Foil Strip For Transformer Winding

Ø Specification of signi aluminum foil strip

The signi aluminium foil strip is in accordance with the following items below:

l Denomination: Aluminium foil strip

l Alloy: 1060, 1070, 1350 Temper: 0

l Standards applicable:

The signi aluminium foil strip is in accordance with conditions specified on this specification and, fo lacks on this procedure it is in accordance with standard EN 10204-3.1.b

l The applicable dimension of coil shall conform to table 1.

Table1 Unit: mm

Thickness	0.2 to 3.0
Width	10 to 1250

Ø Characteristics and properties

The coils of aluminium foil strip is produced in high pure aluminum (99.7%) and is in accordance with the following items:

Table 2 Unit: Weight%

Others

Al.

Individual

Total

Max. 0.20

Max.

0.25

Max.

0.04

Max.

0.03

Max.

0.03

—

Max.

0.04

Max.

0.03

Max.

0.03

—

Min. 99.7

l Thermal treatment:

The typical Brinell hardness for the material must determinate after annealing process( Hardness Brinell Typical: 18HB).

l Surface finish

l The signi aluminium foil strip surface is flat, smooth, polished with MILL-FINISH. The maximum roughness absolute is from 5-7 micron inches.

l The signi aluminium foil strip should not present wrinkles, folds, scratches, deformations and specially, on the edges, do not must have burr, scratches or others factors which could harm the isolation material to be assembled over this material. The material is free from any type of damages.

l The signi aluminium foil strip surface is free from any impurity, as greases, liquid detergents, powdered metals, incrustations and others, and particularly do not should present chemical products used during pickling process.

Moreover, if used at the final stage, backing antioxidant surface, as a film form, it is chemically compatible with the electric fluids used in transformers and step voltage regulators.

l Edge(ends) shapes

The edge finishing of the signi aluminium foil strip shall meet the requirements of the figures below, and the quality level decrease from A to D. The “D” format is the minimum acceptable quality.

SIGNI ALUMINIUM ACCEPTABLE SHAPES OF THE FOIL EDGES

SIGNI ALUMINIUM NOT ACCEPTABLE SHAPES OF THE FOIL EDGES

l Waves and lateral curvature

In rolled signi aluminium foil strip will not be allowed bending and lateral undulations.

The tolerance of lateral curvature of strip is according table 5( see figure below).

l Amendment

In the same coil, amendments are not acceptable.

Ø Characteristics

l Chemical composition and electric conductivity

The signi aluminium foil strip is laminated by aluminum whose properties are presented on Table 1.

l Mechanical characteristics (Table 2)

TABLE 1

Aluminum Chemical Composition	99.7% (Min)
Electrical Conductivity at 20 ℃	>= 62.7% IACS(Min)

TABLE 2

	Tensile Test		Bending Test
Thickness(mm)	Tensile Strength(Mpa)	Elongation（%）	Angle	Bend Radius
Up to 0.30	Min. 60 Max. 90	15	90 ° and 180 °	0
0.31~0.50		23		0
0.51~1.50		25		0
1.51~2.50		29		0

Ø DIMENSIONS TOLERANCE

l Tolerances for thickness, width and lateral curvature are presented on Table 3, Table 4 and Table 5, respectively.

Table 3

Thickness (mm)	Tolerance (mm)
Up to 0.19	±0.01
0.20 ≤ T ≤0.50	±0.02
0.51≤ T ≤ 1.00	±0.03
1.01≤ T ≤ 1.50	±0.04
1.51 ≤ T ≤ 2.00	±0.05
2.01 ≤ T ≤ 2.50	±0.06

Table 4

Width(mm)	Tolerance (mm)
＜200	﹢0.3/-0
201≤W≤400	+0.4/ -0
401≤W≤600	+0.6/-0
601≤W≤1000	+1.5/-0
＞1000	+2.0/-0

Table 5

Width (mm)		Lateral Curvature Measured on 2000/1000mm Strip length
Over	Up to and Including	Lateral Curvature Measured on 2000/1000mm Strip length
15	100	6mm /1.5mm
100	300	4mm /1.5mm
300	600	3mm /0.7mm
600	1540	2mm / 0.5mm

l Length

The tolerance for length shall be from -0% to +2%, considering the total indicated on Purchase Order.

l Burr

For the thickness < 0.8mm=> Burr< 0.01mm

For the thickness >0.8mm => Burr < 0.02mm

Ø DIMENSIONS AND PRODUCTS WEIGHT

l Coil core ( Interal dimensions from bobbin)

signi aluminium foil strip thickness T≤0.15mm, the internal dimension from bobbin shall be ∮I=76.2mm(3”). The material from internal bobbin shall be by aluminum with thickness such that it resists the efforts of the coil and prevent deformations during transport and handling.

signi aluminium foil strip thickness 0.15<T<2.5mm, the internal dimension from bobbin shall be ∮I=390mm. The material from internal bobbin shall be by press paper with thickness such that it resists the efforts of the coil and prevents deformations during transport and handling.

The width of the internal bobbin shall be the same as the aluminum foil.

l Coil of signi aluminium foil strip

The external diameter from coil of aluminum foil shall not exceed 650mm.

The weight from coil of aluminum foil shall not exceed the total gross weight of 650kg.

l Symmetry of the signi aluminium foil strip

During the winding of the signi aluminium foil strip (lamination). Shall be maintained the symmetry by the layers, keeping the perfectly lateral face milling.

The maximum tolerance acceptable for face milling alignment shall be 1mm, as presented on Figure below.

Ø CERTIFICATE AND TEST REPORT

For each purchase order is supplied the material certificate according EN10204-3.1B. It shall present at least the following tests:

* Visual inspection

l Chemical composition( aluminum purity confirmation)

l Electrical conductivity

l Mechanical properties ( Tensile and Bending tests)

l Hardness measurement

Ø PACKING AND SHIPPING

The packaging should be such that packaging does not unwind, do no harm or allow entry of moisture. Thus, there should be no failures in handing, in the event of mechanical shock or rust; The following measures is observed below:

l Supports with fillers in all coils.

l Wooden packing: is protected with felt.

l Wrapped with plastic: to avoid moisture.

Remarks: The requirements for packaging and transport are shown in items 9 and 12 of this specification.

IDENTIFICATION ON THE PACKAGING

The packaging should present identification with at least the following items:

l Product type

l Dimensions( Thickness, Width, Length in mm)

l Quantity(kg).

l Manufacturing date.

l Serial number

l Manufacturer.

l The net weight of the internal bobbin shall be indicated on its internal side, visible to the user.

ACCEPTANCE AND REJECTION OF PRODUCT

l The signi aluminium foil strip will be accept if accomplish all items from these specification. Therefore, if detected defects later, during the handling and / or manufacturing process, the material with problems will be rejected. In this case, should be returned to the manufacturer the rejected material and the scraps from the process.

l If during measurement, analysis or test performance the material fails to meet any of the requirements of this specification, you could reject the product.

DIVERGENCES FROM THIS SPEDIFICATION

When there is disagreement with this specification,the supplier shall notify the buyer responsible for the Purchase Order and request formal approval in advance.

PACKAGING AND TRANSPORT POSITION

l The packaging shall be as shown in the figure below, or can be sent without the central support is at least 560mm, The alternatives are mutually exclusive, ie, either the 1^st or 2^nd. Table 6 presents the details of it.

l The position for transport should be as suggested by the figure below, ie with the axis paralled to the plane of the coil support. Other position is strictly forbidden.

TABLE 6.

MATERIAL	Identification
A	Internal Bobbin(Aluminum or paperboard)---See item 6.1.
B	aluminium foil(coil)
C	Felt（Protection with adequate dimensions/Upper side and Down side）
D	Felt, Corrugated paperboard or Isopod( Axial plates)
E	Retractable Plastic（ Packaging）
F	Structure wooden box * Closed Wooden box