Film-forming T die for low viscosity resin

Claim 1

A film-forming T die for a low viscosity resin comprising a die block housing defining a melted resin inlet for receiving said low viscosity resin; a supply manifold passage which communicates with said melted resin inlet; and a pressure equalizing manifold passage arranged substantially parallel and coextensive to said supply manifold passage and which is provided with an outlet extending along the length thereof and which forms the inlet of a die slit, said supply manifold passage and said pressure equalizing manifold passage being connected by a plurality of melted resin passageways provided along the entire lengths of the manifold passages, the cross-sectional area of the passageways per unit length of the manifold passages gradually increasing along the manifold in a direction away from said melted resin inlet, and said supply manifold passage having a volume at least 1.5 times greater than the volume of said pressure equalizing manifold passage; said die slit terminating in die lips and having means for adjusting the spacing of said die lips at spaced points along the slit.