Electrical Insulation Materials are fundamental components in the manufacturing and operation of electrical and electronic equipment. According to national classification standards, insulation materials are systematically divided into seven principal series. YILONG, a leader in advanced insulation solutions, presents this comprehensive overview of each series to support industry professionals in selecting the optimal materials for their applications.
This category encompasses a wide variety of formulations designed to provide robust electrical insulation through impregnation and coating. Key products include:
l 1032 Alkyd Varnish and Lacquer
l 1730 Enameled Wire Varnish
Impregnating varnishes are available in solvent-based and solvent-free variants and are primarily utilized to dip coils in motors and transformers. Once cured, they form a continuous, durable insulating film that fills voids and reinforces structural integrity.
Enameled wire varnish serves as the primary insulation layer for wire conductors, offering excellent adhesion, abrasion resistance, elasticity, and electrical properties, alongside solvent and heat resistance — all without corroding the conductor.
Additional products include coating varnishes designed for silicon steel sheets and impregnated coil components, forming critical insulation layers in electrical machinery.
While demand for varnishes is substantial due to their indispensable role, YILONG acknowledges the environmental challenges associated with their production and application and continues to pursue greener solutions.
Impregnated fiber materials are integral for reinforcing insulation structures, providing both mechanical strength and electrical resistance. Typical products include:
l 2450 Silicone Varnished Glass Cloth
l XU2110 Diamond Dotted Insulation Paper
l DMD Epoxy Resin Impregnated Materials
2.1 Silicone Varnished Glass Cloth (Type 2450)
Manufactured from electrical-grade non-alkali fiberglass cloth impregnated with silicone varnish, this product delivers exceptional heat resistance (thermal class H), mechanical durability, dielectric strength, and oil resistance. It is ideal for insulating transformer liners, with roll widths available in 15, 20, and 25 mm, customizable to client specifications. The product complies with standard JBT 8148.1-1999.
2.2 Diamond Dotted Insulation Paper (Type XU2110)
This insulation paper features a quilted structure coated with modified epoxy resin, primarily employed as inter-layer insulation within oil-immersed transformers to ensure long-term mechanical stability and electrical insulation.
2.3 DMD Epoxy Resin Impregnated Material
Made from modified F-class epoxy resin cured by baking, this material boasts long shelf life, low curing temperatures, and rapid cure times. Post-curing, it exhibits superior electrical insulation, adhesion, and heat resistance (thermal class F). It is suitable for low-voltage copper or aluminum foil coil insulation in dry-type transformers, class B and F motors, and electric slot insulation.
Laminated products encompass sheets, tubes, and rods, offering excellent mechanical and electrical insulation properties for a broad range of applications. Key YILONG offerings include:
l 3240 Epoxy Resin Fiberglass Laminated Sheet
l XU-250 Diphenyl Laminated Sheet
l 3640 Epoxy Resin Laminated Tube
l XU-380 Phenolic Cotton Cloth Laminated Tube
l 3520 Laminated Paper Tube
l 3725 Laminated Cotton Cloth Rod
l 3840 Epoxy Resin Laminated Rod
3.1 3240 Epoxy Resin Fiberglass Laminated Sheet
This sheet features a smooth, bubble-free surface with permissible minor defects that do not compromise functionality (e.g., scratches, dents). It conforms to GB/T1303.1-1998 and is available in natural, black, red, or green colors. The product excels in mechanical strength at moderate temperatures and maintains electrical insulation stability under high humidity and temperature. Thickness ranges from 0.5 to 50 mm, with custom thicker options available. Typical uses include machined insulation parts for electrical and mechanical applications.
3.2 3640 Epoxy Resin Fiberglass Laminated Tube
Produced from non-alkali fiberglass cloth impregnated with epoxy-phenolic resin, this tube is known for its high mechanical strength, heat resistance, and excellent dielectric properties. It is suited for wet environments and transformer oil immersion. Standard dimensions range from 4 mm inner diameter to 1000 mm outer diameter.
3.3 XU-380 Phenolic Cotton Cloth Laminated Tube
Made from cotton cloth impregnated with phenolic resin, this tube offers high radial tensile strength and self-lubricating properties, expanding its use beyond insulation to components such as high-speed bearing cages. The tube meets GB/T5132 standards with a density ≥1.2 g/cm³ and radial tensile strength ≥50 MPa.
This series includes molded phenolic plastics (commonly black) and newer white unsaturated polyester plastics, frequently used in household low-voltage lines. Notable products include:
Dough Molding Compound (DMC or BMC)
Sheet Molding Compound (SMC)
DMC consists of chopped fiberglass, unsaturated resin, fillers, and additives, providing excellent electrical and mechanical properties alongside heat and chemical resistance. It is suitable for a variety of molding processes and electrical product requirements.
SMC composites exhibit superior electrical insulation, mechanical stability, thermal resistance, and chemical corrosion resistance. YILONG operates large-scale SMC molding machinery; however, current mold issues have temporarily halted production.
Mica insulation materials are essential for high-voltage and heavy-duty electrical applications. The 54XX series mica tapes stand out as critical components in:
l Thermal and hydroelectric generators
l Nuclear power equipment
l Large motors including railway locomotives and mining motors
l Fire-resistant cables used in subways, mining tunnels, and metal smelting environments
5550-1 Epoxy Fiberglass Powder Mica Tape
This tape uses epoxy-phenolic anhydride adhesive varnish reinforced with electrical non-alkali fiberglass cloth. Post-lamination and cutting, it serves as a ribbon insulation for medium- and large-sized high-voltage motor coils, capable of withstanding temperatures up to 155°C.
YILONG’s portfolio includes a broad range of insulating films and composite products:
l Electrical Polyimide Films
l Polyester and Polypropylene Films
l 6630 and 6640 Polyester Composite Materials (DMD)
The polyester composite DMD material is widely applied in motors for fans, refrigerators, washing machines, and electric vehicles, particularly for slot insulation. It is vital in dry-type power transformer manufacturing.
6630 DMD Polyester Composite Material
Constructed from a polyester film sandwiched between two layers of non-woven polyester fabric, this material offers excellent mechanical strength, dielectric properties, and thermal resistance (thermal classes B to F). Thickness ranges from 0.15 mm to 0.45 mm with widths between 20 mm and 1020 mm.
This diverse category includes:
l Electrical Non-Woven Cloth - used for cable banding and as semi-finished composite material
l Braided Belts and Polyester Shrink Tape - primarily for coil binding
l Cable Paper, Insulation Paper Sheets, and Insulation Oil - essential for oil-type transformers
Selected Products:
l Non-Alkali Fiberglass Tape
l Thickness options: 10, 15, 25, 30, 50 mm
l Features: High heat resistance, insulation resistance, corrosion resistance, low moisture absorption, strong tensile strength
l Standard: JC/T174-2004
Electrical Shrink Tape
l Made from modified polyester fiberglass
l Properties: High heat and electrical insulation resistance, excellent shrinkage, and mechanical strength
l Thermal classes available: B, F, and H
l Applications: Transformers, reactors, military electrical products
l White Cotton Tape
l Materials: Cotton or polyester, in plain or twill weave
l Thickness: 15, 20, 25, 30 mm
l Usage: Banding coils in transformers and motors
YILONG also provides precision-machined insulation components derived from laminated and plastic materials. These include specialized items such as end loops made from epoxy resin fiberglass winding tubes and structural insulation components for phase-shift transformer coils. These products are custom-fabricated to meet stringent dimensional and performance requirements.
Why Choose YILONG?
As a premier supplier of advanced insulation materials, YILONG is committed to:
Delivering superior-quality, reliable insulation solutions for diverse electrical applications
Customizing products to exacting customer specifications and industry standards
Supporting sustainable manufacturing practices and innovation
For inquiries, product details, and technical consultation, please contact YILONG - your trusted partner in electrical insulation solutions.
When performance, durability, and cost efficiency are essential, Phenolic Sheets stand out as a dependable choice. These industrial laminates are engineered to deliver exceptional strength, electrical insulation, and resistance to heat, moisture, and a wide range of chemicals. Built for demanding conditions, Phenolic Sheets perform reliably even in high-stress environments.
In modern industrial manufacturing and electrical insulation sectors, phenolic laminates remain a cornerstone material thanks to their robust mechanical performance, dependable dielectric properties, and notable resistance to chemical corrosion. Among the broad spectrum of phenolic laminate products, Phenolic Paper Sheets and Phenolic Cotton Cloth Sheets represent two of the most widely utilized and technically significant variants. Each offers distinct performance advantages, making them particularly suited for different engineering and operational contexts.
Engineering Plastics are a category of high-performance polymers designed to meet demanding requirements that go beyond the capabilities of most commodity plastics. Known for their exceptional mechanical properties, these materials excel in heavy-duty applications where factors such as shock absorption, chemical resistance, and dimensional stability are critical.
Bearing grade PEEK is specially formulated with solid lubricants such as PTFE, graphite, and sometimes carbon fiber. These additives provide exceptional tribological properties, resulting in very low friction, reduced wear, and extended component life.
While PEEK sheet and PEEK plate are both made from the high-performance thermoplastic Polyetheretherketone (PEEK), there are clear differences in thickness and application focus:
Polyether Ether Ketone (PEEK) is recognized in engineering circles as one of the most capable thermoplastic polymers available. It offers a rare balance of mechanical strength, chemical resistance, and thermal stability, making it an excellent choice for situations where both performance and durability are paramount. From aerospace components to medical implants, PEEK’s reliability in extreme environments ensures its continued relevance as industries demand more from their materials.
Epoxy fiberglass tubes are widely valued in various industries due to their exceptional strength, durability, and insulating characteristics. However, precise handling of these materials demands specialized tools and techniques to ensure both accuracy and safety. This comprehensive guide delves into the key methods for cutting and machining Epoxy fiberglass tubes, offering practical insights for both professionals and DIY enthusiasts.
Electrical Insulation Materials are fundamental components in the manufacturing and operation of electrical and electronic equipment. According to national classification standards, insulation materials are systematically divided into seven principal series. YILONG, a leader in advanced insulation solutions, presents this comprehensive overview of each series to support industry professionals in selecting the optimal materials for their applications.
YILONG, a trusted name in composite material solutions, has announced advancements in its Fiberglass Rod manufacturing process, designed to meet the needs of industries operating in challenging and corrosive environments. Fiberglass Rods are proving to be an ideal replacement for traditional metal products, offering superior corrosion resistance, electrical insulation, and structural performance.
In the field of electrical insulation and printed circuit boards (PCBs), FR4 fiberglass sheet is one of the most reliable and widely used materials. With exceptional thermal resistance, electrical insulation, and mechanical strength, FR4 is trusted across electronics, automotive, aerospace, power distribution, and telecom industries.
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