Overview
ISO 22785-1:2026 – Paints and varnishes - Coatings on plastics and composites - Part 1: General introduction, published by the International Organization for Standardization (ISO), provides a comprehensive introduction to the application and testing of coatings on plastic substrates, including composites. As the first part of the ISO 22785 series, it establishes fundamental concepts, terms, and the particularities distinguishing coatings on plastics from those on traditional metallic substrates.
The standard outlines the general considerations necessary for understanding coatings applied to plastics, focusing on the influence of substrate characteristics on coating performance and testing. It serves as a foundational reference for manufacturers, laboratories, and industries using or developing coated plastic components.
Key Topics
-
Scope and Applicability
ISO 22785-1 discusses the relevance and limitations of general test methods for coatings on plastics, plastics composites, and similar materials, defining when modifications may be needed.
-
Terminology
The standard adopts and references key terms from ISO 4618 and ISO 472, ensuring consistent use of terminology related to paints, varnishes, plastics, and composites.
-
Substrate Characteristics
A major focus is on the specific properties of plastics as coating substrates, including:
- Thermal conductivity and specific heat capacity
- Transparency and opacity
- Sample thickness
- Deformation, elasticity, and phase transitions (including glass transition temperature)
- Ageing and additive migration
- Barrier properties (moisture and oxygen diffusion)
- Volume changes due to water absorption/release
- Density and mechanical strength
- Electrical and magnetic properties
-
Functional Requirements of Coatings
Coatings on plastics often serve multiple roles-decorative (color, gloss), mechanical (scratch and abrasion resistance), adhesive, thermal (insulation/IR reflection), and protective (UV, barrier, and sealing functions).
-
Comparison with Metal Substrates
The standard highlights key differences affecting coating performance and testing-such as thermal and mechanical behavior, and the lower relevance of corrosion protection for plastics versus metals.
-
Conditioning for Testing
Guidance is provided on the necessary conditioning of coated plastic substrates prior to testing, which may differ significantly from procedures for metals due to plastic-specific sensitivities.
Applications
ISO 22785-1:2026 is essential for:
-
Product Development and Quality Assurance:
Facilitates accurate testing and evaluation of coated plastic products, supporting innovation and quality control in sectors like automotive, electronics, consumer goods, and industrial equipment.
-
Test Laboratories and R&D:
Guides laboratories in selecting appropriate test conditions and interpreting results for coated plastics, ensuring reliable, repeatable measurements.
-
Manufacturing Process Optimization:
Informs substrate preparation, coating application, and post-coating conditioning practices to enhance product durability and performance.
-
Specification and Procurement:
Assists specifiers in setting realistic coating requirements for plastics, taking into account unique substrate influences that affect longevity and aesthetics.
Related Standards
ISO 22785-1 forms the introduction to a comprehensive series addressing specialist testing for coatings on plastics and composites. Related standards include:
Practical Value
Adoption of ISO 22785-1:2026 helps ensure consistency and reliability in the specification, testing, and evaluation of coatings on plastics, leading to enhanced performance, durability, and customer satisfaction across a wide range of industries. This standard is a crucial resource for any organization working with coated plastic or composite materials.
