Police and the Health and Safety Executive have launched a joint investigation following the double tragedy at the Sonae factory on Moss Lane on Knowsley Industrial Estate, Kirkby yesterday.
Fire crews and paramedics, who were called to the factory at about 1545 GMT, tried to help the men but they died at the scene.
Sonae makes woodchip for the construction and furniture industries.
Local reports said the victims were maintenance workers who had been dragged into a woodchip storage silo.