Overview
ISO 6453:1985 defines specifications for flexible polyvinyl chloride (PVC) cellular foam sheeting used in applications such as dielectric high-frequency welding, filling and upholstery. The standard covers two fundamental product types: type 1 (open-cell, porous) and type 2 (closed-cell, cellular). It sets requirements for hardness, dimensional properties, mechanical performance, ageing and resistance to low temperatures, plus an annexed procedure for assessing staining by organic materials.
Key Topics
- Product types and structure: Type 1 is essentially an open-cell foam (may contain a small percentage of closed cells); Type 2 is essentially closed-cell and often manufactured with multiple plies or on a backing.
- Hardness grading: Hardness is specified via an indentation hardness index (measured according to ISO 2439). For type 1 a single hardness level is specified (table example: 210 ± 40 N). For type 2 a range of degrees is defined (examples: 280, 340, 400 with product indentation indices such as 280 ± 30 N, 340 ± 30 N, 400 ± 30 N).
- Thickness and test pieces: For sheeting up to approximately 100 mm thickness the material indentation hardness index is used. For thin type 2 materials (typically much less than 50 mm) a test piece made of a number of plies is required and the product indentation hardness index is specified.
- Performance requirements: The standard includes limits for variation after accelerated oven ageing, residual compression, tensile strength and elongation, and mandates no cracking under specified low-temperature bending tests.
- Staining (Annex): An integrated annex describes a test to determine whether the PVC sheet will transfer or cause discoloration of adjacent organic-finished surfaces under heat and pressure. The procedure uses representative test panels and exposure at 70 ± 2 °C followed by UV comparison against an ISO greyscale reference.
- Marking and labelling: Rolls or lots must be marked with manufacturer identification, lot number, nominal thickness/width/length and the standard/type suffix (for example: ISO 6453/1/210).
Applications
ISO 6453:1985 applies where consistent physical and mechanical properties of flexible PVC foams are required:
- Sealing, cushioning and insulation in automotive and transport interiors
- Upholstery and furniture filling where low-temperature performance is critical
- Components requiring dielectric welding or lamination
- Situations where staining of adjacent organic materials must be avoided
Related Standards
Standards referenced in ISO 6453:1985 include:
- ISO 2439 – Indentation hardness of cellular polymers
- ISO 2440 / ISO 2440 – Accelerated ageing tests
- ISO 845 – Apparent density of cellular plastics
- ISO 1798 – Tensile and elongation tests for cellular plastics
- ISO 1923 – Determination of linear dimensions for cellular materials
- ISO 105 – Colourfastness tests (staining/greyscale)
For procurement, testing and specification writing, ISO 6453 provides practical, testable requirements to ensure consistent quality and fitness for service of flexible PVC foam sheeting.