a container has first and second walls , each formed of a thermoplastic sheet having a peripheral edge . a peripheral seal joins the peripheral edges together to form an interior chamber enclosed by the first and second walls . a port communicates with the interior chamber . the port is spaced from and does not extend through the peripheral seal . the port comprises a hollow thermoplastic tube , which extends through a slit in one of the first and second sheets and is oriented tangentially thereto . the slit is fused by heat about the tube , forming a heat fused junction . a medical product or a blood filter material can be housed in the interior chamber .