In cable manufacturing, reliable internal insulation, mechanical reinforcement, and cost-effective layer separation are essential for maintaining electrical integrity and long-term performance. PET Polyester Tape, commonly known as Mylar Tape, is a premium biaxially oriented polyester (BOPET) film tape engineered specifically for the cable industry. Produced from high-grade polyethylene terephthalate (PET) resin, this versatile tape delivers exceptional tensile strength, outstanding dielectric properties, and superior thermal stability — making it the ideal choice for longitudinal or helical wrapping, binding, shielding isolation, and mechanical protection across a wide range of cable constructions.
As a trusted B2B supplier of complete cable materials and technical solutions with over 30 years of global experience, we recognize PET Polyester Tape as a lightweight, high-performance insulation material that enhances cable durability while optimizing production efficiency and total cost of ownership in signal transmission, data, coaxial, control, instrumentation, and power cable applications.
What is PET Polyester Tape (Mylar Tape) and Why Is It Standard in Cable Manufacturing?
PET polyester tape is a non-adhesive or lightly adhesive biaxially oriented PET film supplied in slit widths from 5 mm upward. In cable construction it is applied longitudinally or helically after cabling of the cores. Its primary functions are:
- Mechanical binding of the assembled cores to prevent looseness during subsequent armouring, sheathing or installation
- Provision of an additional dielectric barrier
- Moisture and chemical barrier
- Smooth bedding surface for metallic screens or armour
Mylar is the historical DuPont (now Mylar Specialty Films) trade name; in technical specifications the material is correctly designated as PET or BOPET film. Standard electrical grades meet the performance requirements of IEC 60674-3-2 and ASTM D5213.
Composition & Engineered Manufacturing Process
PET Polyester Tape is manufactured from premium-grade PET resin that undergoes biaxial orientation to create a highly crystalline, dimensionally stable film. Key characteristics include:
- Base material: Biaxially oriented polyethylene terephthalate (BOPET) film — known for its high molecular alignment and uniformity.
- Thickness range: Typically 0.025–0.1 mm (custom options available up to 0.25 mm).
- Surface options: Transparent, bright silver/metallized, or matte finishes for visual identification and enhanced reflectivity.
Precision slitting ensures clean edges and tight tolerances, enabling seamless integration into high-speed cable wrapping lines. When required, acrylic or silicone adhesives can be applied for self-adhesive versions, providing strong yet residue-free bonding to conductors, shields, or jackets.
How Cable Designers Select the Correct PET Tape Thickness and Width
Selection follows three engineering criteria:
- Core diameter and lay-up tension Larger cores and higher lay lengths require thicker film (25–50 μm) to withstand the tension applied by the taping head without tearing or necking.
- Required dielectric contribution In low-loss or high-voltage designs the tape itself may form part of the insulation system. Designers calculate the additional breakdown voltage provided by the chosen thickness.
- Taping equipment capability Modern precision pay-offs can run 12–15 μm film at high speed with controlled tension. Older or high-tension machines demand 23 μm minimum to avoid film breakage.
Standard slit widths for cable lines range from 10 mm to 60 mm; jumbo rolls up to 1300 mm are converted to customer width. Core diameters are normally 76 mm (3″) or 152 mm (6″).
Key Technical Advantages & Performance Benefits
Exceptional Mechanical Reinforcement High tensile strength (typically 150–300 MPa or 80–150 N/cm) combined with excellent elongation ensures reliable binding and wrapping without cracking or stretching during high-speed production. The tape adds structural integrity to cable cores while maintaining overall flexibility.
Superior Electrical Insulation Outstanding dielectric strength (≥5–8 kV/mm, with breakdown voltages up to 5.5 kV or higher depending on thickness) provides effective isolation between conductors, shields, and layers. Low dissipation factor minimizes signal loss in high-frequency applications such as coaxial and RF cables.
Thermal & Environmental Stability
- Melting point: Approximately 250–255°C
- Continuous operating temperature: Up to 150–180°C (Class F rating in many grades)
- Excellent resistance to moisture absorption (<0.5%), UV radiation, chemicals, solvents, humidity, and thermal aging.
Flame-retardant grades are available to meet stringent fire safety requirements in specialty cables.
Processing Efficiency & Clean Application Easy to tear and apply with no residue, the tape features uniform thickness and precision-slit edges that reduce waste and ensure smooth, wrinkle-free wrapping. Its bright silver or transparent appearance aids quality inspection on the production line.
Cost-Effective & Sustainable Lightweight design reduces overall cable weight compared to thicker alternatives, supporting lower material costs and easier installation while remaining fully recyclable.
Primary Applications in Cable Systems
PET Polyester Tape (Mylar Tape) is widely specified for:
- Signal Transmission, Data & Instrumentation Cables: Binding and separation layers to maintain pair geometry and electrical isolation.
- Coaxial & RF Cables: Internal wrapping for dielectric support and shielding isolation.
- Control & Power Cables: Mechanical reinforcement and additional dielectric strength between conductors and shields.
- Specialty Cables: Composite constructions requiring smooth, uniform layers for improved flexibility and long-term reliability in industrial, automotive, aerospace, and renewable energy applications.
It excels in longitudinal or helical wrapping where a thin, high-strength insulating barrier is needed without adding significant bulk.
Key Technical Parameters of Cable-Grade PET Polyester Tape
| Parameter | Typical Range / Value | Test Method / Note |
|---|
| Thickness | 12 – 100 μm (most common: 12, 15, 19, 23, 25, 36, 50 μm) | Micrometer |
| Tensile strength (MD) | ≥ 150 MPa | ASTM D882 / GB/T 1040 |
| Elongation at break (MD) | ≥ 50 – 80 % | ASTM D882 |
| Dielectric strength | ≥ 170 – 200 V/μm | ASTM D149 |
| Melting point | ≈ 255 °C | DSC |
| Continuous temperature | 130 °C (Class B) | IEC 60085 |
| Short-term temperature | 150 °C | — |
| Moisture absorption | < 0.5 % | 24 h immersion |
| Density | 1.39 – 1.40 g/cm³ | — |
| Heat shrinkage (150 °C, 30 min) | ≤ 3.5 % | — |
Standards, Compliance and Quality Requirements
Cable-grade PET tape is routinely specified to:
- IEC 60674-3-2 (plastic films for electrical purposes)
- UL 510 (where adhesive versions are used)
- RoHS / REACH
- ISO 9001 manufacturing control
Critical incoming-inspection parameters for cable manufacturers are thickness tolerance (±10 % or tighter), tensile strength, elongation, pin-hole count (especially for Al/PET), and absence of surface contamination that could affect subsequent extrusion.
PET Tape vs Aluminium/PET (Al-Mylar) Composite – Functional Comparison
| Property | Pure PET Polyester Tape | Aluminium/PET (Al-Mylar) Composite |
|---|
| Primary function | Binder / separator / dielectric | EMI/RFI shielding + binder |
| Shielding effectiveness | None | 55 – 80 dB (30 MHz – 1 GHz) |
| Tensile contribution | High | High (PET backbone) |
| Temperature range | –70 °C to +130 °C continuous | –40 °C to +130 °C |
| Typical thickness | 12 – 50 μm | Al 6–12 μm + PET 9–23 μm |
| Cost relative | Lower | Higher |
| Preferred applications | Power, control, instrumentation cores | Data, coaxial, instrument, 5G, medical cables |
Packaging & Storage for Optimal Performance
PET Polyester Tape is available in two convenient formats:
- PAD Type: Inner diameter 53 mm (2″) or 76 mm (3″), max outer diameter 650 mm, width 5–1300 mm, paper or plastic core.
- Spool Type: Inner diameter 76 mm (3″), max outer diameter 500 mm, max width 400 mm, paper core.
Store at room temperature in a dry environment, away from direct sunlight, pollution, and mechanical forces to preserve optimal performance.
Key Takeaways for Procurement and Design Engineers
PET polyester (Mylar) tape remains the most cost-effective, mechanically robust and dielectrically reliable binder film for the majority of industrial cable constructions. Correct thickness selection, controlled application tension and verified incoming material properties directly determine long-term cable reliability and diameter consistency.
For project-specific technical data sheets, custom widths, colours or laminated constructions (Al/PET, Cu/PET), contact our engineering team with core diameter, voltage class and processing-line parameters.
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PET Polyester Tape (Mylar Tape) – Reliable Cable
PET Polyester Tape (Mylar Tape) – high dielectric strength, 130°C Class B insulation for cable wrapping, motor coils & transformers. Custom sizes. Request quote & samples today.
Product SKU:
PET Polyester Tape
Product Brand:
RLB Machinery
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