Natural rubber sheets,known for their high elasticity,tear resistance,wear resistance,and shock absorption,are widely used in applications such as mechanical sealing,equipment gaskets,workshop flooring,and anti-corrosion linings in water conservancy projects.To ensure product quality and avoid procurement losses,it is essential to adhere to current execution standards.Currently,the primary national standard for industrial-grade natural rubber sheets in China is GB/T 5574-2008″Industrial Rubber Sheets,”which serves as the legal basis for production,testing,bidding,and acceptance.
GB/T 5574-2008 came into effect on October 1,2008,replacing the older version GB/T 5574-1994.It was jointly issued by the State Administration for Market Regulation and the National Standardization Management Committee.Jingdong Rubber Co.,Ltd.is one of the drafting organizations for this standard.The standard clearly applies to various pure rubber and fabric-reinforced natural rubber sheets made primarily from natural rubber through vulcanization,with rectangular rubber strips also regulated under this standard.The new standard optimizes thickness tolerances,hardness grading,and product labeling rules,introduces a new ultra-high hardness grade(90A),and refines additional performance indicators such as aging resistance and chemical resistance.This unifies production and inspection criteria across the industry,providing a standardized and authoritative reference for manufacturing,testing,and acceptance within China’s natural rubber sheet sector.
In terms of product classification,the national standard categorizes natural rubber sheets into three types based on oil resistance:Type A—general-purpose natural rubber sheets(non-oil-resistant;the mainstream black rubber sheets available in the market);Type B—moderately oil-resistant sheets,exhibiting a volume change of+40%to+90%after 72 hours of immersion in No.3 standard oil at 100°C;and Type C—oil-resistant modified natural rubber sheets,with volume change controlled between-5%and+40%.Buyers can select appropriate types according to specific operating conditions.Regarding dimensional parameters,the standard specifies conventional thicknesses ranging from 0.5 mm to 50 mm,with thickness tolerances varying by specification—for example,±0.3 mm for thicknesses up to 3 mm and±2.0 mm for thicknesses over 20 mm.Widths are standardized between 500 mm and 2000 mm,with a tolerance of±20 mm.Non-standard lengths and widths are agreed upon contractually between buyer and supplier.
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For physical and chemical performance,multiple supporting national standards apply:tensile properties follow GB/T 528,tear strength refers to GB/T 529,Shore A hardness is tested per GB/T 531,while thermal aging and resistance to acidic/alkaline liquids comply with GB/T 3512 and GB/T 1690,respectively.The standard classifies tensile strength into seven grades(3 MPa to 17 MPa)and elongation at break into nine levels(100%to 600%).High-quality virgin natural rubber sheets typically achieve strengths above 15 MPa and an elongation of 500%,offering superior rebound performance compared to recycled rubber sheets.Thermal aging tests are conducted under two conditions—70°C/72h and 100°C/72h—with post-aging reductions in strength and elongation strictly limited within the ranges defined by the standard.
Beyond general industrial rubber sheet standards,specialized specifications exist for special-purpose natural rubber sheets:insulating natural rubber sheets must meet relevant power industry insulation pad regulations;anti-static natural rubber sheets conform to national standards for anti-static materials;products exported to the EU must additionally comply with REACH environmental regulations and ISO 37 international rubber testing standards,ensuring dual compliance with both domestic and international requirements.Surface quality is also strictly specified—qualified sheets must be free from cracks,bubbles,holes,or raised impurities,though minor processing marks are acceptable.Large-scale depressions or damage result in rejection.
For manufacturers and buyers alike,adherence to national standards is key to quality control.As a drafting organization,Jingdong Rubber has been deeply involved in the development and revision of these standards,possessing in-depth knowledge of all core technical requirements.Before shipment,manufacturers conduct batch-by-batch sampling tests for hardness,tensile strength,and dimensions in accordance with GB/T5574-2008.Buyers can verify these parameters upon receipt,effectively preventing the purchase of substandard or adulterated recycled rubber products,thereby reducing issues such as equipment sealing leakage and gasket cracking requiring rework.
In summary,GB/T5574-2008 serves as the core standard for natural rubber sheets,distinguishing between general-purpose and specialized applications through detailed specifications.It is a crucial reference for product selection,manufacturing,and acceptance.When purchasing natural rubber sheets,prioritize checking whether the product meets national standards to ensure stability and reliability in engineering and equipment applications from the source.
Jingdong Rubber Co., Ltd. is a professional rubber sheet manufacturer, producing silicone rubber sheet, natural rubber sheet, fluorine rubber sheet, neoprene rubber sheet, insulating rubber sheet,EPDM rubber sheets, oil-resistant rubber sheets, anti-static rubber sheets, flame-retardant rubber sheets, conductive rubber sheets, anti-slip rubber sheets, and cowshed mats, etc. with over 40 years of industry experience, are popular both at home and abroad. If you need any of our products,please send emails to sales@jingdongrubber.com.