A cleaning piston for a mixing head of a reaction moulding machine includes a main part which has a cylindrical casing region, and a clearing part. The material and geometry of the clearing part are designed to remove residual material adhering to a channel of the mixing head. The clearing part is at least partly made of non-polar material.

A device for mixing at least two fluid to pasty substances has a housing (2) with at least two openings (5, 6) for feeding the substances and with a discharge opening (8), a mixing element (3) which can rotate in the housing (2), which mixing element (3) can be displaced in the direction (17) of its axis (7) in relation to the housing (2) in order to adjust the size of a gap (18) between a conically tapering part (14) of the mixing element (3) and a likewise tapering region (15) of the housing (2) in order to adjust the shear rate in the region of the gap (18). The mixing element (3) has a region (9) in which annular ribs (11) are provided which project from the mixing element (3) and which engage between adjacent annular ribs (12) which project from the inner surface (10) of the housing (2).

A longitudinal sealer includes a housing, an arm, and a heating element. The housing is configured to be installed in a foam-in-bag system. The arm is movably coupled to the housing. The heating element has a leading edge exposed through an exterior surface of the arm. A position of the arm with respect to the housing is controllable so that the arm is movable between a first location where the leading edge of the heating element is not in contact with a film in a film path of the foam-in-bag system and a second location where the leading edge of the heating element is in contact with the film in the film path of the foam-in-bag system.

An injecting machine includes an injection cylinder, a plunger, a plunger moving mechanism, and a mixing mechanism. The plunger is reciprocally received in the injection cylinder for moving between an advanced position and a retracted position, with the injecting a liquid mixture of two different liquid materials as the plunger moves to the advanced position. The plunger moving mechanism causes the plunger to move between the advanced position and the retracted position. The mixing mechanism is disposed on the injection cylinder for mixing the two different liquid materials together to feed the liquid mixture into the injection cylinder. The plunger includes a front portion having a helical groove formed on an outer circumferential surface thereof to allow the liquid mixture fed from the mixing mechanism to pass through the helical groove for collecting in a forward space formed forward of the front portion of the plunger.