Insulation class: A (105 °C)
100% sulphate wood pulp
Natural-color
Precompressed pressboard, even fiber orientation, hard and dimensionally stable
High purity and mechanical strength
Low shrinkage, fiber-free surface
Good compatibility with liquid dielectrics
Product Description
Description and feature:
Duct strip is made from high quality pressboard G4 grade. It has excellent transformer oil impregnation feature, high compressive strength more than corrugated pressboard which is the old technology. It is used at high temperature condition and it could be improved the circuit strength.The character are below:
1. High mechanic strength
2. High electric strength
3. Accurate dimension

Application:
Oil duct strip provides duct for the flow of the cooling oil in layer and strip windings in distribution power transformers. It is manufactured by bonding transformer board sticks onto insulating paper or single-coated diamond dotted paper.
Main strips: Rectangular strips, T-strips, Pigeon cauda strips, Abnormity strips.
TRANSFORMER OIL DUCT STRIP DATA SHEET
PART1: PRESSBOARD STICK4*5*1000MM
ITEM | TYPICAL VALUES | MATTER OF FACT |
Thickness: mm | 4mm±7.5% | 4.1-4.3mm≤7.5% |
Width | 5±0.5mm | 4.95-5.38mm≤0.4mm |
Length of 1000mm: | ±5mm | 1000±3 mm |
Pitch of stick centre: | ±3mm | 23±2 mm |
Apparent density: g/cm3 | 1.1-1.2 | 1.18 |
Moisture content ,% | 4.0 to 9.0% | 5.7 |
PH water extract: | 6.0 to 9.0 | 6.8 |
Ash content,% maximum | 1% | 0.51 |
Tensile strength Mpa Machine direction: Cross machine direction: | ≥90 ≥50 | 107.4 101.3 |
Oil absorption | ≥7.0% | 12.29 |
Shrinkage rate% MD CMD Thickness D | ≤1.0 ≤1.4 ≤6.0 | 0.16 0.25 ≤5 |
Elongation rate MD CMD | ≥3 ≥4 | ≥4.4 ≥4.4 |
Conductivity of aqueous extract Ms/m | ≤10.0 | 5.03 |
Dielectric breakdown:(Kv/mm )In Air In Oil | 10 24 | 16.7 35.7 |
PART2: SINGLE SIDE DIAMOND DOTTED PAPER DATA SHEET
ITEM | TYPICAL VALUES | MATTER OF FACT | |
Caliper: (millimeter) | 0.25mm | ||
Thickness: mm | 0.25±0.025mm+0.06 | 0.260 (0.260,0.258,0.262) | |
Width: mm | 1000±5mm | 1000-1005 | |
Apparent density: g/cm3 | 0.9 to 1.1 | 1.01 | |
Moisture content ,% | 4.0 to 8.0% | 5.6 | |
PH water extract: | 6.0 to 8.0 | 7.5 | |
Ash content,% maximum | 1% | 0. 43 | |
Coating thickness per side mm | 0.006 to 0.012 | 0.011 | |
Tensile strength,N/mm2 Machine direction: Cross machine direction: | 80 35 | 86.6 48.1 | |
Dielectric breakdown: (volts/layer ,dry test) | ≥2100 | 2230 | |
Bond strength: Kpa | 450kpa | 679 | |
FAQ
Q: How long is your delivery time?
A: Generally it is 3-5 days if the goods are in stock. Or it is 15-30 days if the goods are not in stock, it is according to quantity.
Q: Do you provide samples ? is it free or extra ?
A: Yes, we could offer the sample for free charge but do not pay the cost of freight.
Q: How can you guarantee the quality of mass production is same with the sample sent to me before?
A: Our warehouse staff will leave another same sample as yours. The production process will be under your requirement.
Q: What is your terms of payment ?
A: Payment≤1000USD, 100% in advance. Payment≥1000USD, 30% T/T in advance ,balance before shipment.
Q: Can you give me a discount price?
A: It is depending on the volume. The larger the volume, the more discount you can enjoy.
Q: Why is your price a bit higher than other Chinese suppliers?
A: To meet the requirement of different customers and areas, our factory manufactures various kinds of quality for each item at a wide range of price. We can offer the products of different quality levels depending on customer's target price and quality requirement.
Q: How can you guarantee the quality of mass production is same with the sample sent to me before?
A: Our warehouse staff will leave another same sample in our company, with your company name marked on it, which our production will be based on.
Q: How can you deal with quality issues that customer feedback after receiving the goods?
1) Customers take photos of unqualified goods and then our sales staff will send them to Engineering Department to verify.
2) If the issue is confirmed, our sales staff will explain the root cause and take corrective actions in coming orders.
3) Finally, we will negotiate with our customers to make some compensation.
Packaging & Delivery
Packaging Details: Normal Export Packing, Wrapped with plastic film , Moisture proof; then packed with plywood pallet.
Delivery Detail: Within 15 days after receiving T/T payment ( at least 30%)
Miss Lea