Defects in resin transfer molded plaques due to resin age distribution during mold filling

N. S. Losure, K. Jayaraman, C. A. Petty

    Research output: Contribution to journalArticle

    • 1 Citations

    Abstract

    This paper examines the development and consequence of flow structures and possible defects arising in multiple shot injection or multiple-gated injection of two-component resins mixed in-line into a mold with and without fiber preforms. This work may also be relevant to the packing stage. Experiments were run where a premixed batch of vinyl ester resin with peroxide and tracer dye, displaces another older butch of premixed resin in a mold. Polymerization of resin as it flows through the preform during the filling stage sets up an increasing viscosity profile along the fluid filled region and viscous fingering is observed as expected. The types of flow patterns associated with this phenomenon have been explored with random and woven fibrous media packed in a clear mold. The molded plaques were cut up and tested in 3-point bend so that the flexural moduli of specimens with various flow structures could be compared. The flow structures observed include fingers with rounded ends and fingers with multiple tips. Such flow structures lead to regions in the plaques where 'packets' of fluid with different extents of polymerization due to differences in age are juxtaposed prior to gelation of the resin. It was found that finger structures with several sharply defined interfaces tended to decrease the value of the flex modulus by up to 32%, depending on the preform characteristics. Multiple finger tips with diffuse boundaries do not seem to be detrimental to the flex modulus, but multiple tips with sharp boundaries have lowered the flex modulus by 32%.

    Original languageEnglish (US)
    Pages (from-to)284-290
    Number of pages7
    JournalInternational Polymer Processing
    Volume11
    Issue number3
    StatePublished - Sep 1996

    Profile

    Resins
    Flow structure
    Cysticercus
    Amoxicillin
    Polymerization
    Defects
    Fluids
    Dibenzothiepins
    Common Bile Duct Diseases
    Cutaneous Candidiasis
    Abnormal Erythrocytes
    Artificial Heart
    Flow patterns
    Gelation
    Peroxides
    Esters
    Dyes
    Viscosity
    Fibers
    Experiments

    ASJC Scopus subject areas

    • Chemical Engineering(all)
    • Materials Chemistry
    • Polymers and Plastics

    Cite this

    Defects in resin transfer molded plaques due to resin age distribution during mold filling. / Losure, N. S.; Jayaraman, K.; Petty, C. A.

    In: International Polymer Processing, Vol. 11, No. 3, 09.1996, p. 284-290.

    Research output: Contribution to journalArticle

    Losure, N. S.; Jayaraman, K.; Petty, C. A. / Defects in resin transfer molded plaques due to resin age distribution during mold filling.

    In: International Polymer Processing, Vol. 11, No. 3, 09.1996, p. 284-290.

    Research output: Contribution to journalArticle

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