Abstract: In an apparatus and a method of producing a roll of bags, a bag feeding device is arranged to feed bags one by one to a winding device. The winding device includes a rotating spindle which is arranged to engage with each bag separately to wind the bag on it, so as to build a roll of bags in which the bags are unconnected to one another yet firmly held together. The winding device comprises at least two separate winding stations, each winding station being connected to one or more bag feeding devices; and a switch that is arranged upstream of a bag feeding device to direct the bags from one winding station to the other when a roll of bags has been completed in one of the winding stations.

Abstract: In a method for working an elongate web of material, use is made of a machine which comprises a feeding device for feeding the web at a given speed and a cutting device for making cuts in the web. The cutting device comprises a rotary backing roll and a rotary cutting roll with a projecting cutting means. The cutting roll is adapted to move, during a first part of its revolution, the cutting means into engagement with the backing roll to form the cuts in the web and, during a second part of its revolution, define with the backing roll a gap through which the web moves essentially unimpededly. A control means is adapted to control, preferably in an infinitely variable manner, the speed of rotation of the cutting roll relative to the speed of the web during the second part of the revolution for optional adjustment of the distance between succeeding cuts in the web.

Abstract: In an apparatus and a method of producing a roll of bags, a feeding means is arranged to feed bags one by one to a winding station. The winding station includes a rotating spindle which is arranged to engage with each bag separately to wind the bag thereon, thereby building a roll of bags in which the bags are unconnected to one another yet firmly hold together. The apparatus can be of simple construction, which provides for low costs and little wear and tear. Further, there is little risk of inflicting damage to the bags. Additionally, the flow of separate bags can be directed between several sequentially operated winding stations, thereby allowing for high production rates.

Abstract: Method and device for producing rolls (17) of bags. At least one longitudinal side edge (15, 16) of a line of overlapping bags (17) is folded towards the centre axis of said line of bags. The line is then winded to rolls (17).

Abstract: In order to improve a process for producing plastic packaging, particularly using plastic sheets, lateral sections (14) projecting beyond goods to be packaged being at least partly shrunk by heat supply, so that heat-sensitive goods also can be packaged in an economical and visually attractive way, it is proposed that the heat supply be interrupted as soon as the shrinking process starts in an area of plastic packaging subjected to heat, and that mechanical pressure be exerted on the heated areas of plastic immediately afterwards. An apparatus for carrying out the process for producing plastic packaging has an uptake area, a heat supply device and pressure members (15).

Abstract: A welding unit for forming defining weld lines in an elongate web, preferably in a bag-making machine, includes a drive means, which is arranged in an endless loop, and at least one sealing jaw. The sealing jaw is connected to the drive means for movement along said loop. A fixed guide means extends in an endless loop essentially in parallel with the drive means. Each sealing jaw is received on a carriage, which is connected to the drive means and has at least one follower element, which is adapted to abut against and move along the guide means.

Abstract: A device for applying a wrapping round a cylindrical roll of bags comprises a wrapping unit (4) for winding a web section (9) round a roll of bags (13) in a winding station. The wrapping unit (4) comprises a means (17) for feeding the front end portion of the web section (9), as seen in the feeding direction, to a site adjacent to the circumferential surface of the roll of bags (13). In addition, the wrapping unit (4) comprises a means (11, 14) which is adapted to grip the roll of bags (13) and the adjacent front end portion of the web section (9) as well as to rotate the roll of bags (13) about its longitudinal axis so as to wind the web section (9) round it. The wrapping unit (4) further has means for connecting the rear end portion of the web section (9) to the web section (9) wound round the roll of bags. A device of the above type is advantageously utilised in a method for applying a wrapping round a cyclindrical roll of bags.

Abstract: An arrangement in a bag-making machine for forming weld lines in a web continuously fed through the machine, preferably a flattened plastic film tube, comprises a cylindrical, freely rotatable drum; a driving belt which is adapted to rotate the drum and pressed against part of the circumferential surface of the drum; and a number of transverse sealing jaws which, as the drum rotates, are movable into engagement with and drivable together with the web for welding the web through a predetermined angle of drum rotation. In order to achieve a high speed of the web, preferably about 150 m/min., and high flexibility in respect of the available range of bag length, the sealing jaws are freely movable relative to the drum outside the circumferential surface thereof and controlled by a control device which is adapted to hold each sealing jaw in a stand-by-position out of engagement with the web, and successively to bring each sealing jaw into engagement with the web with a certain time delay relative to each other.