Abstract: A ring member (10) of reinforced plastic construction for a wrapping machine, said ring member comprising a box-shaped portion (15) having a plurality of reinforcing fibre layers so arranged that the fibre directions are varied so as to achieve a sufficient strength and flexural rigidity, and a core part (17) of cellular plastic. The walls (14) of the box-shaped portion may deviate from a vertical or horizontal plane, and the wall may be provided with one or more flanges (16) oriented in a direction outward from the ring member or toward the center of the ring member. The box-shaped portion is preferably made of carbon fibre and epoxy resin, and the core part inside the box-shaped portion is of foamed polyurethane plastic. Inside the reinforcing plastic layers of the box-shaped portion it is also possible to laminate a steel reinforcement (18), to which a wrapping film feed apparatus (20) and possibly support rollers are fastened.

Abstract: A method of packaging by wrapping and a wrapping machine (20), in which method a top film (64) is cut into a top film sheet (65) and pulled on top of a top film carrier (54) turned upside down, to a position above the object being packaged (31). After this the carrier and the top film held in place by means of suction nozzles (55) are turned around and pressed with the help of the pressing device (53) onto the object being packaged. During the first stage of wrapping, the edges of the top film sheet are held up by means of the suction nozzles of the carrier and plastic film web is wrapped around the article being packaged from bottom to top. After this, the edges of the top film sheet are pressed down by means of blow nozzles, and plastic film web is also wrapped on top of the edges of the plastic film sheet.

Abstract: A method and device for treating plastic film, according to which method plastic film web used as packaging material is wrapped around the object to be packaged. According to the method, the plastic film layers are seamed together and the plastic film web is cut off by heating the seaming point and cutting-off point by means of a heat radiator. Heat-absorbent counterpieces are preferably placed at both the seaming point and the cutting-off point, the said counterpieces being heated through the plastic layers. When the counterpieces absorb heat from the heating radiator, they heat up and at the same time heat the plastic films to be seamed and cut off. In the most advantageous embodiment, the infrared heat radiator is placed inside a tubular gripping counterpiece, which gripping counterpiece comprises slots through which the heat radiation is able to pass to the counterpieces.