What are the dielectric strength and voltage withstand capabilities of high-barley paper?
Publish Time: 2025-12-09
In the internal structure of electrical equipment such as motors and transformers, insulating materials play a crucial role as a "safety barrier"—they must not only isolate current between conductors at different potentials but also withstand the combined effects of electric fields, thermal stress, and mechanical vibrations during long-term operation. High-barley paper (also known as green shell paper), a functional insulating material derived from natural plant fibers, is widely used in the manufacture of gaskets, liners, or interlayer separators due to its flexibility, moldability, fire resistance, and heat insulation properties.First, it's important to understand that the insulating properties of high-barley paper do not come from synthetic polymers or ceramic components, but rather from its dense and uniform natural fiber network structure. During manufacturing, carefully selected barley straw fibers undergo special treatment and hot pressing to form a tightly structured board with low porosity. This microstructure effectively hinders the free migration of electrons under the influence of an electric field, thus possessing excellent intrinsic insulation properties. Simultaneously, the material itself contains no conductive impurities and has a low moisture absorption rate in a dry state, further ensuring its electrical insulation reliability in normal operating environments. Secondly, the voltage withstand capability of high-density barley paper is reflected in its dual adaptability to transient overvoltages and long-term power frequency voltages. Between motor windings or transformer coils, local electric fields may concentrate due to design or manufacturing deviations. If the insulation material's withstand voltage is insufficient, partial discharge can easily occur, leading to insulation degradation or even breakdown. High-density barley paper, with its multi-layered labyrinthine pathways formed by interwoven fibers, effectively disperses electric field stress and delays the formation and development of electrical trees. More importantly, its natural fibers do not melt and drip when heated. Even if carbonization occurs under abnormal temperature rises, it often maintains structural integrity, preventing the rapid establishment of short-circuit paths and providing valuable fault buffer time for the system.It is worth noting that high-density barley paper is often impregnated or coated to further enhance its electrical performance. For example, in practical applications, it is often used in conjunction with insulating varnishes, epoxy resins, or silicone oils. These impregnating agents fill the fiber gaps, expelling air (a major cause of partial discharge), significantly improving overall dielectric strength and moisture resistance. This composite system of "natural substrate + functional impregnation" allows Highland Barley paper to meet industrial-grade insulation requirements while maintaining its environmental and processability advantages.Furthermore, its flexibility and moldability indirectly enhance insulation reliability. In complex geometries of iron cores or winding gaps, Highland Barley paper can be stamped into precisely fitted sheets, ensuring air gap-free and wrinkle-free coverage of critical areas. Compared to rigid insulation materials, this tight fit significantly reduces the risk of electric field distortion, improving voltage withstand performance from a structural perspective.Of course, the performance of any insulation material is affected by environmental factors. In extremely humid or long-term oil-immersion environments, the insulation performance of Highland Barley paper may degrade without adequate protection. Therefore, in harsh operating conditions such as high humidity or oil-cooled transformers, modified green-shell paper with special waterproof or oil-resistant treatments is usually selected, or it is used as part of a multi-layer insulation system, working in conjunction with other materials.Finally, compliance is the guarantee for performance implementation. High-quality Highland Barley Paper products undergo electrical performance verification according to international electrical standards to ensure their dielectric strength meets the requirements of equipment with corresponding heat resistance classes (such as Class B and Class F) and passes relevant safety certifications.In summary, while Highland Barley Paper's dielectric strength and voltage withstand capability as insulating pads in motors and transformers may not match those of some high-performance synthetic materials, its natural structural advantages, impregnation-strengthening properties, and excellent bonding ability make it a reliable and economical insulation material under medium- and low-voltage, medium-temperature conditions. It is not only a mature choice for the traditional electrical industry but also continues to thrive in the trend of green manufacturing due to its renewable and low-pollution characteristics.
