ISO 28762:2010

Overview

ISO 28762:2010 specifies functional and aesthetic requirements for vitreous and porcelain enamel coatings applied to plain steel intended as writing surfaces (whiteboards and chalkboards). The standard focuses on performance attributes that affect durability, appearance and usability, including coating thickness, adhesion, abrasion and chemical resistance, surface hardness, gloss, writability and erasability.

Key Topics

• Steel substrate: Steel for enamelling shall conform to EN 10209 and be agreed between supplier and purchaser. Surface defects that affect finish appearance are not acceptable.
• Final fired enamel thickness: Measured per ISO 2178. Limits: ≤ 250 µm for whiteboards and ≤ 200 µm for chalkboards on the outer face.
• Adherence: Determined per EN 10209 Annex D; for steel < 0.6 mm use a 300 mm drop. Required adherence is at least level 3.
• Wear resistance: Taber abrasion per ASTM C501 using S 33 emery paper and 1 kg load. Mass loss after 1 000 revolutions must be ≤ 0.10 g.
• Impact resistance: Per ISO 4532 with a pistol load of 20 N; no damage exceeding 2 mm diameter after 24 hours.
• Surface hardness and scratch resistance:
  • Mohs hardness per EN 15771: minimum 5 for whiteboards, minimum 3 for chalkboards.
  • Scratch resistance per ISO 15695: minimum 7 N for whiteboard, 4 N for silk-screened whiteboard.
• Gloss and appearance: Measured per ISO 2813 or agreed methods. Gloss at 60°: chalkboards 2–20 units, whiteboards ≥ 35 units. Colour and surface texture (orange peel, patterns) are to be agreed by parties.
• Chemical and acid resistance: Citric acid resistance for whiteboards is class A (ISO 28706-1). Chemical resistance class A for deionized water, ethanol, MEK, xylene and toluene (15 min test).
• Writability and erasability: Chalkboard surfaces must be easy to write on and erase with a dry felt eraser. Whiteboards must accept dry-erasable, water-soluble or permanent markers and permit removal per the specified methods. After thorough cleaning, pigment-related colour change shall not exceed ΔE = 0.5* (CIELAB).
• Graffiti resistance: After eight days’ ageing, inks and paints on whiteboards shall be removable with suitable solvents without visible colour or gloss change.

Applications

ISO 28762:2010 is relevant to manufacturers, specifiers and purchasers of whiteboards, chalkboards and other writing surfaces employing vitreous or porcelain enamel on steel. It supports quality control in production, product specification in procurement, and assessment of durability and maintenance characteristics in educational, corporate and public environments.

Related Standards

• EN 10209 (steel for enamelling)
• ISO 2178 (coating thickness)
• ISO 2813 (gloss measurement)
• ISO 4532 (impact)
• ISO 15695 (scratch resistance)
• ISO 28706-1 (chemical corrosion resistance)
• EN 15771 (Mohs surface hardness)
• ASTM C501 (Taber abrasion)

For procurement and testing, reference these normative documents and agree specific aesthetic criteria (colour, gloss, texture) between contracting parties.