Determination of cure mechanism inside die for a part manufacturing during large-scale pultrusion.

Mukherji, Arindam; Tarapore, Nozer; Njuguna, James

Abstract

The cure kinetics of resin, heat capacity and thermal conductivity of reinforcing materials of uncured mass dictates the ultimate curing of reinforced thermosets manufactured component. In this study, degree of conversion from heat capacity by ‘Lumry and Eyring Model’ and order of reaction by multi-regression technique using ‘Borchardt and Daniels Model’ are calculated in finding cure kinetics (ɣ) of the resin. Experimental results from differential scanning calorimetry (DSC), thermogravimetry (TGA) and rheological measurements were used to determine thermal conductivity, heat capacity and rheological parameters of the resin through several model fitting. The calculated thermal conductivity of uncured composite from ration of (length vs contact area) and thermal resistivity extracted from TGA data was fitted into specific mathematical model which predicts the thermal behaviour of heated prepreg during pultrusion operation. These parameters used in a separate mathematical partial differential equation-based model equation to predict the change in temperature and resin conversion along axial distance and radial thickness. The influence of operating conditions, such as rate of heating (Early and late Heating) and fibre volume fraction while curing inside die were calculated and validated with experimental results. This study evaluates the extent of heat transfer and degree of conversion inside pultrusion die during scale up steady state process. It is observed that paradigm of influencing parameters like pulling speed, die radial thickness and heater engagement (Early and late heating) on heat flow from die wall to core (i.e., thickness of the part being pulled) follows the data captured experimentally.

Citation

MUKHERJI, A., TARAPORE, N. and NJUGUNA, J. 2022. Determination of cure mechanism inside die for a part manufacturing during large-scale pultrusion. Journal of applied polymer science [online], 139(17), article 52035. Available from: https://doi.org/10.1002/app.52035

• Journal Article Type: Article
• Acceptance Date: Nov 3, 2021
• Online Publication Date: Dec 18, 2021
• Publication Date: May 5, 2022
• Deposit Date: Dec 10, 2021
• Publicly Available Date: Dec 19, 2022
• Journal: Journal of Applied Polymer Science
• Print ISSN: 0021-8995
• Electronic ISSN: 1097-4628
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 139
• Issue: 17
• Article Number: 52035
• DOI: https://doi.org/10.1002/app.52035
• Keywords: Cure kinetics; Resin; Thermal conductivity; Heat transfer; Curing mechanism; Manufacturing; Polyesters; Pultrusion; Rheology; Synthesis and processing techniques
• Public URL: https://rgu-repository.worktribe.com/output/1545129