Preparation method of wrapped polytetrafluoroethylene ultra-micro filter tube membrane

Abstract

The invention discloses a preparation method of a wrapped polytetrafluoroethylene ultra-micro filter tube membrane. A sintered or unsintered drown polytetrafluoroethylene membrane of which the aperture is 0.03-0.3micon and the thickness is 10-50micon is cut into polytetrafluoroethylene strip-shaped membranes which are 5-25mm in width; the membranes are wrapped on a porous support tube which resists a temperature of 300-500 DEG C and is corrosion resistant and organic solvent resistant; and the support tube wrapped with the prepared polytetrafluoroethylene membranes is sintered for 20-80s at the temperature of 300-400 DEG C so as to prepare the wrapped polytetrafluoroethylene ultra-micro filter tube membrane of which the aperture of a filtering layer is 0.01-0.05micon. The wrapped polytetrafluoroethylene ultra-micro filter tube membrane has the advantages of high porosity, small aperture, uniformity in filtering layer, blocking resistance, internal and external pressure resistance, capability of back washing and the like, and can be used in solid-liquid and gas-liquid separation with high viscosity, high solid content and high pollution in food concentration, waste penetration liquid treatment, oil-water separation, membrane biologic reactor and the like.

Description

technical field

[0001] The invention relates to a preparation method of a polytetrafluoroethylene tubular membrane, in particular to a preparation method of a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane. Background technique

[0002] Membrane modules for membrane separation include four forms: plate and frame, hollow fiber, roll and tube. The membrane materials used are flat plate membrane, hollow fiber membrane, roll membrane and tubular membrane. The tubular membrane has the characteristics of being strong, not easy to block, not easy to break, and easy to maintain. The pretreatment requirements of the tubular membrane for the feed liquid are relatively simple. It only needs to remove the hard particles that will directly damage the membrane through the coarse and fine grids before entering the unit. The pretreatment is simple. The flow rate of the feed liquid in the tubular membrane module is high, it is turbulent flow, it is not sensitive to cl...

Examples

Embodiment 1

[0026] a) Slit the unsintered polytetrafluoroethylene microporous membrane with a pore size of 0.03 microns and a film thickness of 50 microns into polytetrafluoroethylene strip-shaped films with a width of 10 mm;

[0027] b) Wrap the polytetrafluoroethylene strip membrane prepared in step a) on a stainless steel wire braided tube (aperture 5000 microns) with an outer diameter of 10 mm and a wall thickness of 0.5 mm at a helix angle of 65 degrees for 3 layers, and the inner tape of the same layer The overlapping distance of the polytetrafluoroethylene film is 0 mm, and the stagger distance between different layers is 25 mm.

[0028] c) Sintering the support tube wrapped with the polytetrafluoroethylene membrane prepared in step b) at 400° C. for 20 seconds to prepare a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane with a filter layer pore size of 0.01 μm.

Embodiment 2

[0030] a) Divide the biaxially stretched unsintered polytetrafluoroethylene microporous membrane with a pore size of 0.1 microns and a film thickness of 30 microns into polytetrafluoroethylene strip-shaped films with a width of 5 mm;

[0031] b) Wrap the polytetrafluoroethylene tape film prepared in step a) on a porous aluminum alloy tube (pore diameter 1 micron) with an outer diameter of 25 mm and a wall thickness of 5 mm for 12 layers at a helix angle of 50°, and the inner tape of the same layer The overlapping distance of the polytetrafluoroethylene film is 0.5 mm, and the stagger distance between different layers is 2.5 mm.

[0032] c) Sintering the support tube wrapped with the polytetrafluoroethylene membrane prepared in step b) at 380° C. for 80 seconds to prepare a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane with a filter layer pore size of 0.03 μm.

[0033] Examples 3-9 are shown in Table 1.

[0034] Table 1: for Examples 3-9

[0035]

...

technical field

[0001] The invention relates to a preparation method of a polytetrafluoroethylene tubular membrane, in particular to a preparation method of a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane. Background technique

[0002] Membrane modules for membrane separation include four forms: plate and frame, hollow fiber, roll and tube. The membrane materials used are flat plate membrane, hollow fiber membrane, roll membrane and tubular membrane. The tubular membrane has the characteristics of being strong, not easy to block, not easy to break, and easy to maintain. The pretreatment requirements of the tubular membrane for the feed liquid are relatively simple. It only needs to remove the hard particles that will directly damage the membrane through the coarse and fine grids before entering the unit. The pretreatment is simple. The flow rate of the feed liquid in the tubular membrane module is high, it is turbulent flow, it is not sensitive to cl...

Examples

Embodiment 1

[0026] a) Slit the unsintered polytetrafluoroethylene microporous membrane with a pore size of 0.03 microns and a film thickness of 50 microns into polytetrafluoroethylene strip-shaped films with a width of 10 mm;

[0027] b) Wrap the polytetrafluoroethylene strip membrane prepared in step a) on a stainless steel wire braided tube (aperture 5000 microns) with an outer diameter of 10 mm and a wall thickness of 0.5 mm at a helix angle of 65 degrees for 3 layers, and the inner tape of the same layer The overlapping distance of the polytetrafluoroethylene film is 0 mm, and the stagger distance between different layers is 25 mm.

[0028] c) Sintering the support tube wrapped with the polytetrafluoroethylene membrane prepared in step b) at 400° C. for 20 seconds to prepare a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane with a filter layer pore size of 0.01 μm.

Embodiment 2

[0030] a) Divide the biaxially stretched unsintered polytetrafluoroethylene microporous membrane with a pore size of 0.1 microns and a film thickness of 30 microns into polytetrafluoroethylene strip-shaped films with a width of 5 mm;

[0031] b) Wrap the polytetrafluoroethylene tape film prepared in step a) on a porous aluminum alloy tube (pore diameter 1 micron) with an outer diameter of 25 mm and a wall thickness of 5 mm for 12 layers at a helix angle of 50°, and the inner tape of the same layer The overlapping distance of the polytetrafluoroethylene film is 0.5 mm, and the stagger distance between different layers is 2.5 mm.

[0032] c) Sintering the support tube wrapped with the polytetrafluoroethylene membrane prepared in step b) at 380° C. for 80 seconds to prepare a wrapped polytetrafluoroethylene ultramicrofiltration tubular membrane with a filter layer pore size of 0.03 μm.

[0033] Examples 3-9 are shown in Table 1.

[0034] Table 1: for Examples 3-9

[0035]

...

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