IEC 60674-1:1980 pdf download.Specification for plastic films for electrical purposes Part 1: Definitions and general requireme.
IEC 60674-1 is one of a series which deals with plastic films for electrical purposes.
The series will consist of three parts:
Part 1: Definitions and general requirements.
Part 2: Methods of test (Publication 674-2).
Part 3: Specifications for individual materials (Publication 674-3).
1. Scope
IEC 60674-1 is applicable to plastic films used for electrical purposes.
This Part 1 gives definitions for, and specifies general requirements to be fulfilled by, plastic films used for electrical purposes.
2. Definitions
For the purpose of IEC 60674-1, the following definitions apply:
2.1 Bias — Camber
When a length of slit film is laid flat on a plain surface, it will usually lie with its edges forming parallel straight lines. However, if the film contains a distortion such that onc edge of the slit length is slightly longer than the other, the length will lie with its edges forming parallel, curved lines and the slit film is said to exhibit “bias”.
This form of distortion is sometimes known as the “curved sword effect”, and film exhibiting this distortion is said to “wander” or is said not to “track” correctly.
2.2 Sag
If a length of slit film is supported near its extremities (e.g. by draping it over a pair of parallel rollers or bars) so that the film is under light, uniform mechanical tension and lies approximately in a horizontal plane, the length of film will usually form a smooth catenary surface.
However, if the film contains a distortion such that certain areas lie below the general level of the catenary surface, the film is said to exhibit “sag” or “bagginess”. This distortion arises from the stretching of certain portions of the film either during manufacture or subsequent handling.
Where sag occurs at a slit edge, it may be known as “edge sag”, “edge flute”, “cockle” or “droop”.
When the sag occurs along a line within the width of the film it forms a “sag lane”, “pucker lane”, “stretch lane” or “gauge band”.
2.3 Telescoping
The axial shifting of sections of the reel of film relative to other annular sections. The effect is so named because of the visual similarity with the draw-tubes of a partly extended optical telescope.
3. General requirements
3.1 Quality
All material in any one consignment shall be consistent. The properties of the film shall be within the limits of IEC 60674-1 throughout the whole length of each roll. The surface shall be uniform and the film shall be substantially free from defects such as creases, tears, gas bubbles, pinholes, inclusions of foreign matter.
3.2 Rolls
The outside diameter of each roll shall be within the range agreed between the purchaser and supplier. The rolls shall be essentially circular and shall be wound sufficiently tightly to avoid telescoping during transit and subsequent normal use.
Rolls shall be capable of being unrolled easily. There shall be no hard bands which adversely affect unwinding and use. In any roll each end face shall at no point depart from its principal plane perpendicular to the axis of the core by more than ± 1 mm unless otherwise specified.
3.3 Joins (splices)
The number of joins (splices), where these are permitted, shall be in accordance with the requirements given in Part 3 (under consideration).
Where joins are permitted, they shall be suitable to withstand the mechanical and thermal stresses normally encountered in subsequent use.
Special requirements such as visibility, heat or solvent resistance, shall be agreed upon between purchaser and supplier.
Joins shall be as thin as possible and may be made by fusion processes such as, for example, welding or with adhesive tape. Adhesive tape, if used, shall be preferably not thicker than the film itself and there shall be no exudation of or from the adhesive.
Joins shall not impair the unwinding of the film and shall be clearly visible when viewed from the end faces of the roll, unless otherwise agreed between purchaser and supplier.
3.4 Cores
The material shall be supplied rolled on a round core. The core shall not flake, collapse or distort under winding tension, nor shall it damage or cause degradation of the film.
The purchaser and supplier shall agree on all core properties and dimensions including the associated tolerances. The preferred inner diameters of the core arc 76 mm and 150 mm with a tolerance of ±1 %. Cores may protrude at each end of the roll or be flush with the ends and the purchaser and supplier should agree on which arrangement is to be used and on the associated tolerances.
4.1 Thickness
Unless otherwise specified in Part 3, the measured thickness shall be within ±10 % of the nominal value when determined in accordance with the method described in Part 2.
4.2 Width
The preferred width shall be given in the sheets of Part 3. Unless otherwise specified in Part 3, the tolerance on the measured width shall be as follows:
5.1 Packaging
The individual rolls shall be packaged in such a manner that they are adequately protected from damage and detcrioration during normal conditions of transit and storage.
5.2 Labelling
Each unit pack, and each package containing a number of unit packs, shall have at least the following information clearly and indelibly marked on it:
a) the number of the appropriate standard based on these specifications;
b) the type of the film (sheet number of Part 3);
c) the nominal thickness of the film;
d) the width of the film;
e) the net weight of the film;
f) other information required by Part 3.IEC-60674-1-1980