US007802685B2
`
`(12) United States Patent
`Allen et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,802,685 B2
`Sep. 28, 2010
`
`(54) MULTISTEP SEPARATION OF PLASTICS
`
`(75) Inventors: Laurence E. Allen, San Rafael, CA
`(US); Brian L. Riise, Richmond, CA
`(US); Paul C. Allen, El Cerrito, CA
`(US); Ron C. Rau, Oakland, CA (US);
`Michael B. Biddle, El Cerrito, CA (US)
`
`(73) Assignee: Mes Polymers, Inc., Richmond, CA
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 1353 days.
`
`(21) Appl. No.:
`
`10/511,224
`
`(22) PCT Filed:
`
`Apr. 14, 2003
`
`(86). PCT No.:
`
`PCT/USO3A11642
`
`S371 (c)(1)
`Jun. 28, 2005
`(2), (4) Date:
`(87) PCT Pub. No.: WO03/086733
`
`PCT Pub. Date: Oct. 23, 2003
`
`(65)
`
`Prior Publication Data
`
`US 2006/OOO1187 A1
`
`Jan. 5, 2006
`
`Related U.S. Application Data
`(60) Provisional application No. 60/372,001, filed on Apr.
`12, 2002, provisional application No. 60/397.948,
`filed on Jul. 22, 2002, provisional application No.
`60/397,808, filed O Jul. 22, 2002, provisional appli-
`cation No. 60/397,953, filed on Jul. 22, 2002, provi-
`sional application No. 60/397.980, filed on Jul. 22,
`2002.
`
`(51) Int. Cl.
`B04B 5/10
`B07B I5/00
`BO3C 7700
`
`(2006.01)
`(2006.01)
`(2006.01)
`
`(52) U.S. Cl. .................... 209/12.1: 209/127.1: 209/930
`(58) Field of Classification Search ................ 209/12.1,
`209/12.2, 127.1, 127.4, 128,930
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`5,131,212 A
`7/1992 Grey et al.
`5,314,071 A * 5/1994 Christian et al. ............... 209/4
`5,895,790 A
`4, 1999 Good
`6,007,005 A * 12/1999 G les et al. .............. 241.20
`6,090,862 A
`T/2000 E.
`6.1440 A
`9, 2000 Doonan
`6,274.637 B1
`8/2001 Schallenberg
`6,335,376 B1* 1/2002 Allen et al. ................ 521,405
`6,452,126 B1* 9/2002 Xiao et al.
`... 209,127.1
`6,460,788 B1 * 10/2002 de Feraudy .................. 241/19
`6,689,838 B1
`2/2004 Fischer et al.
`7,014, 132 B2* 3/2006 Vandeputte .................. 241.20
`7,037,951 B2
`5/2006 Inagaki
`2004.0004033 A1
`1/2004 Vandeputte
`2004/0164005 A1
`8/2004 Allen, III
`20040182753 A1
`9/2004 Allen, III et al.
`
`FOREIGN PATENT DOCUMENTS
`40 20417 A
`1, 1992
`44 24 143 A 11, 1996
`O761T63. A
`3, 1997
`197 15418. A 10, 1998
`19744964 A
`4f1999
`O 634 260 A2
`1, 1995
`O 696 618 A
`2, 1996
`O 756. 238 A1
`1, 1997
`o 5. A1
`is:
`07.05043 A
`5, 1995
`O7-334583
`12/1995
`08-25.9747 A
`2, 1997
`10-225934
`8, 1998
`2001-323121
`11, 2001
`2002-088212
`3, 2002
`2002-292628
`10, 2002
`WO98/03318
`1, 1998
`WO99,25493 A
`5, 1999
`WOO1,81058 A 11, 2001
`WOO3,087.215
`10, 2003
`
`DE
`DE
`DE
`DE
`DE
`EP
`EP
`EP
`F.
`JP
`JP
`JP
`JP
`JP
`JP
`JP
`WO
`WO
`WO
`WO
`
`crplastics
`>.18)
`
`8a .2S
`
`ads at .
`-Y
`
`| grwcpcs.)
`
`offi)
`
`
`
`C
`
`ESD2
`
`E83
`
`E.
`
`Drc"-ikto
`3D.IXs
`
`ABSFR-rich
`to TsI24-36
`
`cHIPsrR
`product
`
`CARSRR and
`'P' enriched to
`as C3-c.
`
`EPL LIMITED EX1017
`U.S. Patent No. 10,889,093
`
`0001
`
`

`

`US 7,802,685 B2
`Page 2
`
`(57)
`
`ABSTRACT
`
`Multistep recycling processes for preparing recycled plastic
`materials. The processes feature a sequence of operations
`selected from the group consisting of preprocessing opera
`tions, size reduction operations, gravity concentration opera
`tions, color sorting, sorting by thickness, friction, or differ
`ential terminal Velocity or drag in air, Surface to mass control
`operations, separation processes enhanced by narrow Surface
`to mass distributions, blending operations, and extrusion and
`compounding operations. Plastic-rich mixtures are Subjected
`to the process, and one or more recycled plastic materials are
`collected as outputs of the sequence of processes.
`
`P-R->
`
`/ B->E->dark PP product
`
`PP-rich
`
`C
`B->E->light PP grade 1
`NTF
`- B->E->light PP grade 2
`
`1, 2004
`WO WO 2004/009200 A1
`1, 2004
`WO WO 2004/009242 A1
`WO WO 2005,123817 A1 12/2005
`OTHER PUBLICATIONS
`D. E. Karvelas et al., “Separation and Recovery of Thermoplastics by
`Froth Floatation”, Nov. 9-11, 1999, 6' Annual Recycling Conference
`Proceedings Book, Detroit, Michigan, pp. 233-237.
`European Search Report for Application No. EP 09 177754.0, dated
`Jan. 20, 2010, 4 pages.
`Notice for Reasons for Rejection for Application No. JP 2003
`583720, dated Jun. 16, 2009, 11 pages.
`First Examination Report for Application No. IN 2533/CHFNP/
`2004, dated Aug. 21, 2009, 2 pages.
`Notification of the First Office Action for Application No. CN
`03813514.0, dated May 25, 2007, 4 pages.
`Notification of the Second Office Action for Application No. CN
`03813514.0, dated Aug. 15, 2008, 4 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Dec. 20, 2004, 5 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Jul 14, 2005, 5 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Nov. 25, 2005, 4 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Jun. 1, 2006, 5 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Oct. 12, 2006, 5 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Dec. 27, 2006, 5 pages.
`Communication pursuant to Article 96(2) EPC for Application No.
`EP 03746 760.2, dated Jul. 20, 2007, 5 pages.
`Communication pursuant to Article 9(3) EPC for Application No. EP
`03 746 760.2, dated Mar. 10, 2008, 7 pages.
`Communication pursuant to Article 94(3) EPC for Application No.
`EP 03746 760.2, dated Jul. 16, 2008, 4 pages.
`Communication pursuant to Article 94(3) EPC for Application No.
`EP 03746 760.2, dated Mar. 16, 2009, 2 pages.
`* cited by examiner
`Primary Examiner John Q Nguyen
`Assistant Examiner—Mark Hageman
`(74) Attorney, Agent, or Firm Fish & Richardson P.C.
`
`W ABS and
`HIPS rich
`
`i?/
`N
`
`suc-MK
`SMC-SMK B->E->light HIPS grade 2
`SMC-SMIC B->E->dark HIPS
`
`B->E->light ABS grade 1
`
`B->E->light HIPS grade 1
`B->E->light ABS grade 2
`
`B->E->dark ABS
`
`42 Claims, 25 Drawing Sheets
`
`0002
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 1 of 25
`
`US 7,802,685 B2
`
`Size
`(<75 mm)
`
`Size
`(<30 mm)
`
`Size
`(<20 mm)
`
`Size TV
`(<8 mm)
`
`FIG.1
`
`
`
`O
`
`a
`
`X
`
`we with
`
`as as a
`
`2EP=0.016
`
`1.02
`
`1.03
`
`O —
`1.04
`1.05
`1.06 1.07 1.08
`separation density
`
`FIG.2
`
`0003
`
`

`

`U.S. Patent
`U.S. Patent
`
`Sep. 28, 2010
`Sep. 28, 2010
`
`Sheet 2 of 25
`Sheet 2 of 25
`
`US 7,802,685 B2
`US 7,802,685 B2
`
`C
`
`FIG. 3
`FIG._3
`
`A
`A
`
`
`, \/|\
`Fo s/ \
`
`B
`B
`
`FIG. 4
`FIG._4
`
`0004
`
`0004
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 3 of 25
`
`US 7,802,685 B2
`
`pure A
`
`A+B+ some C
`-- trace metal
`
`B+. Some A
`
`metal
`
`B+ remaining C
`
`FIG. 5
`
`
`
`
`
`
`
`
`
`oversize thick flakes
`
`fines
`
`Air aspirator or
`screening
`
`Separation process
`dependent on S/M
`
`FIG. 6
`
`0005
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 4 of 25
`
`US 7,802,685 B2
`
`L
`
`qrparticle charge
`EFvoltage/plate separation
`m particle mass
`ggravitational acceleration
`
`FIG. 7
`
`
`
`FIG. 8
`
`0006
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 5 Of 25
`
`US 7,802,685 B2
`
`H
`
`L
`
`
`
`low S/m
`
`intermediate
`S/m
`
`
`
`high S/m
`
`0007
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 6 of 25
`
`US 7,802,685 B2
`
`low S/m feed
`w
`
`high S/m feed
`W
`
`--
`
`
`
`
`
`-
`
`IX
`X
`X
`X
`X
`
`FIG 11
`
`
`
`Direction of product
`Flow
`-->
`
`X
`X
`X
`X
`X
`X = Optional trapdoor or diverter
`
`FIG. 12
`
`0008
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 7 Of 25
`
`US 7,802,685 B2
`
`
`
`Byproduct
`8 &
`containing C
`
`A-rich
`Product
`product
`
`B-rich
`Product
`product
`
`Byproduct
`containing D
`
`FIG. 13
`
`P ). R D W ) C D R ). SMC ) SMD D B D E
`
`FIG. 14
`
`P · R ). TF ) W D C ) SMC ) SMD ) B ) E
`
`FIG.15
`
`P ). C C) R ) W ) SMC ) SMD ) B > E
`
`FIG. 16
`
`0009
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 8 of 25
`
`US 7,802,685 B2
`
`P d R ). W ) C ) TF d SMC ) SMD ) B ) E
`
`FIG.17
`
`P C) R D W D C ) B D E
`
`FIG. 18
`
`P D) R ). W ) C ) SMC ) SMD D C ) B ) E
`
`FIG. 19
`
`P ). R D SMC ) SMD ) B > E
`
`FIG. 20
`
`P ad R D W D SMC ) SMD DW D B O E
`
`FIG 21
`
`P } R ). SMC d SMD ) W D B > E
`
`FIG.22
`
`0010
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 9 Of 25
`
`US 7,802,685 B2
`
`P D R D W D C D R D SMC ) SMD » E
`
`FIG. 23
`
`P D R D W D C ) R O SMC O SMD ) B
`
`FIG.24A
`
`P ). R D W ) C D R D SMD D B D E
`
`FIG.24B
`
`0011
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 10 of 25
`
`US 7,802,685 B2
`
`PP
`PP
`PP
`PP
`PP
`PP
`PP, ABS, HIPS
`PP, ABS, HIPS
`PP, ABS, HIPS
`PP, ABS, HIPS
`
`P G R ). W G TF
`P } R )W ) TF C
`P ) C ) Rid W 3 TF
`P C ) Red W ) TF 3 C
`P d C D R ) W ) SMC ) SMD d C
`P ) R ). W G SMC ) SMD
`P } R ). SMC d SMD W dC
`P ) Rid SMC Gd SMD d W
`P d C ) R ). SMC ) SMD >W C
`P d C ) R ). SMC ) SMD W
`P d W - C - RC) SMC ) SMD - W - C
`P G W ) C R ). SMC ) SMD d W
`Pre W red R ). SMC G) SMD d W - C
`P d W G R ). SMC ) SMD d W
`P d W ) Red W ) SMC ) SMD) W ) C
`P DW d R ) W ) SMC) SMD d W
`P ad W 3 Rad W 3 SMC d SMD d W ) C
`P d R ). We SMC ) SMD d C
`P d R ) W SMC d SMD
`
`POW ) R W ) SMC Gd SMD
`
`ABS, HIPS
`(truncated cone metal remove)
`ABS, HIPS
`(pregrind elutriation)
`ABS, HIPS
`(final grade bracketing)
`P ). SMC ) R ) W ) SMC ) SMD - C
`P C) SMC ) R ). W G SMC ) SMD
`P d SMC ) Red W - SMC ) SMD ) C
`
`P Cod Red W 3 SMC ) SMD 0 W
`
`FIG.24C
`
`0012
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 11 of 25
`
`US 7,802,685 B2
`
`P D C ) R ). W
`
`P D R O W ) SMC
`
`W D) SMC ) SMD D W
`
`W ) SMC ) SMD
`
`R D W O SMC ) SMD
`
`R ) W ) SMC ) SMD d W
`
`R - W d SMC ) SMD
`
`C ) R D W ) SMC DSMD
`
`C ) R ). W D SMC ) SMD
`
`FIG.24D
`
`0013
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 12 of 25
`
`US 7,802,685 B2
`
`C
`
`- re- E - dark PP product
`Bid E ) light PP grade 1
`B > Es) light PP grade 2
`
`PP-ri
`
`-
`
`P · R ). W
`
`ABS and
`HPS rich
`
`a
`B - E > light ABS grade 1
`
`SMC)SMD
`-Y
`YAB > E-) light HIPS grade 1
`C C) "S,
`B > End light ABS grade 2
`SMC-SMDY
`AB ) E-) light HIPS grade 2
`
`B - E - dark ABS
`SMC->SMD-1
`aB 3 E3 dark HIPS
`
`FIG. 25
`
`100%
`
`
`
`90% - Overal
`1/2-3/4" (thick)
`1/2-3/4" (thin)
`A 3/8-1/2" (thick)
`a 3/8-1/2" (thin)
`
`80%
`
`70%
`O
`
`0.02
`
`0.04
`
`0.08
`0.06
`velocity (m/s)
`
`0.1
`
`0.12
`
`0.14
`
`FIG. 26
`
`0014
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 13 Of 25
`
`US 7,802,685 B2
`
`100%
`
`3 75%
`
`d
`
`50%
`
`dry (1/4")
`- - - - wet (6 mm)
`
`d
`
`s
`
`D 25%
`
`0%
`O
`
`2
`
`6
`4.
`round role screen size (m)
`
`8
`
`FIG. 27
`
`as
`S
`
`60%
`
`
`
`40%
`
`20%
`
`0%
`
`<1.04
`
`104-
`1.05
`
`1.06-
`1.05-
`1.07
`1.06
`density range
`
`>1.08
`
`1.07-
`1.08
`
`FIG. 28
`
`0015
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 14 of 25
`
`US 7,802,685 B2
`
`100%
`
`75%
`
`5 O %
`
`0.00
`
`0.02
`
`0.04
`
`0.08
`0.06
`velocity (m/s)
`
`0.0
`
`0.12
`
`0.14
`
`FIG. 29
`
`
`
`
`
`6 O %
`
`
`
`50%
`
`
`
`40%
`O
`
`-o-light product
`- - - - heavy product
`
`...
`
`0.02
`
`0.04
`
`0.08
`0.06
`velocity (m/s)
`
`0.1
`
`0.12
`
`0.14
`
`FIG. 30
`
`0016
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 15 Of 25
`
`US 7,802,685 B2
`
`5
`8
`9.
`&
`z
`
`3. d
`
`S
`
`1060-1.065 1.065-1070 1070-1.075 1075-1.080 1080-1.085 1.085-1.11
`density range
`
`pro
`
`O.2S
`
`
`
`2
`e
`
`O.15
`
`.
`
`O.S
`
`O
`
`O k14"
`O 1 fa-33
`D 38-12
`
`.
`
`2
`
`.3
`
`.
`
`0.5
`
`O.
`
`0.7
`
`D.B.
`
`FIG. 32
`
`0017
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 16 of 25
`
`US 7,802,685 B2
`
`Plastic
`sheet
`
`chute
`
`O
`
`Accumulation here
`
`60%
`
`
`
`2 O %
`
`FIG.33
`
`particle size (cm)
`
`FIG. 34
`
`0018
`
`

`

`U.S. Patent
`U.S. Patent
`
`Sep. 28, 2010
`Sep. 28, 2010
`
`Sheet 17 of 25
`Sheet 17 Of 25
`
`US 7,802,685 B2
`US 7,802,685 B2
`
`100%
`100%
`
`80%
`80%
`
`60%
`60%
`
`40%
`40%
`
`100%
`
`
`
`80%
`
`60%
`
`40%
`
`20%
`
`%belowS/V
`%belowS/V
`
`0% is
`
`S/V (cm-1)
`
`FIG. 36
`FIG._36
`
`0019
`
`0019
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 18 of 25
`
`US 7,802,685 B2
`
`
`
`0.8
`
`0.6
`0.4
`
`2
`
`S
`S 0.2
`i
`
`O
`
`- - - H(cumulative)
`
`:
`
`<2.4 mm
`
`2.4-3.2 mm
`thickness range
`
`>3.2 m
`
`FIG 38
`
`20
`
`10
`
`FIG. 39
`
`0020
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 19 Of 25
`
`US 7,802,685 B2
`
`1.0000%
`
`r
`
`0.1000%
`
`O
`A.
`2 0.01.00%
`A 0.0010%
`O
`SS
`
`0.0001%
`0%
`
`- l stage
`2 stage
`- - 3 stage
`
`25%
`
`50%
`% FR in Feed
`
`75%
`
`100%
`
`FIG. 40
`
`
`
`PC/ABS-FR
`PC/ABS
`
`0021
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 20 of 25
`
`US 7,802,685 B2
`
`C+ plastics
`(p>1.10)
`
`DPDS at 1.25
`
`DPDS at 1.17
`
`Eplastics
`(e.g. PVC, POM)
`POMfille)
`
`
`
`plastics
`
`
`
`plastics
`
`D'PC-rich to
`TESD7-D9
`
`DABSFR-rich
`to TESD4-D6
`
`CHIPS-FR
`product
`
`CABSFR and
`"PC enriched to
`TES C3-C11
`
`FIG. 42
`
`0022
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 21 of 25
`
`US 7,802,685 B2
`
`D ABSFR
`rich
`from
`
`negative
`BP
`
`D ABSFR
`product
`
`DPC-rich
`BP
`
`FIG.43A
`
`6PC2
`D
`rich from
`
`
`
`ABSFR
`enriched
`BP
`
`D (PC?
`product
`
`FIG.43B
`
`0023
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 22 of 25
`
`US 7,802,685 B2
`
`(PC?'
`C ABSFR and
`enriched from TES C1
`
`T
`ES C3
`
`
`
`C ABS-
`ER
`product
`
`
`
`C 66 PC2- C
`rich BP
`ABSFR-
`rich BP
`FIG. 44
`
`C (PC)
`product
`
`0024
`
`

`

`U.S. Patent
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`Sep. 28, 2010
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`Sheet 23 of 25
`
`US 7,802,685 B2
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`C Stream HPSFR
`C Stream "PC"
`ED Stream "PC"
`DC Stream ABSFR
`D Stream ABSFR
`Byproducts
`
`FIG. 45
`
`100.00%
`
`
`
`10.00%
`g
`
`a 1.00%
`
`s
`
`0.10%
`
`0.01%
`
`is
`
`reas
`
`m
`
`O C Stream HPSFR
`C Stream "PC"
`D Stream "PC"
`C Stream ABSFR
`D Stream ABSFR
`
`number of TES stages
`
`FIG. 46
`
`0025
`
`

`

`U.S. Patent
`
`Sep. 28, 2010
`
`Sheet 24 of 25
`
`US 7,802,685 B2
`
`C Stream HPSFR
`C Stream "PC"
`C. Stream ABSFR
`Byproducts
`
`
`
`ABS-FR
`st ABS-FR
`ABS-FR
`
`FIG. 48
`
`0026
`
`

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`U.S. Patent
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`Sep. 28, 2010
`
`Sheet 25 Of 25
`
`US 7,802,685 B2
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`100,000%
`
`10,000%
`1.000%
`0.100%
`
`0.010%
`
`e
`
`e
`
`0.00%
`O
`
`3
`2
`number of TES stages
`
`4.
`
`FIG. 49
`
`
`
`
`
`PCII
`PC II
`EPC
`PCIABS-FR III
`PC/ABS-FR II
`PC/ABS-FR
`PC/ABS II
`PC/ABS II
`PC/ABSI
`
`FIG.50
`
`0027
`
`

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`US 7,802,685 B2
`
`1.
`MULTISTEP SEPARATION OF PLASTICS
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims the benefit of Provisional Applica
`tion Ser. Nos. 60/372,001, filed Apr. 12, 2002, 60/397.948,
`filed Jul 22, 2002, 60/397,808, filed Jul 22, 2002, 60/397,
`953, filed Jul 22, 2002 and 60/397,980, filed Jul 22, 2002
`which are incorporated by reference herein. This application
`is also related to International Application Serial No. PCT/
`US03/11602, titled “Compositions of Materials Containing
`Recycled Plastics' to L. E. Allen, III, B. L. Riise, Ron C. Rau
`and Michael B. Biddle, filed on Apr. 14, 2003, which is also
`incorporated by reference herein.
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`TECHNICAL FIELD
`
`This invention relates to recycling plastics.
`
`BACKGROUND
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`2
`reinforcements, and pigments; metal; paint and metallic coat
`ings; and highly variable part sizes and shapes.
`A grade of plastic is a formulation of plastic material with
`a particular set of targeted physical characteristics or proper
`ties. The particular physical characteristics or properties of a
`grade are controlled by the chemical composition of the poly
`mers in the grade, the average molecular weights and molecu
`lar weight distributions of polymers in the grade, the rubber
`morphology for impact modified grades, and the group of
`additives in the grade.
`Different grades of a given plastic type are generally com
`patible. Grades can generally be melt mixed to create a new
`material with a different property profile.
`Different plastic types, on the other hand, cannot generally
`be melt combined as easily unless the types happen to be
`compatible. Blending different plastic types such as HIPS and
`ABS is often avoided except in special situations.
`Typical Suppliers of plastics-rich feed stocks are metal
`recyclers or shredders who can process a number of types of
`durable goods in a single facility. Feedstocks derived from
`durable goods can therefore be highly variable mixtures of
`different types of durable goods.
`In order to create high value products, the plastic recycling
`process must be able to separate highly mixed streams on a
`flake-by-flake basis to achieve high throughput rates of prod
`ucts with acceptable purity. Methods such as separation by
`density, Density Differential Alteration, froth flotation, color
`sorting and triboelectrostatic separation (TES), have been
`used to achieve some purification of the plastics derived from
`durable goods, as described, for example, in Paul Allen,
`Development of Hydrocyclones for Use in Plastics Recy
`cling, American Plastics Council, 1999, U.S. Pat. No. 6,238,
`579, U.S. Pat. No. 6,335,376, U.S. Pat. No. 5,653,867, and
`U.S. Pat. No. 5,399.433, each of which is incorporated by
`reference herein. The acceptable purity depends on the pri
`mary plastic and contaminants.
`
`SUMMARY
`
`The invention provides processes and apparatus imple
`menting techniques for separating plastics with multiple pro
`cessing steps. In general, in one aspect, the invention provides
`method for defining recycling processes. The methods
`include defining an arrangement of four or more different
`processes to be used to prepare a recycled plastic product. The
`processes of the arrangement are selected from the group
`consisting of preprocessing operations, size reduction opera
`tions, gravity concentration operations, color sorting, sorting
`by thickness, friction, or differential terminal velocity or drag
`in air, Surface to mass control operations, separation pro
`cesses enhanced by narrow surface to mass distributions,
`blending operations, and extrusion and compounding opera
`tions. The four or more processes are selected and arranged
`based on one or more properties of the plastic rich mixture to
`be separated and/or one or more desired properties of a
`recycled plastic material to be prepared from the waste plastic
`material.
`In general, in another aspect, the invention provides plas
`tics recycling processes. The processes include Subjecting a
`plastic-rich mixture to a sequence of processes selected from
`the group consisting of preprocessing operations, size reduc
`tion operations, gravity concentration operations, color sort
`ing, Sorting by thickness, friction, or differential buoyancy in
`air, Surface to mass control operations, separation processes
`enhanced by narrow Surface to mass distributions, blending
`
`By generating over 10 of millions metric tons of material,
`hundreds of billions of dollars of production per year, and
`being responsible for approximately millions of jobs, plastics
`and related businesses represent the fourth largest industry in
`the United States. Unlike other material industries such as
`steel and aluminum, however, this industry depends almost
`solely on nonrenewable raw material, mostly imported petro
`leum. This dependence becomes even more significant as the
`growth rate of plastics continues to outpace that of all other
`materials.
`Most of the plastic supplied by today's manufacturers ends
`its life in landfills or incinerators simply because the technol
`ogy has not been available to recover it economically. The
`Environmental Protection Agency estimates that the amount
`of plastic in municipal Solid waste grew from less than 1
`million metric tons prior to 1960 to over 20 million metric
`tons by 2000. Take-back and producer-responsibility legisla
`tion is becoming increasingly common to help deal with the
`quantities of plastics being produced.
`Durable goods, such as automobiles, appliances and elec
`tronics equipment, account for about one-third of the plastics
`in municipal Solid waste. Durable goods are increasingly
`being collected and partially recycled at the end of their useful
`lives to avoid disposal costs and potential liabilities, and to
`recover metals and other marketable raw materials.
`The recovery of plastics from durable goods requires a
`plastic-rich raw material. Automobiles, appliances and elec
`tronics generally contain metals. Generally, the metals con
`tent is higher than the plastics content (typically plastics
`content is less than 30%) in these items, so a metal recovery
`operation must precede plastic recovery. Most metal recovery
`operations shred equipment in order to cost-effectively liber
`ate metals from whole parts. Large-scale plastic recovery
`operations must be able to source this plastic-rich raw mate
`rial from a number of metal recovery operations.
`Most plastic parts coming from durable goods streams
`present unique challenges that are not met by the plastics
`bottle cleaning and Sorting processes developed for curbside
`feedstocks. The principle practice today for the recovery of
`highly contaminated Scrap is hand-separation done overseas
`at significant local environmental cost. The challenges in
`recycling plastics from durable goods include: multiple plas
`tic types, multiple resin grades of plastic (there can be over 50
`different grades of one plastic resin type such as ABS); fillers,
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`US 7,802,685 B2
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`operations, and extrusion and compounding operations, and
`collecting a recycled plastic material as an output of the
`sequence of processes.
`Particular implementations can include one or more of the
`following features. The sequence of processes can be defined
`based on one or more properties of the plastic-rich mixture
`and/or one or more desired properties of the recycled plastic
`material. Subjecting the plastic-rich mixture to a sequence of
`processes can include separating the plastic-rich mixture into
`different grades of plastic material. Subjecting the plastic
`rich mixture to a sequence of processes can include separat
`ing the plastic-rich mixture into different types of plastic
`material. The process can include selecting the plastic-rich
`mixture from a source selected from the group consisting of
`white goods, office automation equipment, consumer elec
`tronics, automotive shredder residue, packaging waste,
`household waste, building waste, industrial molding and
`extrusion scrap according to one or more desired properties of
`the recycled plastic material. The process can include select
`ing the plastic-rich mixture based on a geographic location of
`origin of the plastic-rich mixture according to one or more
`desired properties of the recycled plastic material. One or
`more of the processes can be repeated in the sequence of
`processes. Subjecting the plastic-rich mixture to a sequence
`of processes can include blending two or more materials to
`obtain a desired property in the recycled plastic material.
`Subjecting the plastic-rich mixture to a sequence of processes
`can include compounding the recycled plastic material with
`one or more additives. Collecting a recycled plastic material
`as an output of the sequence of processes can include collect
`ing a plurality of recycled plastic materials. Subjecting the
`plastic-rich mixture to a sequence of processes can include
`reducing the average size of plastic particles in the sequence
`of processes from about 75 mm to less than about 8 mm. The
`average size of plastic particles in the sequence of processes
`is reduced over a plurality of processes in the sequence of
`processes.
`In general, in another aspect, the invention provides appa
`ratus for recycling waste plastic materials. The apparatus
`includes three or more devices configured to perform the
`processes described herein.
`In general, in another aspect, the invention provides plastic
`recycling processes for recovery of purified or enriched plas
`tics. The purified or enriched plastics are recovered from
`Sources including one or more of office automation equip
`ment, white goods, consumer electronics, automotive shred
`der residue, packaging waste, household waste, building
`waste, industrial molding and extrusion scrap.
`In general in another aspect, the invention provides plastic
`recycling processes and apparatus implementing four or
`more, six or more, operations selected from pre-processing
`operations, size reduction operations, gravity concentration
`operations, color Sorting operations, sorting by thickness,
`friction, or differential terminal velocity or drag in air, surface
`to mass control operations, separation processes enhanced by
`narrow Surface to mass distributions, such as triboelectric
`sorting, blending, extrusion and compounding.
`Particular implementations can include one or more of the
`following features. The operations can include size reduction
`of particles from less than about 75 mm in size to less than
`about 8 mm in size. The size reduction can be performed in
`one or more steps. The size reduction can be performed in two
`or more steps.
`In general, in still another aspect, the invention provides
`pre-processing processes and apparatus for use in separation
`of plastic materials. The pre-processing processes and appa
`ratus are configured to implement one or more operations
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`selected from metal removal, removal of fluff, foam and/or
`paper, removal of rubber, removal of wires, removal of non
`target plastics, size reduction, blending, and optical sorting.
`Particular implementations can include one or more of the
`following features. Non-target materials can be eliminated
`from further processing. Materials that may damage or cause
`excessive wear to size reduction equipment can be removed.
`Bulk density of plastics in the mixture can be increased.
`Compositional variability with time or feed source can be
`reduced.
`In general, in still another aspect, the invention provides
`size reduction processes and apparatus for use in separation
`of plastic materials. The size reduction processes and appa
`ratus feature one or more of size reduction equipment for
`performing dry or wet granulation, equipment for removal of
`fines, dust and liberated paper, film or foam, or size screening
`into two or more fractions to enhance removal of fines, dust
`and liberated paper, film or foam.
`In general, in still another aspect, the invention provides
`gravity concentration processes and apparatus for use in sepa
`ration of plastic materials. The gravity concentration pro
`cesses and apparatus are configured to employ one or more
`hydrocyclones, or modified hydrocyclones, cyvors, truncated
`cones, or wet elutriation devices.
`In general, in still another aspect, the invention provides
`separation processes and apparatus employing solid particle
`media with precise particle size control. The use of solid
`particle media provides for more precise and sharp separation
`by density, or for more consistent separation.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing metal removal
`and/or removal of non-target plastics employing one or more
`truncated cones.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus employing an arrangement of
`two consecutive gravity concentration devices. The devices
`can be hydrocyclones or cyvors. The separation is performed
`at an elevated density using a dense media slurry. The density
`of the slurry flowing to the first device is controlled by the
`media concentration in a tank. The overflow from the first
`device is sent to the second device such that the density of the
`slurry flowing to the second device is controlled by the sepa
`ration characteristics of the first device. The underflow from
`the first device is enriched in plastics more dense than the
`density of the separation in the first device. The overflow from
`the second device is enriched in plastics less dense than the
`density of the separation in the second device. The underflow
`from the second device is enriched in plastics more dense than
`the density of the separation in the second device.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus employing an arrangement of
`three gravity concentration devices. The overflow from the
`first device is sent to a second device. The underflow from the
`first device is sent to a third device. The devices can be
`hydrocyclones or cyvors. In particular implementations, the
`second and third devices are cyvors. The underflow from the
`second device is returned to the feed to the first device. The
`overflow from the third device is returned to the feed to the
`first device. The overflow from the second device is a product
`enriched in plastics less dense than the separation density.
`The underflow from the third device is a product enriched in
`plastics more dense than the separation density. The devices
`may be at the density of water or the density may be increased
`by the addition of dense media or by adding a solute (e.g., salt)
`to the media.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing wet elutriation
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`US 7,802,685 B2
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`5
`operations to accomplish the separation of low density plas
`tics from high density plastics.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus employing an arrangement of
`three consecutive gravity concentration devices. The first
`device can be a modified hydrocyclone for removal of metal.
`The second device can be a modified hydrocyclone for
`removal of high density plastics. The second device can be a
`hydrocyclone for the separation of low and medium density
`plastics.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing precise gravity
`concentration separation to create a stream enriched in HIPS
`and a stream enriched in ABS and SAN.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing precise gravity
`concentration separation to create product streams enriched
`in particular grades of the same plastic type. The separation
`processes and apparatus can be operable to separate ABS into
`a higher density product enriched in ABS from a first source,
`Such as refrigerators, and a lower density product enriched in
`ABS from a second source, such as office automation equip
`ment.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing wet elutriation
`to sort by color.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing wet elutriation
`to stabilize the color composition in order to enable or
`improve the effectiveness of color sorting and/or to stabilize
`the color of a final recycled plastic material.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing color sorting
`using a belt sorter or sliding chute color sorter. In particular
`implementations a belt sorter is used for flakes larger than
`about 10 mm, while a sliding chute color sorter is used for
`flakes between about 6 mm and about 12 mm.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing color Sorting to
`remove dissimilar plastics from the waste plastic stream.
`In general, the invention provides separation processes and
`apparatus configured to sort waste plastic material by thick
`ness or friction. In particular implementations, the thickness
`or friction sorting is performed on particles between about 4
`and about 20 mm. The thickness or friction sorting can be
`performed for rubber removal.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus configured with a sliding
`chute device for removal of rubber.
`In general, in still another aspect, the invention provides
`separation processes and apparatus implementing thickness
`or friction sorting to purify plastics by type. In particular
`implementations, the thickness or friction Sorting can be used
`to purify HIPS by removing PP. ABS, general purpose PS,
`and contaminants. In other implementations the thickness or
`friction sorting can be used to purify ABS by removing SAN,
`HIPS, and contaminants.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing thickness or
`friction Sorting to purify plastics by color.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing Surface to mass
`control to enable processes which are improved by a narrow
`Surface to mass distribution.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing Surface to mass
`control. The Surface to mass control is accomplished using
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`size reduction, air aspiration, Sorting using thickness or fric
`tion, a slot thickness Sorter, such as a roll sorter, or a combi
`nation thereof.
`In general, in another aspect, the invention provides sepa
`ration processes and apparatus implementing tribelectrostatic
`separation on one or