A design method for right angle die with non-symmetric flow channels for double-lumen micro-tubes was presented by using flow balance of polymers.First

based on the flow balance of polymers

a relationship among the structural parameters of non-symmetric flow channels in the right angle die was built.Second

in the opposite direction of extrusion

the lengths of the flow channels that were created by the relationship were calculated

and the ends of the lengths were fitted.Then

there was an objective function for the structural optimization of the flow channel in the right angle die to be established through the fitting deviations.Finally

the non-symmetric flow channels in the right angle die were designed and manufactured according to the optimization results.The experimental results of extrusion indicated that the design for the non-symmetric flow channels of extrusion die was reasonable and the design method for right angle extrusion die of polymeric double-lumen micro-tube according to the non-symmetric flowing balance was correct and effective.