Process of confection of polyamide compounds with natural fibers and compounds of polyamides with natural fibers
View Patent ↗The present invention relates to a process of production of polyamide compounds with natural fibers and polyamide compounds with natural fibers, establishes the fact of using natural fiber to obtain a compound with mechanical properties close to the one obtained with inorganic loads by means of continuous process with extrusion and molding by injection process; the processes presented allows the obtainment, by means of injection, of finished products with precise dimensional and complex features; the fact that the compound with natural Curauá fiber presenting suitable mechanical properties combined to a lesser density than the compound with inorganic load is interesting to the automotive industry as vehicles manufactured with lighter parts consume less fuel.
1. A process for the production of polyamide compounds with natural fibers characterized by using: (A) natural fibers in bulk form and (B) natural fibers dried for 1.5 hour at 100° C. in a conventional kiln without superficial treatment; the process including the following stages:
(1) preparing of natural fibers and
(2) producing polyamide compounds with natural fibers; wherein the stage (1) includes the following sub-stages:
(1.1) grinding of natural fibers in the form A and form B, until obtaining a mean length of about 0.1 to 15 mm;
(1.2) superficially treating the natural fibers of stage 1.1 with cold plasma of O 2 or N 2 in a quartz reactor;
(1.3) treating the fibers of stage 1.2 in a solution of 10% in NaOH mass, washed once in water from a main water supply, and once with distilled water; and
(1.4) drying the fibers of stage 1.3 in a kiln at 100° C. for 2 hours; wherein stage (2) establishes the following sub-stages:
(2.1) separating the amount of natural fibers to be used;
(2.2) homogenizing the natural fibers prepared in advance with the polymeric matrixes of said polyamide compounds to obtain a compound; and
(2.3) extruding the compound obtained in sub-stage (2.2).
2. A process according to claim 1 , wherein the quartz reactor of sub-stage (1.2) has an RF source of 13.56 MHz, power of 30 W, and pressure of 4×10 −2 Torr for 15 min; and wherein in sub-stage (1.3), the fibers are treated for a period of 30 minutes to 2 hours, and wherein the solution of 10% in NaOH mass has a pH of about 5.0 and the distilled water has a pH of about 6.
3. A process according to claim 1 , characterized by the fact that the amount of fibers used is of 10 to 50% in ground fiber mass in relation to the mass of the polymeric matrixes used.
4. A process according to claim 1 , characterized by the fact that the polyamide compounds are polyamide-6 and the natural fibers are Curaua fibers.
5. A process according to claim 4 , characterized by the fact that the polyamide matrixes used are: polyamide-6 without any modification, and polyamide-6 containing about 1 to 10% in poly (ethyle-ne-co-propylene-co-diene) elastomer mass, functionalized with anhydrous maleic.
6. A process according to claim 1 , characterized by the fact that the extrusion of the compound obtained in sub-stage (2.2) take place in extrusion equipment of single- or double-worm thread, using from 50 to 300 rpm and temperature profile of 200 to 250° C.
7. A process for the production of polyamide compounds with natural fibers characterized by using: (A) natural fibers in bulk form and (B) natural fibers dried for 1.5 hour at 100° C. in a conventional kiln without superficial treatment; the process including the following stages:
(1) preparing of natural fibers and
(2) producing polyamide compounds with natural fibers; wherein the stage (1) includes the following sub-stages:
(1.1) grinding of natural fibers in the form A and form B until obtaining a mean length of about 0.1 to 15 mm;
(1.2) superficially treating the natural fibers of stage 1.1, with cold plasma of O 2 or N 2 in a quartz reactor;
(1.3) treating the fibers of stage 1.2 in a solution of 10% in NaOH mass; and
(1.4) drying the fibers of stage 1.3 in a kiln at 100° C. for 2 hours;
wherein stage (2) establishes the following sub-stages:
(2.1) separating an amount of natural fibers from stage 1.4;
(2.2) homogenizing the thus separated natural fibers prepared with a polyamide polymeric matrix to obtain a compound that is a blend of natural fibers and the polyamide polymer matrix; and
(2.3) extruding the compound obtained in sub-stage (2.2).
8. The process of claim 7 , wherein the polyamide polymer matrix is selected from the group consisting of polyamide-6 without any modification, and polyamide-6 containing about 1 to 10% in poly (ethyle-ne-co-propylene-co-diene) elastomer mass, functionalized with anhydrous maleic.
9. The process of claim 7 , wherein the compound of stage 2.2. comprises 80 wt % of polyamide-6 and 20 wt % of Curauá fiber, and wherein the compound has a density of about 1.16 g cm 3 .
10. The process of claim 7 , wherein the amount of natural fibers used is of 10 to 50% in ground fiber mass in relation to the mass of the polyamide polymeric matrix used.
11. The process of claim 7 , further comprising the step of washing the fibers treated with NaOH mass with distilled water.
12. A process for the production of polyamide compounds with natural fibers comprising:
grinding of Curaua fibers to have a mean length of about 0.1 to 15 mm;
treating the ground fibers with cold plasma of O 2 or N 2 ;
treating the fibers treated with cold plasma in a solution of NaOH mass;
drying the fibers treated with NaOH mass;
homogenizing the fibers with a polyamide polymeric matrix;
extruding the homogenized fibers and polyamide polymeric matrix.
13. The process of claim 12 , wherein the polyamide polymeric matrix comprises polyamide-6.
14. The process of claim 12 , further comprising the step of washing the fibers treated with NaOH mass with distilled water.
15. The process of claim 12 , wherein the fibers are dried in a kiln at 100° C. for 2 hours.
16. The process of claim 12 , wherein the extruded homogenized fibers and polyamide polymeric matrix comprises 80 wt % of polyamide-6 and 20 wt % of Curauá fiber.
17. The process of claim 12 , wherein the polyamide polymer matrix contains 1 to 10% of poly (ethylene-co-propylene-co-diene).
18. The process of claim 12 , wherein the solution of NaOH mass is a solution of 10% in NaOH mass.
19. The process of claim 12 , wherein the Curaua fibers comprise (A) Curaua fibers in bulk form and (B) Curaua fibers dried for without superficial treatment.
20. A process for the production of polyamide compounds with natural fibers characterized by using: (A) natural fibers in bulk form and (B) natural fibers dried without superficial treatment; the process including the following stages:
(1) preparing of natural fibers including
(1.1) grinding of natural fibers in the form A and form B, until obtaining a mean length of about 0.1 to 15 mm;
(1.2) superficially treating the natural fibers of stage 1.1 with cold plasma of O 2 or N 2 ;
(1.3) treating the fibers of stage 1.2 in a solution of NaOH; and
(1.4) drying the fibers of stage 1.3; wherein stage (2) establishes the following sub-stages:
(2) producing polyamide compounds with natural fibers, including
(2.1) separating the amount of natural fibers to be used;
(2.2) homogenizing the natural fibers prepared in advance with the polymeric matrixes of said polyamide compounds to obtain a compound; and
(2.3) extruding the compound obtained in sub-stage (2.2).