Mfg. hopper plate for folding hopper on rotating pressure machine - involves placing cores with air inlets in hopper plate=shaped tool, casting polymer over cores, curing and bonding to hopper plate

摘要

A hopper plate for a folding hopper has a conical shape with a semi-circular section. At least one air pressure-chamber is formed in the curved plate by a plastic wall(18). Openings in the plate allow pressurised air to escape. Air is supplied to each chamber via an inlet (13) in the plastic wall (18). The plastic wall (18) is mfd. in a tool (3) corresponding to the profile of the hopper plate. Reusable cores (7) are placed in the tool (3) to form the air chambers and air inlets (13) are inserted in a recess (10) in each core before a polymer is cast into the tool (30) to form the wall (18). When cured the plastic wall (18) with integral air inlets (13) is separated from the tool (3) and cores are bonded to an identically-shaped hopper plate. Pref. each pressurised air inlet (13) is let into a recess with a radiused entrance in the respective core. Cast polymer enters the radiused area to give an increased area of bonding to the air inlet (13). USE/ADVANTAGE - For prodn. or an air reservoir attached to a hopper plate of a folding hopper on a rolling machine. The plastic wall is produced independently of the hopper plate using reusable cores and does not require the use of solvents. A good seal is achieved between the plate and plastic wall.