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.

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 Melt Polycondensation for the Synthesis of Polyester Amides using Kneader Reactor Technology

2020 ◽  
Vol 74 (12) ◽  
pp. 1024-1025
Author(s):  
Lucien Blanchard ◽  
Chris Rader ◽  
Ennio Vanoli ◽  
Roger Marti
Keyword(s):  
Mechanical Properties ◽  
Mass Transfer ◽  
High Temperature ◽  
Process Development ◽  
Scale Up ◽  
Laboratory Scale ◽  
Critical Parameters ◽  
Thermal And Mechanical Properties ◽  
Reactor Technology ◽  
Melt Polycondensation

In this work, we discuss the process development and scale-up of the melt polycondensation of polyester amides from a laboratory scale to kg-scale in a kneader reactor. We identified and optimized the most important critical parameters and produced kg-quantities of polyester amides with Mn up to 25'000 g/mol and reproducible thermal and mechanical properties. The special kneader reactor allows safe and efficient scale-up of polymerisation reactions at high temperature and viscous melts due to good mixing and efficient mass transfer.

A process-oriented scale-up/scale-down strategy for industrial blown film processes: Theory and experiments

2017 ◽  
Vol 34 (3) ◽  
pp. 324-349 ◽  
Author(s):  
Benedikt Neubert ◽  
Christoph Dohm ◽  
Johannes Wortberg ◽  
Marius Janßen
Keyword(s):  
Mechanical Properties ◽  
Scale Up ◽  
Laboratory Scale ◽  
Process Time ◽  
Process Conditions ◽  
Scale Production ◽  
Film Properties ◽  
Blown Film ◽  
Scale Down ◽  
Process Oriented

To gain a competitive edge in developing innovative products, new multi-layer film manufacturers need to know whether laboratory-scale blown film line results reliably translate to large-scale production. This, however, is not always the case: Transferring process conditions and getting equal final film properties are not ensured. To address this problem, this paper presents a scale-independent scale-up/scale-down strategy to produce films with consistently similar properties regardless of a plant’s size and design. A second aim is to prove this strategy is applicable by comparing the reference and experimental film mechanical properties. Here, experimental scale-down runs were carried out based on a process-oriented scale-up/scale-down strategy for the blown film process. An industrial production process (>800 kg/h), successfully transferred to a laboratory-scale blown film line, was used as the reference. The introduced process-oriented scale-up/scale-down is based on geometric and dynamic similarity. In this context, blow-up ratio, draw-down ratio and process time have been identified as major scale-up/scale-down variables. Unlike existing scale-up strategies, the process-oriented approach is more flexible in practice. Film mechanical properties taken from the experimental runs were determined by tensile and puncture resistance tests. The compared results confirmed that process-oriented scale-up/scale-down is feasible for the applied material and under the existing plant-specific restrictions. The comparison indicated that most film properties produced on the laboratory-scale plant were comparable to those from the high-capacity blown film line.

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