| 摘要 |
PURPOSE:To effect an extracting operation without use of a filter support, keeping the opening widened with fingers on using, by forming a bag to be of a reversed conical shape and fitting a plastic core material at the periphery of the opening. CONSTITUTION:A core material 1 having plasticity is caught in the roll-in part 6 provided at the end of a long sized heat-melting filter base material 5. The core material 1 having plasticity is fitted to the end of the heat-melting filter base material 5 by sticking with heat and pressure the rolled-in end. The double-superimposed heat-melting filter base materials 5 are stuck to each other with heat and pressure so that the part fitted with the core material 1 may be the opening 2 of bag. The stuck material is cut off along the center of the part 7 stuck with heat and pressure to obtain a number of bag-formed filters When the opening 2 is widened, the widened form can be kept by fitting the core material 1 having plasticity at the periphery of the opening 2. |
