Method and equipment for producing bidirectional stretching plastic film

[0012] The equipment for producing biaxially stretched plastic film provided by the present invention is designed as follows: it includes a film extrusion device, a stretching traction device, a cooling device, a platform winding device and an electrical control device, etc., and is characterized in that: The upper part of the traction device is provided with two-way stretching rotating heating devices 11 and 12 for the two-way stretching of the film.

[0013] The method of the biaxially stretched plastic film provided by the present invention will be further described below with reference to the accompanying drawings:

[0014] After the blank enters the hopper 1, it is melted and extruded by the extruder 2, and the film head socket 3 introduces the melted and kneaded plastic from the extruder into the bubble tube die 4, and the bubble tube die 4 extrudes the molten plastic The membrane is tubular. The plastic film tube is led out from the die by the first clamping rod 6, and the thickness is controlled. The cooling and shaping of the film tube are accelerated by the air ring 5 cooling and the cooling water tank 7, and then the second clamping rod 10 is pulled to the upper part of the tower through the idlers 8, 9 , Reheated by the rotary heating devices 11, 12 to a high elastic stretchable temperature. At this time, the tube film is filled with a suitable amount of air, and the longitudinal traction roller 17 is gradually increased and stretched at the same time and space. Both sides in the horizontal direction are stretched outwards and the thickness of the bubble film is controlled. The cooling air rings 13 and 14 are rotated to uniformly cool and shape the bubble. The sizing plate 15 stabilizes the diameter of the bubble, and the guide splint 16 stabilizes the shape of the bubble, so that the bubble is fixed along a certain direction. The angle is flattened, the traction nip roller 17 is introduced, and then it enters the heat setting. The edge-cutting film breaking device 18 breaks the film bubble into a film or trims the film edge. The auxiliary nip roller 21 increases the edge-cutting tension to make the cut edge The film is smoothed, and the film is transferred to the winding device 22 through the supporting rollers 19 and 20, and the winding device 22 winds the plastic film, and the trimming blower 23 blows away the thin edges cut by the trimming knife. The unqualified coils and trim materials enter the recycling machine, and the recycled pellets and new pellets will enter the mixer for reuse.

[0015] A rotary platform 24 can also be provided on the tractor base 25. The transmission device below the rotary platform 24 makes the rotary platform 24 slowly rotate 360 ​​degrees, thereby driving the splint, the nip roller and the winding device to rotate to make the film The cooling is uniform, and the winding can be smooth when the plastic film is rolled.