摘要:
A method of manufacturing a filter medium that has a PF value that exceeds 32, the PF value calculated from the pressure loss and the collection efficiency of the filter medium according to the following formula: PF=[−log(permeability (%)/100)/(pressure loss (Pa)]×1000[Formula 1] in which permeability (%)=100−collection efficiency (%). In this method, 380 ml or more of a liquid lubricant at 20° C. is added per 1 kg of a PTFE fine powder, this compound is processed into a tape shape and elongated to obtain a PTFE porous film, and an air permeable support member is heat laminated to at least one surface of the PTFE porous film.
摘要:
An air filter medium is provided with a porous film made from a polytetafluoroethylene, and a non-woven fabric laminated on at least one side of the porous film. The non-woven fabric has an apparent density satisfying the following equation: apparent density (g/cm3)
摘要翻译:空气过滤介质设置有由多三氟乙烯制成的多孔膜和层叠在多孔膜的至少一侧上的无纺布。 无纺布的表观密度满足下列等式:表观密度(g / cm 3)<1.5×(基重(g / m 2)/ 1000)+0.11。 过滤介质是通过包括由聚四氟乙烯形成的多孔膜制造的第一工序的工序制造的,第二工序是将多孔膜的至少一侧的多孔膜的至少一面层压到经过 非粘合剂处理。 过滤介质用于制造空气过滤器组件,而空气过滤器组件用于制造空气过滤器单元。
摘要:
An air filter medium comprising a porous polytetrafluoroethylene film and an air-permeable support member laminated on at least one surface of said porous film and having a PF1 value exceeding 22, which is calculated according to the following formula: PF1=[−log(Penetration (%)/100)/Pressure loss (mmH2O)]×100 in which the penetration (%)=100−Collection efficiency from a pressure loss (unit: mmH2O) measured when an air is flowed through the air filter medium at a flow velocity of 5.3 cm/sec. and a collection efficiency (unit: %) measured using dioctyl phthalate having a particle size of 0.10 to 0.12 &mgr;m. This air filter medium has a low pressure loss and a high collection efficiency.
摘要:
This invention relates to a multi-stage stretching operation for production of expanded stretched porous polytetrafluoroethylene (ePTFE) fibrous materials with minimal node size and minimized filament sizes. A plurality of stretching or expansions may be implemented on the film including combinations of MDO and TDO stretches including at least two longitudinal stretches and at least one transverse stretch. Subsequent stretches occur at rates generally less than a prior similar longitudinal or transverse type of expansion.
摘要:
Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a PTFE porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a fibrillable modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.
摘要:
A filter medium includes a porous film and a support material supporting the porous film. The porous film includes polytetrafluoroethylene, has an average pore diameter of at least 2.5 μm, and has a porosity of at least 95%. A pressure loss is less than 100 Pa when air is passed through the filter medium at a velocity of 5.3 cm/sec. A collection efficiency of NaCl particles is at least 95% when air including NaCl particles with a particle diameter of 0.3 μm is passed through the filter medium at a velocity of 5.3 cm/sec. A PF value is at least 30, where PF={−log [(100−collection efficiency (%))/100]/pressure loss (Pa)}×1000. A dust holding capacity of polyalphaolefin particles held in the filter medium is at least 15 g/m2 when air including polyalphaolefin particles with a count median diameter of 0.25 μm is continuously passed through the filter medium at a velocity of 5.3 cm/sec and pressure loss reaches 300 Pa.
摘要:
Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a polytetrafluoroethylene porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the modified polytetrafluoroethylene having an extrusion pressure to a cylinder, at a reduction ratio of 1600, of 70 MPa or higher.
摘要:
A filter medium for an air filter unit for collecting dust from an airflow includes a pre-collection layer, a principal collection layer and an air-permeable cover layer. The pre-collection layer collects a part of the dust in the air flow. The principal collection layer includes a porous polytetrafluoroethylene film. The principal collection layer is positioned on a downstream side of the air flow relative to the pre-collection layer to collect dust that passes through the pre-collection layer. The air-permeable cover layer is positioned as an outermost surface layer of the filter medium on an upstream side of the air flow to allow dust in the air flow to pass through. The air-permeable cover layer is configured to suppress deformation of a surface of the filter medium caused by pressing force from an outside. Preferably, an air filter unit includes the filter medium in a zigzag shape.
摘要:
Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a polytetrafluoroethylene porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the modified polytetrafluoroethylene having an extrusion pressure to a cylinder, at a reduction ratio of 1600, of 70 MPa or higher.
摘要:
Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a PTFE porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a fibrillable modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.