CN102307713B

CN102307713B - Method and apparatus for separating plastics

Info

Publication number: CN102307713B
Application number: CN200980156093.4A
Authority: CN
Inventors: 平野则子; 谷村纯二; 中慈朗; 真下麻理子; 衣川胜; 小笠原忍; 筒井一就
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2009-02-13
Filing date: 2009-11-09
Publication date: 2014-06-04
Anticipated expiration: 2029-11-09
Also published as: DE112009004345T5; KR101327623B1; CN102307713A; KR20110102952A; TWI449578B; WO2010092645A1; DE112009004345B4; KR101427548B1; TW201032909A; JP5498400B2; JPWO2010092645A1; KR20130110230A

Abstract

A method which comprises: a first gravity separation step in which plastics lighter than a first specific-gravity threshold (P1) are separated from mixed crushed plastics by the gravity separation method; a step in which the specific-gravity threshold (P1) to be used in the first gravity separation step is determined from a specific-gravity distribution of the light plastics to be separated; and a bromine-containing-plastic removal step in which the separated light plastics are irradiated with X rays emitted from an X-ray source, the transmitted X rays which have passed through the separated light plastics are detected by an X-ray transmission detector, data on the detection of transmitted X-rays are analyzed, and bromine-containing plastics are removed from the separated light plastics based on the presence or absence of bromine, i.e., based on signals from a data process unit which determines whether or not bromine is present in the separated light plastics.

Description

The method for separating of plastics and sorting unit

Technical field

The co-grinding separating plastic the present invention relates to from being obtained by useless family electrical article can recycle in method and the device thereof of the plastics of family's electrical article.

Background technology

In the method for separating of recycled plastic in the past, there is the wet separation function (gravity separation function) by having utilized difference in specific gravity, for each kind, plastics are carried out to the technology (for example, patent documentation 1) of sorting.In addition, have and wait by friction that to make to have the plastics of charging property charged, utilize the difference of the charged characteristic of various plastics, the technology (for example, patent documentation 2) of carrying out sorting in electrostatic field for each kind.Be in the plastics that use in electrical article, a part has been used the flame retardant resin that contains fire retardant.Its fire retardant amount is generally 1～30 % by weight, mainly utilizes brominated flame retardant as this fire retardant.

On the other hand, in order to ensure, management recycled plastic performance, fire retardant contains resin and the non-sorting technology that contains resin becomes important technology.In addition, in promoting that recycled plastic is to effective utilization of family's electrical article, in order to observe the amount rule of the brominated flame retardant in the harmful substance rule of representative take European RoHS instruction (limiting relevant instruction to the use of special harmful substance contained in electric/electronic device), be also necessary to prevent that brominated flame retardant is sneaked into recycled plastic in the recirculation operation of plastics.

In the time making the such flame-retardant plastic that contains fire retardant recirculation, be importantly separated into the flame-retardant plastic that contains fire retardant and the plastics that do not contain fire retardant, in order to avoid remaining brominated flame retardant is sneaked into the isolation technics of recycled resin.

In the past, as the separator of plastics, existed and transported separate object thing by carrying members such as conveyers, irradiate radioactive ray to separate object thing, measure the transmitance through the radioactive ray of material, according to measurement result, distinguish separate object thing, and be fetched into the separator of returnable.(for example,, referring to patent documentation 3).

Formerly technical literature

Patent documentation

Patent documentation 1: TOHKEMY 2003-112156 communique

Patent documentation 2: TOHKEMY 2007-111600 communique

Patent documentation 3: Japanese kokai publication hei 5-131176 communique

Summary of the invention

The problem that invention will solve

In the manufacture method of recycled plastic in the past, especially carry out in the method for sorting according to proportion, be removed than the plastics of heavy brominated flame retardant although contain in a large number than plastics, but, exist the plastics that contain not to be removed micro-ly, exceeded the problem points of the regular amount of brominated flame retardant.In addition, although by reducing the threshold value of gravity separation, improved the rate of removing of the plastics that contain brominated flame retardant, the problem points that exists the rate of recovery of the plastics of conduct recirculation object to reduce.

In addition, in separator as described above, although be to judge according to the transmitance of the radioactive ray that pass at separate object thing the plastics that contain element-specific, but, the transmitance of radioactive ray is except the weight of element contained in separate object thing, amount, also because the increase of thickness reduces.Therefore, have as chippy plastic sheet, in the fixed situation of the size of separate object thing, variable thickness, mistake is judged the problem points of the plastic sheet that contains element-specific.

The present invention is the invention of making in order to solve problem points as described above, its object is, a kind of high speed is provided and removes accurately the method for separating of the plastics relevant to manufacture method recycled plastic plastics that contain brominated flame retardant from co-grinding plastics.

In addition, in above-mentioned method for separating, to provide in the lump the sorting unit of plastics that can there is the plastic sheet of various thickness take high precision sorting as object.

About the manufacture method of recycled plastic of the present invention has: by differential-density saparation by the first gravity separation operation of distinguishing from co-grinding plastics than the light plastics of the first proportion threshold value P1, distribute according to the proportion of the light plastics of above-mentioned differentiation, determine the operation of the proportion threshold value P1 in above-mentioned the first gravity separation operation, with the x-ray from x-ray source to the above-mentioned light plastics irradiation of being distinguished, detect the x-ray that sees through from the above-mentioned light plastics of being distinguished by seeing through x-ray detector, according to the data analysis that sees through x-ray being detected and differentiate the signal of the existence whether data processing division of the bromine in the above-mentioned light plastics of being distinguished, according to the existence of bromine whether, the brominated plastics of brominated plastics being removed from the above-mentioned light plastics of being distinguished are removed operation.

Invention effect

In the manufacture method about recycled plastic of the present invention, owing to can the plastic row that contain in a large number brominated flame retardant being removed by gravity separation, the plastic row that selectively plastics that contain brominated flame retardant is contained to brominated flame retardant from trace removes, so, the rate of recovery as the plastics of recirculation object can be improved, and contain/non-brominated accuracy of identification, raising processing speed can be improved.

Accompanying drawing explanation

Fig. 1 is the flow chart of the manufacture method of the recycled plastic based on embodiments of the present invention 1.

Fig. 2 is the figure that represents the structure of the sorting unit that drifts along of implementing the gravity separation operation based on embodiments of the

present invention

1,2.

Fig. 3 represents based on figure embodiments of the

present invention

1,2, that implement to survey the existence of bromine the apparatus structure of operation that brominated plastics are removed.

Fig. 4 is the flow chart of the manufacture method of the recycled plastic based on embodiments of the present invention 2.

Fig. 5 is the figure that represents the structure of the electrostatic separation apparatus of implementing the electrostatic separation operation based on embodiments of the present invention 2.

Fig. 6 is the figure of the example that distributes of the proportion of the PP, the PSABS that represent co-grinding plastics.

Fig. 7 is for the figure about the validity of manufacture method of the present invention is described.

Fig. 8 is for the figure about the validity of manufacture method of the present invention is described.

Fig. 9 is the skeleton diagram representing about the sorting unit of the plastics of embodiments of the present invention 3.

Figure 10 is the stereogram of the thickness sorting portion in the sorting unit of the plastics shown in presentation graphs 1.

Figure 11 is the top view of the thickness sorting portion shown in Fig. 9.

Figure 12 is the cutaway view of the A-A line of Figure 11.

Figure 13 is the cutaway view of the B-B line of Figure 11.

Figure 14 is the chart representing about the transmitance of x-ray of embodiments of the present invention 3 and the relation of the thickness of plastic sheet.

Figure 15 is the stereogram representing about the thickness sorting portion in the sorting unit of the plastics of embodiments of the present invention 4.

Figure 16 is the stereogram representing about the thickness sorting portion in the sorting unit of the plastics of embodiments of the present invention 5.

Figure 17 represents to use the device about embodiments of the present invention 3, the figure of the apparatus structure of the existence of enforcement detection bromine the operation that brominated plastics are removed.

The specific embodiment

Embodiment 1.

Fig. 1 is the flow chart that represents the method for separating of the plastics relevant to the manufacture method of the recycled plastic based on embodiments of the present invention 1.In Fig. 1, co-grinding plastics are set as predetermining to the value P1 (, P is the capitalization word of Greece character mouth one) of proportion threshold value here, here, if P1 1.0 carries out the first gravity separation, point elect as and to compare heavy 1.0 light plastics and plastics and the metal heavier than proportion 1.0.

Co-grinding plastics are take polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene polymer (ABS) as main, in addition, as a small amount of, by formations such as polyacetals (POM), polybutylene terephthalate (PBT)s (PBT).The proportion of PP is about 0.9, lighter than PS (approximately 1.05), ABS (approximately 1.05), other plastics, is distinguished by the first gravity separation.Remove brominated PP from the PP having distinguished by gravity separation, reclaim the PP that meets RoHS.

RoHS rule objects material, except brominated flame retardant, also has lead, mercury, cadmium, Cr VI, and still, the result that the PP after gravity separation is investigated is that all substances are all below regular amount.Therefore,, by removing brominated PP, the PP that meets RoHS is recovered.

Fig. 2 is as the concrete example of differential-density saparation represent the to drift along structure of sorting unit.

The sorting unit body that drifts along possess can storing liquid medium 9 the tank 2 that drifts along, for stir, transport floating material oar 3, transport the auger conveyor 5a of precipitum.At weigh feeder 1, co-grinding plastics, as shown in the flow direction of arrow 8, are dispersed and drop in liquid medium, floating material in these co-grinding plastics is transported on liquid medium by oar 3, pass through at vibratory sieve 4, as shown in the arrow of floating sort stream 10, floating sorting thing is recovered.Make water (proportion=1.0) by liquid medium, can be only by PP less than water proportion from co-grinding plastics

reclaim as floating sorting thing.In addition, floating sorting thing is recovered, and remaining liquid medium 13 returns to by the tank 7 with pump the tank 2 that drifts along.

On the other hand, proportion,, is discharged from as liquid medium and precipitum from outlet 6a than the large precipitum of water after being transported by auger conveyor 5a as shown in the arrow 11 of express liquid medium and sedimentation logistics.As shown in the figure on the right side in Fig. 2, the precipitum being discharged from is thus lifted to the top compared with being temporarily stored in the liquid medium surface of the tank 2 that drifts along with liquid medium by auger conveyor 5b.Accordingly, liquid medium returns to the tank 2 that drifts along, and only the precipitum shown in arrow 12 is recovered from outlet 6b, completes sorting.

Fig. 3 is the structure that represents to remove as brominated plastics the device of the concrete example of method.In Fig. 3, supply with and pulverize plastics 22 (being formed by brominated plastics 22a, non-brominated plastics 22b) to conveyer 21 from feedway 23 successively.The pulverizing plastics 22 that accelerated at conveyer 21 are gone out from conveyer 21, are passing through for irradiating between X-ray tube ball 24 (roentgen radiation x source is also recited as roentgen radiation x source below) as a kind of x-ray of radioactive ray and x-ray detector 25.The x-ray producing from X-ray tube ball 24 irradiates to pulverizing plastics 22, sees through x-ray and is detected by x-ray detector 25.Differentiate at data processing division 26 brominated and non-brominated, distinguish the brominated plastics 22a of mechanism 27 distinguished at brominated plastics containing box 28, non-brominated plastics 22b is distinguished at non-brominated plastics containing box 29.

As x-ray detector 25, use can be carried out in line, the mensuration of x-ray intensity distributions in face, such as x-ray line sensor, x-ray image intensifier, x-ray CCD camera, x-ray scintillation crystal, location-sensitive proportional counter tube etc. do not have the x-ray detector 25 of energy resolution.If use these detectors, the position of brominated plastics 22a is because see through x-ray weakened, so, can limit the position of brominated plastics 22a.In addition, if use these detectors, can be by the x-ray intensity distributions visual image in line, in face.In the image being visualized, it is little that brominated plastics 22a is expressed as the non-brominated plastics 22b of brightness ratio.

Although the plastics that contain filler (mica, clay, calcium carbonate etc.), reinforcement material (glass fibre), colouring agent (titanium oxide etc.) are also to see through x-ray weak strength, differentiation precision reduces, but, the plastics that contain them are because proportion is than 1.0 weights, so, be excluded by gravity separation in advance, distinguishing precision can be not low.And, can reduce the action load of distinguishing mechanism 27, improve and distinguish precision.

Conveyer 21 can use such as band conveyor etc., supplies with and distinguishes the feedway 23 of object as long as use hopper, loader etc. to band conveyor.Distinguish mechanism 27 as long as according to the signal from data processing division, be accommodated in suitable containing box by air blast, suction nozzle based on vacuum etc., or proceeded to next band conveyor.

Like this, the existence of surveying bromine by arranging in rear class about the manufacture method of the recycled plastic of present embodiment is gone forward side by side and is about to the operation that brominated plastics remove, in the gravity separation operation that can arrange in prime, expand the specific gravity range of distinguishing object, can improve the rate of recovery of the PP that meets RoHS.

Embodiment 2.

Fig. 4 is the flow chart that represents the manufacture method of the recycled plastic based on embodiments of the present invention 2.In Fig. 4, the proportion threshold value P1 that co-grinding plastics have been set as predetermining in the operation of the first gravity separation, carries out gravity separation.Here, establishing P1 is 1.0, point elects as and to compare heavy 1.0 light PP and plastics and the metal heavier than proportion 1.0.Then,, by the proportion threshold value P2 that has been set as predetermining than above-mentioned proportion 1.0 heavy plastics, carry out the second gravity separation.Here, establishing P2 is 1.1, point elects as and to compare heavy 1.1 light PS and the mixture of ABS and plastics and metals heavier than proportion 1.1.Wait and make by the second gravity separation chargedly as the mixture of the PS being gently sorted than proportion 1.1 and ABS by friction, utilize the charged characteristic of PS and ABS different, in electrostatic field, point elect PS and ABS as.Utilize by the illustrated device of removing brominated plastics of Fig. 3, PS, ABS from electrostatic separation remove brominated PS, ABS, and the PS, the ABS that meet RoHS are recovered.

The result that PS after electrostatic separation, ABS are investigated is that any one material in lead, mercury, cadmium, Cr VI is all below regular amount.Therefore,, by removing brominated PS, ABS, the PS, the ABS that meet RoHS are recovered.

In embodiment 1, as establishing the concrete example that proportion threshold value is 1.0 differential-density saparation, illustrate that liquid medium has used the structure of the sorting unit that drifts along of water (proportion=1.0), but, at the second gravity separation, that is, establish proportion threshold value and be in 1.1 situation, also liquid medium can be replaced as to salt solution, chlorinated organic solvent etc. and can set the liquid of proportion.

Fig. 5 is the structure that represents electrostatic separation apparatus.Electrostatic separation apparatus possesses weigh feeder 30, friction belt torch 31, electric field feeding device 32,

electrode

33a, 33b,

power supply

34a, 34b and collection box 35a, 35b in opposite directions.

The PS sheet being sorted by gravity separation and the mixture 40 of ABS sheet are put into weigh feeder 30.In Fig. 5, ο represents ABS sheet, represents PS sheet.The position with in electric array of PS and ABS is different, and PS mono-orientation is in the minus side with in electric array, and ABS mono-orientation is in the positive side with in electric array.

The friction belt torch 31 of having accepted the supply of the mixture 40 of PS sheet and ABS sheet from weigh feeder 30 is stirred vessels of rotatable cylinder type.Friction belt torch 31 can be rotated take its central shaft as pivot, and by rotation, one side stirs the mixture 40 of PS sheet and ABS sheet, and one side makes it friction, makes mixture charged.The electric field feeding device 32 of having accepted the supply of the mixture charged because of friction belt torch 31 has mixture to

electrode

33a, 33b mono-side send in opposite directions function.

The current potential lower than power supply 34a is applied to electrode 33a (negative electrode) in opposite directions, and the current potential higher than power supply 34b is applied to electrode 33b (positive electrode) in opposite directions.Accordingly, between

electrode

33a, 33b, producing electric field in opposite directions, charged mixture is passed through in the part that produces this electric field.In charged mixture, be pulled to the 33b of electrode in opposite directions of hot side at charged negative PS sheet, on the other hand, be pulled to the 33a of electrode in opposite directions of low potential side at the ABS of positively charged sheet.PS sheet is sorted the collection box 35b that is recovered in hot side, and ABS sheet is sorted the collection box 35a that is recovered in low potential side.

The structure of carrying out the device that brominated plastics remove of the structure example of carrying out the device that brominated plastics remove and relevant embodiment 1 is identical.Therefore, omit the explanation of this part.

Here, the method for the gravity separation in embodiment 1 and embodiment 2 is described.Fig. 6 is the chart that represents to account for an example of the most PP of the plastics that reclaim and the distribution of the proportion of PSABS on market.Thick line represents PP, and fine rule represents PSABS.The proportion of PP has the distribution centered by 0.9 in this embodiment, and the proportion of PSABS has the distribution centered by 1.05.Fig. 7 is illustrated in these routine plastics, the chart of the average bromine concentration with respect to proportion in plastics.Thick line is illustrated in the value of removing before brominated plastics, and fine rule represents the value after device is removed brominated plastics of removing by the brominated plastics of Fig. 3, and chain-dotted line represents desired value.Desired value is 300ppm.This is following numerical value: if bromine concentration less than 300ppm, the brominated flame retardant of which kind of RoHS instruction object no matter, all can guarantee less than 1000ppm (meeting RoHS benchmark) as compound.In the chart of removing before brominated plastics, the high part of average bromine concentration of proportion 1.0～1.05 is brominated PP, and the more than 1.1 high part of average bromine concentration of proportion is brominated PSABS.Because bromine proportion compared with plastics is heavier, so if be added in plastics, the proportion of plastics increases.

Remove even if the PP distinguishing by the gravity separation of proportion threshold value 1.0 does not carry out brominated plastics, bromine concentration is also less than 300ppm.Although contain brominated PP in PSABS, can distinguish by the electrostatic separation of rear class.Although in above-mentioned electrostatic separation, mention the differentiation of PS and ABS,, the PS after electrostatic separation contains brominated PP.Because PS is different with PP charged characteristic, so, can, by further carrying out electrostatic separation, PS and PP be distinguished.But, because brominated PSABS can not distinguish by electrostatic separation, so, in the case of not using the existence of the such detection bromine illustrated by Fig. 3 to carry out, method that brominated plastics remove, need to brominated plastics being removed by gravity separation.For brominated plastics being removed by gravity separation, if with reference to Fig. 7, the proportion threshold value of for example gravity separation be 1.1 o'clock excessive, need to make proportion threshold value less than 1.1, be for example set as 1.07, brominated plastics are removed.On the other hand, carrying out by the existence of the illustrated such detection bromine of Fig. 3, carrying out in situation that brominated plastics remove, because can distinguish brominated PSABS in rear class, so, can increase proportion threshold value.That is, can increase the sorting threshold value P2 (being 1.1) of the second gravity separation in embodiment 2 in the example of embodiment 2, reduce the amount of the plastics of removing by the second gravity separation.Fig. 8 is illustrated in using the proportion threshold value in gravity separation as transverse axis, has carried out the figure of the rate of recovery of PP in the situation of gravity separation and PSABS according to this proportion threshold value.As seen in Figure 8, the in the situation that of PP, be 1.0 if establish proportion threshold value, the rate of recovery is roughly 100%.On the other hand, the in the situation that of PSABS, be for example 1.1 if establish proportion threshold value, the rate of recovery is more than 90%, have with to establish proportion threshold value be for example compared with 1.07 situation for brominated plastics being removed by gravity separation, can significantly improve the effect of the rate of recovery.

The proportion threshold value P2 of the second gravity separation in proportion threshold value P1 and the embodiment 2 of the first gravity separation in

embodiment

1,2 determines in the following manner.As illustrated by embodiment 1, be mixed with in plastics main body, that wish is distinguished that proportion distributes in the co-grinding plastics of different plastics becoming, first with PP (polypropylene) like that the proportion of (light) plastics of proportion minimum be distributed as basis, determine P1.Be PP at the lightest plastics, preferably P1 is 1.0, and this point is illustrated by embodiment 1, foregoing.Then, with regard to P2, plastics, the metal etc. of the proportion of the plastics (the multiple plastics that the value that also can contain proportion as PS and ABS approaches) of distinguishing according to heavy (weight), wish and the filler (mica, clay, calcium carbonate etc.) that contains other, reinforcement material (glass fibre), colouring agent (titanium oxide etc.) do not become the proportion of the material of distinguishing object, with in the second gravity separation, the sneaking into than the mode below regulation of material that does not become differentiation object determines P2.

Like this, about the manufacture method of the recycled plastic of present embodiment is surveyed the existence of bromine the operation that brominated plastics are removed by arranging in rear class, can expand the specific gravity range of distinguishing object by setting rightly the proportion threshold value of gravity separation, can improve and meet PP, the PS of RoHS, the rate of recovery of ABS.

Embodiment 3.

In the above-described embodiment, the method for separating of the plastics to the manufacture method about recycled plastic is illustrated, but by the method for separating for the plastics of above-mentioned embodiment by the sorting unit of the plastics about embodiments of the present invention 3, even have the different co-grinding plastics of thickness (by brominated plastics mixing, non-brominated plastics form) situation under, for pulverizing plastics (being also recited as plastic sheet below) separately, detect respectively the transmitance of the x-ray seeing through at the plastic sheet that has carried out thickness sorting by thickness sorting member, see through thickness data in data and the thickness sorting member of x-ray for each thickness sorting according to this detection, carry out separating plastic sheet, accordingly, can prevent the misinterpretation take the thickness of plastic sheet as cause, even there is the plastic sheet of various thickness, also sorting accurately.Therefore, can carry out more high-precision sorting, by the proportion threshold value of appropriate setting gravity separation, can expand the specific gravity range of distinguishing object, can further improve and meet PP, the PS of RoHS, the rate of recovery of ABS.

Use Fig. 9 to Figure 13, the sorting unit of the plastics for implementing embodiments of the present invention 3 is described.In Fig. 9, the sorting unit 50 of plastics is made up of following parts, , as the hopper 59 of feedway of supplying with plastic sheet 51, for each thickness, plastic sheet 51 is carried out the thickness sorting portion 52 of sorting, , thickness sorting member, as the band conveyor 53 of conveyer, to the roentgen radiation x source 54 of plastic sheet 51 exposures, , irradiate member, the x-ray detector 55 transmitance of the x-ray irradiating being detected for each thickness of thickness sorting portion 52, , detection means, transmitance according to the thickness information of thickness sorting portion 52 with the x-ray detecting, differentiate the discriminating gear 56 of plastic sheet 51, , judegment part, according to differentiating result, the air cannon (air blast) 57 as differentiation mechanism that plastic sheet 51 is separated, , separation unit, reclaim the returnable 58a of the plastic sheet 51a that contains the bromine below setting (also having the situation that is categorized as non-brominated plastics) in the plastic sheet 51 being separated by air cannon 57, and reclaim the returnable 58b of plastic sheet 51b (also having the situation that is categorized as brominated plastics) that contains the bromine more than setting.

Thickness sorting portion 52 as shown in figure 10, formed by following parts, that is, be arranged on the below of hopper 59, there is the sliding stand 61 of inclination at length direction and width,, sliding part material, the sorting plate 63a, the 63b that are respectively formed at sidewall 62a, the 62b of the length direction of the both sides of sliding stand 61, the thickness of plastic sheet 51 are carried out to sorting, that is, and sorting portion material and prevent the demarcation strip 64a, the 64b that mix of the plastic sheet that has carried out thickness sorting,, separating part material.

In addition, although sliding stand 61 tilts at length direction and width, also can only tilt at length direction.

Sliding stand 61 has the supply unit 61a of plastics at length direction in the high side that tilts, and has the discharge portion 61b of plastics in the low side that tilts, bonding or one end of welding sorting plate 63a, 63b on the sidewall 62b of the low side of the inclination that is arranged on its width.Sorting plate 63a, 63b as shown in figure 11, extend towards the discharge portion 61b of plastics, and as shown in figure 12, and sliding stand 61 between be formed with the 65a of the portion that passes through, the 65b that the plastic sheet of not enough desirable thickness passes through.Should be by the 65a of portion with compared with the 65b of portion, open height is higher, is arranged on high side at the width of sliding stand 61.

Here, use two sorting plates, but its sheet number is not limited thereto, sheet number is more many more can carry out trickleer thickness sorting.

Bonding or

welding demarcation strip

64a, 64b at the other end of sorting plate 63a, 63b, again mix for fear of the plastic sheet 51 that has carried out thickness sorting, and join with the inclined-plane of sliding stand 61, extend to the discharge portion 61b direction of plastics.In addition, on sliding stand 61, be provided for to plastic sheet 51 apply vibration vibrating device (not shown go out.Though be not particularly limited, for example also can use such vibrating device shown in No. 3035280th, Japan Patent).In addition, although

demarcation strip

64a, 64b and sorting plate 63a, 63b individually form, also can be formed by a plate.

In the downstream of thickness sorting portion 52, band conveyor 53 is set, this band conveyor 53 transport road in arrange to the roentgen radiation x source 54 of plastic sheet 51 exposures, for each thickness that carries out thickness sorting, detect and in the x-ray irradiating, seen through the x-ray detector 55 of the transmitance of the x-ray of this plastic sheet 51.Use the x-ray line sensor of the mensuration that can carry out the x-ray intensity distributions in line as this x-ray detector 55, but also can use the parts (such as x-ray image intensifier, x-ray CCD camera, x-ray scintillation crystal, location-sensitive proportional counter tube etc.) of the mensuration of the intensity distributions that can carry out the x-ray in line, in face.

The thickness information of the transmitance of the x-ray being detected by x-ray detector 55 and thickness sorting portion 52,, be formed on the open height information of the 65a of the portion that passes through, 65b on sorting plate 63a, 63b together, be transferred to the discriminating gear 56 as data processing division of processing as basis using these data, at discriminating gear 56, the determinating reference value of setting according to this thickness information and the transmitance of the x-ray detecting are compared, differentiate plastic sheet 51a (below setting, contain brominated flame retardant), its result is exported as the control signal of air cannon 57.

Air cannon 57 is arranged on the terminal part of band conveyor 53, correspondingly spray with the control signal receiving from discriminating gear 56, to plastic sheet 51a (containing the brominated flame retardant below setting) and plastic sheet 51b (containing the brominated flame retardant more than setting) are separated.The returnable 58a, the 58b that are configured in front and back or left and right according to injection direction are being set at the lowering position of injected

plastic sheet

51a, 51b.

Then, action is described.The plastic sheet with various thickness 51 (for example thickness is below the above 3mm of 0.5mm) that is supplied to the supply unit 61a of sliding stand 61 from hopper 59 is applied vibration by vibrating device through sliding stand 61, become a scattered layer state, as shown in the arrow of Figure 11, one side moves to the discharge portion 61b of plastic sheet on the inclined-plane of sliding stand 61, and one side is carried out thickness sorting by sorting plate 63a, 63b.

For example, as shown in figure 12, be to be respectively 2mm, 1mm apart from a side of the close supply unit 61a of sliding stand 61 in the case of establishing by the height of the 65a of portion, 65b, thickness in plastic sheet 51 is more than 0.5mm, is passing through by the 65a of portion, 65b less than the plastic sheet of 1mm, and thickness is more than 1mm, plastic sheet less than 2mm is passing through by the 65a of portion, but do not passing through by the 65b of portion, thickness is more than 2mm, and which the plastic sheet 51 below 3mm do not pass through by the 65a of portion, 65b at.

Its result is that it is three kinds (thickness 0.5mm is above above following less than the above 3mm of 2mm, 2mm less than 1mm, 1mm) that plastic sheet 51 is sorted for each thickness.

Like this, three kinds of plastic sheets 51 that are sorted for each thickness as shown in figure 13 respectively by

sidewall

62a, 62b and

demarcation strip

64a, 64b (thickness is more than 0.5mm, less than the plastic sheet of 1mm by sidewall 62b and demarcation strip 64b; Thickness, more than 1mm, is being separated

plate

64a, 64b less than the plastic sheet of 2mm; Thickness is more than 2mm, and the plastic sheet below 3mm is by sidewall 62a and demarcation strip 64a) inclined-plane of the sliding stand 61 that surrounds moves, is discharged from from the discharge portion 61b of plastic sheet.After this, the plastic sheet 51 being discharged from is transported by band conveyor 53, in the time of the irradiation area by roentgen radiation x source 54, and illuminated x-ray.In irradiated x-ray, the x-ray that has seen through plastic sheet 51 is detected transmitance by x-ray detector 55 for each thickness of thickness sorting portion 52, is transferred to discriminating gear 56 together with detecting the positional information of transmitance.

In discriminating gear 56, take the thickness information of the positional information based on above-mentioned as basis, from the transmitance of predefined x-ray, determine respectively determinating reference value, transmitance to this determinating reference value and the x-ray that detected by x-ray detector 55 compares, then, if the transmitance of the x-ray detecting is more than determinating reference value, differentiate for plastic sheet 51a (containing the brominated flame retardant below setting), if less than determinating reference value, differentiate for plastic sheet 51b (containing the brominated flame retardant more than setting), to air cannon 57 transmission of control signals.

If air cannon 57 is received control signal from discriminating gear 56, the plastic sheet 51 of jet that is transported to air cannon 57 by band conveyor 53 is according to this control signal, for each by the thickness of thickness sorting, mechanically be separated into plastic sheet 51a (containing the brominated flame retardant below setting) and plastic sheet 51b (containing the brominated flame retardant more than setting), be recycled to returnable 58a, 58b separately.

Here, use Figure 14, describe the method for discrimination of above-mentioned discriminating gear 56 in detail.

Figure 14 represents and the chart of the transmitance of the corresponding x-ray of thickness of plastic sheet, has represented that brominated rate is 0 quality %, the article of 1 quality %.(transmitance of x-ray refers to that establishing through the x-ray amount before plastic sheet is 1, the value that the x-ray gauge that has seen through each sample has been formatted.)

Even if brominated rate is 0 quality %, it is to represent because the carbon of the inscape as plastic raw materials etc. also absorbs x-ray that the transmitance of x-ray does not become 1 yet, so the reduction of the transmitance of x-ray not only increases because of the containing ratio of bromine, also produces because the thickness of plastics increases.

As the determinating reference value of the plastic sheet 51 for certain specific thickness, as long as be chosen in it below thickness, and there is the determinating reference value of desirable brominated rate.That is, differentiate in Figure 14 thickness more than 0.5mm less than 1mm, the plastic sheet 51a of brominated rate below 1 quality %, as long as the transmitance of the x-ray when thickness 0.5mm and brominated rate are 1 quality % is as determinating reference value.Now, in the thickness range of regulation (0.5mm is above less than 1mm), the transmitance of the x-ray of the plastic sheet 51b of (brominated rate is higher than 1 quality %) is inevitable below determinating reference value, can carry out the differentiation of plastic sheet 51a.

Equally, with regard to the thickness of plastic sheet more than 1mm less than with regard to 2mm, plastic sheet below the above 3mm of 2mm, as long as determinating reference value is made as respectively to thickness 1mm, 2mm and brominated rate is the transmitance of the x-ray of 1 quality %.Accordingly, in discriminating gear 56, can, for each thickness of thickness sorting, differentiate

plastic sheet

51a, 51b.

In addition, to use brominated rate be that the transmitance of the x-ray of 1 quality % is the reason based on following to above-mentioned determinating reference value.Through existing quality of material separator, be, with every 1000 ratios by a left and right, several～20 of the plastic sheet after sorting, to sneak into the plastic sheet that brominated rate exceedes 1 quality % to not meeting the result that the recycled resin of RoHS instruction investigates.From these plastic sheets by brominated rate exceed 1 quality % plastic sheet remove result be, recycled resin meets RoHS instruction, therefore, in the present embodiment, having adopted brominated rate as determinating reference value is the transmitance of the x-ray of 1 quality %.

Figure 17 be represent using the sorting unit of the plastics for implementing embodiments of the present invention 3 use as the use of the above-mentioned embodiment 1 shown in Fig. 3 the brominated plastics of x-ray remove the concrete example of the situation of the device of the concrete example of method.Basic structure itself does not change compared with the sorting unit of the plastics shown in Fig. 9, but contrast Fig. 3, change air cannon 57 into lower injecting type from upper injecting type, make also this some difference at the rear of band conveyor 53 of roentgen radiation x position, x-ray detection position and the demarcation of location based on air cannon 57.

According to present embodiment, there is the plastic sheet 51 of various thickness for each thickness sorting, then, to these plastic sheet 51 exposures, detect its transmitance for each thickness being sorted, the transmitance of this x-ray detecting and the determinating reference value based on thickness information are compared, differentiate, according to the result of differentiating, the plastic sheet 51a that contains the brominated flame retardant below setting is carried out to sorting, accordingly, prevent the misinterpretation take the thickness of plastic sheet 51 as cause, can carry out sorting with high sharpness of separation.Especially be low to moderate below 10 quality % with the containing ratio of brominated flame retardant, situation about only judging by the transmitance of x-ray is compared, due to the determinating reference value having used based on thickness information, so, can be with high sharpness of separation separating plastic sheet 51.

In addition, use and form the 65a of the portion that passes through, sorting plate 63a, the 63b of 65b that pass through less than the plastic sheet 51 of desirable thickness via thickness sorting portion 52, can carry out thickness sorting to the plastic sheet 51 with various thickness easily with simple structure.

In addition, owing to making sliding stand 61 tilt at length direction and width via thickness sorting portion 52, more plastic sheet 51, in inclined plane expansion, moves on sliding stand 61, so, can improve the thickness sorting precision of plastic sheet 51.

In addition, due to by being provided with vibrating device in thickness sorting portion 52, the plastic sheet 51 that has been applied in vibration becomes a scattered layer state, on sliding stand 61, move, so, can further improve the thickness sorting precision of plastic sheet 51.

In addition, downstream

equipment demarcation strip

64a, 64b by thickness sorting portion 52, the plastic sheet 51 having prevented by interim thickness sorting mixes again, can improve thickness sorting precision.

Embodiment 4.

Figure 15 is other the embodiment that represents thickness sorting portion in the present invention.In Figure 15, thickness sorting portion 70 is made up of following parts, , there is the first sliding stand 71a of inclination at length direction and width, , slide unit, be arranged on the side of the length direction of the first sliding stand 71a, and the supply port 75 in the highest position that tilts with supply plastic sheet is the sidewall 72a of supply unit, with the first sliding stand 71a plate in opposite directions 73 in opposite directions, be arranged on the second sliding stand 71b of the low side of the inclination of length direction of the first sliding stand 71a, be arranged on the sidewall 72b of the side of the length direction of the second sliding stand 71b, the demarcation strip 74 that is arranged on the inclined-plane of the second sliding stand 71b and for each thickness being sorted, plastic sheet 51 is separated.In addition, at the first sliding stand 71a, the vibrating device (not shown go out) that plastic sheet 51 is applied to vibration is set.

The inclination of plate 73 width compared with the first sliding stand 71a is large in opposite directions, and between is formed with the portion that passes through 76 passing through less than the plastic sheet 51 of desirable thickness, has the height of its width the closer to the wider wedge shape of the supply port 75 of plastic sheet.

In addition, the demarcation strip 74 being arranged on the inclined-plane of the second sliding stand 71b tilts to extend along it, prevents from again being mixed by portion 76 by the plastic sheet 51 of thickness sorting.

Then, action is described.

The plastic sheet with various thickness 51 that is supplied to the first sliding stand 71a from the supply port 75 of plastic sheet is applied vibration by vibrating device through the first sliding stand 71a, become a scattered layer state, the wedge shape that even plastic sheet 51 of thin thickness all forms along the width by portion 76 is to the low side shifting that tilts.And this plastic sheet 51 is pressed thickness order at width and is arranged, simultaneously respectively along moving by the second sliding stand 71b that is tilted to of portion 76.

The plastic sheet 51 having moved to the second sliding stand 71b and the thickness being sorted correspondingly on the inclined-plane being surrounded by sidewall 72b and demarcation strip 74 in the drawings the direction of arrow move, discharge to band conveyor 53.The plastic sheet 51 of discharging to band conveyor 53 is similarly sorted with embodiment 1 afterwards.

According to this embodiment, use at the first sliding stand 71a of length direction and width inclination and the plate in opposite directions 73 configuring in opposite directions with it by thickness sorting portion 70, the portion that passes through 76 that forms wedge shape at width, can carry out sorting to the thickness of plastic sheet easily with simple structure.Have again, because the thickness that carries out thickness sorting is by determining by the shape of portion 76, so, can elect 51 points of plastic sheets as multi-thickness with few number of spare parts.

Embodiment 5.

Figure 16 is other the other embodiment that represents the thickness sorting portion in the present invention.In Figure 16, thickness sorting portion 80 is made up of following parts, , there is the first sliding stand 81a of inclination at length direction and width, , slide unit, be arranged on the side of the length direction of the first sliding stand 81a, and there is in the highest position that tilts the supply port 85 of supplying with plastic sheet 51, , the sidewall 82a of supply unit, with the first sliding stand 81a plate in opposite directions 83 in opposite directions, be installed in the second sliding stand 81b of the low side of the inclination of length direction of the first sliding stand 81a, be arranged on the sidewall 82b of the side of the length direction of the second sliding stand 81b, the demarcation strip 84 that is arranged on the inclined-plane of the second sliding stand 81b and for each thickness being sorted, plastic sheet 51 is separated.In addition, the vibrating device (not shown go out) that plastic sheet 51 is applied to vibration is set on the first sliding stand 81a.

Plate 83 has stairstepping at width in opposite directions, and the first sliding stand 81a between mode to broaden near the side of the supply port 85 of plastic sheet, form the portion that passes through 86 that passes through less than the plastic sheet 51 of desirable thickness of making.

In addition, the demarcation strip 84 being arranged on the inclined-plane of the second sliding stand 81b tilts to extend along it, prevents from again being mixed by portion 86 by the plastic sheet 51 of thickness sorting.

Then, action is described.

The plastic sheet with various thickness 51 that is supplied to the first sliding stand 81a from the supply port 85 of plastic sheet is applied vibration by vibrating device through the first sliding stand 81a, become a scattered layer state, the stairstepping that even plastic sheet 51 of thin thickness all forms along the width by portion 86 is to the low side shifting that tilts.And the thickness order that this plastic sheet 51 is pressed end difference at width is arranged, simultaneously respectively along moving by the second sliding stand 81b that is tilted to of portion 86.

The plastic sheet 51 having moved to the second sliding stand 81b correspondingly moves along the direction of arrow in figure with the thickness being sorted on the inclined-plane being surrounded by sidewall 82b and demarcation strip 84, discharges to band conveyor 53.The plastic sheet 51 of having discharged to band conveyor 53 is similarly sorted with embodiment 1 afterwards.

According to this embodiment, use at the first sliding stand 81a of length direction and width inclination and the plate in opposite directions 83 configuring in opposite directions with it by thickness sorting portion 80, the portion that passes through 86 that forms stairstepping at width, can carry out sorting to the thickness of plastic sheet easily with simple structure.Have again, because the thickness that carries out thickness sorting is by determining by the shape of portion 86, so, can elect 51 points of plastic sheets as multi-thickness with few number of spare parts.

Symbol description

1: weigh feeder; 2: tank drifts along; 3: oar; 4: vibratory sieve; 5a～5b: auger conveyor; 6a～6b: outlet; 7: with the tank of pump; 8: co-grinding stream of plastic; 9: liquid medium; 10: floating sort stream; 11: liquid medium and sedimentation logistics; 12: sedimentation logistics; 13: the liquid medium stream being recovered; 21: conveyer; 22: pulverize plastics; 22a: brominated plastics; 22b: non-brominated plastics; 23: feedway; 24:X spool ball; 25:X thread detector; 26: data processing division; 27: distinguish mechanism; 28: the containing box of brominated plastics; 29: the containing box of non-brominated plastics; 30: weigh feeder; 31: friction belt torch; 32: electric field feeding device; 33a～33b: electrode in opposite directions; 34a～34b: power supply, 35a～35b: collection box; The mixture of 40:PS sheet and ABS sheet; 50: the sorting unit of plastics; 51: plastic sheet; 51a: the plastic sheet that contains the brominated flame retardant below setting; 51b: the plastic sheet that contains the brominated flame retardant more than setting; 52: thickness sorting portion; 53: band conveyor; 54:X line irradiation source; 55:X thread detector; 56: discriminating gear; 57: air cannon; 58a: returnable; 58b: returnable; 59: hopper; 61: sliding stand; 62a: sidewall; 62b: sidewall; 63a: sorting plate; 63b: sorting plate; 64a: demarcation strip; 64b: demarcation strip; 65a: by portion; 65b: by portion; 70: thickness sorting portion; 71a: the first sliding stand; 71b: the second sliding stand; 72a: sidewall; 72b: sidewall; 73: plate in opposite directions; 74: demarcation strip; 75: supply port; 76: by portion; 80: thickness sorting portion; 81a: the first sliding stand; 81b: the second sliding stand; 82a: sidewall; 82b: sidewall; 83: plate in opposite directions; 84: demarcation strip; 85: supply port; 86: by portion

Claims

1. a method for separating for plastics, is characterized in that, has:

The first gravity separation operation, it will distinguish than the light plastics of the first proportion threshold value P1 by differential-density saparation from co-grinding plastics;

Distribute according to the proportion of the light plastics of above-mentioned differentiation, determine the operation of the proportion threshold value P1 in above-mentioned the first gravity separation operation;

Brominated plastics are removed operation, it irradiates x-ray from x-ray source to the above-mentioned light plastics of being distinguished at the above-mentioned light plastics of being distinguished from conveyer is gone out, detect the x-ray that sees through from the above-mentioned light plastics of being distinguished by the x-ray detector that sees through being located at position in opposite directions, above-mentioned x-ray source, above-mentioned x-ray source and the above-mentioned rear that is disposed at above-mentioned conveyer through x-ray detector on carriage direction, according to the signal from data processing division, according to the existence of bromine whether, from the above-mentioned light plastics of being distinguished, brominated plastics are removed, above-mentioned data processing division is to the data analysis that sees through x-ray being detected, and the existence of differentiating the bromine in the above-mentioned light plastics of being distinguished whether, with

Electrostatic separation operation, it,, by electrostatic separation method, according to the material difference of plastics, is distinguished above-mentioned plastics.

2. a method for separating for plastics, is characterized in that, has:

The first gravity separation operation, it will distinguish than the light plastics of the first proportion threshold value P1 with than the heavy plastics of above-mentioned the first proportion threshold value P1 by differential-density saparation from co-grinding plastics;

Distribute according to the proportion of the light plastics of above-mentioned differentiation, determine the operation of above-mentioned the first proportion threshold value P1;

The second gravity separation operation, distinguishes its plastics that plastics lighter than the second proportion threshold value P2 weighed from above-mentioned the first proportion threshold value P1 of ratio distinguishing in above-mentioned the first gravity separation operation by differential-density saparation;

Distribute and be not the proportion of distinguishing the material of object according to the proportion of the light plastics of above-mentioned the second proportion threshold value P2 of ratio of distinguishing in above-mentioned the second gravity separation operation, determine the operation of above-mentioned the second proportion threshold value P2;

By electrostatic separation method, the electrostatic separation operation that the plastics of being distinguished by any one operation in above-mentioned the first and second gravity separation operations are distinguished according to the material difference of plastics; With

Brominated plastics are removed operation, it irradiates the x-ray from x-ray source from conveyer is gone out at the above-mentioned light plastics of being distinguished to the above-mentioned plastics of being distinguished, detect the x-ray that sees through from the above-mentioned plastics of being distinguished by the x-ray detector that sees through being located at position in opposite directions, above-mentioned x-ray source, above-mentioned x-ray source and the above-mentioned rear that is disposed at above-mentioned conveyer through x-ray detector on carriage direction, according to the signal from data processing division, according to the existence of bromine whether, brominated plastics are removed from the above-mentioned plastics of being distinguished, above-mentioned data processing division is to the data analysis that sees through x-ray being detected, and the existence of differentiating the bromine in the above-mentioned plastics of being distinguished whether.

3. the sorting unit of plastics, it is characterized in that, comprise: for the thickness sorting member of each thickness sorting plastic sheet, to by this thickness sorting member sorting the irradiation member of plastic sheet exposure and the detection means detecting having seen through the transmitance of x-ray of the above-mentioned plastic sheet being sorted, and the sorting unit of these plastics is according to the thickness data separating plastic sheet in data and the above-mentioned thickness sorting member of x-ray that sees through being detected by this detection means.

4. the sorting unit of plastics as claimed in claim 3, it is characterized in that, according to the thickness data in data and the above-mentioned thickness sorting member of x-ray that sees through being detected by above-mentioned detection means, for each thickness being sorted, the plastic sheet to the transmitance of x-ray below setting carries out sorting.

5. the sorting unit of plastics as claimed in claim 3, it is characterized in that, above-mentioned thickness sorting member have from the supply side of plastic sheet towards discharge the inclined plane of side and intersects at least on one point with the incline direction on this inclined plane and from the supply side of above-mentioned plastic sheet towards the sorting portion material of discharging side and arranging, the plastic sheet of the not enough thickness stipulating passes through between above-mentioned inclined plane and above-mentioned sorting portion material.

6. the sorting unit of plastics as claimed in claim 3, is characterized in that, above-mentioned thickness sorting member is provided with vibrating mechanism.

7. a method for separating for plastics, is characterized in that, has:

Brominated plastics are removed operation, it irradiates the x-ray from x-ray source to the above-mentioned light plastics of being distinguished, detect the x-ray that sees through from the above-mentioned light plastics of being distinguished by seeing through x-ray detector, according to the signal from data processing division, according to the existence of bromine whether, from the above-mentioned light plastics of being distinguished, brominated plastics are removed, above-mentioned data processing division sees through the data analysis of x-ray to what be detected, and the existence of differentiating the bromine in the above-mentioned light plastics of being distinguished whether; With

Electrostatic separation operation, it,, by electrostatic separation method, according to the material difference of plastics, is distinguished above-mentioned plastics, wherein,

The method for separating of these plastics possesses the sorting unit of following plastics, the sorting unit of these plastics comprises: the detection means detecting for the thickness sorting member of each thickness sorting plastic sheet, to the irradiation member of the plastic sheet exposure by this thickness sorting member sorting with to having seen through the transmitance of x-ray of the above-mentioned plastic sheet being sorted, and the sorting unit of these plastics is according to the thickness data separating plastic sheet in data and the above-mentioned thickness sorting member of x-ray that sees through being detected by this detection means.

8. a method for separating for plastics, is characterized in that, has:

According to distributing at the proportion of above-mentioned the second gravity separation operation plastics that distinguish, lighter than above-mentioned the second proportion threshold value P2 and not being the proportion of distinguishing the material of object, determine the operation of above-mentioned the second proportion threshold value P2;

Brominated plastics are removed operation, it irradiates the x-ray from x-ray source to the above-mentioned plastics of being distinguished, detect the x-ray that sees through from the above-mentioned plastics of being distinguished by seeing through x-ray detector, according to the signal from data processing division, according to the existence of bromine whether, brominated plastics are removed from the above-mentioned plastics of being distinguished, above-mentioned data processing division is to the data analysis that sees through x-ray being detected, and the existence of differentiating the bromine in the above-mentioned plastics of being distinguished whether, wherein