Overview
ISO 9665:1998 - "Adhesives - Animal glues - Methods of sampling and testing" defines standardized laboratory procedures for sampling and testing bone and skin (animal) glues supplied as powders, granules, pearls or cubes. The second edition (1998) describes how to prepare representative samples, control moisture, and run core physical and chemical tests that indicate glue quality and usability. The standard is intended for producers, buyers and quality laboratories needing consistent, comparable test results for animal-origin adhesives.
Key topics and technical requirements
- Sampling and sample reduction
- Select containers across a consignment to obtain a representative preliminary sample; reduce to 1 kg+ laboratory samples and grind to ≤3 mm particle size for testing.
- Store all samples in clean, dry, airtight, non-absorbent containers to prevent moisture changes.
- Moisture content
- Determined by drying a thin film at 105 °C for 18 h; small moisture changes significantly alter other test results and should be reported with gel strength/viscosity.
- Gel strength (Bloom)
- Measured on a gel prepared at 12.5% concentration, matured 16–18 h at 10 °C, using a standard plunger (diameter 12.7 mm) depressed 4 mm. Results are expressed in newtons (historical “grams Bloom” values are convertible).
- For very strong gels (>400 g Bloom), a 6.67% (single Bloom) solution is used.
- Viscosity and other physical tests
- Viscosity (capillary viscometers), softening/setting points, foam, pH, grease content and keeping quality are specified with sample masses and dilution volumes (see standard’s Table 1 for concentrations).
- Practical test controls
- Avoid mechanical grinding-induced moisture loss-use a separate hand-ground sample for moisture determination and calculate adjustments.
- The document notes that interlaboratory precision data were not available at publication; users are encouraged to reference ISO 5725 principles when determining accuracy.
Applications and users
- Quality control laboratories in adhesive manufacturing and supply chains
- Purchasers and specifiers verifying conformance of animal glue consignments
- Conservation, bookbinding and woodworking professionals who rely on consistent animal-glue performance
- R&D teams developing animal-based adhesive formulations
Adopting ISO 9665:1998 helps ensure reproducible measurements of critical properties like gel strength and moisture sensitivity, enabling informed selection and acceptance of animal glues.
Related standards
Keywords: ISO 9665:1998, animal glues, adhesive testing, gel strength, Bloom test, moisture content, viscosity, sampling, gelometer.