DE2304093C3 - Foamed plastic packing material and process for its manufacture - Google Patents

Description

The invention relates to a packing material made of foamed plastic in the form of continuously open tubular profile sections for protecting sensitive packaged goods in packaging containers.

Hollow body units for the purpose of preventing the packaged goods from migrating as a result of vibrations during transport as well as the flowability of the packaging material are maintained. According to the embodiment, this object is achieved in that, in the case of a packing material of the type specified at the beginning, the tubular profile sections are eight-shaped. This training surprisingly results in one significant improvement in the dimensional stability under the effects of forces, such as when transporting a packaging container with one in it using the Sensitive goods packed in new packing material can occur. The new design in the The packaging material is made up of a multitude of units in the shape of a figure 8 or double loop consists of a foamed semi-rigid plastic, an increased shock and impact absorbing, i.e. energy-absorbing property, so that the individual

of the material under normal stress have a sufficiently high inherent strength and dimensional stability, but can be deformed to absorb impact when exposed to very strong external forces. Bumps up to a certain strength, as is normally

wait, become elastic without permanent deformation recorded. Therefore, the new packaging material can generally be reused without reducing the protection of the transported goods packed in it for the second time when it is reused.

According to an already known earlier proposal 30, the comparatively higher load capacity of the

(DT-OS 1 914 236) such a packing material is characterized in that the tubular hollow bodies have the shape of rings, the outer Diameters ranged between; J, 18 and 31.75 mm

new material before permanent deformation or breakage occurs, as well as its elastic resilience to a greater extent before reaching the breaking load due to the fact that the loop shape is one. The present invention aims at a print on the overall shape, especially a small opening Conversion and still further improvement of a sol · allowed to use the double loop or packing material. Eight shape of the new packaging material units made possible

The above-mentioned, already known packing material, which is also comparatively particularly small in use, has good flowability and therefore allows lower wall thicknesses, and thus a lower foam density a high working speed with the machine 40 and finally greater economic efficiency as a result

Pack. In addition, within a finished pack, through a certain interlocking of the individual ring-shaped packing units, it ensures sufficient dimensional stability of the filling body to prevent the packaged goods from "wandering" in the filling within a packaging container and provides particularly reliable protection of the packaged goods against shock loads due to its ability to a two-stage consolidation in such a way that first the shape of the individual packing units is changed elastically and then, with even greater stress, their material structure is also destroyed. The aforementioned packing material also has a particularly low Schüttgewtcht, high resistance to moisture, rot and vermin and high Eleständigkeit against r ^v »blend influences.

The present invention is based on the object of developing a packing material of the type specified at the beginning, which has the above In addition to the advantages mentioned, an even better stability, d. H. an even greater resistance to deformation under static and dynamic loads and in particular an even greater resistance to compression or breakage under the action of external forces can be achieved, while at the same time the other favorable properties, such as in particular Possibility of interlocking the individual lower manufacturing costs, based on the volume unit

A packing material of the type mentioned at the beginning can be produced in such a way that it is expanded Plastic foam brought into the shape of an elongated tube by extrusion, then cut into short slices and then expanded will. A method based on this principle for the production of the new one described above Packing material with eight-shaped tubular profile sections according to the invention consists in that before cutting the diametrically opposite outer surfaces of the pipe continuously deformed inward, compressed and due to the Extrusion heat are firmly connected in the middle, so that the pipe cross-section eiuwr the shape 8 receives

The invention is explained in more detail below with reference to the drawings, for example. It shows

F i g. 1 is a perspective view of a quantity of packaging material with the eight-shaped tubular profile sections according to the invention;

FIG. 2 illustrates the crimping process serving end elevation of a crimping device for producing the in F i g. 1 illustrated packing material units designed as eight-shaped tubular profile sections;

F i g. 3 a horizontal section along the line

60

Fi for 4 is a reduced schematic representation one for carrying out the method according to the invention serving establishment;

F i g. Figure 5 shows the crimping device in side elevation the establishment of F i g. 4;

6a, 6b and 6c each show a plan view in Section and in a side elevation the cutting device from Fig-4;

Figs. 7a, 7b and 7c show packaging material units according to the invention.

The individual, by eight-shaped tubular profile sections formed packaging material units 10 of the packaging material according to the invention shown in FIG. 1 consist, as shown in FIGS. 7a to 7c can be seen, each from an elongated, relatively flat, self-contained ring band made of expanded foam plastic, which is packed in its center 12 and its inner walls are adhesively connected to one another in this area. To this In this way, there are two for each packing material unit 10 Rings 14 connected at one point are formed, which give the shape of an 8. As the F i g. 7a to 7c show, the side surfaces 16 on both sides of such a packaging material unit are essentially 2 * flat and parallel to each other. In the case of the FIGS. 1 and 7 close the embodiment shown the side surfaces 16 each have a small angle with the axes of the connected rings 14, the is denoted by 18 in FIG. That way The resulting configuration of the packing material gives each individual unit a high degree of dimensional stability, i.e. H. a high resistance to stresses due to deformation, due to which the packaging material units particularly suitable as packing material. In particular, the rings 14 have a raised Resistance to permanent deformation in directions perpendicular to the axes 20 (FIG. 7). In addition, the figure of eight gives the individual packing material units 10 in a packing material mass special property, without being compressed or permanently deformed, shock-absorbing in several Directions to act when vibrations, shocks, shocks or other undesirable or .. harmful mechanical effects on one in the Packaging material wrapped object, for example during transport or handling the pack.

As from the IF i g. 1 and 7, ensures the described design of the packaging material units 10 a controlled deformability in practically every direction perpendicular to the axes 20 of the rings 14 (see arrows 22 in Fig. 7b). Effect accordingly the packing material units 10 a good shock absorption, since their deformation resistance in static or dynamic loading in directions perpendicular to the planes of the side surfaces 16 (arrows 24 in F i g. 7a) is particularly large. In addition, the annular halves 14 with their openings have an advantageous effect Interlocking and mutual hooking of adjacent packaging material units in a packaging material mass, so that not only a firm padding, but also a high resistance to the Wandering of a packaged item is achieved within the packaging material mass. On the other hand, the Eight-form of the! Units the packing material in its mass also the desired pourability. Hence lets the packaging material is conveniently placed in recesses and openings in a shipping box or the like Pour in objects of complex shape so that the packaged goods do not come into contact with the carton side walls. in the For commercial use, pouring or leaving the packaging material can be poured in quickly and conveniently with automatic filling machines or by hand by unskilled workers a

A device such as that shown in FIG F i g. 4 and 5 is shown. It includes an extruder 30 with an extruder head 32 and other known ones Components such as B. a funnel 34 and a conveying chamber 36. With the assistance of a (not shown) Conveyor screw or another not shown, pressure generating device is a Liquid or heat-softened plastic mixture through an annular channel in the form of a hollow one Plastic tubing 38 extruded After exiting the machine, the heat-softened coolant Plastic in the surrounding air quickly up to Solidification so that the pipe string 38 can be pulled off with frictional engagement in the direction of arrow 40 can. As a result, the cells of the foam plastic are stretched in the longitudinal direction. The peeling of the hollow pipe strand from the extrusion press is carried out by endless conveyor belts that grasp the strand with friction 42 or the like, which is part of a pulling device 44 form. In this way, the pipe string 38 continuously enters the working area of a cutting device 46. At the same time, FIG. 4 and 5 the mode of operation of Krimpfrädem 48 and 50 of a Knmpf- or squeezing device 52, by means of which the still warm and soft hollow pipe string 38 before it is cut in the cutting device 46, continuously at diametrically opposite points its outer surfaces is deformed inward and compressed, so that the outer walls of the pipe due to the extrusion heat in the middle are firmly connected to each other and the pipe cross-section is given the shape of an 8. The crimping device 52 is shown in FIGS. 2 and 3 are shown even more clearly. As in particular F i g. 2 shows the Crimping wheels 48 and 50 cooperating circumferential surfaces with groove-shaped recesses 54 and an annular bead 56 arranged between them. There are also at the ends of the crimping wheels edge flanges 58 guided closely past one another, through which the space between the opposing groove-shaped recesses 54 and a pressing or squeezing zone 60, as in FIG. 2 indicated, is given. The upper crimping wheel 48 is guided by guide disks 62 of the lower crimping wheel 50 held in alignment with the latter as it rotates.

F i g. Figure 5 illustrates the operations in the manufacture of the packing material according to the invention. The hollow elongated plastic tubing 38, which has been softened by heat, is moved in the direction of the arrow 40 drawn from the extruder head 32 of the extrusion press by the crimping wheels 38 and 50 of the crimping device 52. The upper crimping wheel 48 lies within the guide washers 56 against the surface of the lower one Kripvpfrades 50 on. It is carried by a pivotable lever arm 66 with a fork 68 which passes through Weights 64 is weighted down. A frame 70 carries a bearing block 72 for the lower Krimpfrad 50 and one higher bearing block 74 for the lever arm 66.

The crimping wheels 4β, 50 practice as in Figures 2 and 3 shown. Pressure or squeezing forces on diametrical opposite points of the wall of the still warm and soft pipe string 38, through which the inner pipe surfaces are pressed against each other at these points and adhesively connected to each other. The pipe string 38 has already cooled down a little compared to the extrusion temperature and has become stiff, but not in such a way that an adhesive connection in the area of the pressing or squeezing zone 60 no longer occurs it is possible. In practice, the vaccination device can be at a distance of about 0.9 to 1.5 m from the extruder head be remotely located, the linear extrusion speed being approximately in the range of 8 to 93 m per minute.

Following the crimping process in the crimping device 52 is the flat crimped tube 78 by means of the pulling device 44 in the cutting and separating device 46 drawn. In this the rotating cutting knife 80 cuts in connection with a pipe guide 82 relatively short disc-shaped parts. 84 from the flat crimped tube 78. These cut-off parts 84 then result in the packaging material units with the desired figure-of-eight shape.

The packaging material units 10 are distinguished by their figure eight shape in comparison to similar known ones Packing material units of a different shape due to a particularly high resistance to permanent deformation the end. The figure of eight changes little under most conditions of use, so that the packaging material units can be used several times without noticeable deterioration. Only with extremely high forces does a strong change in shape occur in the middle Section 12 and in the annular end portions 14 of the packaging material units 10, through which the Shock absorbed and damage or destruction of the packaged goods is prevented. The property the flowability and pourability remains unaffected, although the individual units 10 with other similar units in a packing material mass interlock with one another can, so that the packaged goods in its position within a mass of the packaging material in is held in a container.

The new packaging material is particularly suitable for packaging if it can be used repeatedly of fragile or sensitive objects such as B. electronic and optical devices, Components, lenses, radio and television tubes, glass and porcelain ware, works of art and many others sensitive items by changing their

Position within the packaging material could be damaged.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1. Packing material aas foamed plastic in the form of continuously open tubular profile sections to protect sensitive packaging goods in packaging containers, thereby characterized in that the tubular profile sections are eight-five. 2. A method for producing a packing material according to claim 1, wherein the expanded Plastic foam into the mold by extrusion brought an elongated tube, then cut into short slices and then expanded, characterized in that before the diametrically opposite outer surfaces of the pipe continuously after cutting deformed inside, compressed and on grand the heat of extrusion are firmly connected in the middle, so that the pipe cross-section the Receives form an 8