DE6751805U - CUTTING AND STRETCHING DEVICE FOR THERMOPLASTIC PLASTIC STRIPS. - Google Patents

Description

PJUOE 607 * 12.7.

Cutting and stretching device for thermoplastics

Plastic strips

The firing relates to a cutting and Warmstreekvor- \

direction for thermoplastic plastic strips to the h

, position of artificial textile fibers, which in particular |

as a substitute for animal and vegetable pastes, such as f

Jute, Bast Uodgl »are useful. ■

It is well known that thermoplastics can be found in the. \ Textile sector as a substitute for jute and other yarns normally used for the production of sacks, packaging material and the like.

These plastics are normally extruded at high temperature as continuous films, but possess the films produced in this way have an extremely low mechanical strength, which is completely inadequate for the use as textile fibers is *

The material is therefore subjected to a stretching which takes place in the heat at temperatures which between 100 and ISO G ham. In other words, it will be accordingly heated material is extended in the desired stretching ratio, which for each material depending on the intended Use is predetermined. This caused by the combined effect of warmth and draft Stretching causes molecular alignment in the

675180

material and consequently a significant increase in mechanical strength of the same "

Since it is a question of producing textile fibers, i. E. .Stripes - which are a few millimeters wide and very thin, The film produced must be drawn into strips prior to stretching are cut, which are usually 4-10-12 mm wide and whose width, according to the drying, is 2-3 mm is reduced, while the strength® a few hundredth! Millimeter is

The known plants for the production of such strips, which are usually called plants for the production of synthetic Said bezeidhnet consist essentially of an extruder, which a film of certain Thickness and certain width produced- The correspondingly cooled EiIm, which comes directly from the extruder exits, is then passed through a series of shoulders driven at a certain speed «

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homely razor blades used) before the said If they are to be arranged, cut the FiIa into a corresponding one Number of strips of a predetermined width (usually 6-12 mm), making plastic strips ready to be drawn.

K & ch of the mentioned sieve from Sollen reach the Streifes through a tunnel in which warm air is usually circulated is then detected at the exit of the tunnel on the part of another row of ought. In this section The stretching takes place, which, as I said, is due to the combined effect of the warmth and the pull on the part of the second-mentioned series of ought, after this second-mentioned series of ought rotates at a speed that is a predetermined multiple of the speed of the first group of rollers, ent corresponding to the desired draw ratio.

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The strips obtained in this way are then fed to a winding machine, where appropriate beforehand be led through a second, smaller tunnel in order to achieve some stabilization.

The subject of haying is a cutting and stretching device for strips, in the case of the stretching tunnel is replaced by a heated plate, over which the strips cut immediately in front of the plate are spread

The cutting and stretching device according to the innovation allows, thanks to the support formed by said plate, the risk of tearing of the strips to be reduced considerably and in the pail of a bite there is no risk of Calibrate to wind the torn strips around the calender rolls and cause more bites

The cutting and stretching operation, the strip may FER jojBT with safety and be visible controlled by the operator, who can easily intervene if necessary. ^

Another advantage of the device according to the invention lies in the fact that the strips are heated faster and more uniformly and therefore provide a significantly better result. product quality is achieved. ,.

Perner is the advantage of lower cost and lower structural difficulty of the device compared not to ignore the devices used so far

The hiring is explained in more detail on the basis of exemplary embodiments with reference to the drawing.

Fig. 1 shows schematically in a perspective view

a first embodiment of the device according to the furnace and

Jig »2 is a schematic side view of a further en embodiment of the device.

Pig.1 shows a PiIm "or a pile 10, which comes for example from an extruder or from a supply reel (not shown) and is guided through a first group of rollers 11, 12 and 13, of which, for example, the set 12 is passed through a not shown Drive is driven, while the pods 11 and 13 are freely rotatable.After the roller 13, the foil encounters a group of blades H-, which are held accordingly by means not shown and in a two-dimensional height is the movement path * of the film 10. The blades 14 are at a mutual distance which corresponds to the desired width of the strip formed by them _;

t if en 1? before it is stretched, the blades 14 are then drawn across a convex surface

■■ -ehe 15 out of a heating plate 16 on which it is free ieleiteii. on-wool they cms'eÄ they total surface under =

"* Be used. Subsequent to the plate 16 are the Strip 17 passed through another calender, -which

_v consists of a group of roles 18, 19 and 20, which are

.-v sentlichen the rollers 11, 12 and 13 correspond, check _{JE> r} but rotate at a greater speed. ■ ~ - ^{> -}

The surface 15 is preferably very smooth, even mirror-smooth and chrome-plated to prevent oxidation and improve the sliding properties of the material.

The plate 16 is normally heated to an appropriate temperature to 100 ⁰ C to 180 ⁰ C, which iPemperatur is adjusted by means of a thermostat.

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In general, the plate 16 is heated with the aid of suitable means which allow an adjustable heat dissipation. For example, electrical heating resistors that are let into the plate, provided the same from a Piece, or a heating fluid, such as oil or another diathermic fluid, which in the plate is included if it has an interior space in which the heating medium can be circulated, is used will.

The difference in speed of rotation between the caves 11, 12 and 13 and those 18, 19 and 20 will of course depend on the stretch ratio desired, besides the properties of the material forming the film 10. The material carried out by the plate 16 obviously also depends on this material Warming, be it for the temperature or for the duration, from «

In Fig.2 is another embodiment of the device shown according to the innovation, in which both the upper surface 15 and the lower surface 21 of the plate 16, over the two foils 10 made of thermoplastic material slide, are used

As can be seen from the figures, the convex shape of the surfaces 15 and 21 is particularly important, the extent of which in the direction of movement of the strips depends on the desired stretching ratio and on the temperature which the strips are to reach.

It will be understood that G _{s-rundgeuäükens} many other possible embodiments exist within the scope of the innovation and while maintaining the de3 using a heated convex plate in the draw zone, which directly to the cutting zone fol t _6.

Claims (5)

P.A.ye-607 * 12.7.E8 Protection claims 1. Cutting and stretching device for thermoplastic plastic strips, in particular for the production of fibers, with feed means for the thermoplastic material in the form of foils, mi _u multiple blades for cutting the foil into strips and with stretching rollers for the strips, characterized in that the stretching rollers have two Role groups (11, 12, 13 and 18, 19, 20) include, of which those in movement! The following group (11, 12, 13) is driven, a heating and support plate (16) for the thermoplastic plastic strips being arranged between these roller groups as they move between the two roller groups. 2. Apparatus according to claim 1, characterized in that the support plate (16) has a convex support and heating surface (15), over which the thermoplastic plastic strips (17) slide, whereby the convex support and heating surface is polished and chrome-plated. 3. Device according to claims 1 and 2, characterized in that that the support plate (16) find two opposite / support and heating surfaces (15,21), over wel at the same time the two parallel thermoplastic plastic films obtained strips 4. Apparatus according to claim 1, characterized in that the support plate (16) by incorporated therein electrical Heating resistors is heated. Iff 5. Apparatus according to claim 1, characterized in that the support plate (16) is provided with a cavity through wclciieii eili Κβίζϊΰΐυΐβΐ ij.iiiuuruii-is guided. 6. Apparatus according to claim 1, characterized in that 805 the support plate (16) for the strips directly to the multiple blades (14) is upstream or downstream. dai 7 device according to claims 1 and 6, characterized in that / the multiple blades (H) between the support plate (16) and the roller group driven at a lower speed (11, 12, 13) is arranged. 8. Apparatus according to claim 7, characterized in that two groups of! »teaching blades (14) arranged one above the other are, each group to cut up at least one of the at least twice one on top of the other foils in strips ve seen.