DE2514105A1 - REINFORCED FILMS, PROCESS AND DEVICE FOR THEIR CONTINUOUS PRODUCTION - Google Patents

Description

25 U 10b

HOECHST AKTIENGESELLSCHAiT

File number: HOE 75 / F 083

Date: March 27, 1975 Dr.BU / L

Reinforced films, process and apparatus for their continuous Manufacturing

The invention relates to reinforced films and a method and a device for producing a film web that is reinforced by crossing ribbons.

It is known that the strength, especially the tear resistance of foils or paper webs through inserted fabrics, knitted fabrics or scrims of metal wires or stretched Plastic monofilament can be increased significantly. Bringing in the reinforcement thread can be produced directly during the production of the foils or by lamination on or in between Slides take place.

For reinforcements made from stretched thermoplastic threads, lamination or coating processes are used, in which the temperature can be kept so low or so briefly that there is no disorientation of the threads entry.

Woven or knitted fabrics can be used without difficulty, since finished webs are connected to the film or films. The same reinforcing effect can be achieved with crossed threads, with the additional operation of the

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There is no weaving or working. So far, however, there is still no technically usable and economical process, to produce such cross-laid fabrics continuously and to fix them until they are bonded to the film. The DOS 1 411 335 and 2 031 771 do describe devices for inserting individual longitudinal and transverse threads between film webs, the devices but are very complicated and work much slower than a modern film extrusion system. It is also It has already been proposed (DOS 1 704 933 and 1 801 957) to reinforce foils with nonwovens or split fiber webs. However, the reinforcement that can be achieved with the same amount of fiber material is less than with woven or cross-woven fabrics, partly because the threads are disordered, partly because the orientation is less or only runs in one direction. It has now become a very favorable process for the continuous production of a film reinforced by crossing threads found that the speed of modern film manufacturing processes can be adapted, so that the introduction of reinforcement can be carried out directly after the film production.

The subject of the invention is a reinforced film consisting of zv / ei cover films, between which diagonally crossing strips are welded, as well as a process for continuous Manufacture of a film reinforced by crossing threads, which is characterized in that between two equal wide, forward moving film webs placed a band of ribbons in a zigzag shape through a crosswise back and forth running comb which are fixed at the reversal points to the right and left of the film webs by hook chains and the so produced Scrim, consisting of two / one cover foils and the intersecting ones tensioned ribbon is pressed together and, after being released from the hook chains, is united by means of heated lamination rollers. This process gives reinforced foils with diagonally running, crossing ligaments, which are completely regular

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ORIGINAL INSPECTED

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moderate and straight in the network. The angle at which the Ribbon crossing depends on the relative speed of the foil and the comb. Preferably with a band of ribbons worked, the width of which corresponds to twice the distance between the two hook chains. When the two slides and move the hook chains while crossing the ridge by the distance between the two hook chains, cross each other the ribbons at right angles.

The cover foils can be produced by any desired method. It is of course possible to subtract them from roles. However, it is particularly advantageous if the two cover films are produced by cutting open a blown film tube and laminated with the reinforcement tapes immediately after production. The reinforcement ribbons are produced from a film by known methods, preferably by cutting and stretching. You can in between be wound up and then processed by bobbins. Preferably, however, you will also go straight through the band of ribbons Cut and stretch a freshly extruded film and insert it between the films. This has the advantage that the work of spooling is omitted and the tapes accumulate endlessly, so that no spool change is necessary. The special one The advantage of the method according to the invention is that, starting from the respective granules or powders for Cover foils and tapes, the reinforced foil can be produced directly in one operation.

All thermoplastics that can be processed into foils and that can be welded or are suitable as material for the foils are sealable. Soft PVC or polyolefins such as polyethylene, polypropylene or copolymers are preferred of ethylene and propylene among themselves or with up to 20 percent by weight of other 1-olefins, such as butene-1, pentene-1 or

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Hexen-1, used. Instead of foils, paper webs can also be used used v / earth made wholly or partly from thermoplastic fibers, for example from polyethylene fibers are.

All thermoplastics from which tapes can be made are suitable as material for the tapes. Above all suitable Rigid PVC, linear polyethylene with a density of 0.94 to 0.96 g / cm, polypropylene and polyethylene terephthalate. To one To ensure a good bond, it is preferable to use related materials for tapes and cover films, with the The softening point of the film should always be slightly lower, so that there is no disorientation of the stretched ribbon during lamination. For example, foils made of soft PVC be reinforced with tapes made of rigid PVC, or polyethylene films with polypropylene tapes, or films made of a propylene copolymer with a low proportion of ethylene with ribbon made of polypropylene or polyethylene terephthalate. Particularly proven has a composite of foils made of high-pressure polyethylene

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a density of 0.92 to 0.94 g / cm with ribbons made of low

3 pressure polyethylene with a density of 0.945 to 0.96 g / cm or Polypropylene.

The use of ribbons instead of monofilaments has the advantage of that the entire crowd can be made from one film. In addition, the ribbons are less bulky for the same titer as round threads, so that the foils have a smaller distance during the lamination and weld better. The fat the ribbon is preferably between 15 and 40 μm, particularly preferably between 20 and 30 μm. The width should be χ to 20 mm, preferably 3 to 8 mm. The distance between the ribbons depends of course on the intended use of the film and the required strength. He should at least correspond to the width of the ribbon. In the case of light foils, the distance can be up to 100 mm, in special cases even more. The distance between the ribbons is preferably 5 to 20 mm.

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The reinforced films according to the invention are suitable for all types of application in which the film has a high tear strength important is. In addition to other uses, they can be used, for example, as packaging material (in the form of tarpaulins or Sacks etc.).

Suitable for producing the film reinforced according to the invention a device consisting of devices for feeding two equally wide foils and a band of ribbons a support table over which the lower film runs synchronously between two hook chains, and one at right angles to the film running direction reciprocating comb that zigzagged the ribbons between the hook chains, with the individual ribbons taken by the hook and fixed to a cross-mesh, a roller at the end of the table for pressing the second film, devices for heating the composite and heated press rollers that the composite after release from the Weld the hook chains.

Figures 1 and 2 show the essential parts of the invention Device from the side and from above.

Figure 3 shows a partial view of a ribbon structure. In the figures:

1) the ribbon

2.) the lower foil

3) the top slide

4) the synchronously running hook chains

5) the support table

6) and 7) stretch rollers
8) and 9) dancer rollers

10) the synchronously running drive roller

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11) the synchronously running roller for pressing on the upper "film"

12) heated press rolls

13) a pulley

14) Guide rollers

15) a cold air shower

16) a radiant heater to preheat the underside

17) a radiant heater to preheat the top

18) the reciprocating comb

19) Guide roller for hook chains

20) Drive roller for hook chains.

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example

From high-pressure polyethylene with a density of 0.922 g / cm and a melt index MFI 190/2 according to DIN 53 735 of 1.5 g / 10 min, a film was produced in the usual tubular film process and, after leaving the squeeze rollers, slit on the right and left in the lay-flat fold so that Two equally wide, separately guided flat films were created. The films were fed into the apparatus shown in Figures 1 and 2 so that the lower web between the two hook chains ran at the same speed over the feed table. With the comb moving back and forth across the direction of the film, a band of ribbons was placed in a zigzag shape over the film and picked up and held by the hooks of the chains at the reversal points. At the end of the table, the upper film was pressed onto the fabric by a roller, then the composite was heated from both sides by radiant heaters and, after being released from the hook chains, fed to the heated press rollers. The lamination took place at 120 ° C. The reinforced film produced in this way was then rolled up like a conventional flat film. The speeds of the film and comb were coordinated so that when the comb moved transversely, the film moved forward by one comb width. Since the comb width corresponded to twice the distance between the two hook chains, a reinforced film with a diagonal grid, the ribbons of which crossed at an angle of 90 ° C., was obtained.

A low-pressure polyethylene was used to produce the ribbon

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a density of 0.947 g / cm and a melt index MFI 190/5 of 1.6 g / 10 min. The ribbon set was produced from a film by cutting and stretching. The tapes had a titer of 700 denier, a thickness of 20 μm and a width of 4 mm and had been drawn in a ratio of 1: 7. The mean ribbon-to-ribbon spacing was

/8th

2 13 mm. The weight of the reinforcement was 8 g / m.

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For comparison, the same film was cut open and laminated together in the device without interposing reinforcing tapes.

In a tensile test, tear strength and elongation were increased and unreinforced film on 50 mm wide strips with a clamping length of 50 mm and a feed speed of 50 mm / min measured. In addition, the damage force and damage work were determined in a puncture test according to DIN 53 443 sheet 2. The table shows the mean values of each 10 measurements.

Tabel

,around unreinforced reinforced Thickness of the foil kp / mm 120 130 Tear resistance % 1.1 2.66 strain kp / mm 240 34 Damaging force kp cm / mm 44.6 94.2 Damage work 14.6 30.7

By incorporating only 8 g / m of tape, the strength was increased the film increased by 2 to 2.5 times. The film bond was excellent. The ribbon could not be pulled out will. The film looked good because the ribbons lay straight and evenly between the cover films.

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Claims (9)

2 5 Ί 4 1 O 5 - 9 - HOE 75 / F 083 claims 1. Reinforced film, consisting of two cover films, between which are welded diagonally crossing ribbons. 2. J method for the continuous production of a film reinforced by crossing threads, characterized in that a band of ribbons is placed in zigzag shape between two equally wide, forward moving film webs by a crosswise back and forth running comb, which at the reversal points to the right and left of the film webs is fixed by hook chains and the fabric produced in this way, consisting of two cover films and the crossing, tensioned ribbons, is pressed together and, after releasing the hook chains, is united by means of heated lamination rollers. 3. The method according to claim 2, characterized in that the two cover films by cutting open a blown film tube getting produced. 4. The method according to claim 2 and 3, characterized in that the band of ribbons by cutting and stretching from a Foil is produced. 5. The method according to claim 2 to 4, characterized in that the width of the ribbon array is twice the distance corresponds to the two hook chains. 6. The method according to claim 5, characterized in that the two films and the hook chains during a crossing of the comb by the distance between the two hook chains. 6Q9841 / 0S37 25 H 105 - 10 - HOE 75 / F 083 7. The method according to claim 2 to 6, characterized in that polyethylene films with a cross-laid structure of polypropylene tapes be reinforced. 8. The method according to claim 2 to 6, characterized in that high-pressure polyethylene films with a cross-laid structure be reinforced by ribbon made of low-pressure polyethylene. 9 «Device for carrying out the method according to claim 2 to 8, characterized in that it consists of devices for feeding two equally wide foils and a band of ribbons to a support table, over which the lower foil runs synchronously between two hook chains, a chimney that goes back and forth transversely to the direction of the film, which zigzag the ribbons laid between the hook chains, with the ribbon be grasped by the hooks and fixed to a cross-laid, a roller for pressing on the second film at the end of the support table, devices for heating the composite and heated press rolls, which make the composite, after release of Weld hook chains. 9 D & 8 i · 1/0 8 ^ 7