Physical And Chemical Properties Of Insulating Rubber Mats

Insulating rubber mats possess high volume resistivity and resistance to electrical breakdown.

 

Insulating rubber mats are primarily made of rubber-based insulating materials, using non-polar rubbers with excellent insulating properties such as NR, SBR, and IIR.

The upper and lower surfaces of the insulating mat should be free of harmful irregularities. Harmful irregularities refer to defects that disrupt uniformity or damage the smooth surface contour, such as pinholes, cracks, localized bulges, cuts, inclusions of conductive foreign matter, creases, voids, uneven ripples, and casting marks. Harmless irregularities refer to surface irregularities formed during the production process. Appearance quality requirements include: the depth or height of blemishes or uneven areas must not exceed the thickness tolerance of the rubber sheet; no more than 5 bubbles per square meter with an area not exceeding 1 cm², and the distance between any two bubbles must be no less than 40 mm; the depth and length of impurities must not exceed the thickness of the rubber sheet and must be no less than 40 mm; the width of uneven edges or spongy portions of the mat must not exceed 10 mm, and the length must not exceed 1/10 of the total length of the rubber sheet; cracks are not allowed [1-2]. Thickness measurements should be taken at least five different points randomly selected across the entire insulating mat. A micrometer or an instrument of equivalent precision can be used. The micrometer's accuracy should be within 0.02 mm, the measuring drill diameter should be 6 mm, the flat pressure foot diameter should be (3.17±0.25) mm, and the pressure foot should be able to apply a pressure of (0.83±0.03) N. The insulating mat should be laid flat to ensure smooth micrometer measurements.

 

According to relevant standards, the electrical performance of insulating mats is related to their thickness. Common configurations include: 5kV insulating mat thickness 3 mm; 10kV insulating mat thickness 5 mm; 15kV insulating mat thickness 5 mm; 20kV insulating mat thickness 6 mm; 25kV insulating mat thickness 8 mm; 30kV-35kV insulating mat thickness 10 mm or 12 mm. Its power frequency withstand voltage test requirements are as follows: for an insulating pad with a nominal voltage of 10kV, the preventive test voltage is 15kV, and the withstand time is 1 minute.