| 摘要 |
A dispensing valve for flowable material comprises a valve plate (26) of resilient polymeric material in which at least one elongate discontinuity is formed. The discontinuity defines at least one valve flap (28) which is an integral part of the valve plate but whose margin defined by the discontinuity is not connected to the adjacent material of the valve plate. The valve flap (28) is movable under the application of pressure from a closed position, in which the adjacent margins of the discontinuity form a substantial seal, to an open position, in which the margins for the discontinuity are spaced from one another and material can flow through the valve member. The polymeric material is a polyolefin material and the discontinuity is a rupture line. The margins defining the rupture line are of decreasing thickness towards their free edge and overlie one another.
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