Filled polymer composite and synthetic building material compositions
View Patent ↗The invention relates to composite compositions having a matrix of polymer networks and dispersed phases of particulate or fibrous materials. The matrix is filled with a particulate phase, which can be selected from one or more of a variety of components, such as fly ash particles, axially oriented fibers, fabrics, chopped random fibers, mineral fibers, ground waste glass, granite dust, or other solid waste materials. A system for providing shape and/or surface features to a moldable material includes, in an exemplary embodiment, at least two first opposed flat endless belts spaced apart a first distance, with each having an inner surface and an outer surface.
1. A method of continuously forming a molded material comprising:
mixing a highly filled composite mixture in a multi-zone extruder essentially at room temperature and without adding heat, wherein the composite mixture comprises:
a monomeric or oligomeric poly or di-isocyanate;
a first liquid polyol having a first molecular weight and a second polyol having a second molecular weight higher than the first molecular weight, wherein the second liquid polyol comprises about 5 wt % to about 20 wt % of the total weight of the first and second polyols;
wherein the first polyol has a viscosity in the range of about 480 cP to about 840 cP at 25° C., and the second polyol viscosity is in the range of about 480 cP to about 840 cP at 25° C.;
a foaming agent;
an inorganic particulate material comprising about 60 wt % to about 85 wt % of the composite mixture; and
a catalyst;
extruding the highly filled composite mixture through a die;
molding the mixture in a forming system comprising:
at least a first and a second opposed mold belt, each having an inner surface and an outer surface;
at least a first and a second opposed endless belt spaced apart a distance, each having an inner surface and an outer surface, wherein the inner surface of the first belt is contactable with the outer surface of the first mold belt to move with and support the first mold belt during molding, and wherein the inner surface of the second belt is contactable with the outer surface of the second mold belt to travel with and support the second mold belt during molding;
a mold cavity disposed between the inner surfaces of the at least two opposed mold belts; and
removing the molded material from the mold cavity after sufficient time has passed for the mixture to cure or harden into the molded material, wherein the molded material comprises a density of at least about 30 lb/ft 3 .
2. The method of claim 1 , further comprising transferring the mixture along the mold cavity.
3. The method of claim 1 , wherein the forming system further comprises a drive mechanism for imparting motion to the at least two opposed endless belts.
4. The method of claim 1 , further comprising exerting pressure on the mixture with the at least two opposed endless belts.
5. The method of claim 1 , further comprising providing shape, surface features, or both to the molded material.
6. The method of claim 1 , further comprising embossing or impressing a pattern on the mixture in the forming system.
7. The method of claim 6 , wherein the pattern comprises a simulated wood grain.
8. The method of claim 1 , further comprising introducing fiber rovings on, in, or beneath the surface of the mixture.
9. The method of claim 8 , wherein the fiber rovings are axially oriented fiber rovings.
10. The method of claim 1 , wherein the inorganic particulate material is fly ash, bottom ash, or particulate glass.
11. The method of claim 1 , wherein the inorganic particulate material has a particle size distribution ranging from about 0.0625 in. to below about 0.0017 in.
12. The method of claim 1 , wherein the inorganic particulate material contains less than about 0.5 wt % water.
13. The method of claim 1 , wherein the polyol is mixed with the catalyst prior to being mixed with the isocyanate.
14. The method of claim 1 , wherein the polyol and the catalyst are mixed prior to being introduced to the extruder.
15. The method of claim 1 , wherein the polyol, the catalyst, and the inorganic particulate material are mixed prior to being mixed with the isocyanate.
16. The method of claim 1 , wherein the molded material is a building material.
17. The method of claim 16 , wherein the building material is lumber.
18. The method of claim 16 , wherein the building material is roofing.
19. The method of claim 16 , wherein the building material is siding.
20. The method of claim 16 , wherein the building material comprises a relatively porous material and a relatively non-porous toughening layer disposed on and adhered to the porous material.
21. The method of claim 1 , wherein the outer surface of the at least opposed endless belts is supported by a rigid supporting surface.
22. The method of claim 21 , wherein the opposed endless belts are upper and lower endless belts.
23. The method of claim 21 , wherein the rigid supporting surface comprises a slider bed or platen.
24. The method of claim 1 , wherein the opposed endless belts are adjustable such that the mold cavity can be varied.
25. The method of claim 1 , wherein at least two endless opposing profile mold belts are adapted to fit within the mold cavity.
26. The method of claim 25 , wherein the mold cavity is at least partly defined by the inner surfaces of the at least two opposed profiled mold belts disposed inside the at least two opposed endless belts.
27. The method of claim 26 , wherein the profile mold belts form the mixture into a shape having a cross-section at least approximately corresponding to that of the mold cavity.
28. The method of claim 26 , wherein the profile mold belts impart a surface pattern to the molded material.
29. A method of continuously forming a molded material comprising:
forming a highly filled composite mixture in a continuous mixing device, wherein the composite mixture comprises:
a monomeric or oligomeric poly or di-isocyanate;
a first polyol having a first molecular weight;
a second polyol having a second molecular weight lower than the first molecular weight, wherein the second polyol comprises about 5 wt % to about 20 wt % of the total weight of the first and second polyols;
wherein the first polyol has a viscosity, in the range of about 480 cp to about 840 cP at 25° C., and the second polyol has a viscosity in the range of about 480 cp to about 840 cP at 25° C.;
a foaming agent;
inorganic particulate material comprising about 60 wt % to about 85 wt % of the composite mixture; and
a catalyst;
wherein the exothermic reaction is allowed to proceed without additional heat and without forced cooling except to control runaway exotherm;
passing the mixture through the exit of the continuous mixing device;
molding the mixture in a forming system comprising:
at least two opposed endless belts spaced apart a distance, each having an inner surface and an outer surface;
a mold cavity defined at least in part by the inner surfaces of the at least two opposed endless belts; and
removing the molded material from the mold cavity after sufficient time has passed for the mixture to cure or harden into the molded material, wherein the molded material comprises a density of at least about 30 lb/ft 3 .
30. The method of claim 29 , wherein the first and second polyol are mixed prior to being introduced to the continuous mixing device.
31. The method of claim 29 , wherein the first and second polyol are mixed with the catalyst prior to being mixed with the isocyanate.
32. The method of claim 29 , wherein at least one of the first or second polyols is mixed with the catalyst prior to being introduced to the extruder.
33. The method of claim 29 , wherein the first polyol, the second polyol, the catalyst, and the inorganic particulate material are mixed prior to being mixed with the isocyanate.
34. The method of claim 1 , wherein the composition mixture has a density in the range of about 20 lb/ft 3 to about 90 lb/ft 3 .
35. The method of claim 1 , wherein the poly- or di-isocyanate comprises methylene diphenyl diisocyanate.
36. The method of claim 29 , wherein the molded material comprises a density of about 40 lb/ft 3 .
37. The method of claim 29 , wherein the molded material comprises a density of about 50 lb/ft 3 .
38. The method of claim 29 , wherein the molded material comprises a density of about 60 lb/ft 3 .
39. The method of claim 29 , wherein the second polyol comprises about 10 wt % of the total weight of the first and second polyols.
40. The method of claim 29 , wherein the inorganic particulate material comprises about 74 wt % of the composite mixture.
41. The method of claim 29 , wherein the composite mixture further comprises fibers.
42. The method of claim 41 , wherein the fibers comprise about 4 wt % of the composite mixture.
43. The method of claim 29 , wherein the continuous mixing device comprises an extruder.
44. The method of claim 29 , wherein the step of passing the mixture through the exit of the continuous mixing device comprises the step of pouring the mixture.