Side-by-side bicomponent meltblown fiber webs were developed on REICOFIL(R) bicomponent (bico) meltblown line at The University of Tennessee's Textiles and Nonwovens Development Center (TANDEC), using polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), polytrimethylene terephthalate (PTT), and so forth. The posttreatment was performed by hydroentanglement to investigate the fiber-splitting behavior in this research. Microscopy analysis and SEM were applied to examine the web structure. The change in web property after posttreatment and the adhesion mechanism of the polymer interface were also addressed. (C) 2004 Wiley Periodicals, Inc.