CN1245437C - Process for producing polytetrafluoroethylene presintering powder - Google Patents
Process for producing polytetrafluoroethylene presintering powder Download PDFInfo
- Publication number
- CN1245437C CN1245437C CN 200410067229 CN200410067229A CN1245437C CN 1245437 C CN1245437 C CN 1245437C CN 200410067229 CN200410067229 CN 200410067229 CN 200410067229 A CN200410067229 A CN 200410067229A CN 1245437 C CN1245437 C CN 1245437C
- Authority
- CN
- China
- Prior art keywords
- polytetrafluoroethylpresintering
- sintering
- presintering powder
- deionized water
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Processes Of Treating Macromolecular Substances (AREA)
Abstract
The present invention relates to a process for producing polytetrafluoroethylene presintering powder. The process comprises the steps that the coarse particles of polytetrafluorethylene after a polyreaction is uniformly mixed with deionized water; then the mixture is continuously delivered to a washing tank and a trace amount of ammonium carbonate is added into the washing tank; the mixture is sent to a separator after being washed; wet purified particles are dried and sintered in a sintering furnace after being separated; a sintered polytetrafluoroethylene plate is sent to a pulverizing and screening machine to be made into the high-grade dried polytetrafluorethylene presintering powder.
Description
Technical field
The present invention relates to the complete processing of polymer materials, relate in particular to a kind of preparation method of polytetrafluoroethylpresintering presintering powder.
Background technology
Tetrafluoroethylene (being called for short PTFE) is the fabulous material of a kind of performance, and it can be ageing-resistant, and good chemical stability is arranged, excellent electrical insulating property and good lubrication, and the use temperature scope is wide, by the every profession and trade widespread use.
Though PTFE is a thermoplastic polymer, it is made up of long carbochain, and this polymkeric substance has first-order transition temperature at 327 ℃, under this temperature condition, the crystallization of polymkeric substance disappears, and polymer particle bonds together, form the fine and close thing of gel structure of high melt viscosity, because PTFE melt viscosity height does not possess melt flow characteristics, so, can not process with the thermoplastic method, can only process with compression molding, promptly the PTFE polymkeric substance is made blank at mould inner pressure, blank moulding in high temperature sintering furnace then.
PTFE melt extrudes and mould pressing technology in order to improve, must be the PTFE pre-treatment, pretreated PTFE particle can be behind the certain pressure condition compacted under of die cavity, freely sinter half compactness finished product into, thereby the physicals of PTFE pre-treatment powder, as: parameters such as particle diameter, pattern, compressibility are very important, and the extrusion performance of this polymer powder depends primarily on powder flowbility.
The report of external production PTFE presintering powder method is as follows:
1. U.S. Pat 3152201, exercise question is " preparation method of PTFE powder ", narration is preheating to 380 ℃ with the PTFE fine powder of buying from the market in the literary composition in air circulating oven, cool to room temperature in air then, it is broken in four paddle agitators to form the brittle cooling powder of porous, behind 8 mesh sieves branch, polymer powder is placed in the PE bag, after dry ice bucket internal cooling is to＜19 ℃, enter Wei Lin Shi crusher for crushing.This method adopts the PTFE fine powder of buying from the market, and cost is higher, has water with the dry ice cooling and is penetrated in the powder, influences quality product.
2. Japanese Patent JP50/087442 narration: condense granulation with the PTFE suspension polymer again after by fine grinding, then, sintering in stove, the pulverizing of cooling back.
3. U.S. Pat 4216265, exercise question is " aftertreatment of hot pre-treatment tetrafluoro ethylene polymer and the preparation of polymer powder ", immovable bed sintering PTFE powder is adopted in narration in the literary composition, thermal treatment temp is 350～380 ℃, cooling back continuous pulverizing in hammer mill or blender, under 22～23 ℃ of temperature condition, be ground into product then, this method processed complex, cost height through jet mill.
The technological method of domestic production PTFE presintering powder is as follows at present:
Fig. 1 is a prior art PTFE presintering preparation technology schema.Whole process of production by polyreaction, smash to pieces, air stream drying and sintering crushing operation form, major equipment comprises polymerization reaction kettle, smashs device to pieces, taper moisture eliminator, cyclonic separator, gas-solid separator, sintering oven, primary crusher, slimer etc.
Technical process: polymerization reactant enters special use with deionized water and smashs device to pieces, smashing to pieces needs in the process with polyreaction auxiliary agent in a large amount of deionized water washing materials, general washing can meet pH value 5～6 times, smash wash temperature to pieces and be controlled at 2～20 ℃, material particular diameter after smashing to pieces is 120～180 μ m, the tilting spiral separation auger of smashing device top to pieces by special use makes material and water sepn then, separate the back wet stock and quantitatively deliver to hot-blast spray nozzle by screw feeder, being cleaned high temperature compressed air attracts, after mixing, send into the cyclone dryer heating, enter 1 again
#Cyclonic separator makes the air separation of material and water content, thermal material with purify normal temperature air and mix once more, by 2
#Cyclonic separator separates the back packing, and dry PTFE is put into dish, sends the sintering oven sintering to, enters the primary crusher coarse crushing after the cooling, enters by spiral conveyer to be product after slimer is pulverized again.1
#With 2
#The gas phase of cyclonic separator enters 3 respectively
#With 4
#Cyclonic separator is gas solid separation once more, and solid phase is a reclaimed materials, and gas phase enters two gas-solid separators respectively and carries out emptying after the gas solid separation at last.
There is following defective in the technological method that above prior art is produced the PTFE presintering powder:
Prior art processes flow process complexity, investment cost is big, operating cost is high.
2. prior art processes flow process complexity, material is many through equipment, and medium scopes such as contact deionized water, air are wide, the PTFE easy pollution of products.
3. the product of prior art production is mobile poor.
Summary of the invention
Purpose of the present invention is exactly to provide in order to overcome the defective that above-mentioned prior art exists that a kind of technology is simple, operating cost is low, the preparation method of the polytetrafluoroethylpresintering presintering powder of good product mobility.
Purpose of the present invention can be achieved through the following technical solutions: the preparation method of polytetrafluoroethylpresintering presintering powder, it is characterized in that, this method comprises following processing step: will be sent to rinse bath continuously behind tetrafluoroethylene coarse particles after the polyreaction and the deionized water uniform mixing earlier, and the micro-volatile salt of adding washs together in rinse bath, enter separator after the washing, the particle that separates the back wet purification is at sintering oven inner drying, sintering, the agglomerating polyfluortetraethylene plate is sent into the pulverizing screen-dividing machine again, makes the polytetrafluoroethylpresintering presintering powder of dry and high quality.
The volatile salt and the tetrafluoroethylene weight ratio that add in the described rinse bath are 0.05%～0.1%.
After described rinse bath repeatedly washs, deionized water specific conductivity in the groove≤15 μ s/cm, material particular diameter is 300～650 μ m.
The particle of described wet purification is when sintering oven inner drying, sintering, sintering temperature is 360～385 ℃, kept 4～8 hours, be cooled to 330～340 ℃ with 10～30 ℃/h speed then, kept 0.5～2 hour, and dropped to 310～320 ℃ at the same rate again, kept 0.5～2 hour, after continuation was cooled to 260 ℃ with 20～40 ℃/h speed, fast cooling was to normal temperature.
Described pulverizing screen-dividing machine comprises breaking unit, unit in small, broken bits and sizing screen unit, and described breaking unit comprises trapezoidal tooth rotor and stator, and described unit in small, broken bits is the impact type structure, and described sizing screen comprises rotor and frame sieve.
The present invention is owing to adopted above technical scheme, promptly, behind tetrafluoroethylene coarse particles and deionized water uniform mixing after the polyreaction, deliver to the rinse bath washing continuously, after forming the particle and water natural separation that purifies, in sintering oven inner drying, sintering and cooling, coarse crushing then, in small, broken bits and classification, generate the good PTFE presintering powder of dry, flowable, as shown in Figure 2; Therefore, compared with prior art, the present invention has the following advantages:
The present invention compared with prior art, investment cost can descend 50～70%, operating cost can descend 30～50%.
2. technical process of the present invention is simple, easily guarantees the product degree of cleaning.
3. even, the good fluidity of the product particle of the present invention's production helps the processing thin-walled the part with complicated structure of Denging.
In a word, PTFE presintering preparation technology flow process of the present invention is simple, good quality of product, and uniform particles, particle diameter is regulated arbitrarily in 300～650 mu m ranges; Good fluidity, numerical value are 3～4s/100g; Processing characteristics is excellent, can prepare high-quality PTFE thin-walled tube and the part with complicated structure.
Description of drawings
Fig. 1 is a prior art PTFE presintering preparation technology schema;
Fig. 2 is a process flow sheet of the present invention.
Embodiment
Again to produce the example that is embodied as of 700 tons of PTFE presintering powders per year, preparation technology of the present invention is described further below.
Embodiment 1
At 1.6m
3After the polymeric kettle internal reaction finishes, open nitrogen valve, make to be malleation in the reactor, make material and deionized water uniform mixing again after, open the polymeric kettle baiting valve, utilize liquid level difference material in reactor and deionized water all to be entered in the rinse bath by materail tube.
Start lift pump, put mother liquor in the rinse bath, the stop pumping water pump adds 1.2m again
3Deionized water and 70g volatile salt are driven the rinse bath agitator, and rotating speed is 710rpm, and washing material is taken out the deionized water that contains impurity with lift pump then, adds 1.2m again
3Deionized water, repeat 3 washings after, making the deionized water specific conductivity is 10 μ s/cm, washing back material median size is 500 μ m.
Material and deionized water after the washing enter separator, and deionized water flows into pond for recovering from filter screen, and material is sent into sintering oven drying and sintering on the filter screen.
Material is warmed up to 380 ℃ in sintering oven, kept 4 hours; Be cooled to 340 ℃ with 30 ℃ of speed per hour, kept 1.5 hours; Drop to 320 ℃ at the same rate again, kept 1 hour; Continuation is cooled to 260 ℃ with 40 ℃ of speed per hour, and fast cooling is to normal temperature.
PTFE plate behind the sintering, length 640mm, width 460mm, thickness 35mm sends this plate to the pulverizing screen-dividing machine, and it is broken to enter fine powder after the first coarse breaking automatically, comminuting matter is regulated back finished product materials median size 450 μ m along with carrying airflow to enter the rotating screen classification, and flowability is 3.2s/100g.
Embodiment 2
At 1.6m
3After the polymeric kettle internal reaction finishes, open nitrogen valve, make to be malleation in the reactor, make material and deionized water uniform mixing again after, open the polymeric kettle baiting valve, utilize liquid level difference material in reactor and deionized water all to be entered in the rinse bath by materail tube.
Start lift pump, put mother liquor in the rinse bath, the stop pumping water pump adds 1.0m again
3Deionized water and 80g volatile salt are driven the rinse bath agitator, and rotating speed is 800rpm, and washing material is taken out the deionized water that contains impurity with lift pump then, adds 1.0m again
3Deionized water, repeat 3 washings after, making the deionized water specific conductivity is 8.5 μ s/cm, washing back material median size is 420 μ m.
Material and deionized water after the washing enter separator, and deionized water flows into pond for recovering from filter screen, and material is sent into sintering oven drying and sintering on the filter screen.
Material is warmed up to 360 ℃ in sintering oven, kept 8 hours; Be cooled to 330 ℃ with 10 ℃ of speed per hour, kept 1.0 hours; Drop to 310 ℃ at the same rate again, kept 1.0 hours; Continuation is cooled to 260 ℃ with 30 ℃ of speed per hour, and fast cooling is to normal temperature.
PTFE plate behind the sintering, length 640mm, width 640mm, thickness 40mm sends this plate to the pulverizing screen-dividing machine, and it is broken to enter fine powder after the first coarse breaking automatically, comminuting matter is regulated back finished product materials median size 400 μ m along with carrying airflow to enter the rotating screen classification, and flowability is 3.5s/100g.
Embodiment 3
At 1.6m
3After the polymeric kettle internal reaction finishes, open nitrogen valve, make to be malleation in the reactor, make material and deionized water uniform mixing again after, open the polymeric kettle baiting valve, utilize liquid level difference material in reactor and deionized water all to be entered in the rinse bath by materail tube.
Start lift pump, put mother liquor in the rinse bath, the stop pumping water pump adds 0.8m again
3Deionized water and 90g volatile salt are driven the rinse bath agitator, and rotating speed is 900rpm, and washing material is taken out the deionized water that contains impurity with lift pump then, adds 0.8m again
3Deionized water, repeat 3 washings after, making the deionized water specific conductivity is 8 μ s/cm, washing back material median size is 320 μ m.
Material and deionized water after the washing enter separator, and deionized water flows into pond for recovering from filter screen, and material is sent into sintering oven drying and sintering on the filter screen.
Material is warmed up to 370 ℃ in sintering oven, kept 6 hours; Be cooled to 330 ℃ with 15 ℃ of speed per hour, kept 0.5 hour; Drop to 310 ℃ at the same rate again, kept 0.5 hour; Continuation is cooled to 260 ℃ with 30 ℃ of speed per hour, and fast cooling is to normal temperature.
PTFE plate behind the sintering, length 640mm, width 640mm, thickness 40mm sends this plate to the pulverizing screen-dividing machine, and it is broken to enter fine powder after the first coarse breaking automatically, comminuting matter is regulated back finished product materials median size 360 μ m along with carrying airflow to enter the rotating screen classification, and flowability is 3.7s/100g.
Claims (5)
1. the preparation method of polytetrafluoroethylpresintering presintering powder, it is characterized in that, this method comprises following processing step: will be sent to rinse bath continuously behind tetrafluoroethylene coarse particles after the polyreaction and the deionized water uniform mixing earlier, and the micro-volatile salt of adding washs together in rinse bath, enter separator after the washing, the particle that separates the back wet purification is at sintering oven inner drying, sintering, the agglomerating polyfluortetraethylene plate is sent into the pulverizing screen-dividing machine again, makes the polytetrafluoroethylpresintering presintering powder of dry and high quality.
2. the preparation method of polytetrafluoroethylpresintering presintering powder according to claim 1 is characterized in that, the volatile salt and the tetrafluoroethylene weight ratio that add in the described rinse bath are 0.05%～0.1%.
3. the preparation method of polytetrafluoroethylpresintering presintering powder according to claim 1 is characterized in that, after described rinse bath repeatedly washs, and deionized water specific conductivity in the groove≤15 μ s/cm, material particular diameter is 300～650 μ m.
4. the preparation method of polytetrafluoroethylpresintering presintering powder according to claim 1, it is characterized in that, the particle of described wet purification is when sintering oven inner drying, sintering, and sintering temperature is 360～385 ℃, keeps 4～8 hours, be cooled to 330～340 ℃ with 10～30 ℃/h speed then, kept 0.5～2 hour, and dropped to 310～320 ℃ at the same rate again, kept 0.5～2 hour, after continuation was cooled to 260 ℃ with 20～40 ℃/h speed, fast cooling was to normal temperature.
5. the preparation method of polytetrafluoroethylpresintering presintering powder according to claim 1, it is characterized in that, described pulverizing screen-dividing machine comprises breaking unit, unit in small, broken bits and sizing screen unit, described breaking unit comprises trapezoidal tooth rotor and stator, described unit in small, broken bits is the impact type structure, and described sizing screen comprises rotor and frame sieve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067229 CN1245437C (en) | 2004-10-18 | 2004-10-18 | Process for producing polytetrafluoroethylene presintering powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067229 CN1245437C (en) | 2004-10-18 | 2004-10-18 | Process for producing polytetrafluoroethylene presintering powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1621435A CN1621435A (en) | 2005-06-01 |
| CN1245437C true CN1245437C (en) | 2006-03-15 |
Family
ID=34765029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410067229 Active CN1245437C (en) | 2004-10-18 | 2004-10-18 | Process for producing polytetrafluoroethylene presintering powder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1245437C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE602008006245D1 (en) * | 2007-10-22 | 2011-05-26 | Solvay Solexis Spa | METHOD FOR PRODUCING DRIED FINE POWDER FROM MELTABLE OR NON-MELTABLE TFE (CO) POLYMERS |
| CN112776207A (en) * | 2021-01-12 | 2021-05-11 | 上品兴业氟塑料（嘉兴）有限公司 | Method for manufacturing polytetrafluoroethylene pre-sintered material |
-
2004
- 2004-10-18 CN CN 200410067229 patent/CN1245437C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN1621435A (en) | 2005-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1202943C (en) | High smelting point resin dewatering device of double screw extruder rotating in the same direction | |
| CN203460352U (en) | Crushing, regenerating and moulding equipment for plastic difficult to recover | |
| CN109735076A (en) | A kind of preparation method of high-performance biology base/polylactic acid Wholly-degradable material | |
| CN1876530A (en) | Delivery spray nozzle, polytetrafluoroethylene fine particle processing method and apparatus using the spray nozzle | |
| CN109575572A (en) | A method of improving polymer matrix composite dielectric properties | |
| CN1245437C (en) | Process for producing polytetrafluoroethylene presintering powder | |
| CN111763418B (en) | High-elasticity nylon and preparation method thereof | |
| CN1040487A (en) | Coffee glass ﹠ and production method thereof | |
| CN102888182A (en) | Modified nylon 1012 powder coating and preparation method thereof | |
| CN105778547B (en) | Method for preparing wood-plastic composite material by subcritical alcohol extrusion | |
| CN112538276A (en) | Straw/fly ash/waste plastic composite material and preparation method and application thereof | |
| CN101518752B (en) | Crushing device and crushing method for preparing suspended polytetrafluoroethylene (PTFE) resin | |
| CN1693432A (en) | Process for producing gasification briquette | |
| CN107199649B (en) | Granulation method of thermosetting plastic filling material powder | |
| CN1320064C (en) | Novel materials made of waste plastic and plant fibre and method for making same | |
| CN1915632A (en) | Pressure forming method for sintering green pressing products under normal pressure | |
| CN114031934A (en) | Polyamide composite material with high thermal conductivity coefficient and preparation method thereof | |
| CN209519828U (en) | A kind of broken machine of heparin sodium raw material mixed powder | |
| CN106346010A (en) | Method for preparing additive manufacturing material | |
| CN106832670A (en) | High-strength PVC heat-conductive composite material and preparation method thereof | |
| CN1743101A (en) | Method and aparatus of energy-saving and environment-protecting type for producing cobalt sheet | |
| CN114130303B (en) | TGIC efficient devolatilization and melt extrusion granulation integrated processing method | |
| CN215031130U (en) | Feed particle sorting device | |
| CN212191246U (en) | Bismuth powder manufacturing device | |
| CN206724652U (en) | Improve the device of FEP fine polymer powder drying efficiencies |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20180525 Address after: 200025 Xujiahui Road, Huangpu District, Shanghai, room 1301, room 560 Patentee after: Shanghai 3F new Mstar Technology Ltd Address before: No. 4411 Longwu Road, Shanghai City, Shanghai Patentee before: Sanaifu New Material Co., Ltd., Shanghai |
|
| TR01 | Transfer of patent right | ||
| CP03 | Change of name, title or address |
Address after: Room 801, 560 Xujiahui Road, Huangpu District, Shanghai 200025 Patentee after: Shanghai Huayi sanaifu New Material Co., Ltd Address before: 200025 Xujiahui Road, Shanghai, room 560, No. 1301, room Patentee before: SHANGHAI 3F NEW MATERIAL TECHNOLOGY Co.,Ltd. |
|
| CP03 | Change of name, title or address |