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Manufacturing defects in thermoplastic composite pipes and their effect on the in-situ performance of thermoplastic composite pipes in oil and gas applications.

Okolie, Obinna; Latto, Jim; Faisal, Nadimul; Jamieson, Harvey; Mukherji, Arindam; Njuguna, James


Jim Latto

Harvey Jamieson

Arindam Mukherji


Thermoplastic composite pipes (TCP), which are a form of fibre reinforced thermoplastic pipes, have proven benefits such as being lightweight and non-corrosive. However, during manufacturing, certain defects are induced because of certain parameters, which eventually affect TCP performance in-service. Current manufacturing techniques are challenged with on-the-spot detection as the pipe is regularly monitored. When a defect is noticed, the process stops and action is taken. However, stopping the process is costly; hence it is vital to decrease downtime during manufacturing. Potential solutions are through process optimisation for defect reduction and an in-depth understanding of the effect of parameters that cause defect formation in the pipe. This article provides an overview of manufacturing influence on end performance. This is intimately linked to the material features, properties and performance in-service. The material features are the determinants for the manufacturing technique to be used. For TCP, it is a melt fusion bonding process involving heating and consolidation (other factors are consolidation speed and pull force). Thermal behaviour is essential at this phase as it determines the curing rate, hence it is deduced that laser heating is the better heat source in efficiency terms. Defects such as fibre misalignments, voids and delamination are induced here. The sources of these defects have been discussed herein as well as the secondary defects caused by them, with consideration of residual stress impact. The presence of manufacturing defects has been identified to influence performance in terms of strength and stiffness, interlaminar shear strength, toughness and creep. The next phase is to explore the state of the art in defect characterization during manufacturing for TCP. The in-situ characterization aims to derive high-quality TCP with reduced defects and need for repairs, and increased production rate in safe and eco-friendly conditions, while maintaining the current manufacturing process.


OKOLIE, O., LATTO, J., FAISAL, N., JAMIESON, H., MUKHERJI, A. and NJUGUNA, J. 2023. Manufacturing defects in thermoplastic composite pipes and their effect on the in-situ performance of thermoplastic composite pipes in oil and gas applications. Applied composite materials [online], 30(1), pages 231-306. Available from:

Journal Article Type Article
Acceptance Date Sep 6, 2022
Online Publication Date Nov 15, 2022
Publication Date Feb 28, 2023
Deposit Date Sep 27, 2022
Publicly Available Date Sep 27, 2022
Journal Applied composite materials
Print ISSN 0929-189X
Electronic ISSN 1573-4897
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 30
Issue 1
Pages 231-306
Keywords Thermoplastic composites; Manufacturing defects; Manufacturing techniques; Thermo-mechanical performance
Public URL


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