Method and device for the production of a plastic profile
View Patent ↗Straight plastic profiles from a plastics material and a continuous reinforcement are predominantly produced continuously in a strand, usually by the pultrusion method. As the plastic profile is pulled through a mold, only straight plastic profiles are formed in known pultrusion methods. In the production of plastic profiles using semi-finished products or complex fibrous constructions, congestion of the fibrous constructions or of the semi-finished products, and thus solidification of the material, may arise when entering the mold, such that the process has to be stopped. A method and a device for the simple production of individually molded plastic profiles is provided in that the mold is formed from at least two mold parts that in relation to the cross section of the plastic profile are split and are moved in a temporally offset manner counter to a production direction of the plastic profile along a portion of the plastic profile.
1. A method for the production of a curved plastic profile ( 10 ) having a continuous reinforcement ( 11 ) from strands ( 13 ) or woven fabrics, wherein a mold ( 20 , 34 , 34 ) is moved counter to a production direction ( 19 ) of the plastic profile ( 10 ) along a portion of the plastic profile ( 10 ), and the plastic profile ( 10 ) herein is retained by at least one holding means that, when viewed in the production direction ( 19 ), is positioned ahead of the mold ( 20 , 34 , 34 ), comprising forming the mold ( 20 , 34 , 34 ) from at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) that in relation to the cross section of the plastic profile ( 10 ) are split and that are moved in a temporally offset manner counter to a production direction ( 19 ) of the plastic profile ( 10 ) along a portion of the plastic profile ( 10 ).
2. The method as claimed in claim 1 , wherein the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) are moved in a periodically alternating manner, at least at times simultaneously or separately, respectively, counter to the production direction ( 19 ) of the plastic profile ( 10 ) along a portion of the plastic profile ( 10 ).
3. The method as claimed in claim 1 , wherein the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) are moved discontinuously or in steps, respectively, in a mutually parallel manner, so as to be at least partially opposite or protruding along a longitudinal axis of the plastic profile ( 10 ), wherein a movement of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) relative to the plastic profile ( 10 ) takes place only during a reverse movement of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) counter to the production direction ( 19 ).
4. The method as claimed in claim 1 , wherein the plastic profile ( 10 ), during the movement of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) on the plastic profile ( 10 ) that is stationary relative to the latter, is retained by at least one holding means in structured as a gripper ( 21 ).
5. The method as claimed in claim 4 , wherein the at least one holding means in phases during which the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) are stationary is brought out of contact with the plastic profile ( 10 ), and the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) to move conjointly with the plastic profile ( 10 ) in the production direction ( 19 ) toward the at least one stationary holding means, and the at least one holding means, in order to reach an initial position, is subsequently brought back into contact with the plastic profile ( 10 ).
6. The method as claimed in claim 4 , wherein the at least one holding means in phases during which the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) are stationary is brought out of contact with the plastic profile ( 10 ) and is moved relative to the stationary plastic profile ( 10 ) in the direction of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) that are likewise stationary, then is moved back counter to the production direction ( 19 ), and then is again brought into contact with the plastic profile ( 10 ), and subsequently the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ), in order to reach an initial position, are moved conjointly with the plastic profile ( 10 ) and the holding means in the production direction.
7. The method as claimed in claim 1 , wherein initially a first mold part ( 14 , 30 , 32 ) of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) is structured as a convex mold part ( 14 , 30 , 32 ) and is moved counter to the production direction ( 19 ) along the stationary plastic profile ( 10 ), and subsequently a second mold part ( 15 , 29 , 33 ) of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ), that is shorter than the first mold part and is structured as a concave mold part ( 15 , 29 , 33 ), is moved in a manner likewise to that of the first mold part ( 14 , 30 , 32 ), wherein in the case of each movement of a one of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) counter to the production direction ( 19 ) at least part of a newly produced portion of the plastic profile ( 10 ) is demolded or released, respectively, from the moving one of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ).
8. The method as claimed in claim 7 , wherein in the case of the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) moving, the reinforcement between the at least two mold parts ( 14 , 15 , 29 , 30 , 32 , 33 ) and a material reserve is pretensioned by way of the convex mold part ( 14 , 30 , 32 ), the reinforcement ( 11 ) being pretensioned in the shape of the plastic profile ( 10 ) to be produced.