Bakelite / Hylam Insulation Sheets — Electrical Insulation Materials Manufacturer in India
Of all the materials that have been tried out for insulation applications, bakelite sheet is one of the most successful. Even after decades of being used, the bakelite sheet continues to be an ideal material for engineers looking for reliable insulation material for high voltage applications without compromising on practicality, and we here at Harnawa Inc., as a leading manufacturer of Electrical Insulation Material Manufacturer in India, continue the tradition with hylam sheet and super hylam sheet.
Bakelite, Hylam, or Super Hylam — What’s the Difference?
The most commonly raised question by the buyers involves the constituents of “bakelite sheet,” “hylam sheet,” and “super hylam sheet.” Actually, all three sheets are of the same class but can differ in the names used in certain geographical locations or due to the tradition of a certain brand in India. “Hylam” has been a well-known term for phenolic sheeting for several decades already, similar to “Bakelite” being the universally recognized name for phenolic resin. “Super Hylam” is yet another variation of the phenolic paper laminate group, which differs from others by the higher manufacturing consistency but retains the same physical properties. The correct term is “Phenolic Resin-Bonded Paper Laminate.”
How Bakelite / Hylam Sheets Are Made
The formation of a phenolic laminate involves the treatment of insulating paper sheets with phenolic resins and compressing them at high temperatures and pressures. The resins get cured as they form cross-linkages with each other. This forms an interwoven structure of insulating papers, which becomes hard and compact due to the formation of cross-linkages between the layers. This gives the phenolic laminate paper good mechanical strength and dielectric stability, which are the properties which make it suitable for manufacturing of electrical panels and appliances.
Technical Specification Overview
Harnawa Inc.’s bakelite / hylam insulation sheets are manufactured to the following specification:
- Product Type: Phenolic Paper Laminate
- Thermal Classification: Class B
- Type of Insulating Sheets: Bakelite / Hylam
- Color: Red Brown – unique color that is easily recognizable
- Thermal Rating: Continuous operating up to 120°C
- Highest Voltage Rating: More than 100 kV – suitable for high voltage insulation
- Fire Retardant: Yes – phenolic resins are fire retardant
- Oil Resistant: Oil resistant, suitable for working in transformer oil
- Range of Application: Insulating materials and parts in motors, transformers, and switchgears
It is the combination of Class B thermal resistance property, high dielectric strength, and transformer oil resistance that makes the bakelite/hylam sheet a suitable choice for use in the Indian electrical industry.
Why Engineers Still Specify Phenolic Laminate
High Voltage Durability – Since it can withstand a voltage rating greater than 100 kV, bakelite insulation board is able to provide sufficient dielectric strength in applications involving switchgears, transformers, and high voltage motors.
Inherent Flame Retardant Characteristics – Being inherently fire retardant, phenolic resin does not catch fire easily within enclosed electrical applications.
Compatibility with Transformer Oil – Bakelite/hylam boards are designed to function effectively in transformer oils without losing their dielectric and mechanical characteristics.
Machining – Reddish brown color phenolic resin laminate is easy to cut, drill, and mill, making it useful for manufacturing gears, insulators, gaskets, spacers and similar electrical parts.
Cost-effectiveness at Bulk – In comparison with glass epoxy and high temperature composites, phenolic paper laminate provides Class B performance at a much lower cost.
Where Bakelite / Hylam Sheets Are Used
- Transformers – insulation barriers, terminals, and supporting structures for transformer oil
- Switchgears – insulation barriers, partitions, and supporting structures in LV & MV assemblies
- Motors & Generators – structural insulation materials, slots, and terminal insulation
- Electrical General – gears, gaskets, spacers, and insulating plates for industrial equipment
Completing the Insulation System
Bakelite/hylam sheet is rarely the only insulation material in a build. Motor, transformer, and switchgear manufacturers typically pair it with complementary materials to form a complete, multi-layer insulation system:
Sourcing these materials together from one certified supplier keeps quality consistent across the full insulation stack and simplifies procurement for OEMs.
Certifications & Quality Assurance
Certified production process of Bakelite/hylam sheets by Harnawa Inc. includes following certifications:
- UL approved
- CE certified
- RoHS certified
- ISO 9001:2015 certified production process
- REACH compliant
Harnawa Inc. — Electrical Insulation Materials Manufacturer in India
As an experienced provider of Electrical Insulation Materials in India, Harnawa Inc. provides bakelite, hylam, and super hylam phenolic paper laminate sheets to manufacturers of transformers, motors, switchgears, and industrial machines in cities like Mumbai, Delhi, Pune, and Ahmedabad as well as all around India. Each sheet comes with quality certification and is available in customizable sizes for immediate use.
Frequently Asked Questions
1.Is bakelite sheet the same as hylam sheet?
Yes, both bakelite sheet and hylam sheet are synonymous names given to the same type of material in the industrial field. Hylam is an often used trademark that is now a common generic term used in India just like Bakelite which is generic for phenolic resins.
2.What voltage rating are bakelite/hylam sheets rated at?
The bakelite/hylam sheets from Harnawa Inc. are rated for maximum voltages greater than 100kV.
3.Could one use bakelite sheet in transformer oil?
Yes. The bakelite/hylam sheets have the ability to function effectively in transformer oil and remain dielectrically stable when immersed in oil.
