Summary of the invention
The first object of the present invention is to provide a kind of Efficient electret filtration material, and it has effect that filtering accuracy is high, filtration resistance is low, filter efficiency is high, be convenient to deashing and have long service life.
In order to reach above-mentioned purpose, solution of the present invention is:
A kind of Efficient electret filtration material, wherein, comprise nonwoven layer and the charged coating through electret process, this coating is positioned at the outer surface of nonwoven layer.
Further, this coating be by inorganic electret material with foaming technological forming on nonwoven layer, this inorganic electret material is selected from barium titanate, lead zirconate titanate, zinc oxide, tantalum oxide, aluminium oxide or titanium oxide.
Further, this nonwoven layer is formed with the polytetrafluoroethylene fibre of 30-70wt% by the polyphenylene sulfide fibre of 30-70wt% after mixing shredding, carding, lapping and acupuncture, the line density of this polyphenylene sulfide fibre is 1.0-1.5D, fibre length is 51-76mm, the line density of this polytetrafluoroethylene fibre is 1.0-1.5D, and fibre length is 48-65mm.
The second object of the present invention is the preparation method providing a kind of Efficient electret filtration material, wherein, comprises the steps:
1. nonwoven layer is molded;
2. on the outer surface of nonwoven layer, coating is molded by the mode of foaming;
3. electret process is carried out to coating and become electret to make coating.
Further, this step 1. in nonwoven layer be formed after mixing shredding, carding, lapping and acupuncture with the polytetrafluoroethylene fibre of 30-70wt% with the polyphenylene sulfide fibre of 30-70wt%, the line density of this polyphenylene sulfide fibre is 1.0-1.5D, fibre length is 51-76mm, the line density of this polytetrafluoroethylene fibre is 1.0-1.5D, and fibre length is 48-65mm.
Further, in mixed process, non-ionic antistatic agent is added; In carding process, adopt titanium alloy pin cloth, carding machine speed is 600-800r/min; In laid process, upper little vehicle speed 25-40m/min, lapping carriage 30-45m/min, lower little vehicle speed 8-15m/min; In acupuncture course, adopt 5 needing machines, latter two is that dystopy is to thorn machine, first punch frequency and the degree of depth are respectively 150-200r/min, 12-14mm, second punch frequency and the degree of depth are respectively 200-350r/min, 7-9mm, 3rd road punch frequency and the degree of depth are respectively 300-450r/min, 4-6mm, and the 4th road punch frequency and the degree of depth are respectively 250-400r/min, 4-6mm, and the 5th road punch frequency and the degree of depth are respectively 250-400r/min, 2-4mm.
Further, this coating is by inorganic electret material dissolves in organic solvent, and after milled processed, under the acting in conjunction of blowing agent 10-20g/ml and thickener 5-15g/ml, carry out foaming process and obtain, this inorganic electret material is 0.5-5g/ml.
Further, this organic solvent is ethanol.
Further, this inorganic electret material is selected from barium titanate, lead zirconate titanate, zinc oxide, tantalum oxide, aluminium oxide or titanium oxide.
Further, 3. this step is adopt the mode of corona discharge or thermal poling to carry out electret.
After adopting said structure, a kind of Efficient electret filtration material that the present invention relates to and preparation method thereof, it by being formed with coating on the outer surface of nonwoven layer, and electret process is carried out to this coating and charged, thus a kind of brand-new electret air filtering material can be formed, namely there is the feature that filtering accuracy is high, filtration resistance is low and filter efficiency is high.
Compared with prior art, also at least there is following beneficial effect in the present invention:
One, the inorganic electret material adopted due to this coating has high temperature resistant and high performance feature, so effectively can improve charge storage and the charge stability of whole filtering material, add electret effect and electrostatic effect, utilize the electret effect of material, effectively can improve the filter efficiency of material.
Two, this coating can by surface electrostatic effect, forms ultrafiltration dust cake, dust can be blocked in filter felt surface, improve its surface filtration efficiency by the thin space of dust cake and electrostatic interaction.
Three, electret is due to electrostatic interaction, not easily condenses, sticky powder, easy-to-clean ash, and dust is infiltration material deep layer place not easily, and therefore the pressure loss does not extend with service time and increases, and also greatly can improve the service life of whole filtering material thus.
Detailed description of the invention
In order to explain technical scheme of the present invention further, below by specific embodiment, the present invention will be described in detail.
As shown in Figure 1, a kind of Efficient electret filtration material that the present invention relates to, it comprises nonwoven layer 1 and coating 2, and this coating 1 is positioned at the outer surface of nonwoven layer 2, and this coating 2 is electriferous state through electret process.More specifically, this coating 2 be by inorganic electret material with foaming technological forming on nonwoven layer 1, this inorganic electret material is selected from barium titanate, lead zirconate titanate, zinc oxide, tantalum oxide, aluminium oxide or titanium oxide.
The present invention also provides a kind of preparation method of Efficient electret filtration material, comprises the steps:
1. nonwoven layer is molded; Particularly, this nonwoven layer is formed after mixing shredding, carding, lapping and acupuncture with the polytetrafluoroethylene fibre of 30-70wt% with the polyphenylene sulfide fibre of 30-70wt%.
Wherein, the line density of this polyphenylene sulfide fibre (PPS) is 1.0-1.5D, and fibre length is 51-76mm, and the line density of this polytetrafluoroethylene fibre (PTFE) is 1.0-1.5D, and fibre length is 48-65mm.Namely this polyphenylene sulfide fibre and polytetrafluoroethylene fibre all adopt superfine fibre, so greatly can improve dust catching efficiency, its average efficiency rises to 99.9% (fine fiber) than traditional structure electret fiber from 95%, improvement may come from the rising of free space random distribution rate between fiber, cause hold dirt place and filter mechanism more perfect; In addition, the improvement of the new construction air cleaner performance that meticulous electret fiber is formed is because filter material space structure shows larger appearance dirt space and stronger electric field divergence.Because polytetrafluoroethylene fibre electrostatic efficiency is large, therefore add non-ionic antistatic agent in mixed process.
In carding operation, because polytetrafluoroethylene fibre density is large, single fibre strength is poor, curling little, so adopt titanium alloy pin cloth at carding process, carding machine speed is 600-800r/min.
In laid process, because fibre cohesion is little, between each dolly, drawing-off is little, little vehicle speed 25-40m/min, lapping carriage 30-45m/min on this, lower little vehicle speed 8-15m/min.
In acupuncture course, adopt 5 needing machines, latter two is that dystopy is to thorn machine, first punch frequency and the degree of depth are respectively 150-200r/min, 12-14mm, second punch frequency and the degree of depth are respectively 200-350r/min, 7-9mm, 3rd road punch frequency and the degree of depth are respectively 300-450r/min, 4-6mm, and the 4th road punch frequency and the degree of depth are respectively 250-400r/min, 4-6mm, and the 5th road punch frequency and the degree of depth are respectively 250-400r/min, 2-4mm.
Preferably, the nonwoven layer of above-mentioned formation also carries out following functional processing:
1. press polish: upper roll temperature is 200-220, and lower roll temperatures is 230-250, and pressure is 0.4Mpa, and speed is 7.5-8.5m/min.By press polish operation, control the thickness of needled filtering felt, improve its density, contribute to filter efficiency and improve and physical index improvement.
2. singe: adopt natural gas to singe process, the speed 35-40m/min singed by firepower 7-7.5bar and the Nomex of control flame controls the operation of singing, to ensure cloth cover effect.By burning surface hairiness, make fiber surface keep certain smoothness, this can reduce adsorbing powder dust filter bag surface, can improve cleaning efficiency simultaneously.
3. flood: adopt soft rubber roller, surfacing, reduce adhesion, effectively control impregnation resin content.Pressure roller is 0.5MPa, and grammes per square metre is 20-30g/m2, and the speed of a motor vehicle is 5m/min, this polytetrafluoroethylene fibre impregnation process, improves heatproof, corrosion resistance, gives fiber surface smooth structure.
2. on the outer surface of nonwoven layer, coating is molded by the mode of foaming; Particularly, this coating is by inorganic electret material dissolves in organic solvent, and after milled processed, under the acting in conjunction of blowing agent 10-20g/ml and thickener 5-15g/ml, carry out foaming process and obtain, this inorganic electret material is 0.5-5g/ml.This organic solvent is preferably ethanol, and this ethanol plays the work of solvent on the one hand in order to dissolve inorganic material, is entering in baking oven process on the other hand, and volatilization heat absorption, contributes to cloth cover drying.
Preferably, this inorganic electret material is selected from barium titanate, lead zirconate titanate, zinc oxide, tantalum oxide, aluminium oxide or titanium oxide.For the ratio of inorganic electret material, it has considerable influence effect according to fibrous raw material and Nomex thickness, processing mode, if ratio is too high, by corona discharge or thermal poling effect, accumulated multi-charge, and caused fibre dust cake blocked up, resistance increases, even accumulate excessive, can cause damaging Nomex.And ratio is too low, be unfavorable for charge accumulated, certain thickness dust cake cannot be formed, affect filtering accuracy; And the surface utilizing inorganic material to be formed is not easily because the reasons such as moisture produce adhesion, is convenient to deashing.
3. electret process is carried out to coating and become electret to make coating; The mode of corona discharge or thermal poling is preferably adopted to carry out electret.
Embodiment 1:
1. shredding: this nonwoven layer with 70% the polytetrafluoroethylene fibre PTFE of polyphenylene sulfide fibre PPS and 30% for raw material, through mixing shredding, after carding, lapping and 5 road acupunctures, form non-woven felt.The line density of this polyphenylene sulfide fibre is 1.5D, and fibre length is 60mm, and the line density of polytetrafluoroethylene fibre is 1.0D, and fibre length is 51mm.Because PTFE fiber electrostatic effect is large, in mixed process, add non-ionic antistatic agent.
2. combing: because PTFE fibre density is large, single fibre strength is poor, curling little, so carding process adopts titanium alloy pin cloth, reducing carding machine speed is 750r/min.
3. lapping: fibre cohesion is little, between each dolly, drawing-off is little.Upper little vehicle speed 33m/min, lapping carriage 40m/min, lower little vehicle speed 12m/min.
4. acupuncture: adopt 5 needing machines, latter two is that dystopy is to thorn machine.First punch frequency and the degree of depth are respectively 150r/min, 14mm, and second punch frequency and the degree of depth are respectively 280r/min, 8mm.3rd road punch frequency and the degree of depth are respectively 300r/min, 6mm.4th road punch frequency and the degree of depth are respectively 400r/min, 4mm.5th road punch frequency and the degree of depth are respectively 400r/min, 2mm.
Functional processing
1. press polish: upper roll temperature is 210, and lower roll temperatures is 230. pressure is 0.4MPa.Speed is 8m/min.
2. singe: adopt natural gas to singe process, the speed 35m/min singed by firepower 7bar. and the Nomex of control flame controls the operation of singing, to ensure cloth cover effect.
3. flood: adopt soft rubber roller, surfacing, reduce adhesion, effectively control impregnation resin content.Pressure roller is 0.5MPa, and grammes per square metre is 20-30g/m2, and the speed of a motor vehicle is 5m/min
4. intumescent coating: adopt intumescent coating process, can effectively form one deck electret material on surface, improves functional processing effect.Gas release and foaming effect: control gas release is 20-30g/m2, because this electret material is inorganic material, so higher to the quality requirement of gas release and one-tenth bubble.The object of uniform gluing and controlled quentity controlled variable is reached by the ratio controlling blowing agent and thickener.By being dissolved in organic solvent ethanol, carry out milled processed.Under blowing agent 12g/m2 and thickener 8g/m2 acting in conjunction, carry out intumescent coating process.Inorganic electret material 1.5g/m2.Because PPS proportion of fibers is large, Nomex is fluffy and PPS fibres fasten power is better than PTFE fiber.
5. corona discharge or thermal poling carry out electret.
Embodiment 2
1. shredding: this nonwoven layer with 50% the polytetrafluoroethylene fibre PTFE of polyphenylene sulfide fibre PPS and 50% for raw material, through mixing shredding, after carding, lapping and 5 road acupunctures, form non-woven felt.The line density of this polyphenylene sulfide fibre is 1.0D, and fibre length is 51, and the line density of polytetrafluoroethylene fibre is 1.0, and fibre length is 51mm.Because PTFE fiber electrostatic effect is large, in mixed process, add non-ionic antistatic agent.
2. combing: because PTFE fibre density is large, single fibre strength is poor, curling little, so carding process adopts titanium alloy pin cloth, reducing carding machine speed is 700r/min.
3. lapping: fibre cohesion is little, between each dolly, drawing-off is little.Upper little vehicle speed 30m/min, lapping carriage 34m/min, lower little vehicle speed 10m/min.
4. acupuncture: adopt 5 needing machines, latter two is that dystopy is to thorn machine.First punch frequency and the degree of depth are respectively 170r/min, 13mm, and second punch frequency and the degree of depth are respectively 300r/min, 9mm.3rd road punch frequency and the degree of depth are respectively 320r/min, 6mm.4th road punch frequency and the degree of depth are respectively 400r/min, 4mm.5th road punch frequency and the degree of depth are respectively 400r/min, 2mm.
Functional processing
1. press polish: upper roll temperature is 220, and lower roll temperatures is 240. pressure is 0.4MPa.Speed is 7.5m/min.
2. singe: adopt natural gas to singe process, the speed 35m/min singed by firepower 7bar. and the Nomex of control flame controls the operation of singing, to ensure cloth cover effect.
3. flood: adopt soft rubber roller, surfacing, reduce adhesion, effectively control impregnation resin content.Pressure roller is 0.5MPa, and grammes per square metre is 20-30g/m2, and the speed of a motor vehicle is 5m/min
4. intumescent coating: adopt intumescent coating process, can effectively form one deck electret material on surface, improves functional processing effect.Gas release and foaming effect: control gas release is 20-30g/m2, because this electret material is inorganic material, so higher to the quality requirement of gas release and one-tenth bubble.The object of uniform gluing and controlled quentity controlled variable is reached by the ratio controlling blowing agent and thickener.By being dissolved in organic solvent ethanol, carry out milled processed.Under blowing agent 15g/m2 and thickener 10g/m2 acting in conjunction, carry out intumescent coating process.Inorganic electret material 1g/m2.
5. corona discharge or thermal poling carry out electret.
Above-described embodiment and graphic and non-limiting product form of the present invention and style, any person of an ordinary skill in the technical field, to its suitable change done or modification, all should be considered as not departing from patent category of the present invention.