TY - JOUR

T1 - Influence of Epoxy Spray Binder on Infusion and Cure in Liquid Composite Molding Processes

AU - Möllers, Hendrik

AU - Schmidt, Carsten

AU - Meiners, Dieter

N1 - Funding Information: The authors would like to thank the federal state of Lower Saxony and the European Regional Development Fund (ERDF) for financial and organizational support of the project AutoBLADE. The binder was supplied free of charge by CTP Advanced Materials.

PY - 2024/4

Y1 - 2024/4

N2 - Binders are known to influence the different steps in liquid composite molding process chains. Most reseach focuses on powder binder and veils. Spray binders are rarely studied. Therefore, the effect of an epoxy spray binder on the infusion and cure steps of liquid composite molding processes is studied in this paper. Permeability measurements, solubility tests and measurements of glass transition temperature, resin cure time and resin viscosity show a complex interaction between binder and resin depending on the process conditions. The binder mostly increased the permeability of the tested preforms. This effect increases with increasing binder loading. At low fiber volume fractions the binder had a positive effect on preform permeability, most likely by to delaying the closure of macro flow channels or textile inhomogeneity. The binder did not dissolve in the resin until temperatures of around 120 °C, while remaining as a separate phase at 22 °C, 40 and 80 °C. This has to be considered when defining the cure profile of the resin, as the binder is expected to participate in the cure reaction. The glass transition temperature remained unchanged for the binder-resin combination used. An increase in viscosity by a factor of 1.5-2 was observed when the binder was dissolved in the resin. Samples with dissolved binder cured slightly faster than pure resin. The experimental results were theoretically transferred to real infusion processes.

AB - Binders are known to influence the different steps in liquid composite molding process chains. Most reseach focuses on powder binder and veils. Spray binders are rarely studied. Therefore, the effect of an epoxy spray binder on the infusion and cure steps of liquid composite molding processes is studied in this paper. Permeability measurements, solubility tests and measurements of glass transition temperature, resin cure time and resin viscosity show a complex interaction between binder and resin depending on the process conditions. The binder mostly increased the permeability of the tested preforms. This effect increases with increasing binder loading. At low fiber volume fractions the binder had a positive effect on preform permeability, most likely by to delaying the closure of macro flow channels or textile inhomogeneity. The binder did not dissolve in the resin until temperatures of around 120 °C, while remaining as a separate phase at 22 °C, 40 and 80 °C. This has to be considered when defining the cure profile of the resin, as the binder is expected to participate in the cure reaction. The glass transition temperature remained unchanged for the binder-resin combination used. An increase in viscosity by a factor of 1.5-2 was observed when the binder was dissolved in the resin. Samples with dissolved binder cured slightly faster than pure resin. The experimental results were theoretically transferred to real infusion processes.

KW - Binder

KW - Composites

KW - Fiber-reinforced Plastics

KW - Infusion

KW - Permeability

UR - http://www.scopus.com/inward/record.url?scp=85180260311&partnerID=8YFLogxK

U2 - 10.1007/s10443-023-10189-7

DO - 10.1007/s10443-023-10189-7

M3 - Article

AN - SCOPUS:85180260311

VL - 31

SP - 721

EP - 738

JO - Applied composite materials

JF - Applied composite materials

SN - 0929-189X

IS - 2

ER -