Get access

Investigation on high strength laser welds of polypropylene and high-density polyethylene

Authors

  • Thomas Brokholm Juhl,

    Corresponding author
    1. Department of Mechanical and Manufacturing Engineering at Aalborg University, Fibigerstraede 16, 9220 Aalborg Ø, Denmark
    • Department of Mechanical and Manufacturing Engineering at Aalborg University, 9220 Aalborg, Denmark
    Search for more papers by this author
  • Jesper deClaville Christiansen,

    1. Department of Mechanical and Manufacturing Engineering at Aalborg University, Fibigerstraede 16, 9220 Aalborg Ø, Denmark
    Search for more papers by this author
  • Erik Appel Jensen

    1. Department of Mechanical and Manufacturing Engineering at Aalborg University, Fibigerstraede 16, 9220 Aalborg Ø, Denmark
    Search for more papers by this author

Abstract

Mechanical strength in polymer weld interfaces in semi-crystalline high density polyethylene (HDPE) and polypropylene (PP) is investigated. The welding method investigated is through transmission laser welding (TTLW). Utilizing the TTLW process with 0.4 wt % carbon black as absorber, a lap-joint is formed which is tested for mechanical properties using an Instron tensile testing machine. In contrast to earlier investigations, the tensile tests conclude that 89% of the strength of a HDPE/HDPE weld was developed in a PP/HDPE weld with HDPE as the absorbing part. This high weld strength is explained from: (1) a relatively low reptation time being in the millisecond range for both HDPE and PP; (2) a polymer mesh size (tube diameter (a)) being similar to the equilibrium interpenetration depth, determined from Helfand's theory and the interaction parameter (χ); (3) The selected HDPE and PP were both metallocene catalyzed and constituted a similar crystallization temperature which is required for high crystallinity in/near the interface. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Get access to the full text of this article

Ancillary