Introduce
LP Industry manufactures custom paper covered rectangular copper and aluminum strips for power transformers, distribution transformers, dry-type transformers, reactors, traction transformers, and other electrical equipment. With more than 30 years of manufacturing experience, we supply reliable transformer winding conductors to customers worldwide.
MPCC Twin, Triple, and Quad Paper Rectangular Insulated Copper & Aluminum Strips are flexible composite conductors for internal electrical connections in transformers and heavy electrical equipment. We offer both paper insulated strips and paper covered wires to meet different application requirements.
We use high-purity EC Grade Copper and Aluminum together with premium insulation paper from trusted suppliers. Our manufacturing process ensures stable electrical performance, excellent mechanical strength, and long service life.
Different paper materials, insulation structures, and covering thicknesses determine the conductor’s electrical, thermal, and mechanical performance. We customize the paper type, insulation thickness, and number of paper layers according to your transformer design and technical requirements.
Power transformers require winding conductors with high electrical conductivity, strong mechanical performance, and reliable insulation. MPCC Twin, Triple, and Quad Paper Covered Rectangular Copper & Aluminum Strips are designed to meet these demanding requirements.
Our engineers work closely with every customer to deliver winding conductors that match international standards and ensure reliable transformer performance.
What Are MPCC Paper Covered Rectangular Conductors?
MPCC (Multiple Paper Covered Conductor) is a rectangular copper or aluminum strip insulated with multiple layers of high-quality electrical insulation paper.
Insulation Type : – Electrical Grade Kraft Paper, Nomex Paper, Mica Paper, Thermally Upgraded Paper (TUP), Crepe Paper, Polyester Paper, Tomoegawa Paper.
Conductor material is used according to GB/T5584 or DIN EN 13601. Cu-ETP or Cu-OF are used predominantly and if requested, can be delivered with increase strength. Conductor can be bare rectangle copper or enamel rectangle copper or bare rectangular aluminum.
Wrapping Method
In order to meet different customer and application demands, we can use different wrapping methods according to the paper insulation layer construction.
Method 1: Butt-wound Wrapping
Method 2: Overlapped Wrapping
Method 3: Interlocked Wrapping
Specifications
For winding in oil-cooled transformer, we offer a wide range of winding wires whose insulation is compatible with synthetic and in mineral-oil based cooling agents.
Paper-insulated flat wires are manufactured as individual conductor or as multi-conductor (twin or triple). Technical specification should be according to IEC60317-27, GB/T7673
| Name | Combined Conductor |
| Conductor | flat copper / aluminum wire, paper / fim-wrapped flat copper / aluminum wire, enameled flat copper / aluminum wire |
| Combination method | Radial twin conductor flat-wise Radial twin conductor edge-wise Axial twin conductor 2×2 quad conductor Radial enamelled twin conductor Axial quad conductor Customized according to customer requirements |
| Single wire Dimension | Single-wire thickness (mm):1.00-8.00; single-wire width (mm):4.00-25.00; single-wire width-to-thickness ratio < 20 |
| Number of Conductors | 2~4 |
| Wrapped insulation material | Power cable paper, high-density insulating paper, heat-resistant insulating paper, high-elongation fiber paper, aramid paper(Nomex), PET film,etc. |
| Application | Oil-immersed transformers, power transformers, reactors and distribution transformers |
Key Advantages
Lightweight design: Through aluminum/copper and other light metal composite technologies, which is particularly suitable for applications in weight-sensitive fields such as aerospace.
Excellent Mechanical Strength
Multifunctional Integration
The special composite design can simultaneously achieve multiple functions such as conductivity, shielding, and anti-electromagnetic interference, simplify the equipment wiring structure, and improve system reliability.
Exceptional thermal conductivity
High electrical conductivity
Appreciable machinability
Phenomenal ductility
Wide Environmental Adaptability: Considerable biofouling and corrosion resistance
Non-magnetic characteristics
Antibacterial properties
Recyclability, hence environment-friendly
Applications of Custom Paper Covered Rectangular Copper & Aluminum Strips
Our paper-covered rectangular conductors are widely used in:
Power Transformers
Distribution Transformers
Dry-Type Transformers
Oil-Immersed Transformers
Wind Power Transformers
Solar Power Transformers
Reactors
Inductors
Railway Transformers
Industrial Transformers
Copper vs Aluminum Conductors: Which One Is Right for Your Transformer?
Selecting the right conductor material is essential for transformer performance, efficiency, and project cost. The following comparison helps engineers and procurement managers choose the most suitable option.
| Feature | Copper Conductor | Aluminum Conductor |
| Electrical Conductivity | ★★★★★ Excellent (100% IACS) | ★★★☆☆ About 61% IACS |
| Electrical Resistance | Lower | Higher |
| Current Carrying Capacity | Higher | Lower (requires larger cross-section) |
| Mechanical Strength | Excellent | Good |
| Weight | Heavier | About 50% lighter than copper |
| Thermal Conductivity | Excellent | Good |
| Corrosion Resistance | Excellent | Excellent with proper insulation |
| Service Life | Longer | Long-lasting |
| Transformer Efficiency | Higher | Good |
| Material Cost | Higher | More economical |
| Processing & Winding | Easier to bend and wind | Requires larger bending radius |
| Typical Applications | High-voltage transformers, power transformers, generator transformers, reactors | Distribution transformers, dry-type transformers, renewable energy transformers |
| Best Choice For | Maximum performance and long service life | Cost-sensitive projects with lower weight requirements |
Why Choose LP Industry?
Picking the correct manufacturer is just as critical as picking the right Paper Covered Magnet Wire. Backed by more than 30 years of manufacturing excellence, LP Industry has been a reliable provider of Paper Covered Flat Copper Wire, Rectangular Magnet Wire, and Transformer Strip for transformer manufacturers around the globe.
Our Advantages
Established in 1993: professional manufacturer of transformer winding.30+years experience.
Is a world leading manufacturing operation with a 20,000 square mtr production facility, and 30 automated production lines with the ability to produce 600 tons per month.
Quality Control – Due to the nature of every part being inspected, strict quality control measures were put into place to ensure the quality was consistent. For example, as the part was of a sensitive nature each part was checked for dimensions, insulation, voltage and appearance.
Designed to your requirements OEM Solutions – Built to IEC, NEMA, GB or your technical drawing and specification.
Global Export Experience – Exported to over 80 countries, have customers in Europe, Asia, Middle East, Africa, North and South America.
Quality assured – Certified to ISO 9001 and, UL, RoHS and REACH compliant for assured international conformity.
Speed & reliability in delivery– Consistent level of production capacity enables us to deliver on schedule, whether your order is for standard products or customized applications.
Frequently Asked Questions
The key variation is the quantity of the insulation paperlayers. The greater number of layers the stronger the insultaion, hence the Triple and Quad paper is used for higher voltages.
Aluminium has the advantages of less weight and cost than copper, but more expensive and weaker than copper. The optimum benefit is depending upon your transformer type, whether it‘s designed to use aluminium or copper.
Our products can be manufactured according to IEC, NEMA, GB, or customer-specific standards.
Our general minimum order quantity is 500 kg per size; for items currently in stock, the minimum is 300 kg.
Our delivery time generally depends on the order quantity.
