T-die and method of manufacturing the same

Abstract

On at least the edge portion ( 9 e ) of the lip portion ( 9 ) of a T-die ( 1 ), a cladding layer ( 10 ) is provided. The cladding layer is formed by laser build-up welding to a base material with a powder of a corrosion resistant and wear resistant alloy comprising a nickel-based alloy or a cobalt-based alloy. The cladding layer has a metallographic structure in which metal borides are dispersed in a binder phase. The lip portion has high quality and has high durability. The manufacturing costs of the T-die can also be kept relatively low.

1 . A T-die comprising a die main body, the die main body being provided therein with a fluid material flow channel, and the die main body having a lip portion that forms a slit-shaped discharge portion at a tip end of the fluid material flow channel, wherein
 the lip portion includes a cladding layer formed at least an edge portion thereof, the cladding layer being formed by laser build-up welding to a base material with a powder of a corrosion resistant and wear resistant alloy comprising a nickel-based alloy or a cobalt-based alloy.   
     
     
         2 . The T-die according to  claim 1 , wherein a plating layer is provided on an inner wall surface of the fluid material flow channel in continuity with the cladding layer. 
     
     
         3 . The T-die according to  claim 1 , wherein the cladding layer has a metallographic structure in which a metal borides or a metal carbides are dispersed in a binder phase. 
     
     
         4 . The T-die according to  claim 1 , wherein the cladding layer is formed to
 extend at a first width within a range of 0.2 to 1.7 mm from the edge of the lip portion along a lip mating face, and   extend at a second width within a range of 0.2 to 2.4 mm from the edge of the lip portion along a lip end face.   
     
     
         5 . An extrusion molding machine having the T-die according to  claim 1 . 
     
     
         6 . A method of manufacturing the T-die according to  claim 2 , the method including:
 a step of providing a material having a first surface that is a lip mating face, a second surface that is a lip end face, and a third surface that connects the first surface and the second surface and is inclined thereto;   a step of forming a cladding layer by laser build-up welding over the third surface with a powder of a corrosion resistant and wear resistant alloy;   a step of subsequently grinding the first surface and the second surface of the material together with portions of the cladding layer adjacent to the first surface and the second surface;   a step of subsequently forming a plating layer over the surface of the cladding layer and over the first surface of the material; and   a step of subsequently grinding the plating layer such that the cladding layer is exposed and the cladding layer has a surface flush with the surface of the plating layer lying over the first surface of the material.   
     
     
         7 . The method according to  claim 6 , wherein the width of the third surface is not smaller than 0.28 mm but not larger than 3 mm. 
     
     
         8 . The T-die according to  claim 2 , wherein the cladding layer has a metallographic structure in which a metal borides or a metal carbides are dispersed in a binder phase. 
     
     
         9 . The T-die according to  claim 2 , wherein the cladding layer is formed to
 extend at a first width within a range of 0.2 to 1.7 mm from the edge of the lip portion along a lip mating face, and   extend at a second width within a range of 0.2 to 2.4 mm from the edge of the lip portion along a lip end face.   
     
     
         10 . The T-die according to  claim 3 , wherein the cladding layer is formed to
 extend at a first width within a range of 0.2 to 1.7 mm from the edge of the lip portion along a lip mating face, and   extend at a second width within a range of 0.2 to 2.4 mm from the edge of the lip portion along a lip end face.