Non-uniform crystallinity and temperature distribution during adjacent laser-assisted tape winding process of carbon/PA12 pipes

Abstract

The non-uniform temperature and crystallinity distributions present in carbon fiber–reinforced PA12 composite pipes, produced via laser-assisted tape winding (LATW), are investigated in this paper. The width of the laser source is usually larger than the substrate width which causes multiple heating and cooling of some regions of the (neighboring) substrate and hence temperature and crystallinity gradients during the adjacent hoop winding. A kinematic-optical-thermal (KOT) model coupled with a non-isothermal crystallinity model is developed to capture the transient temperature and crystallinity distributions for growing substrate thickness and width. The predicted temperature trends are validated with thermocouple and thermal camera measurements. The substrate temperature varies in the width direction up to 52%. This will lead to extra polymer remelting and possible degradation. The maximum variation of the crystallinity degree across the width is found to be 270% which shows agreement with the trend of the measured crystallinity degree. It is found that a more realistic description of the melting behavior of the matrix is needed to obtain a more accurate prediction of the crystallinity distribution.

Crystallinity studies of PEKK and carbon fibre/PEKK composites: A review

“…The figure outlines the crystallinity distribution uncertainty in the resulting laminate from ATP, and the current need of post-processing in order to obtain a uniformed and controlled crystallinity. This is not a challenge only applicable to PEKK, but to any semicrystalline thermoplastic matrix composite consolidated by ATP [94]. There are several studies available on CF/PEEK in ATPmanufactured laminates focusing on mechanical characterisation and consolidation quality [13,15,70,[95][96][97][98][99], and fewer in the case of CF/PEKK [97], however literature covering variation in crystallinity specifically is sparse [16].…”

Optimization of the laser-assisted tape winding process using an inverse kinematic-optical-thermal model

“…The process temperature, speed, compaction pressure [1][2][3][4][5], fiber path planning [6][7][8][9], and processinduced defects [10][11][12] are the important factors for developing a proper bonding quality at the interface between the tape and substrate to manufacture products with high mechanical performance. In addition, optimal ranges of the tape winding and placement parameters such as tape tension and roller force are necessary to reduce the void content [13,14] and residual stress [15,16] and to increase the tensile strength [13,15], interlaminar shear strength [17,18], peel strength [19,20], and production rate [16,18,19] The nip point temperature serves as an indicator for the process temperature and might vary during the LATW process, possibly resulting in a substantial variation in the consolidation quality.…”

“…A schematic view of the heating zones (highlighted areas) during placement with changing and constant fibre path orientation. This is used to show the variation of heating duration for 1D thermal domains on the top surface depending the corresponding location.where vector d was the right hand side of Equations (3)-(5).…”

Composto de PA12 contendo resíduos de polietileno reticulado (XLPE):propriedades e avaliação de resíduos de ionômeros na sua compatibilização em relação a um agente compatibilizante comercial

“…O grau de cristalinidade da poliamida 12 foi determinando de acordo com a equação abaixo, na qual ∆𝐻𝑓 é a entalpia de fusão da amostra e ∆𝐻𝑓° é a entalpia de fusão do polímero 100% cristalino (CANEVAROLO, 2010). No caso da poliamida 12, o valor utilizado para ∆𝐻𝑓° foi de 209,3 J/g (HOSSEINI et al, 2020).…”