To reclaim thermoplastic resin is the production method of the film-coated controlled release fertilizer of degradable membrane
(1) technical field
The invention belongs to the controlled-release fertilizer production field, is to form the thermoplastic resin membrane wrapping coating at the solution that plastics are reclaimed in the spraying of compound (mixing) fertilizer or urea granules surface, and film-coated controlled release fertilizer and working method thereof that solvent recuperation is recycled.
(2) background technology
The type of film-coated controlled release fertilizer mainly contains high polymer film-coated fertilizer and inorganics coated fertilizer two big classes both at home and abroad at present.The inorganics coated fertilizer is representative (US3295950) with the sulfur-coated urea (SCU) of U.S. TVA company exploitation, though production cost is not high, is difficult to the rate of release and the controlled release time of strict its nutrient of control.Because the sulphur film is easy oxidized becoming fragile in air, breaking of putamina takes place in meeting in the nutrient dispose procedure, causes the whole suddenly releases of nutrient in the film, claims " crushing release " again.Therefore this fertilizer regular meeting works the mischief to crop root, and putamina is more crisp in addition, store and use in easily from urea or the compound fertilizer granules surface comes off or fragmentation, lose the coated slow-release function.In addition, a large amount of sulphur shells by after microbiological degradation or the oxidation, easily cause soil acidification in soil.In the organic high molecular polymer coating controlled-release fertilizer, mainly contain thermosetting resin and thermoplastics coating controlled-release fertilizer two big classes." Osmocote " that the thermohardening resin coated controlled-release fertilizer material is produced with U.S. Scotts company is main representative, its coated fertilizer is Synolac class or polyurethane kind polymkeric substance, this coated with resin fertilizer has good controlled release properties, but costing an arm and a leg of this resin, therefore the release and release control fertilizer cost of producing is too high, is difficult to apply on field crop." Meister " that produces with the Chisso-Asahi fertilizer company of Japan with the release and release control fertilizer of thermoplastic resin membrane wrapping and " Nutricote " be representative, its coated fertilizer mainly is that polyethylene and ethylene vinyl acetate (EVA) dissolve in organic solvent according to certain mixed and back, in fluidized-bed coating tower, spray to then on the fertiliser granulates and film forming, this coated fertilizer has the function of nutrient sustained release equally, but costing an arm and a leg of this resin, cause the production cost and the selling price of coated fertilizer higher, in addition, the residual film after fertilizer dissolves needs the long period to degrade in soil.Therefore developing the present invention utilizes recovery waste thermoplastic resin (polyethylene film, polystyrene foam etc.) not only to reduce the mould material cost greatly, and the materials such as recovery rubber powder that in mould material, add grain flour, mineral powder and quicken the mould material degraded, not only effectively control the rate of release and the release period of nutrient, and the putamina of controlled release fertilizer is owing to add rubber powder, aging speed is accelerated, thereby promoted the degraded of thermoplastic resin, grain flour of Tian Jiaing and starch etc. can be microorganism and provide condition to the decomposition of residual film simultaneously.Therefore the invention solves at present in the world fertile too high being difficult to of cost of controlled release promotes a gordian technique difficult problem that is difficult to degrade with the residual film of polymer, and the produce market prospect is very wide.
(3) summary of the invention
The purpose of this invention is to provide a kind of utilization and reclaim waste thermoplastic resin, add multiple filler, be suitable for quick mass industrialized production, adopt film-coated controlled release fertilizer of heated fluidized bed coating process and preparation method thereof.This invention to put the more weak recovery polyethylene film resin of the first recovery polystyrene foam resin that water-permeable is stronger and water-permeable according to certain mixed, add mineral additives such as talcum powder, diatomite, SULPHUR POWDER simultaneously, the ratio by two kinds of resins and the quantity of mineral additive are regulated the nutrient release rate of coated release-controlled fertilizer product; It two is mixed solvents with zellon and methylene dichloride, and two kinds of solvents can be regulated the solubleness of two kinds of resin materials in mixed solvent according to certain mixed; It three is earlier various fertiliser granulates are preheated to certain temperature in ebuillition of heated formula fluidized-bed after, the solution that is dissolved with two kinds of hybrid films materials is sprayed on the fertiliser granulates equably through two-fluid spray nozzle, form smooth densification and have the high polymer film-coated of different water-permeables and different thickness; It four is to be added under the light action aging rubber powder faster in the mould material, makes residual putamina capable of being fast degraded in soil.
Content of the present invention is: be 1 with polystyrene foam resin and the polyethylene film resin that reclaims according to weight ratio at first: 1-1: 4 mixed, add mineral powder, the grain flour of 1-5% and the rubber powder of 2-10% that its weight accounts for coated fertilizer weight 2-10%, they are miscible in the mixed solvent of zellon and methylene dichloride, in heated fluidized bed, uniformly spray on the fertiliser granulates, the mould material that is sprayed at the granulated fertilizer surface accounts for the 3-10% of granulated fertilizer gross weight, finally makes the high polymer film-coated controlled release fertilizer of smooth densification.The fertilizer of finally making has different water permeabilities.
In this production method, the solvent of dissolved polystyrene foamed resin and polyethylene film resin is the mixed solvent of zellon and methylene dichloride, and the part by weight of preferred two kinds of solvents is 1: 1-5: 1.The mineral powder that adds can be selected from one or more in talcum powder, diatomite, clay, lime carbonate, metal oxide, the SULPHUR POWDER.The grain flour that adds can be selected wheat-flour, Semen Maydis powder, rice powder, sweet potato flour or potato block root tuber starch for use.
Unusual effect of the present invention is: the nutrient sustained release of product is regulated according to the ratio and the thickness of two kinds of mould materials period, can accurately be controlled at and not wait in 1 month to 12 months, also the product with different release period, different release characteristics can be mixed according to a certain percentage in addition, simulate various crops to nutrient demand, make various special coated controlled release fertilizers, the nutrient release profiles and the crop of controlled release fertilizer are matched to the nutrient absorbing curve, reach the purpose of the accurate controlled release of nutrient.The main mould material of this making method adopts and reclaims the waste or used plastics resin; the foam and the film quantity of domestic and international this recovery at present are very big; be suitable for industrialization scale operation; the product of gained not only cost is low; and the quality of nutrient controlled release and effect are splendid; the more important thing is and utilize the recovery waste or used plastics can reduce serious day by day " white pollution " at present; the putamina of coated fertilizer after being manured into soil simultaneously is owing to added the rubber powder that can induce its rapid ageing and degraded in coated fertilizer; the mineral powder; additive such as grain flour and starch; make its residual film can rapid ageing and by soil microbial degradation; unlikely residual in the soil midium or long term; very be fit to the trend of development of the present world and domestic fertilizer and environment protection, have and brilliant market developing prospect.This product has carried out a large amount of pot experiments, field test and demonstration on crops such as paddy rice, corn, tobacco, peanut, wheat, cotton, strawberry, potato, multiple flowers, vegetables, fruit tree, lawn, test-results shows, this product all has significant volume increase and synergism on above-mentioned crop, have popularizing application prospect very widely.
(4) description of drawings
Fig. 1: film-coated controlled release fertilizer preparation process schema of the present invention.
1. at first with in the input boiling heated fluidized beds (3) such as granular complex fertilizer, urea or granular potassium sulfate among the figure, the 2nd, in fluidized-bed, make fertilizer be preheating to 60~80 ℃, the 3rd, polyethylene, polystyrene and additive are miscible in the reactor that zellon and methylene dichloride mixed solvent are housed with reclaiming, after being heated to 100~150 ℃, mixed solution evenly is sprayed on the fertiliser granulates in fluidizing fluid-bed through two-fluid spray nozzle, forms the organic high molecular layer of smooth densification.The 4th, the fertilizer behind the coating is changed in the water cooler, make it be cooled to room temperature, the 5th, with cooled coated fertilizer weighing and bagging.
(5) embodiment
Embodiment 1:
With the 100kg diameter be the granular compound fertilizer of 2~5mm pack into fluidizing fluid-bed in, be heated to 60~80 ℃, to reclaim polyethylene plastic film 3.0kg and to reclaim polystyrene foam 3.0kg miscible in 50kg methylene dichloride and zellon respectively account for 1/2 mixed solvent, add diatomite, Semen Maydis powder and rubber powder 0.5kg altogether, be heated to 90~100 ℃, is the progress spraying of 4kpa with per minute 2kg with two-fluid spray nozzle at air atomizing pressure, and 100kg solution is all sprayed on the fertiliser granulates.The controlled-release compound fertilizer of gained, polymeric membrane account for about 6% of fertilizer gross weight, and this fertilizer is in 25 ℃ water or soil, and the nutrient sustained release time is about 6 months.
Embodiment 2:
With the 200kg diameter is that 2~4mm granular urea is packed in the boiling sulfuration bed, be heated to 50~70 ℃, miscible in 100kg zellon and methylene dichloride respectively account for 1/2 mixed solvent with reclaiming polyethylene plastic film 4kg and reclaiming polystyrene foam 6kg, add light calcium carbonate powder, wheat-flour and rubber powder 1.0kg altogether, be heated to 80~90 ℃, being 4kpa with two-fluid spray nozzle at atomizing pressure is sprayed on the granular urea with the speed of per minute 2kg, and the fertile film of gained controlled release accounts for about 5% of the fertile gross weights of whole controlled releases.This fertilizer is in 25 ℃ of water or soil, and the nutrient sustained release time is about 3 months.
Embodiment 3:
With the 100kg diameter is that the granular potassium sulfate of 2-5mm is packed in the boiling sulfuration bed, be heated to 70-80 ℃, will reclaim polyethylene 3kg and reclaim polystyrene 2kg miscible is totally 0.5 kilogram of adding 400 order talcum powder in 2: 1 the mixed solvent, sweet potato flour and rubber powder in 40kg tetrafluoroethylene and methylene dichloride ratio.Be heated to 100 ℃, being 4kpa with two-fluid spray nozzle at atomizing pressure is sprayed on the fertiliser granulates with the speed of per minute 2kg, and gained controlled-release fertilizer, film account for about 5% of whole fertilizer gross weights, and in 25 ℃ water or soil, the nutrient sustained release time is about 4 months.
Embodiment 4:
With the 250kg diameter is that the granular compound fertilizer of 2-5mm is packed in the boiling sulfuration bed, be heated to 70-80 ℃, to reclaim polyethylene plastic film 15.5kg and to reclaim polystyrene foam 5kg miscible in 100kg zellon and methylene dichloride ratio are 4: 1 mixed solvent, add diatomite, Semen Maydis powder and rubber powder be 1.5kg altogether, be heated to 100 ℃, being 5kpa with two-fluid spray nozzle at atomizing pressure is sprayed on the compound fertilizer granules surface with the flow of per minute 2.5kg, about 8% of the fertile weight of the shared whole controlled releases of the fertile film of gained controlled release, this fertilizer is in 25 ℃ water or soil, and the nutrient sustained release time is about 9 months.