A valve assembly includes an elongate first member 20, an elongate second member 22 arranged adjacent the first member 20 to form an elongate channel 14 therebetween, wherein the first member 20 includes a resiliently flexible spine 32 to allow the first member 20 to be flexed between an open position, in which the channel 14 is open, and a closed position, in which the channel is closed by mutual engagement of the first 20 and second 22 members along the elongate length of the channel 14； and drive means 28 for flexing the first member 20 between the open and closed positions. The drive means may comprise a shaft carryings an eccentric 30. The valve is said to be particularly suitable for use in the production of deposited sheets of foodstuff.
