foot having an outlet through which adhesive can be fed on to the central region of the part of the workpiece to be folded the passage in the creaser foot is supplied through a delivery tube 24 which is connected 34 upstream 34 to a gear pump 26 which in turn is fed from a melt chamber 28 because the adhesive is a hot melt the melt chamber 28 delivery tube 24 and creaser foot 22 are each provided with a separate heater respectively h1 h2 and h3 of the electric cartridge type the delivery tube furthermore is clad with appropriate thermal insulation for moving the creaser foot 22 out of its operative position a manually operable lever 38 is provided which together with the lever 20 thus facilitates the introduction of a workpiece to the operating locality of the machine the heightwise position of the creaser foot 22 is adjustable by an adjustment knob 40 the machine as so far described above is conventional furthermore also as is conventional the machine comprises a snipping knife arrangement generally designated 30 and comprising a fixed blade 32 and a movable blade 34 mounted on the fixed blade the blades being so arranged 34 downstream 34 of the block 12 that they can cut the upstanding edge portion of the workpiece which is supported by the block 12 in general the snipping knife arrangement 30 is used where the edge of the workpiece defines a so called 34 inside 34 curve for feeding a workpiece past the block 12 and the creaser foot.