SPECIFICATION for FILMS

 

POLYPROPYLENE FILM

POLYESTER FILM

Thickness (Micron)

4.5,5,6,6.5,7,8,9 & 10

3.5, 4.8, 5.0, 6.0, 8.0 & 12.0

Tolerance on thickness

 ± 8%

±8%

Standard film width (mm)

25,30,37.5, 50,55,75,100&110

7,10,12.5,14,15, 20,21,25,30&35

Tolerance on film width up to 37.5mm

Greater than 37.mm

 

± 0.3 mm

± 0.4 mm

 

± 0.3 mm

Free margin

2.5 ±  0.4 mm

1.5 mm  ± 0.3 mm

Heavy edge width

3 to 5mm

 

Resistance at active area

7.0 W / Sq

 

Tolerance

+2.0 W /Sq & -1.5 W /Sq

 

Resistance at heavy edge

3.0 W /Sq

 

Tolerance

 ± 1W /Sq

 

Average resistance

6.0 W /Sq

2 to 4 W /Sq

Tolerance

+ 2.0 W /Sq & -1.0 W /Sq

 

Resistance for aluminum metallised films

2 to 4 W/Sq

1 to 2 W/Sq

 

TYPICAL PROPERTIES:

 

Cores

Plastic/metal cores, with internal diameter of 75mm. The cores shall not project or recede more than 0.8mm for end face of the roll. The outer diameter of roll shall be 180mm to 250mm

Winding

Winding tension in checked by holding the film hardness horizontally and observing if for unwinding on its own weight easily. Further, the rolls shall withstand an axial weight of 1.5 kg/cm slit width without moving out of core. Wrinkles in the longitudinal direction will not be allowed. The film shall not extend more than 0.5mm beyond the edge of the next film. However, few turns in the beginning of the roll or at the break point may extend upto 0.8mm sometimes. The film is free from scratches, but sometimes small scratches do appear which are harmless. The facts shall be free from scratches or other markings.

Breaks

All breaks (Splices) are identified by colored tape and visible at the end faces. At maximum, splices in each slit roll do not exceed two for 190mm outer diameter of the roll and three for 250mm.  

Electrostatic

The electrostatic charges are very less and do not affect the winding of the metallised film.

Adhesion

The adherence of Zinc Alloy coating on the film is taken care during vacuum Metallising and does not peel off during usual handling / production of capacitors.

Reel wobble

The max. reel wobble shall not exceed 0.3mm

Working temp

The metallised film can satisfactorily work at + 85 °C

Melting point

165 °C