Abstract: An apparatus for the production of a continuous length of polymeric foam from a liquid foam mix comprising an open-topped trough to the bottom of which the liquid foam mix is supplied to expand upwardly therein, until it flows therefrom over a weir structure associated with said trough into an open-topped channel shaped conveyor associated with said weir structure and arranged continuously to convey expanding foam away from the weir structure while it completes its expansion process, the open-topped channel shaped conveyor comprising a bottom wall and separate side walls which join said bottom wall downstream of the weir structure, the apparatus also including means operable to alter the length of the trough, and conveyor width adjustment means operable to alter the width of the bottom wall of the channel shaped conveyor and to move its said walls correspondingly in synchronism with width alterations of said bottom wall and sealing means for maintaining a seal where the side walls meet the bottom wall of the