PRS ( Pull Roll Stand )

PRS – Complete system of individually driven rolls (when needed), provided with easy and automatic threading of film from the TDO unit to the winder, adjustable to any operating speed. It has been designed to carry out the following functions:

 

  • cooling of the surface of the film after stretching
  • measurement of the thickness: high accuracy and low energy X-ray gauge (up to 10 meters width), totally non-radioactive
  • safety guaranteed
  • treatment of film surface: corona or flame treatment
  • edge trimming: advanced edge cutting system



1 Heating/cooling roll             -     BMS 2000

2 Heating/cooling roll             -    Chrome

3 Guide roll cfrp                      -    Lacquer ceramic

4 Guide roll cfrp                      -    BMS 2000

5 Guide roll cfrp                      -    Lacquer ceramic

6a Nip roll                               -     Rubber

6 Corona treatment roll           -     Rubber

7a Nip roll                               -     Rubber

7 Corona treatment roll           -     Rubber

8a Nip roll                               -     Rubber

8 Heating/cooling roll             -     Stainless steel


Oscillation-

The thick edges of the film form a larger diameter on the roller than at the point where

the film has been evenly stretched. Due to this fact it is not possible to get an even

tension over the whole film.


Edge Chopping Device -

The edge strip is separated by the edge trim devices. When production starts, the

edge strip is cut off once by the chopping device.

The chopping device is arranged after the edge trim device on both sides on edge

area of film. 


Part Nip Roller Device - 

Two pneumatically energized nip rollers are used to isolate the edge trim cut from

the edge trim funnels.


Spreading Device -

The spreading device tightens the film track in transverse direction to reduce wrin‐

kling and ensures more constant film flow.


Film Break Detector -

The film break detector provides a non-contact, ultra-sonic monitoring of the film track

by proximity switches.

Thickness Gauge -

The thickness gauge provides a non-contact and continuous measurement of the

thickness profile of the end film by means of an X-ray source. It is arranged before

the treatment units. generally called film gauge scanner.


Corona Treatment Station -

The corona treatment prepares the surface of the film for subsequent processing

(printing, vacuum evaporation etc.).

The station consists of a rubber-coated roll, treatment electrodes and an ozone ex‐

haust system. The electrodes are arranged in a circular arc.


Nip Roll -

The nip roll is pressing the film against the following rolls:

• Corona treatment roll

• Guide roll

It thereby helps to prevent the occurrence of air bubbles between film and cooling

roll.


Ozone Exhaust System -

Ozone is constantly created in the treatment. The corona treatment causes appear‐

ance of ozone (O3). Ozone is harmful to health, therefore the ozone has to be ex‐

hausted by radial fans.

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