Method and apparatus for the single-stage continuous production of a rubber base compound and a rubber end compound

An apparatus for continuously producing a rubber base compound (g) and a rubber end compound in a single stage from crude rubber, the arrangement including:

• a first twin-screw extruder having a first housing and having a predetermined first length;
• a first pair of two intermeshing screws rotatably mounted in said first housing and defining respective longitudinal axes;
• first drive means for driving each of said screws of said first pair about the longitudinal axis corresponding thereto;
• a second twin-screw extruder having a second housing and having a predetermined second length;
• a second pair of two intermeshing screws rotatably mounted in said second housing and defining respective longitudinal axes;
• second drive means for driving each of said screws of said second pair about the longitudinal axis corresponding thereto;
• first crude rubber inlet means formed in said first housing for admitting said crude rubber (a) into said first twin-screw extruder wherein the crude rubber (a) is plasticized and homogenized;
• second crude rubber non-reactive mixing additives inlet means formed in said first housing for admitting said non-reactive mixing additives needed for producing the base compound (g) into said first twin-screw extruder at preselected distances along said first housing whereby said non-reactive mixing additives become mixed and homogenized with the crude rubber in said first twin-screw extruder at temperatures in the range of 100.degree. C. to 160.degree. C. to form the base compound (g);
• outlet means for conducting the base compound (g) out of said first housing and said first twin-screw extruder;
• third inlet means formed in said second housing for continuously receiving said base compound (g) from said first twin-screw extruder;
• cooling means in said second twin-screw extruder for cooling the base compound (g) down to a temperature in the range of 100.degree. C. to 120.degree. C.;
• fourth crude rubber reactive mixing additives inlet means formed in said second housing for admitting all said reactive mixing additives needed for producing the end compound into said second twin-screw extruder at preselected distances along said second housing whereby said reactive mixing additives become mixed and homogenized with said base compound (g);
• and,
• said cooling means being arranged along said second twin-screw extruder for maintaining the temperature of said base compound within said range of 100.degree. C. to 120.degree. C. as said reactive mixing additives are mixed and homogenized with said base compound (g) thereby preventing vulcanization and producing the rubber end product.

An apparatus for continuously producing a rubber base compound (g) and a rubber end compound in a single stage from crude rubber, the arrangement including:

• extruder having a housing and having a predetermined length subdivided into two zones A and B along said length so as to be disposed one behind the other;
• first pair of intermeshing screws rotatably mounted in said housing in said zone A thereof and defining respective longitudinal axes;
• first drive means for driving each of the screws of said first pair about the longitudinal axis corresponding thereto;
• a second pair of intermeshing screws rotatably mounted in said housing in said zone B thereof and defining respective longitudinal axes;
• second drive means for driving each of the screws of said second pair about the longitudinal axis corresponding thereto;
• first crude rubber inlet means formed in said housing for admitting said crude rubber (a) into zone A of said extruder wherein the crude rubber (a) is plasticized and homogenized;
• second crude rubber non-reactive mixing additives inlet means formed in said housing within said zone a for admitting said non-reactive mixing additives needed for producing the base compound (g) into the twin-screw extruder at preselected distances along said zone A whereby said non-reactive mixing additives become mixed and homogenized with the crude rubber in said extruder at temperatures in the range of 100.degree. C. to 160.degree. C. to form the base compound (g);
• cooling means in said zone B for cooling the base compound (g) down to a temperature in the range of 100.degree. C. to 120.degree. C.;
• third crude rubber reactive mixing additives inlet means formed in said housing within said zone B for admitting all said reactive mixing additives needed for producing the end compound into tile twin-screw extruder at preselected distances along said zone B whereby said reactive mixing additives become mixed and homogenized with said base compound (g);
• said cooling means being arranged along said zone B for maintaining the temperature of said base compound within said range of 100.degree. C. to 120.degree. C. as said reactive mixing additives are mixed and homogenized with said base compound (g) thereby preventing vulcanization and producing the rubber end product;
• and,
• each of the screws of said first pair of tightly intermeshing screws having a diameter d.sub.1 and each of the screws of said second pair of tightly intermeshing screws having a diameter d.sub.2 greater than said diameter d.sub.1.