Methods and apparatus for coating substrates

A system for applying a pressurized coating material to an elongated substantially rigid substrate, said system comprising:

• a die for contacting said substrate with said pressurized coating material, said die defining a pressurizable coating cavity, a coating supply channel, a substrate inlet, and a substrate outlet;
• and
• a substrate feeder for aligning said substrate with said substrate inlet and pushing said substrate at least partly through said die via said substrate inlet, coating cavity, and substrate outlet,
• wherein said die comprises a die block, a guide plug removably coupled to said die block, and a die plate removably coupled to said die block,
• wherein said guide plug defines said substrate inlet and said die plate defines said substrate outlet,
• wherein said guide plug includes an outer profile protrusion extending from a face of said guide plug for interfacing said guide plug with said die block,
• wherein said outer profile protrusion of said guide plug extends forward from a front face of said guide plug,
• wherein said outer profile protrusion of said guide plug is correspondingly-shaped with at least a portion of said die block, so as to form a substantially airtight seal when said guide plug is coupled with said die block, and
• wherein said die is configured to maintain an elevated pressure of at least 25 psi in said coating cavity when said pressurized coating is supplied to said coating cavity and said substrate is received in said substrate inlet, said coating cavity, and said substrate outlet.

A method of coating a substrate, said method comprising:

• (a) introducing a pressurized coating material into a coating cavity of a die;
• (b) pushing a first elongated substrate into said die through a first substrate inlet;
• (c) passing said first elongated substrate through said coating cavity to contact said first elongated substrate with said coating material, wherein said coating material in said coating cavity is maintained at a pressure of at least 25 psi during said passing;
• and
• (d) discharging said first elongated substrate from said die through a first substrate outlet to form an at least partially coated first substrate,
• wherein said die comprises a die block, a guide plug, and a die plate,
• wherein said guide plug and said die plate are removably coupled to said die block,
• wherein said guide plug defines said first substrate inlet,
• wherein said substrate inlet includes an inner profile and an entrance profile, with said inner profile having a lateral cross-section of a different shape than a lateral cross-section of said entrance profile,
• wherein said die plate defines said first substrate outlet,
• wherein said guide plug includes an outer profile protrusion that extends forward from a front face of said guide plug, and
• wherein said outer profile protrusion of said guide plug is correspondingly-shaped with at least a portion of said die block, so as to form a substantially airtight seal when said guide plug is coupled with said die block.