Method and Apparatus for Packaging Smeltable or Fluid Material

The invention relates to a method and apparatus for packaging smeltable or fluid material, especially molten bitumen, in flexible synthetic foil containers resistant to water and to the molten material, by pouring in the material in its fluid state and, in the case of materials which are solid at room temperature, allowing hardening after the container is sealed, the containers being cooled during the filling stage by a water bath.

In a known process, the containers are fixed above the water bath prior to the start of filling, and are progressively lowered into the bath as filling progresses, while the surface of the molten material remains at approximately the same height as the water surface. This process is cumbersome, since it necessitates first attaching a previously prepared bag, open at the top, to a support, then introducing the filler material through the open end, removing the bag from the support, closing it above the water surface, and then cooling it in a water bath. The process by its very nature is a discontinuous one, and has the further disadvantage that a fusing foil packing cannot be used i.e., that the user is required to remove the packing foil before processing the packaged material, e.g., in the case of bitumen, to smelt such material.

The object of the invention is to provide for a simplified packaging method permitting more rapid operation and hence augmented production. Furthermore, the invention permits the use in every instance, i.e., in the case of both hard and soft bitumins, of fusing foil, thus obviating the need for removing the packaging foil. According to the invention, this object is attained by using synthetic foil in the automatically operating packaging apparatus, the foil being folded into tubular shape and fused along the longitudinal seam, whereupon the tube is sealed at the end which is at the front in the direction of movement, the fusible or fluid material is then introduced into a water bath far below the surface thereof by way of the still open back end of the tube, the tube is closed to make it into a container, and finally a further tube portion having an opening at the top is formed, filled, and sealed, and the sack band is continuously led through the water bath, and, if appropriate, to an adjoining cooling bath.

The principal advantages of the novel process are the following:

1. The method is automatic and fully continuous, so that the performance of the installation is markedly increased, and considerable savings in personnel are made possible. 2. In every case fusing foil can be used, since the introduction of high temperature material occurs totally under water, and hence there is no danger that the foil will melt. 1. Even soft, i.e., easily fusible foil can be used, this being particularly important in packaging, e.g., bitumins having a low melting point.

An apparatus suitable for carrying out the process according to the invention is shown in the accompanying drawing, wherein:

FIG. 1 shows a vertical section through the filling apparatus;

FIG. 2 shows a plan view of such apparatus;

FIG. 3 shows a vertical partial section through a plunger suitable for introducing the material, and

FIG. 4 shows the manner of closing the containers.

FIG. 1 shows a foil roll arrangement, consisting in the present embodiment of two foil rolls 1a and 1b. When foil roll 1a is empty, a continuous, unending connection with the foil on roll 1b can be made by means of a pulse welding station 2. The band then reaches compensating attachment 3, whose purpose is to effectuate an even feed at the moment of fusing the ends of the foils from rolls 1a and 1b, which requires a short pause. This compensation is achieved by means of equalizer roller 3a, which permits the foil guided over guide roll 3b to feed at constant speed, due to the fact that it moves up- and downwardly with the aid of balancing sheave 3c, in accordance with the length of the pause. The foil next passes along a hydraulic cylinder 6 which actuates plunger 5 whose significance will be explained hereinbelow. It then reaches a tube forming means 4, in which the foil is folded into tubular shape. The longitudinal seam is formed with the aid of pulse welder 4a, so that a tubular foil is produced. Two welding means 10 then seal this foil by means of a double mash seam weld producing the seal closing the bottom of the tube, and shown in FIG. 4 by numeral 21.

The sealed tube, is next fed down into cooling basin A, until it reaches the position also shown in FIG. 4, wherein 22 designates the water level. In the position here shown the tube, still open at the top, is filled by way of the plunger 5 which is arranged inside the tube forming means 4. The design of plunger 5 can be seen in FIG. 3, and includes a bitumen valve 5a and, an air outlet 5b. Air is forced by blower 5L (see FIG. 1) into plunger 5, and passes through air outlet 5b into the foil tube, in order to counterbalance the predominating water pressure and thus to prevent collapse of the foil tube through such water pressure. Simultaneously valve 5a opens by action of hydraulic cylinder 6, which actuates plunger 5 for up-and-down movement. When plunger 5 is moved away from the sealed lower end of the tubular container by action of hydraulic cylinder 6, a predetermined amount of material is introduced into the still open end of the container by means of dosage means 8, 9. The filler material is conveyed to plunger 5 by way of tube 8a, and from plunger 5 (as noted above) into the container, which is filled below the water level, to about level 23. At this point, the pulse welding means 10 go into operation to seal the filled container, which is completely immersed in the water bath, by means of a double mash seam weld 24. The pulse welding means 10 simultaneously forms a further double mash seam weld 25, so that the next container, which is still open at the top, is ready for filling in a continuous mode of operation.

The process just described is repeated continuously, so that the operation is fully automatic. The filled containers are now moved through cooling basin A, and suction pump 11 facilitates the feeding of the container binding in the area of plunger 5, and simultaneously the circulation of cooling water. Conveyor belts 12 and 13, which effect movement of the container chain in synchronism with the feeding through plunger 5, move inside cooling basin A. Where the filler material is, e.g., hot bitumen, oil or the like, conveyor belt 13 simultaneously serves to prevent surfacing of such material, which often has a lower specific weight than water.

The container chain finally reaches collecting trough 15, and is separated into separate containers by cutting means 14.

FIG. 2 illustrates cooling basin B, which is considerably longer than cooling basin A. For example, the length of cooling basin B may be 50 meters, and that of cooling basin A 20 meters. Cooling basin B serves for the further cooling and storage of the filled containers, which are moved in cooling basin B in the direction of arrows C by a water current produced by circulating pump 16, which pumps the water in the direction of arrows D by way of a recooling or refrigerating arrangement 17, and leads it back to cooling basin B at E. The cooled containers, now ready for shipment, are raised out of the water by means of lifting device 18. Finally, 19 indicates a water level control unit, which acts on pumping station 20, whereby water can be added to cooling basin B from a reservoir beneath, or led back to such reservoir depending on the volume of the containers situated in cooling basin B. In this manner, the water level in both cooling basins A and B remains constant, and the water consumption is limited to natural evaporation.