Chapter 40 covers rubber and articles thereof, including natural rubber, synthetic rubber, reclaimed rubber, unvulcanized rubber, and vulcanized rubber products. This chapter is divided into raw materials, semi-finished products, and finished products, but certain rubber products may be classified under other chapters (e.g., footwear under Chapter 64). The core is rubber material itself and its primary forms. Heading 4005 includes unvulcanized rubber compounds, including mixtures of natural rubber and synthetic rubber, mixtures of unvulcanized rubber with compounding agents (such as rubber compounds), and primary forms of unvulcanized rubber (plates, sheets, strips, rods, etc.). However, it excludes simple unmixed natural rubber or synthetic rubber (classified under 4001 and 4002 respectively). First 2 digits 40: Chapter 40, representing rubber and articles thereof. Digits 3-4, 05: Heading 4005, referring to unvulcanized rubber compounds, including rubber compounds and mixtures of unvulcanized rubber with compounding agents such as carbon black and silica. Digits 5-6, 91: Subheading 4005.91, specifically referring to plates, sheets, and strips of unvulcanized rubber compounds. Note: Subheadings are divided by shape; 91 covers plates, sheets, and strips, while other shapes such as blocks and granules fall under other subheadings. The goods are unvulcanized rubber compounds in plate form, meeting the description of 4005.91. If it were unmixed natural rubber, it would be classified under 4001; unmixed synthetic rubber under 4002; vulcanized rubber products under 4006 and later. If it were in plate form but already vulcanized, it would be classified under 4008. Therefore, being unvulcanized, compounded, and in plate form are the key factors for classification under this code.

Product Name: The specific name of the declared goods, such as 'unvulcanized rubber compound sheet.' It should accurately reflect the product's attributes. Appearance: Describe the shape of the goods, such as plate, sheet, or strip, and specify dimensions (length, width, thickness). Composition: List the rubber types (e.g., natural rubber, styrene-butadiene rubber) and compounding agents (e.g., carbon black, sulfur, accelerators) with their proportions. Vulcanization Status: Clearly declare 'unvulcanized'; if partially vulcanized, note it. Brand: If there is a brand, declare the brand name; if none, write 'none.' Model: Declare the model or specification of the goods for identification. Use: Explain the final use of the rubber compound, such as for manufacturing tires, hoses, etc. Packaging Specification: Such as weight per box, length per roll, etc., for customs inspection. Product Name: Unvulcanized rubber compound sheet; Appearance: Black plate form, 1000mm length × 500mm width × 5mm thickness; Composition: Natural rubber 60%, styrene-butadiene rubber 20%, carbon black 15%, sulfur 2%, accelerator 1%, others 2%; Vulcanization Status: Unvulcanized; Brand: None; Model: NR-100; Use: For manufacturing tire treads; Packaging Specification: 50 sheets per box, each sheet weighs 5kg. Mistakenly classifying unvulcanized rubber compounds under 4001 or 4002, ignoring the compounded nature. Failing to indicate 'unvulcanized,' resulting in classification under 4008 (vulcanized rubber products). Inaccurate shape description, such as actually in block form but declared as plate form, affecting the applicability of subheading 91. Composition proportions not provided, making it impossible to determine whether vulcanizing agents are present, possibly mistaken as vulcanized.

Core classification basis: 1) The goods are unvulcanized rubber; 2) They are compounds (containing compounding agents); 3) They are in plate, sheet, or strip form. All three are indispensable. If unmixed, classify under 4001 or 4002; if vulcanized, under 4008; if in other shapes, under other subheadings of 4005 (such as 4005.99). Reference should also be made to the Explanatory Notes to Heading 4005 and national subheading notes. 4001 Natural rubber: 4001 covers unmixed natural rubber, while 4005.91 covers compounds containing compounding agents. If natural rubber has only a small amount of anti-aging agent added, it may still be classified under 4001. 4002 Synthetic rubber: 4002 covers unmixed synthetic rubber, including latex. If synthetic rubber is mixed with compounding agents, it is classified under 4005. 4005.99 Other unvulcanized rubber compounds: 4005.99 covers unvulcanized rubber compounds in other shapes (such as blocks, granules), while 4005.91 is limited to plates, sheets, and strips. Shape is the key distinguishing factor. 4008 Vulcanized rubber products: 4008 covers plates, sheets, strips, etc. of vulcanized rubber, while 4005.91 covers unvulcanized. Vulcanization status is the essential difference. 3812 Rubber compounding agents: 3812 covers rubber compounding agents (such as accelerators, anti-aging agents), while 4005.91 covers compounds of rubber with compounding agents, having formed a rubber compound. Is the product unvulcanized? Does it contain compounding agents (is it a compound)? Is the shape plate, sheet, or strip? Does the composition contain vulcanizing agents? Has it been formed into a final product?

How to determine whether an unvulcanized rubber compound is classified under 4005.91? First confirm the product is unvulcanized, then that it contains compounding agents (such as carbon black, sulfur, etc.), and finally that its shape is plate, sheet, or strip. If all three conditions are met, it is classified under 4005.91. If any condition is missing, other codes must be considered. How to distinguish rubber compound sheets from vulcanized rubber sheets during declaration? Rubber compound sheets are unvulcanized, typically soft and plastic; vulcanized rubber sheets are cross-linked and highly elastic. During declaration, proof of vulcanization status such as test reports must be provided. Misdeclaration may lead to classification errors and penalties. If a rubber compound sheet contains sulfur, is it considered vulcanized? Containing sulfur but not having undergone the vulcanization process (heat and pressure) is still unvulcanized, classified under 4005. Vulcanization refers to the process of rubber molecule cross-linking; merely adding sulfur does not equal vulcanization. What is the main difference between 4005.91 and 4005.99? 4005.91 applies only to plates, sheets, and strips, while 4005.99 applies to other shapes such as blocks, granules, and powders. Shape is the sole distinguishing criterion and must be accurately described in the declaration. What declaration elements are required for importing rubber compound sheets? Product name, appearance, composition, vulcanization status, brand, model, use, and packaging specifications are required. The composition should list rubber types and compounding agent proportions so that customs can confirm classification. If a rubber compound sheet is cut into a specific shape, does it affect classification? If after cutting it remains in plate, sheet, or strip form, it does not affect classification under 4005.91. If cut into non-plate/sheet/strip shapes (such as rings), it may be classified under 4005.99 or other codes. How to check the import tariff rate for 4005.91? It can be checked through the General Administration of Customs website, China International Trade Single Window, or the Import and Export Tariff of the People's Republic of China. Tariff rates may vary due to trade agreements, rules of origin, etc.; the latest tariff schedule should be consulted. What should be noted when declaring rubber compound sheets for cross-border e-commerce sales? Ensure the goods meet the description of 4005.91 and that declaration elements are complete and accurate. Note the distinction between personal items and goods; if they are goods, formal customs declaration is required. Also pay attention to environmental and safety requirements for rubber products.