Fast mold surface temperature evolution: relevance of asymmetric surface heating for morphology of iPP molded samples

RSC Advances ◽  
2015 ◽  
Vol 5 (46) ◽  
pp. 36434-36448 ◽  
Author(s):  
S. Liparoti ◽  
A. Sorrentino ◽  
G. Guzman ◽  
M. Cakmak ◽  
G. Titomanlio

It is widely accepted that mold temperature has a strong effect on the amount of molecular orientation and morphology developed in a non-isothermal flowing melt.

2016 ◽  
Author(s):  
Sara Liparoti ◽  
Andrea Sorrentino ◽  
Gustavo Guzman ◽  
Mukerrem Cakmak ◽  
Giuseppe Titomanlio

Author(s):  
Shia-Chung Chen ◽  
Yaw-Jen Chang ◽  
Jen-An Chang ◽  
Hsin-Shu Peng ◽  
Ying-Chieh Wang

Dynamic mold surface temperature control (DMTC) has the advantage of improving molded part qualities without significant increases in cycle time. A gas-assisted heating system combined with water cooling was developed to achieve DMTC for injection molding. With gas-assisted heating, it takes 2s for the mold surface temperature to vary from 60 °C to 120 °C whereas it requires 186s using water heating. Further, it takes 21s and 84s for the mold surface to cool to 60 °C under gas heating and water heating, respectively. The gas-assisted heating system also shows excellent efficiency for micro injection molding of biochips to achieve high replication accuracy of the micro channels.


2019 ◽  
Author(s):  
S. Liparoti ◽  
A. Sorrentino ◽  
V. Speranza ◽  
R. Pantani ◽  
G. Titomanlio

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 377-389
Author(s):  
Jordan Hristov

Non-linear heat conduction with a power-law thermal diffusivity and ramped surface temperature has been solved by the double-integration technique of the integral-balance integral method. The case of a semi-infinite medium and infinite ramp of surface temperature has been considered as example demonstrating the versatility of the solution approach. The thermal penetration depth and solution behaviours with finite speeds have been analyzed.


Author(s):  
Byoung Hee You ◽  
Daniel S. Park ◽  
Christopher W. Mock ◽  
Wilfredo M. Caceres ◽  
Dimitris E. Nikitopoulos ◽  
...  

Simulations and experiments to assess the predictability of dimensional and locational tolerances of passive alignment structures on injection molded microfluidic components were performed. A center-gated disk with microscale assembly features, to aid metrology, was reproduced using injection molding. The feature dimensions were 100, 200, 300, and 400 μ. Dimensions of the features were measured using optical profilometery and optical microscopy. Simulations using a commercial package overestimated replication fidelity. Mold surface temperatures and injection speeds significantly affected the replication fidelity as the ratio of surface area to volume increased. The location of better replication fidelity, at each mold surface temperature, moved from the edge of the mold cavity to the injection point as the mold surface temperature increased from 100°C to 150°C. Therefore, process parameters and the design of a mold have to be considered for successful replication of the features.


2008 ◽  
Vol 21 (5) ◽  
pp. 1104-1121 ◽  
Author(s):  
Sergey Kravtsov ◽  
Christopher Spannagle

Abstract This study identifies interdecadal natural climate variability in global surface temperatures by subtracting, from the observed temperature evolution, multimodel ensemble mean based on the World Climate Research Programme's (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset. The resulting signal resembles the so-called Atlantic multidecadal oscillation (AMO) and is presumably associated with intrinsic dynamics of the oceanic thermohaline circulation (THC). While certain phases of the oscillation are dominated by the anomalies in the North Atlantic region, other phases are characterized by global teleconnections to the North Pacific Ocean, tropical Atlantic Ocean, as well as the Southern Ocean. In particular, natural variability of sea surface temperature in the Atlantic hurricanes’ main development region has a peak-to-peak amplitude comparable in magnitude to this region’s surface temperature increase over the past century, for all seasons. Evidence suggests that the AMO influence on secular trends in the global-mean surface temperature can arise via direct, regional contribution to the surface temperature evolution, as well as via an indirect route linked to variability of the oceanic uptake of CO2 associated with AMO-related THC changes.


Soft Matter ◽  
2020 ◽  
Vol 16 (41) ◽  
pp. 9568-9577
Author(s):  
Lu Shen ◽  
Junheng Ren ◽  
Fei Duan

Controlled ethanol droplet evaporation shows a five-phase surface temperature evolution and two transitions among the three radial surface temperature distributions.


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