Source: http://www.google.com/patents/US20060068215?ie=ISO-8859-1
Timestamp: 2014-08-22 15:12:00
Document Index: 777407144

Matched Legal Cases: ['Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10', 'Application No. 10']

Patent US20060068215 - Improved variegated composites and related methods of manufacture - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsAbstract of the Disclosure Embodiments of the invention include a composite. The composite includes a crystalline polymer, a plurality of wood fibers blended with the crystalline polymer, an outer surface, and an amorphous polymer visible on the outer surface. The amorphous polymer has a first color...http://www.google.com/patents/US20060068215?utm_source=gb-gplus-sharePatent US20060068215 - Improved variegated composites and related methods of manufactureAdvanced Patent SearchPublication numberUS20060068215 A2Publication typeApplicationApplication numberUS 11/094,795Publication dateMar 30, 2006Filing dateMar 31, 2005Priority dateJun 8, 2004Also published asUS7410687, US20050271872, US20050271889, US20070087180, US20070087181Publication number094795, 11094795, US 2006/0068215 A2, US 2006/068215 A2, US 20060068215 A2, US 20060068215A2, US 2006068215 A2, US 2006068215A2, US-A2-20060068215, US-A2-2006068215, US2006/0068215A2, US2006/068215A2, US20060068215 A2, US20060068215A2, US2006068215 A2, US2006068215A2InventorsBlair DolinarOriginal AssigneeTrex Company, Inc.Export CitationBiBTeX, EndNote, RefManReferenced by (6), Classifications (6), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetImproved variegated composites and related methods of manufactureUS 20060068215 A2Abstract Abstract of the Disclosure
a plurality of wood fibers dispersed in the first polymer;
a second polymer adapted to not blend substantially with the first polymer;
wherein the first polymer and the second polymer form a pattern on the outer surface of the composite.
2. The composite of claim 1, wherein the first polymer further comprises at least one of polypropylene and polyethylene.
3. The composite of claim 1, wherein the second polymer further comprises at least one of a polymethylmethacrylate, an alphamethylstyrene acrylonitrile, and a polycarbonate.
4. The composite of claim 1, wherein the outer surface includes streaks of the second polymer.
5. The composite of claim 1, wherein the first polymer has a melting temperature that is substantially the same as a melting temperature of the second polymer.
6. The composite of claim 1, wherein the outer surface is variegated.
7. The composite of claim 1, wherein a first portion of the outer surface has a first color and a second portion of the outer surface has a second color.
8. The composite of claim 1, further comprising a third polymer configured to resist blending with the first polymer;
wherein the composite is manufactured such that the third polymer is deliberately visible on the outer surface,
wherein the third polymer has a third color different from the first polymer and the second polymer.
10. The composite of claim 1, further comprising a colorant blended with one of the first polymer and the second polymer.
11. A method of manufacturing a wood-plastic composite, comprising:
providing a first polymer;
providing a plurality of wood fibers;
providing a second polymer not substantially soluble in the first polymer;
melting the first polymer;
blending the first polymer and the plurality of wood fibers to form a blend;
adding the second polymer in an unmelted state to the blend to form a feed; and
forming a profile body from the feed, the profile body further comprising a pattern formed by the first polymer and the second polymer.
12. The method of claim 11, further comprising forming streaks of the second polymer on the outer surface.
13. The method of claim 11, further comprising forming streaks of the first polymer on the outer surface.
14. The method of claim 11, further comprising shifting the second polymer towards the outer surface.
15. The method of claim 11, further comprising variegating the outer surface.
16. The method of claim 11, further comprising providing at least one of a single screw extruder and a double screw extruder,
wherein the step of extruding includes extruding the feed via the at least one of the single-screw extruder and the double screw extruder.
17. The method of claim 11, wherein the step of mixing includes forming a first color from the second polymer and forming the second color from a blend of the first polymer and the plurality of wood fibers.
18. The method of claim 11, further comprising providing a third polymer not substantially soluble in the first polymer;
adding the third polymer in an unmelted state to the blend to form the feed,
wherein the pattern is formed by the first polymer, the second polymer, and the third polymer.
19. The method of claim 11, further comprising providing a core,
wherein the step of forming the profile body includes forming the profile body around at least a portion of the core.
20. The method of claim 11, further comprising providing a colorant; and
blending the colorant with one of the first polymer and the second polymer.
21. The composite of claim 1, wherein the first polymer has a first color and the second polymer has a second color.
22. The composite of claim 1, wherein the second polymer is not substantially soluble in the first polymer.
23. The method of claim 11, wherein the first polymer has a first color and the second polymer has a second color.
24. The method of claim 11, wherein the second polymer is not substantially soluble in the first polymer.
25. A composite, comprising:
a first polymer comprising polyethylene;
a second polymer comprising polyethylene;
26. The composite of claim 25, wherein the plurality of wood fibers comprise about 38% of the composite by weight.
27. The composite of claim 25, wherein the plurality of wood fibers are configured to pass through a size 30 mesh or smaller sieve.
28. The composite of claim 25, wherein the second polymer includes a polycarbonate.
29. The composite of claim 25, wherein at least one of the first polymer and the second polymer has a melting temperature of about 132�.
30. The composite of claim 25, wherein at least one of the first polymer and the second polymer comprise between about 53% and about 55% of the composite by weight.
31. The composite of claim 25, wherein the second polymer comprise about 2% of the composite by weight.
32. A composite, comprising:
a second polymer comprising polypropylene;
33. The composite of claim 32, wherein the plurality of wood fibers comprise about 38% of the composite by weight.
34. The composite of claim 32, wherein the plurality of wood fibers are configured to pass through a size 30 mesh or smaller sieve.
35. The composite of claim 32, wherein the polypropylene is one of a polypropylene homo polymer and a polypropylene co-polymer.
36. The composite of claim 32, wherein at least one of the first polymer and the second polymer has a melting temperature of about 132�.
37. The composite of claim 32, wherein at least one of the first polymer and the second polymer comprise between about 53% and about 55% of the composite by weight.
38. The composite of claim 32, wherein the second polymer comprises about 2% of the composite by weight.
39. The composite of claim 1, wherein the second polymer further comprises at least one of polypropylene and polyethylene.
40. The composite of claim 1, wherein both the first polymer and the second polymer each further comprise at least one of polypropylene and polyethylene.
41. A method of manufacturing a wood-plastic composite, comprising:
mixing the first polymer, the plurality of wood fibers, and the second polymer to form a feed; and
42. The method of claim 41, further comprising forming streaks of the second polymer on the outer surface.
43. The method of claim 41, further comprising forming streaks of the first polymer on the outer surface.
44. The method of claim 41, further comprising shifting the second polymer towards the outer surface.
45. The method of claim 41, further comprising variegating the outer surface.
46. The method of claim 41, further comprising providing at least one of a single screw extruder and a double screw extruder,
47. The method of claim 41, wherein the step of mixing includes forming a first color from the second polymer and forming the second color from a blend of the first polymer and the plurality of wood fibers.
48. The method of claim 41, further comprising providing a third polymer not substantially soluble in the first polymer;
adding the third polymer in an unmelted state to the feed,
49. The method of claim 41, further comprising providing a core,
50. The method of claim 41, further comprising providing a colorant; and
51. The method of claim 41, further comprising mixing the first polymer and the plurality of wood fibers and then adding the second polymer.
52. The method of claim 41, further comprising mixing the first polymer and the second polymer and then adding the plurality of wood fibers.
53. The method of claim 41, further comprising mixing the second polymer and the plurality of wood fibers and then adding the first polymer.
54. The method of claim 41, further comprising blending the first polymer and the plurality of wood fibers and then adding the second polymer.
55. The method of claim 41, further comprising blending the second polymer and the plurality of wood fibers and then adding the first polymer.
56. The composite of claim 25, wherein the polyethylene is at least one of a high density polyethylene and a low density polyethylene.
57. The composite of claim 32, wherein the polyethylene is at least one of a high density polyethylene and a low density polyethylene.
58. The composite of claim 25, wherein the pattern is a natural, wood-like pattern.
59. The composite of claim 32, wherein the pattern is a natural, wood-like pattern.
60. The composite of claim 25, wherein the pattern is a splotchy pattern.
61. The composite of claim 32, wherein the pattern is a splotchy pattern.
Detailed Description of the Invention CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part application of U.S. Patent Application No. 10/862,448, filed June 8, 2004, by Blair Dolinar for VARIEGATED COMPOSITES AND RELATED METHODS OF MANUFACTURING, the entirety of which is incorporated herein by reference.
A more environmentally friendly alternative to using wooden components in manufacturing decks and related assemblies is to use a wood-plastic composite made of crystalline polymers. Examples of suitable wood-plastic composites made of crystalline polymers and related methods of manufacture are disclosed in co-owned U.S. Patent Nos. 5,851,469 and 6,527,532, co-pending and co-owned U.S. Patent Application No. 10/292,672 filed November 12, 2002, and co-pending and co-owned U.S. Patent Application No. 10/668,368 filed September 24, 2003, the entirety of all of which are incorporated herein by reference.
SUMMARY OF THE INVENTION An exemplary embodiment of the invention includes a composite. The composite comprises a crystalline polymer, a plurality of wood fibers blended with the crystalline polymer, an outer surface, and an amorphous polymer visible on the outer surface. The amorphous polymer has a first color and the blend of the crystalline polymer and the plurality of wood fibers has a second color different from the first color.
Fig. 4D is a schematic view of a process of manufacturing a composite according to a still further embodiment of the invention.
Fig. 4E is a schematic view of a side feeder used in the process of Fig. 4D.
Composite 1 may include a first polymer 2 which may be a crystalline polymer 2. Crystalline polymer 2 is preferably at least one of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and polypropylene (PP). The polypropylene may be a homo- and/or a co-polymer polypropylene. However, any crystalline polymer may be used, such as one or more polyamides (PA), nylons, polyoxymethylenes, polybutylene terephthalates (PBT), polyethylene terephthalates (PET), and/or acetals. Crystalline polymer 2 may have any suitable size, shape, and/or configuration to be melted, mixed with wood fibers 3, and/or extruded into a dimensionally stable profile. Crystalline polymer 2 may have any suitable size, shape, and/or configuration to be used in any of the apparatuses or methods disclosed in co-owned U.S. Patent Nos. 5,851,469 and 6,527,532, co-pending and co-owned U.S. Patent Application No. 10/292,672 filed November 12, 2002, and co-pending and co-owned U.S. Patent Application No. 10/668,368 filed September 24, 2003, the entirety of all of which are incorporated herein by reference. For example, crystalline polymer 2 may be in the form of a pellet, a flake, a film, and/or a scrap form. In another example, crystalline polymer 2 may range in size from reactor powder having a diameter of about 0.01650 inches to pieces of plastic having dimensions (e.g., length, width, height, depth, and/or diameter) between about 1 inch and about 100 feet. More typically, however, crystalline polymer 2 is film scrap having dimensions (e.g., length, width, height, depth, and/or diameter) between about 0.0787 inches and 0.25 inches.
Composite 1 may include a second polymer 6 which may be an amorphous polymer 6, a polycarbonate (PC), a polymer 6 that has a higher shear viscosity than first polymer 2 and/or crystalline polymer 2, and/or a polymer 6 configured to mix with but resist blending with first polymer 2 and/or crystalline polymer 2. A polycarbonate is a crystalline polymer that may be used as a second polymer 6 because it may have desirable properties relative to other crystalline polymers that may be used as first polymers 2. For example, PC may char while other crystalline polymers may burn. In another example, PC may have a sufficiently higher shear viscosity relative to other crystalline polymers. In various embodiments, using a PC as second polymer 6 in the apparatuses and methods disclosed herein will provide the same results (e.g., a composite 1 with a variegated outer surface 5 and/or streaks 16) as the use of an amorphous polymer 6. Accordingly, PC may be used interchangeably with amorphous polymer 6 in any of the embodiments set forth herein.
Amorphous polymer 6 is preferably a styrenic polymer such as polystrene (PS). However, any amorphous polymer may be used in composite 1, such as one or more of Impact PS, polymethylmethacrylates (PMMA), polyvinyl chlorides (PVC), acrylonitrile-butadine-styrene copolymers (ABS), thermoplastic polyurethanes (TPU), styrene acrylonitrile copolymers (SAN), polyphenyl oxide (PPO), acryla-styrene butyl-acrylate or acrylate styrene acrylonitrile (either of which may be abbreviated as ASA), and/or alphamethylstyrene acrylonitrile (AMSAN). In a preferred embodiment, any one or combination of ABS, PC, AMSAN, and/or PMMA may be used. Amorphous polymer 6 may have any suitable size, shape, and/or configuration. For example, amorphous polymer 6 may be in the form of pellets and/or flakes. In a preferred embodiment, amorphous polymer 6 has a high polarity and/or decreased melt flow relative to crystalline polymer 2. The size of the amorphous polymer 6 used may be dependent on these and other properties of amorphous polymer 6. For example, amorphous polymer 6 may be a substantially solid chunk having dimensions (e.g., length, width, diameter, depth, and/or height) between about 0.25 inches and 0.0165 inches or may have a substantially spherical shape having an average diameter of about 0.0165 inches.
Second polymer 6 may resist blending with first polymer 2 (e.g., second polymer 6 may not be soluble in first polymer 2 and vice versa). For example, if second polymer 6 is an amorphous polymer and first polymer 2 is a crystalline polymer, even when both polymers are in a melted state, the two polymers may resist blending with each other. Thus, while second polymer 6 may be somewhat dispersed throughout crystalline polymer 2, second polymer 6 may not be evenly distributed or blended throughout crystalline polymer 2 (e.g., amorphous polymer 6 may migrate to the outer surface 5). Accordingly, second polymer 6 may form �clumps� and/or �pockets� in crystalline polymer 2, and thus regions of second polymer 6 may be clearly discernible in the otherwise substantially homogenous blend of crystalline polymer 2 and wood fibers 3. For example, second polymer 6 may have a different color and/or consistency than any combination of crystalline polymer 2 and wood fibers 3.
Composite 1 may have a variegated outer surface 5 (i.e., a first portion of outer surface 5 may have a first color and a second portion of outer surface 5 may have a second color different from the first color). For example, outer surface 5 may include streaks 16. Streaks 16 may run in any direction, may have any size and/or shape, may be disposed in and/or on any portion of composite 1, may have any configuration, and/or may have a color different from the rest of composite 1. For example, streaks 16 may assist composite 1 in obtaining a more aesthetically pleasing wood-like appearance. Streaks 16 are preferably present toward outer surface 5. Any surface of composite 1, for example inner surfaces of composite 1, may have streaks 16. Variegated outer surface 5 and/or streaks 16 may provide composite 1 with a more natural wood-like appearance and/or make variegated outer surface 5 look more three-dimensional.
Due to the properties of any second polymer 6 set forth herein, and especially with regard to its possible tendency to resist blending with crystalline polymers, second polymer 6 may be responsible for streaks 16 on outer surface 5 of composite 1. For example, when melted and mixed with crystalline polymer 2 and wood fiber blend, second polymer 6 may be dispersed in the blend (e.g., mixed but not blended with the blend) such that streaks 16 correspond to the location of amorphous polymer 6. As shown in Fig. 3A, second polymer 6 is preferably disposed toward outer surface 5 of composite 1.
Second polymer 6 may have a melting temperature that is substantially the same as a melting temperature of crystalline polymer 2, as shown in the following table:
Polymer Melting Temperature Range (� C.) HDPE 125�-132� LLDPE 110�-125� LDPE 103�-110� PP-Homo 160�-175� PP-Copolymer 150�-175� PS 74�-105� ABS 88�-125� SAN 100�-200� PS - Rubber Mod. 93�-105� PC 145� AMSAN 121� PMMA 212� Thus, for polymers listed above, non-melting mixing (e.g., mixing without blending) of second polymer 6 and crystalline polymer 2 may occur between about 140�C and about 180�C, depending on the exact polymers used. In some embodiments, however, non-melting mixing (e.g., mixing without blending) of second polymer 6 and crystalline polymer 2 may occur at temperatures up to 212�C, for example, if PMMA is used as second polymer 6. Thus, the present invention has the advantage that even though the polymers used (e.g., crystalline polymer 2 and second polymer 6) may have substantially the same melting temperature, the two polymers will still resist blending. In various embodiments, however, any of the polymers set forth herein may be worked at a temperature where it is still pliable in an extruder (e.g., able to be shaped using a die into a composite), yet may not have completely melted.
Composite 1 may include a third polymer 7. For example, third polymer 7 may be an amorphous polymer or any other second polymer set forth herein, for example, a polycarbonate and/or a polymer having a shear viscosity higher than first polymer 2 and/or crystalline polymer 2. Third polymer 7 may be the same polymer as second polymer 6 (e.g., amorphous polymer), or may be a different polymer (e.g., amorphous polymer). Third polymer 7 may have the same color as second polymer 6, or may have a different color. Third polymer 7 may behave similarly to second polymer 6. For example, third polymer 7 may form streaks 16 on outer surface 5 of composite 1 that have a color different from the rest of outer surface 5. Thus, composite 1 may have a plurality of streaks against a base background color of composite 1, with a first set 16A of streaks 16 having a first color and second set 16B of streaks 16 having a second color different from the first color. One of ordinary skill in the art would realize that composite 1 may include any suitable number of wood fiber types and crystalline polymers and/or amorphous or other semi-crystalline polymers and/or other suitable polymers and resins. In the example where amorphous polymers cover substantially entire portions of composite 1 (e.g., as set forth in Fig. 3C), composite 1 may still evince more than color, for example, one color may correspond to the presence of amorphous polymer 6 on some portions of outer surface 5 while another color may correspond to the presence of amorphous polymer 7 on other portions of outer surface 5.
Composite 1 may include a background color 9 and/or pigment. Background color 9 may be configured to color one or more of first polymer 2, second polymer 6, third polymer 7, and/or wood fibers 3. For example, backgound color 9 may be processed with first polymer 2 and/or wood fiber 3 such that background color 9 permeates first polymer 2 and/or wood fiber 3 and forms blend 4 (e.g., background color 9 may permeate associate/engage with portions of the polymer chain of crystalline polymer 2). However, blend 4 may then be processed with second polymer 6 in a suitable manner such that background color 9 does not substantially permeate second polymer 6. For example, the processing of blend 4 and second polymer 6 may occur at a lower temperature than the processing of background color 9, crystalline polymer 2, and/or wood fiber 3. In another example, the aforementioned structures of the respective polymer chains of first polymer 2 and second polymer 6 may be substantially incompatible and/or resistant to blending (e.g., at any temperature). Accordingly, background color 9 may substantially remain attached to/within first polymer 2 and/or blend 4 and not appreciably permeate second polymer 6.
In various embodiments, background color 9 may be added to second polymer 6 in addition to and/or instead of first polymer 2, and any of the aforementioned characteristics may be applicable to second polymer 6 (e.g., because second polymer 6 and first polymer 2 are configured to resist blending, background color 9 will substantially remain associated with second polymer 6 and not first polymer 2). Adding background color 9 to second polymer 6 and then mixing second polymer 6 (which already has been mixed with background color 9) with either a colored or uncolored blend 4 is the preferred embodiment. Background color 9 may have a polarity that increases the likelihood that background color 9 will remain associated with second polymer 6 (e.g., background color 9 and amorphous polymer 6 may have polarities that may cause them to be attracted to each other like magnets with opposing polarities) and not become associated with first polymer 2 (e.g., background color 9 and first polymer 2 may have polarities that may cause them to repel each other like magnets with substantially the same polarities).
In another embodiment, composite 1 may include another material, compound, and/or additive intermixed with at least one of first polymer 2 and second polymer 6, for example, in substantially the same way as background color 9 is intermixed with at least one of first polymer 2 and second polymer 6 as set forth herein, and especially in the previous paragraph. For example, the another material may include a compound that, either on its own or when mixed with at least one of first polymer 2 and second polymer 6, causes at least portions of composite 1 (and preferably outer surface 5 of composite 1) to be resistant to molding and/or mildewing (e.g., keeps the level of microorganisms, mildew, and/or mold in and/or on a composite 1 lower than about 0.1 parts per million). An example of such a material may include a dichloro-octyl-isothiazolone (DCOIT) biostabilizer (e.g., biocide), such as certain grades of VINYZENETM manufactured by ROHM AND HAASTM (or other isothiazolones), however, any other suitable material (e.g., biostabiliter or biocide) that prevents and/or reduces molding and/or mildewing either alone or when mixed with at least one of first polymer 2 and second polymer 6 is also acceptable. Examples of acceptable methods for determining whether a particular material (e.g., biostabilizer, biocide) suitably prevents and/or reduces mold and/or mildew on composite 1 may include American Association for Testing Materials (ASTMTM) standards ASTMTM D-1413-99 SOIL-BLACK, ASTMTM D-4445-91 SAP STAIN, ASTMTM E-1428-99 PINK STAIN, ASTMTM G-21-96 MIXED FUNGI, ASTMTM D-5583-00 SINGLE CULTURE, and/or MILITARY STANDARD 810-E HUMIDITY CHAMBER, and/or their equivalents. Indeed, in any of the embodiments set forth herein, the another material, such as the DCOIT biostabilizer, may be substituted for background color 9 and may exhibit any of the properties of background color 9 relative to the first polymer 2, second polymer 6, and/or blend 4 in any portion of the process.
The DCOIT biostabilizer (examples of which may include VINYZENETM IT 4000 Series, VINYZENETM IT 4010 Series, and VINYZENETM SB 27, all of which are manufactured by ROHM AND HAASTM) may be dispersed throughout the first polymer 2, but preferably the second polymer 6, in any concentration suitable to prevent or reduce mold or mildew growth on the composite 1, for example, between about 800 parts per million and about 2000 parts per million and/or between about 1000 parts per million and 1200 parts per million. The DCOIT biostabilizer may have a thermal stability of about 220�C and/or a solubility in water of about 6 parts per million.
Another example of a suitable biostabilizer may be 10.10'-oxybisphenoxarsine (OBPA), examples of which may include VINYZENETM BP 5-2 Series, VINYZENETM BP 5-5 Series, VINYZENETM SB 1, and VINYZENETM SB 1 Series. The OBPA biostabilizer may be dispersed throughout the first polymer 2, but preferably the second polymer 6, in any concentration suitable to prevent or reduce mold or mildew growth on the composite 1, for example, between about 200 parts per million and about 500 parts per million. The OBPA biostabilizer may have a thermal stability of about 300�C and/or a solubility in water of about 6 parts per million.
A further example of a suitable biostabilizer may be octyl-isothiazoline (OIT), examples of which may include VINYZENETM IT 3000 Series, VINYZENETM IT 3010 Series, VINYZENETM IT 3025 DIDP, and VINYZENETM SB 8. The OIT biostabilizer may be dispersed throughout the first polymer 2, but preferably the second polymer 6, in any concentration suitable to prevent or reduce mold or mildew growth on the composite 1, for example, between about 800 parts per million and about 1200 parts per million. The OIT biostabilizer may have a thermal stability of about 220�C and/or a solubility in water of about 500 parts per million.
Yet another example of a suitable biostabilizer may be trichlorophenoxyphenol (TCPP), examples of which may include VINYZENETM SB 30. The TCPP biostabilizer may be dispersed throughout the first polymer 2, but preferably the second polymer 6, in any concentration suitable to prevent or reduce mold or mildew growth on the composite 1, for example, between about 800 parts per million and about 1200 parts per million. The TCPP biostabilizer may have a thermal stability of about 230�C and/or a solubility in water of about 10 parts per million.
An exemplary embodiment of the invention includes a method of manufacturing a wood-plastic composite. As shown in Figs. 4A-4D, the method may include providing a first polymer 2, providing a plurality of wood fibers 3, providing a second polymer 6 configured to resist blending with first polymer 2, melting first polymer 2, melting second polymer 6, mixing second polymer 6 with first polymer 2 and wood fibers 3 to form a feed 10, and forming a profile body 1. Profile body 1 may include an outer surface 5 deliberately evincing a first color and a second color different from the first color. Profile body 1 may also include an outer surface 5 being substantially composed of second polymer 6, with a cross-sectional profile of profile body 1 showing that a layer of second polymer 6 may be substantially disposed around blend 4 of first polymer 2 and wood fibers 3.
First polymer 2 may include a crystalline polymer 2. First polymer 2 is preferably at least one of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and polypropylene (PP), however, any crystalline polymer may be used in composite 1, such as one or more polyamides (PA), nylons, polyoxymethylenes, polybutylene terephthalates (PBT), polyethylene terephthalates (PET), and/or acetals. First polymer 2 may be provided in any suitable form (e.g., pellets, flakes, sheets, etc.) to be melted, mixed with wood fibers 3, and/or extruded into a dimensionally stable profile. First polymer 2 may have any suitable size, shape, and/or configuration to be used in any of the apparatuses or methods disclosed in co-owned U.S. Patent Nos. 5,851,469 and 6,527,532, co-pending and co-owned U.S. Patent Application No. 10/292,672 filed November 12, 2002, and co-pending and co-owned U.S. Patent Application No. 10/668,368 filed September 24, 2003, the entirety of all of which are incorporated herein by reference. First polymer 2 may be processed prior to extruding the feed 10 using any suitable method. For example, first polymer 2 may be chopped, purified, shredded, heated, and/or demoistured. In various embodiments, first polymer 2 may be heated (e.g., by shear friction with the apparatus or by the application of external thermal energy) to completely melt, partially melt, and/or improve processability.
First polymers 2 may be selected because they have a specific color (e.g., be mixed with a certain color dye) and/or composition (e.g., allows background color 9 to suitable permeate its structure). However, because first polymers 2 (and/or its additives such as background color 9) tend to blend and form a substantially homogenous color, the specific colors and/or compositions of first polymers 2 used in the process need not be tightly controlled. Some specific dyes may affect the resulting color of profile body 1 more than other dyes. One of ordinary skill in the art may control first polymers 2 input into the process in order to achieve the desired resultant color for outer surface 5. Moreover, the resultant color of first polymers 2 after processing (e.g., heating and/or extrusion) may be different from the initial colors of crystalline polymers 2. First polymer 2 may have any suitable size, shape, and/or configuration, exemplary parameters for which have already been set forth herein.
Second polymer 6 may include an amorphous polymer 6, a polycarbonate (PC), a polymer 6 that has a higher shear viscosity than first polymer 2 and/or crystalline polymer 2, and/or a polymer 6 configured to mix with but resist blending with first polymer 2 and/or crystalline polymer 2. A polycarbonate is a crystalline polymer that may be used as a second polymer 6 because it may have desirable properties relative to other crystalline polymers that may be used as first polymers 2. For example, PC may char while other crystalline polymers may burn. In another example, PC may have a sufficiently higher shear viscosity relative to other crystalline polymers. In various embodiments, using a PC as second polymer 6 in the apparatuses and methods disclosed herein will provide the same results (e.g., a composite 1 with a variegated outer surface 5 and/or streaks 16) as the use of an amorphous polymer 6. Accordingly, PC may be used interchangeably with amorphous polymer 6 in any of the embodiments set forth herein.
Second polymer 6 is preferably a styrenic polymer such as polystrene (PS), however, any amorphous polymer may be used in composite 1, such as one or more of Impact PS, polymethylmethacrylates (PMMA), polyvinyl chlorides (PVC), acrylonitrile-butadine-styrene copolymers (ABS), thermoplastic polyurethanes (TPU), styrene acrylonitrile copolymers (SAN), polyphenyl oxide (PPO), acryla-styrene butyl-acrylate or acrylate styrene acrylonitrile (either of which may be abbreviated as ASA), and/or alphamethylstyrene acrylonitrile (AMSAN). In a preferred embodiment, any one or combination of ABS, PC, AMSAN, and/or PMMA may be used. Second polymer 6 may be provided in any suitable form (e.g., pellets, flakes, sheets, films, etc.) Second polymer 6 may be processed prior to extruding the feed 10 using any suitable method. For example, second polymer 6 may be chopped, shredded, heated, purified, and/or demoistured. In another example, background color may be added to second polymer 6, and then second polymer 6 may introduced into a processing apparatus, such as extruder 15, substantially cold (e.g., without processing) to be mixed with blend 4 and/or into the processing apparatus as close to the extruder die 19 of the processing apparatus as possible to be extruded with blend 4.
Second polymer 6 used may be selected based on its color and/or composition. Second polymer 6 may have an initial color and/or resultant color that is different from the initial color and/or resultant color of the one or more crystalline polymers (with or without wood fibers 3) that second polymer 6 is being mixed with. For example, crystalline polymers 2, after processing (with or without wood fibers 3 and/or background color 9), may result in a substantially gray color, while second polymer 6, after processing, may result in a substantially black color. Second polymer 6 may have any suitable size, shape, and/or configuration. For example, second polymer 6 may be provided in flake or pellet form.
First polymer 2 and/or second polymer 6 may be melted using any suitable method. For example, first polymer 2 and/or second polymer 6 may be heated using in an external heat source (e.g., a flame in a heater 13) or may be heated through kinetic energy (e.g., by passing through a barrel 12 with a rotating screw 11, or passing through extruder die 19). First polymer 2 and/or second polymer 6 may be melted at any point in the composite manufacturing process prior to forming profile body 1. First polymer 2 and/or second polymer 6 may be heated separately and/or together. In a preferred embodiment, first polymer 2 and/or wood-fibers 3 may be heated and blended to form blend 4. First polymer 2 may be heated substantially throughout first polymer 2 and/or enough to improve processability (e.g., mixing and/or blending).
Wood fibers 3 may be from any type of suitable wood, for example, one or more hardwoods and/or softwoods. Wood fibers 3 may also be mixed with and/or replaced by any organic or inorganic filler such as those set forth herein. Wood fibers 3 may be of any suitable shape and/or size, and may be configured to be suitably blended with first polymer 2 such that a mixture of wood fibers 3 and first polymer 2 appears substantially homogenous in color. Wood fibers 3 may be processed prior to forming profile body 1 using any suitable method. For example, wood fibers 3 may be ground, crushed, chopped, shredded, heated, purified, and/or demoisturized. Wood fibers 3 may be dried prior to being blended with first polymer 2 to form blend 4. In some cases, pieces of wood fiber 3 may be discernible in blend 4, however, wood fiber 3 will still typically have the same homogenous color as the rest of blend 4.
First polymer 2 may be blended in a processor 13 with wood fibers 3 such that blend 4 is substantially homogenous. For example, blend 4 may have one substantially solid color and/or have a substantially uniform consistency. Blend 4 may be formed using any suitable method. First polymer 2 and wood fibers 3 may be blended by placing them together either before, during, or after first polymer 2 and/or wood fibers 3 are dried. First polymer 2 and wood fibers 3 may be blended using applied heat and/or mechanical agitation. Such blending may be accomplished by an extruder, high shear device, and/or a low shear mixer with or without the application of heat.
In various embodiments, composite 1 may include between about 100% and about 20% of first polymer 2, between about 5% and about 0% of second polymer 6, and between about 0% and about 80% wood fiber or other filler. In a preferred embodiment, composite 1 may include between about 60% and about 53% of first polymer 2, about 2% of second polymer 6, and between about 45% and about 38% wood fiber or other filler
Besides having a more natural, smooth, non-monolithic, and/or three-dimensional looking surface, composites 1 discussed herein may have other advantages. For example, composite 1 may be less susceptible to mold and mildew and/or may be more durable. First polymer 2 and second polymer 6 do not blend in composites 1. Accordingly, the minor component (in this case, second polymer 6) may migrate to the outer surface 5 of composite 1. When the minor component migrates to outer surface 5 of composite 1, the minor component may tend to coat at least portions of outer surface 5 (e.g., top, bottom, and/or side surfaces) with a polymer rich coating that does not absorb moisture, and thus allows outer surface 5 to resist molding and/or mildewing. Moreover, additional additives, such as mold and mildew resistant compounds (e.g., DCOIT biostabilizers or other suitable anti-fungi.bacteria materials/compounds, examples of which are set forth herein, or other materials having other desirable properties for composite 1), may be added to second polymer 6 at any point before or during the manufacturing process of composite 1. During the addition of the additive to second polymer 6, the additive and second polymer 6 may be processed so as to substantially disperse the additive through the matrix of second polymer 6. Once again, because second polymer 6 may migrate to outer surface 5 of composite 1, second polymer 6 with mildew resistant additives (or other materials) may coat at least portions of outer surface 5. Some exemplary reasons why second polymer 6 may migrate toward outer surface 5 of composite 1 are set forth herein, and especially below.
Outer surface 5 of profile body 1 may be variegated. Streaks 16 may be formed on outer surface 5 of profile body 1. For example, if first polymer 2 and second polymer 6 are mixed, the chemical properties of the two polymers and/or the processing conditions (e.g., temperature, extrusion rate, mixing rate that the two polymers are subjected to) may prevent them from blending with each other and forming a homogenous color. Accordingly, �clumps� or �pockets� of second polymer 6 may be dispersed through first polymer 2 and vice versa. As the mixture of second polymer 6 and first polymer 2 (with or without wood fibers 3) is extruded through the die 19, second polymer 6 may tend to go towards outer surface 5 of profile body 1, for example, due the pressures exerted on feed 10 during extrusion. In another example, due to the molecular structure of both first polymer 2 and second polymer 6, the polymer chain of second polymer 6 cannot interlock easily with the polymer chain and/or matrix of first polymer 2. Accordingly, second polymer 6 may tend to separate from the polymer matrix of first polymer 2 and go to outer surface 5 so as to form its own solid polymer matrix of second polymer 6. As second polymer 6 reaches surface 5, because second polymer 6 may have a different initial color and/or different resultant color as the rest of profile body 1 (i.e., blend 4 of first polymer 2 and wood fibers 3), streaks 16 of second polymer 6 may be readily discernible on outer surface 5. Streaks 16 may be generally perpendicular to a cross-section of die 19 through which profile body 1 is extruded. However, streaks 16 may be in any direction, and have any other shape and/or configuration, for example, similar to those set forth in Figs. 2A-2C. Streaks 16 may form any desired or suitable pattern, for example, a natural-wood-like pattern.
In another example, entire portions of outer surface 5 may be composed of second polymer 6, for example, as shown in Fig. 3C. In such an example, the processing may have been such that second polymer 6 forms �clumps� or �pockets� (e.g., as set forth in the previous paragraph) around substantially all of blend 4 so as to form a substantially solid matrix around blend 4 (e.g., with or without wood fibers 3). Any suitable proportions of second polymer 6, first polymer 2, wood-fibers 3, blend 4, blend 18, background color 9, and another other material or compound set forth herein are contemplated as being discernible on outer surface 5.
The method may also include providing another polymer 7, melting another polymer 7, and mixing another polymer 7 with second polymer 6, first polymer 2, and/or wood fibers 3. With the addition of additional polymer 7, the step of extruding may include forming profile body 1 such that outer surface 5 deliberately evinces a third color different from the first color and the second color due to additional polymer 7.
Another polymer 7 may be selected because its initial color and/or resultant color may be different from an initial color and/or resultant color of one or more of first polymer 2 and/or wood fibers 3. Another polymer 7 may processed and/or behave similarly to other second polymers 6, thus, streaks 16B of another polymer 7 may be formed on outer surface 5 of profile body 1. Streaks 16B from another polymer 7 may be of a color different from either the base color of profile body 1 and/or the color of streaks 16A from second polymer 6.
The method also may include the use of a background color 9. As shown in Fig. 4B, background color 9 may be added to first polymer 2 and/or wood fiber 3 (e.g., blend 4) to impart a color to blend 4 different from an initial color of blend 4, first polymer 2, and/or wood fiber 3. Background color 9, first polymer 2, wood fibers 3, and/or blend 4 may be processed by processor 13 using any suitable apparatus and/or method to form resultant blend 14. Resultant blend 14 may then be transferred to extruder 15 and processed with second polymer 6 to form profile body 1 with streaks 16 or other variations of outer surface 5 as set forth herein. Background color 9 may be added to any step of the process and/or any component or subcomponent of the process at any time prior to extrusion through die 19.
In a preferred embodiment, as shown in Fig. 4C, background color 9 may be added to second polymer 6 to impart a color to second polymer 6 different from an initial color of second polymer 6. Background color 9 and/or second polymer 6 may be processed by processor 17 using any suitable apparatus and/or method to form resultant blend 18 of second polymer 6 and background color 9. Resultant blend 18 may then be transferred to extruder 15 and processed with first polymer 2, wood fibers 3, and/or blend 4 to form profile body 1 with streaks 16 or other variations of outer surface 5 as set forth herein. Once again, background color 9 may be added to any step of the process and/or any component or subcomponent of the process at any time prior to extrusion through die 19.
In another preferred embodiment, as shown in Figs. 4D and 4E, first polymer 2 and plurality of wood fibers 3 may be processed (e.g., dried and/or pre-melted) using any suitable apparatus and/or method to form blend 4. Background color 9 may be added to first polymer 2 and/or wood fiber 3 (e.g., blend 4) to impart a color to blend 4 different from an initial color of blend 4, first polymer 2, and/or wood fiber 3. Background color 9, first polymer 2, wood fibers 3, and/or blend 4 may be processed by processor 13 using any suitable apparatus and/or method to form resultant blend 14. Background color 9, first polymer 2, and/or wood fiber 3 may mixed together and/or processed at substantially the same time to form resultant blend 14 without first forming blend 4, or background color 9 may be added to blend 4 after the processing of first polymer 2 and/or wood fiber 3 has already begun and/or has been completed. Resultant blend 14 may then be transferred to extruder 15.
Second polymer 6 may then be added to resultant blend 14 and/or feed 10 that is now disposed in extruder 15. Second polymer 6 may be added in any suitable form, for example, unmelted pellets. The pellets may have any suitable shape, size, and/or configuration. For example, the pellets preferably range in size from 15 pellets per gram to 30 pellets per gram (e.g., 25 pellets per gram) and even up to 40 pellets per gram.
Second polymer 6 may be added to any portion of resultant blend 14 and/or feed 10 disposed in any portion of extruder 15, barrel 12, and/or screw 11. For example, second polymer 6 may be added through a vent port 20 disposed on a side of extruder 15 and/or barrel 12. Vent port 20 may be disposed at approximately a halfway position along a length of extruder 15, barrel 12, and/or screw 11, which may be a low-pressure region relative to the rest of extruder 15. Vent port 20 may be disposed downstream from a blister 11b on screw 11, which may cause region of extruder 15 adjacent to vent port 20 to be a low pressure region. Vent port 20 may be connected to a side feeder 21, for example, as shown in Figs. 4D and 4E.
Side feeder 21 may include a feed screw 22 driven by a variable speed motor drive 23. A barrel 24 may surround feed screw 22 near vent port 20 and may be connected to an outer surface of extruder 15. Feed screw 22 may be disposed such that feed screw 22 places second polymer 6 into extruder 15 without forcing second polymer 6 into screw 11. Feed screw 22 and screw 11 do not contact each other.
Barrel 24 (e.g., also called an extruder vent stack) may include a vacuum section 26 configured to remove impurities from second polymer 6 disposed in barrel 24, for example, turpentine and/or organic materials. This may prevent foaming later in the process. A distal end 27 of barrel 24 may include a door 28. Door 28 may be configured to allow second polymer 6 to be placed therethrough into an interior of barrel 24 such that second polymer 6 may be fed into extruder 15.
Distal to barrel 24 may be basket 31. Basket 31 may be configured to receive second polymer 6 in any suitable form, for example, unmelted pellets. A hose 29 may connect an outlet of basket 31 to door 28 so as to allow second polymer 6 to be advanced from basket 31 to door 28. Hose clamp 30 may connect hose 29 to each of door 28 and the outlet of basket 31. Hose clamp 30 may form a substantially airtight seal between door 28, hose 29, basket 31, and/or barrel 24. Basket 31 may include a lid 32 disposed on a gasket disposed around an upper end of basket 31. Lid 32 may be configured to maintain a substantially airtight seal with basket 31, for example, to maintain a desired air pressure in basket 31. A desired air pressure may be an air pressure above that in barrel 24 so as to assist in moving second polymer 6 from basket 31, through hose 29, and into barrel 24. Lid 32 may include a vent 33, for example a � turn ball valve, to assist in maintaining a desired air pressure in basket 31. Barrel 24 may extend distal to door 28, under basket 31, and/or to motor 23. Barrel 24 in this region may have a smaller cross-sectional area (e.g., diameter) relative to the region of barrel 24 adjacent to vent port 20. A lip seal 34 may provide a substantially airtight seal between feed screw 22 and barrel 24. Any cracks or gaps between any portions of side feeder 21 (e.g., between basket 31, feed screw 22, lip seal 34, barrel 24, door 28, hose 29, and/or hose clamp 30) may be sealed with a sealant, for example, silicon caulk.
Side feeder 21 may be disposed on an adjustable table 35, for example, to adjust the height of side feeder 21 relative to extruder 15. This adjustablility may be desirable, for example, to locate side feeder 21 at an ideal height such that second polymer 6 flows into barrel 12 of extruder 15 at a desired rate and/or at a desired location (e.g., into barrel 12 without exerting excessive force on screw 11 which may cause excessive mixing of second polymer 6 with resultant blend 14 and/or feed 10). A longitudinal axis of side feeder 21, barrel 24, and/or feed screw 22 may be substantially parallel to the ground and/or substantially perpendicular to a longitudinal axis of screw 11, extruder 15, and/or barrel 12.
Once second polymer 6 has been introduced into resultant blend 14 and/or feed 10, second polymer 6 may mix, but not blend, with resultant blend 14 and/or feed 10 and may be extruded into composite 1 via extruder die 19. Composite 1 may have a variegated outer surface 5 and/or streaks 16.
One of ordinary skill in the art will recognize that some aspects of the invention may be modified so as to form different embodiments of the invention. For example, there may be a plurality of first polymers, a plurality of types of wood fibers, and/or a plurality of second polymers used.
Further, various resins other than or in addition to crystalline and/or amorphous polymers may be used for any polymer set forth herein, for example, first polymer 2, second polymer 6, and/or third polymer 7. For example, crystalline, amorphous, and/or semi-crystalline or any other suitable polymer or resin, whether natural or synthetic may be used.
Further, the same polymer or resin may be used as both the first and second polymer, provided that one or the other is modified in some way (i.e., an additive or different levels of an additive) so that they do not blend as used in the invention. An additive may be any suitable material, for example, an organic material and/or a chemical (e.g., any chemicals, such as biocides, set forth herein).
One of ordinary skill in the art will also recognize that some of the aspects set forth herein may be removed to form different embodiments of the invention. For example, first polymer 2 and wood fibers need not be blended prior to mixing them with second polymer 6.
Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7258913Oct 28, 2002Aug 21, 2007Certainteed Corp.Commingled, continuous filament of glass and polymeric fibers of polyethylene, polypropylene and polyesters; resistance to color fading, cold impact strength, well-defined wood grain, lightweightUS7473722Nov 8, 2004Jan 6, 2009Certain Teed Corp.Polymer-fiber composite building material with bulk and aesthetically functional fillersUS7913960Aug 22, 2007Mar 29, 2011The Crane Group Companies LimitedBracketing systemUS8088840Nov 17, 2008Jan 3, 2012Certainteed CorporationPolymer-fiber composite building material with bulk and aesthetically functional fillersUS8629199Dec 20, 2011Jan 14, 2014Certainteed CorporationPolymer fiber composite building material with bulk and aesthetically functional fillersWO2008045754A2 *Oct 4, 2007Apr 17, 2008Fiber Composites LlcMulti-color fiber-plastic composites and systems and methods for their fabrication* Cited by examinerClassifications U.S. Classification428/537.1International ClassificationB32B5/16, D04H1/00, B32B21/04Cooperative ClassificationC08L97/02European ClassificationC08L97/02Legal EventsDateCodeEventDescriptionNov 6, 2009ASAssignmentOwner name: BRANCH BANKING AND TRUST COMPANY, AS COLLATERAL AGFree format text: SECURITY AGREEMENT;ASSIGNOR:TREX COMPANY, INC.;REEL/FRAME:023620/0786Effective date: 20091104Jun 13, 2005ASAssignmentOwner name: TREX COMPANY, INC., VIRGINIAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DOLINAR, BLAIR;REEL/FRAME:016684/0540Effective date: 20050520RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google