature. The loss of mechanical properties ofproducts made from recycled plastic is a major drawback that influences their use. SEM images confirm that the dispersion and distribution of the PET phase is not very uniform. By addition of virgin plastic in various compositions with recycled plastic, processing parameters and mechanical properties can be optimized.

scholarly journals Post-Processing Time Dependence of Shrinkage and Mechanical Properties of Injection-Molded Polypropylene

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 22
Author(s):  
Artur Kościuszko ◽  
Dawid Marciniak ◽  
Dariusz Sykutera
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Injection Molding ◽  
Accelerated Aging ◽  
Mold Temperature ◽  
Degree Of Crystallinity ◽  
Injection Mold ◽  
Secondary Crystallization ◽  
Scanning Calorimetry ◽  
Injection Molded

Dimensions of the injection-molded semi-crystalline materials (polymeric products) decrease with the time that elapses from their formation. The post-molding shrinkage is an effect of secondary crystallization; the increase in the degree of polymer crystallinity leads to an increase in stiffness and decrease in impact strength of the polymer material. The aim of this study was to assess the changes in the values of post-molding shrinkage of polypropylene produced by injection molding at two different temperatures of the mold (20 °C and 80 °C), and conditioned for 504 h at 23 °C. Subsequently, the samples were annealed for 24 h at 140 °C in order to conduct their accelerated aging. The results of shrinkage tests were related to the changes of mechanical properties that accompany the secondary crystallization. The degree of crystallinity of the conditioned samples was determined by means of density measurements and differential scanning calorimetry. It was found that the changes in the length of the moldings that took place after removal from the injection mold were accompanied by an increase of 20% in the modulus of elasticity, regardless of the conditions under which the samples were made. The differences in the shrinkage and mechanical properties of the samples resulting from mold temperature, as determined by tensile test, were removed by annealing. However, the samples made at two different injection mold temperature values still significantly differed in impact strength, the values of which were clearly higher for the annealed samples compared to the results determined for the samples immediately after the injection molding.

Mechanical Properties Simulation of Squeeze Cast Magnesium Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 1464-1467
Author(s):  
Zhi Hong Guo ◽  
Hua Hou ◽  
Shu Wei Qu
Keyword(s):  
Mechanical Properties ◽  
Squeeze Casting ◽  
Tensile Elongation ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Mould Temperature ◽  
Pouring Temperature ◽  
Squeeze Pressure ◽  
Squeeze Cast ◽  
Cast Magnesium

A research program was simulated to study the effects of pouring temperature, squeeze pressure and die temperature on the tensile, elongation and hardness properties of AZ91D magnesium alloys using anycasting software. The curves with different processing parameters on mechanical properties have been painted. The results indicated that mechanical properties increased firstly, then decreased when the pouring temperature increased to 670°C, and gradually increased with the increasing of squeeze pressure. The affect laws of mould temperature are similar as ones of pouring temperature. Eventually found that the squeeze casting got better mechanical properties(σb= 225MPa, δ= 3.6%, Vickers hardness=62) on the pouring temperature 670°C, mold temperature 180°C, holding pressure 120Mpa, pressure duration 25s.

Influence of Injection Molding Parameters on Mechanical Properties of Low Density Polyethylene Filled With Multiwalled Carbon Nanotubes

2011 ◽  
Author(s):  
Catalin Fetecau ◽  
Felicia Stan ◽  
Daniel Dobrea ◽  
Dan Catalin Birsan
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Injection Molding ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Flow Direction ◽  
Mold Temperature ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Temperature

In this paper, we investigated the effect of injection molding parameters such as melt temperature, mold temperature, injection speed and holding pressure on the mechanical properties of low density polyethylene reinforced with 2.5 wt% multi-walled carbon nanotubes. The Taguchi methodology with four factors and two levels was used for the design of the injection molding experiments. The mechanical properties were evaluated by tensile tests in the flow direction at room temperature (23 °C) at crosshead speeds of 1 and 5 mm/min. It was found that the mechanical properties can be modified by manipulating the injection molding parameters. The Young’s modulus of the LDPE-MWNTs composite decreased as the melt temperature increased, while mold temperature, injection molding speed and holding pressure have a moderate influence on the Young’s modulus.

Optimization of the Injection Molding Process Parameters Based on Moldflow and Orthogonal Experiment

2013 ◽  
Vol 561 ◽  
pp. 239-243 ◽  
Author(s):  
Yong Nie ◽  
Hui Min Zhang ◽  
Jia Teng Niu
Keyword(s):  
Injection Molding ◽  
Orthogonal Experiment ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Influential Factors ◽  
Injection Molding Process ◽  
Range Analysis ◽  
Molding Process ◽  
Melt Temperature ◽  
Plastic Parts

This article is using Moldflow analysis and orthogonal experimental method during the whole experiment. The injection molding process of motor cover is simulated under various technological conditions.After forming the maximum amount of warpage of plastic parts for evaluation.According to the range analysis of the comprehensive goal, the extent of the overall influence to the processing parameters, such as gate location, melt temperature, mold temperature and holding pressure is clarified.Through analyzing the diagrams of influential factors resulted from the simulation result,the optimized process parameter scheme is obtained and further verified by simulation.

Numerical and Experimental Study on the Injection Moulding of a Thin-Wall Complex Part

2008 ◽  
Author(s):  
Catalin Fetecau ◽  
Ion Postolache ◽  
Felicia Stan
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Thin Wall ◽  
Molding Process ◽  
Complex Part ◽  
Filling Time ◽  
Wall Injection

The research presented in this paper involves numerical and experimental efforts to investigate the relative thin-wall injection molding process in order to obtain high dimensional quality complex parts. To better understand the effects of various processing parameters (the filling time, injection pressure, the melting temperature, the mold temperature) on the injection molding of a thin-wall complex part, the molding experiments are regenerated into the computer model using the Moldflow Plastics Insight (MPI) 6.1 software. The computer visualization of the filling phase allows accurate prediction of the location of the flow front, welding lines and air traps. Furthermore, in order to optimize the injection molding process, the effects of the geometry of the runner system on the filling and packing phases are also investigated. It is shown that computational modeling could be used to help the process and mold designer to produce accurate parts.

Influence of Injection Molding Process Parameters on Sink Marks of Injection Parts Based on Moldflow

2013 ◽  
Vol 347-350 ◽  
pp. 1163-1167
Author(s):  
Ling Bai ◽  
Hai Ying Zhang ◽  
Wen Liu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Sink Marks ◽  
Research Show

Moldflow software was used to obtain the best gate location and count. Influence of injection molding processing parameters on sink marks of injection-piece was studied based on orthogonal test. The effects of different process parameters were analyzed and better process parameters were obtained. Results of research show that decreasing melt temperature, mold temperature, the increasing injection time and packing pressure can effectively reduce the sink marks index.

LABORATORY-SCALE REACTION INJECTION MOLDING OF POLY(CAPROLACTONE) ELASTOMERS FOR RAPID PROTOTYPING OF STIMULI-RESPONSIVE THERMOSETS

2017 ◽  
Vol 90 (2) ◽  
pp. 337-346
Author(s):  
Yuan Meng ◽  
Xin Huang ◽  
Cynthia Fitzgerald ◽  
Hojun Lee ◽  
Jeh-Chang Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Material Processing ◽  
Injection Molding ◽  
Scale Up ◽  
Polymer Networks ◽  
Laboratory Scale ◽  
Feed Stream ◽  
Stimuli Responsive ◽  
Reaction Injection Molding ◽  
Poly Caprolactone

ABSTRACT Semicrystalline polymer networks offer valuable shape-memory and shape-shifting properties; however, material processing and scale-up remain major challenges. A laboratory-scale reaction injection molding (RIM) apparatus and methodology are described to mold and cure urethane linked poly(caprolactone) networks from commercially available polyols and polyisocyanate. The highly customized RIM system is capable of making small shot sizes (∼39 g) at precise stoichiometric ratios and forming elastomers with low run-to-run variation of mechanical properties. Experiments conducted with a dye in one feed stream enable evaluation of mixing efficacy, and component mixing is substantially improved by recirculating reagents at higher pressures. Networks prepared with excess isocyanate exhibited higher modulus, which is most likely due to the formation of allophanates.

Study on one Dimensional Numerical Simulation in Filling Stage of Water-Assisted Injection Molding

2011 ◽  
Vol 179-180 ◽  
pp. 1193-1198 ◽  
Author(s):  
Tang Qing Kuang
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Water Temperature ◽  
Water Pressure ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Melt Temperature ◽  
Filling Stage ◽  
Short Shot ◽  
Temperature Water

Water assisted injection molding is a pretty novel way to fabricate hollow or more complicated parts. Its molding window and process control are more critical and difficult since additional processing parameters are involved. A simulation model for the filling stage of a pipe cavity during short-shot water assisted injection molding was proposed. The finite element/finite difference/control volume methods were adopted for the numerical simulation. A numerical study, based on the single factor method, was conducted to characterize the effect of different processing parameters on the short shot water-assisted injection-molding of thermoplastic composites, including short-shot size, melt temperature, mold temperature, water temperature and water pressure. For the factors selected in the simulations, short-shot size was found to be the principal parameters affecting the water penetration length while melt temperature, mold temperature, water temperature, water pressure were found to have little effect on the penetration of water.

Sign in / Sign up

Export Citation Format

Share Document