Source: https://patents.justia.com/patent/6254712
Timestamp: 2019-10-17 00:55:13
Document Index: 219773255

Matched Legal Cases: ['ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1', 'ARTS 1']

US Patent for Extrusion coating process for making high transparency protective and decorative films Patent (Patent # 6,254,712 issued July 3, 2001) - Justia Patents Search
Justia Patents By ExtrusionUS Patent for Extrusion coating process for making high transparency protective and decorative films Patent (Patent # 6,254,712)
Extrusion coating process for making high transparency protective and decorative films
Feb 24, 1999 - Avery Dennison Corporation
INGREDIENTS PARTS* 1 Kynar 720 65.00 Polyvinylidene fluoride (PVDE) Atochem North America, Inc. 2 Elvacite 2042 35.0 Polyethyl methacrylate (PEMA) E. I. DuPont (sold to ICI) 3 Tinuvin 234 2.0 UV stabilizer Hydroxyphenylbenzotriazole Ciba-Geigy *In this and other examples, “Parts” identified for each component are on a parts per weight basis.
Kynar 720 is the extrusion grade PVDF homopolymer corresponding to Kynar 301F that is commonly used in a solvent cast PVDF/acrylic formulation. Kynar 720 has a melting temperature of about 167° C., a Tg of about −38 to −41° C., and a melt viscosity at 215° C. (measured in Pas·sec at shear rates of 100,500 and 1,000 sec−1) of 1,153, 470 and 312, respectively. (Melt viscosity in the examples herein is measured at an extrusion device temperature of 215° C. (355° F.) when operated at shear rates of 100, 500 and 1,000 sec−1.) Elvacite 2042 is a polyethyl methacrylate (PEMA) which is compatible with PVDF and is the same acrylic used in the standard solvent cast Avloy® clear coat; this formulation was selected to simulate the formulation of the standard Avloy® clear coat. (Avloy is a trademark of Avery Dennison Corporation, the assignee of this application.)
INGREDIENTS PARTS 1 Kynar 720 70.0 Polyvinylidene fluoride (PVDE) Elf Atochem North America 2 VS100 30.0 Polymethyl methacrylate (PMMA) Atohaas 3 Cyasorb P 2098 2.0 UV stabilizer (pph) 2 hydroxy-4-acrylooxyethoxybenzophenone Cytec
The pellets were extrusion coated on a 1.42 mil high gloss silicone coated PET designated Hostaphan 1545. (The extruded material had a melt viscosity (Pas·sec) at 100, 500 and 1,000 sec−1 of about 803-829, 373-376 and 248-250, respectively.) The polyester carrier provides a smooth glossy surface upon which the hot extrudate can form a thin clear film ranging from about 0.1 mil to about 2-3 mils thick. The thickness of the resulting clear films are adjustable by the extrusion coating line speed and the screw speed of the extruder, as described previously. In this example a 6.0 inch extruder with a single flight screw was used to extrusion coat a one mil thick PVDF/acrylic clear topcoat onto the polyester carrier. The compounded pellets were dried at 130° F. for two hours prior to being fed into the extruder. The extruder had eleven heating zones set at: (1) 380° F., (2) 370° F., (3) 340° F., (4) 340° F., (5) 340° F., (6) 340° F., (7) flange 340° F., (8) adapter 1 (340° F.), (8) adapter 2 (340° F.), (9) pipe 350° F., (10) end cap 100° F., and (11) die 350-365° F.; the die was a T-slot and had five zones: (1) 365°, (2) 360°, (3) 350°, (4) 360°, and (5) 365°. The die temperature profile was used to maintain uniform melt flow across the die. The screw speed was held at 15 rpm and line speed was 170 ft/min. The high gloss chill roll was maintained at 60° F. for the entire run. A harder durometer and smaller diameter nip roll produced the highest nip pressure and the highest gloss finished film. A 200 mesh welded screen pack was used to clean the melt stream. At these settings a clear one mil thick film was produced with a corresponding weight of 38 gm/m2. The finished film was a high gloss film. No corona treatment was used.
SIZE COAT FORMULATION INGREDIENTS PARTS 1 Xylene 61.0 2 Acrylic resin 29.0 3 MEK 10.0
INGREDIENTS PARTS 1 Kynar 720 60.0 Polyvinylidene fluoride (PVDE) Elf Atochem North America 2 VS100 40.0 Polymethyl methacrylate (PMMA) Atohaas 3 Tinuvin 234 2.0 UV stabilizer (pph) Hydroxyphenylbenzotriazole Ciba-Geigy
RED AVLOY ® COLOR COAT INGREDIENTS PARTS 1 Clear vehicle for Avloy ® color coat 74.32 2 DPP Red BO 460-36351 11.26 3 Magenta D-60 dispersions 7.47 4 93 exterior white 0.07 5 D-60 violet dispersions 1.88 6 Methyl propyl ketone 2.50 7 Cyclohexanone 2.50
INGREDIENTS PARTS 1 Kynar 720 65.0 Polyvinylidene fluoride (PVDE) Elf Atochem North America 2 VS100 35.0 Polymethyl methacrylate (PMMA) Atohaas 3 Tinuvin 234 2.0 UV stabilizer Hydroxyphenylbenzotriazole Ciba-Geigy
INGREDIENTS PARTS 1 N-methyl pyrollidone 38.00 2 Elvacite 2042 4.06 3 Kynar 10052 12.00
INGREDIENTS PARTS 1 Black dispersion-GCW #428-A056 20.00 2 N-methyl pyrrolidone 8.3 3 Exterior white 0.54 4 MEK 15.7
INGREDIENTS PARTS 1 Kynar 2850 60.0 Polyvinylidene difluoride (PVDF) Elf Atochem North America 2 VS100 40.0 Polymethyl methacrylate (PMMA) Rohm and Haas 3 Tinuvin 234 2.0 UV stabilizer (pph) Ciba-Geigy
The formulation was compounded using a twin screw extruder to obtain uniform blended pellets. The two resins were dried before being extruded into pellets. During the extrusion process a vacuum vent in the compression zone of the screw was used to further remove moisture and other volatile components. The heating zones of the extruder were set at (1) 100° F., (2) 380° F., (3) 380° F., (4) 385° F., (5) 385° F., (6) 385° F. and (7) 385° F. The crew was maintained at 70 rpm. The melt temperature of this formulation was maintained at 380° F. and a screen pack consisting of three different wire meshes (20, 40 and 60) was used to clean the melt stream. This material was pelletized and extrusion coated on two mil high gloss Hostaphan 2000 polyester carrier film. The hot extrudate can form a thin clear film ranging from 0.1 mil to 2 mils thick. (The extruded material had a melt viscosity (Pas·sec) at 100, 500 and 1,000 sec−1 of about 888, 405 and 266, respectively; a melting temperature of about 147° C., and a Tg of about 23-33° C.) While faster line speeds result in a thinner film, faster screw speeds result in thicker films. In this example a 1.75 inch lab extruder was used to extrusion coat a one mil PVDF copolymer/acrylic clear topcoat onto a two mil high gloss polyester carrier.
The compounded pellets were dried at 150° F. for two hours prior to being fed into the extruder. The extruder had ten heating zones which were set at (1) 330° F., (2) 380° F., (3) 380° F., (4) 405° F., (5) 415° F./clamp, (6) 420° F./tube, (7) 420° F., (8) 420° F., (9) 420° F. and (10) 406° F./die; the die was coat hanger and the melt was maintained at 434° F. The screw speed was held at 166 rpm with a corresponding line speed of 150 ft/min. The high gloss chill roll setting was maintained at 70° F. for the entire run. A welded screen pack was used to clean the melt stream. At these settings the one mil clear coat had a weight of 38 gm/m2. The finished film was high gloss, but had some microgels and some small contaminants were observed. The defects were not objectionable in finished parts. No corona treatment was used.
ADAPTER FLANGE Coextrusion 1 2 3 4 5 1 2 3 4 5 6 A1 A2 Mixer Slide block INITIAL 435 435 410 450 450 480 460 411 450 445 450 400 400 410 400 400 FINAL 430 410 420 409 404 480 470 430 450 460 460 400 400 480 450 400
Die Temp. 440° F. all zones Melt Temp. 408° F. Line Speed 39.8 ft/min Screw -- Ext. A LD ratio 24:1 Screw -- Ext. B LD ratio 32:1 Screen pack at breaker A = 2,40 mesh screens plate B = 3 @ 20, 40 & 60 mesh screens Polished roll temperature START END TOP 170 170 MIDDLE 150 150 BOTTOM 145 180
START END Screw speed (rpm) A 8.4 6.5 B 64.2 7.5 Back pressure (psi) A 3,010 2,920 B 4,240 4,390 Coextruder thickness (mil) A layer 2.5 1.5 B layer 27.5 28.5
INGREDIENTS PARTS 1 Kynar 720 48.0 Polyvinylidene fluoride Atochem 2 Jet Black No. 1 20.0 Copper. chromate black spinel The Shepherd Color Company 3 VS100 32.0 Polymethyl methacrylate (PMMA) Atohaas
The material used for this trial comprised Kynar 720 PVDF/VS100 PMMA/Tinuvin 234 UV stabilizer in a 60:40:[2 pph] blend. The process described above for making PVDF/acrylic pellets with minimal exposure to heat was used to prepare the starting material. The extruder comprised an Egan six-inch single screw, single flight extruder. The distance between the extruder outlet and the extruder exit opening was less than about two feet, and a screen pack using 20/40/60/80/100 mesh screens was interposed between the extruder outlet and the die inlet opening. An extruded clear film coating approximately one mil in thickness was extruded at a web width of 51 inches onto a traveling PET carrier film. Initial start-up was begun utilizing the Kynar/acrylic blend. The extrusion profile was 450° F. to facilitate screw coating at low amps. Once the polymer flow was established, the barrel temperatures were reduced and the coating process was begun on a poly-coated paper substrate to assist in gauge setup. After gauging was sufficient, the PET substrate was begun. The extruder was operated at a low rpm to prepare a total of 13,000 feet of film. Several trials were conducted. In one set of trials, extruder rotation was 24 rpm in order to produce the greatest line speed of 157 ft/min. Other trials were conducted at 19 rpm to produce a line speed of 126 ft/min and at 15 rpm to produce a line speed of 100 ft/min. Melt pressure of the extruded material varied from 830 psi for the 24 rpm operation to 730 psi for the 15 rpm operation. The chill roll temperature was maintained at 75° F. in all trials. Extruder die zone temperature varied from about 400° to 430° F. during the trials and barrel zone temperature varied from about 350° to 375° F. In all trials that were conducted, essentially zero defects were produced in the extruded films, resulting in a film having excellent optical clarity with the requisite quality attributes for exterior automotive use.
Melt Viscosities (Pas · Sec) at 215° C. vs. Shear Rates (sec−1) 100 500 1000 PVDF 1125-1300 450-525 300-350 Acrylic 900-1000 400-450 225-300 Blended PVDF/Acrylic 725-925 275-425 175-300
Barrel 1 360 Barrel 2 375 Barrel 3 375 Barrel 4 375 Barrel 5 375 Barrel 6 375 Flange 400 Adapter 1 400 Adapter 2 400 Downspout 400 Die 1 430 Die 2 400 Die 3 400 Die 4 400 Die 5 430
RPM 25 Line speed (ft/sec) 170 Melt psi 540 Amps 239 Melt Temp (° F.) 402 Corona treater off Chill Roll Temp (° F.) 61
An extruded transparent clear coat film is made by the process of Example 16, with the following modifications. The extruder was a 3.5-inch, 32:1 L:D Black Clawson with a twin flight barrier screw, operated at moderate compression in the range of 3:1 to 3.5:1. This example has shown that improvements in extrusion coating are produced with a moderate compression ratio in the range of about 2.5:1 to about 5:1, and preferably about 3:1 to about 4:1. An advantage of this extruder is reduced feed surging, resulting in a more stable melt and output from the extruder, which in turn yields a flatter web profile in the machine and cross web directions. The 3.5-inch extruder with the low shear moderate compression ratio barrier screw provided an excellent balance in output, residence time and shear with the added benefit of reduced web profile variation when compared with the 6-inch single flight screw of Example 16. Surging and down web variation was reduced from ±25 percent or more from nominal output to less than 5 percent total variation from nominal—less than the gauge noise level on single scans using an NDC Beta gauge device. Output with the twin flight moderate compression ratio barrier screw was equal to the 6-inch single flight screw of Example 16, yielding an ability to run a 56-inch wide coating at 38 gsm nominal thickness at line speeds greater than 300 fpm.
Extruder A (ABS) - Melt Temp (° F.) Barrel Zone 1 435 Barrel Zone 2 450 Barrel Zone 3 300 Barrel Zone 4 240 Barrel Zone 5 320 SC Body 400 Gate 400 Cyl. 400 Free 400 Die 1 403 Die 2 407 Die 3 400 Die 4 400 Die 5 400 Extruder B (ABS) - Melt Temp (° F.) Barrel Zone 1 490 Barrel Zone 2 510 Barrel Zone 3 200 Barrel Zone 4 490 SC Body 450 Tube 1 450 Tube 2 450 Adapter 1 400 Adapter 2 420 RPM 100 Drive amps 200 Back pressure (psi) 4,000 RPM 21 Drive amps 61 Back pressure (psi) 4,000 Top calender roll temp (° F.) 130 Middle roll 180 Bottom roll 140 Line speed (fpm) 60
Extruder A B C Extruder size (in.) 1 ¾ 1 Resin TPO CPO Acrylic Zone 1 (° F.) 380 284 390 Zone 2 (° F.) 410 329 450 Zone 3 (° F.) 410 374 450 Melt T (° F.) 435 422 Pressure (psi) 4,000 1,131 5,000 Rpm 105 50 8
1. A process for extruding a high transparency clear film from a particulate resinous starting material, comprising the steps of:
providing a solventless resinous starting material in particulate form essentially free of contaminants above about 10 microns in size, the resinous material contained in a sealed container to prevent introduction of contaminants from the ambient environment;
conveying said resinous material from the sealed container to an extrusion apparatus in a closed airflow transport system in which transport air for conveying said resinous material is subjected to high efficiency filtration to prevent introduction of contaminants above about 10 microns in size from the ambient environment into the airflow that transports the resinous material to the extrusion apparatus; and
extruding the resinous material via the extrusion apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants, in which the resinous material is extrusion coated onto a traveling polymeric carrier sheet, and in which opposite sides of the carrier sheet contact tacky roll web cleaners for removing airborne particles from the carrier sheet before and after extrusion coating.
2. The process according to claim 1 in which the starting material is essentially free of particulate contaminants above about 10 microns in size, in which the sealed container prevents introduction of airborne contaminants from the ambient environment, and in which the transport air for conveying the resinous material is subjected to high efficiency particulate air (HEPA) filtration that produces HEPA filtered transport air to prevent introduction of airborne contaminants, having a particle size as low as 10 microns in size, from the ambient environment into the air flow that transports the resinous material to the extrusion apparatus.
4. Apparatus according to claim 2 including extruding the resinous material via the extruding apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants, wherein the finished film is extruded to a film thickness in the range of about one to about three mils, and in which the extruded clear coat film has an average defect level of three or less defects for an extruded one mil thick film over measured average area of 1,248 sq. inches, in which measurable defect size is in the range of about 0.4 to about 1.0 mm 2.
7. The process according to claim 1 in which the extruded clear coat film has an average defect level of 3 or less defects for an extruded one mil thick film over a measured average area of 1,248 sq. inches in which measurable defect size is in the range of about 0.4 to 1.0 mm 2.
extruding the resinous material via the extrusion apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants, in which the resinous material is extrusion coated onto a polymeric carrier sheet, and including neutralizing static electric charges on the carrier sheet to remove attracted airborne particles from the carrier sheet prior to extrusion coating.
14. The process according to claim 13 in which the starting material is essentially free of particulate contaminants above about 10 microns in size, in which the sealed container prevents introduction of airborne contaminants from the ambient environment, and in which the transport air for conveying the resinous material is subjected to high efficiency particulate air (HEPA) filtration that produces HEPA filtered transport air to prevent introduction of airborne contaminants, having a particle size as low as 10 microns in size, from the ambient environment into the air flow that transports the resinous material to the extrusion apparatus.
16. Apparatus according to claim 14 including extruding the resinous material via the extruding apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants, wherein the finished film is extruded to a film thickness in the range of about one to about three mils, and in which the extruded clear coat film has an average defect level of three or less defects for an extruded one mil thick film over measured average area of 1,248 sq. inches, in which measurable defect size is in the range of about 0.4 to about 1.0 mm 2.
18. The process according to claim 13 in which the extruded clear coat film has an average defect level of 3 or less defects for an extruded one mil thick film over a measured average area of 1,248 sq. inches in which measurable defect size is in the range of about 0.4 to 1.0 mm 2.
extruding the resinous material via the extrusion apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants, in which the transporting and extruding steps are carried out in a high efficiency air filtered clean room environment which exceeds a class 10,000 rating.
25. The process according to claim 24 in which the vicinity of the extrusion die is contained within a clean room environment which exceeds a class 2,000 rating.
preparing the resinous starting material in a high efficiency air filtered clean room environment which exceeds a class 10,000 rating;
extruding the resinous material via the extrusion apparatus to form a transparent extruded clear coat film essentially free of such filtered contaminants.
3880690 April 1975 Fuchs et al.
4121535 October 24, 1978 Roberts, Jr. et al.
4268464 May 19, 1981 Yoshino et al.
4364886 December 21, 1982 Strassel
4415519 November 15, 1983 Strassel
4440702 April 3, 1984 Susnjara
4500706 February 19, 1985 Mathis et al.
4585701 April 29, 1986 Bartoszek et al.
4810540 March 7, 1989 Ellison et al.
4832991 May 23, 1989 Hayward et al.
4854995 August 8, 1989 Kasper et al.
4877683 October 31, 1989 Bragaw, Jr. et al.
4902557 February 20, 1990 Rohrbacher
4931324 June 5, 1990 Ellison et al.
4936936 June 26, 1990 Rohrbacher
4959189 September 25, 1990 Rohrbacher et al.
4985284 January 15, 1991 Shibata et al.
5030394 July 9, 1991 Sietses et al.
5164245 November 17, 1992 Suzuki
5223311 June 29, 1993 Tsutsumi et al.
5455073 October 3, 1995 Dethlefs et al.
5707697 January 13, 1998 Spain et al.
5985079 November 16, 1999 Ellison
4228194 A1 March 1994 DE
0 137 581 A1 April 1985 EP
0 356 924 A2 March 1990 EP
02165149 June 1990 EP
0 547 506 A1 June 1993 EP
1 225 438 March 1971 GB
2084513 April 1982 GB
61-8349 January 1986 JP
62-138213 June 1987 JP
11536 June 1994 JP
WO9403337 February 1994 WO
“Long-Term Photoprotection of Polymers by Coextrusion with PVDF” by Albert Strassel, 1989.
Patent number: 6254712
Inventors: Howard H. Enlow (Munster, IN), John J. Markey (Crown Point, IN), John E. Roys (Lowell, IN), Keith L. Truog (Crown Point, IN), Frederick Young (Schererville, IN)
Application Number: 09/256,967
Current U.S. Class: By Extrusion (156/244.11); Pretreatment (156/244.23); Running Or Continuous Webs Of Indefinite Length (156/324); Shaping By Extrusion (264/176.1); Application To Opposite Sides Of Sheet, Web, Or Strip (excluding Processes Where All Coating Is By Immersion) (427/209)
International Classification: B29C/3100; B29C/4700;