ISO 3998:1977 Textiles — Determination of resistance to certain insect pests.Remember to share with others.
Some methods previously utilized for testing resistance of textiles to insect pests relied solely on loss of mass of the test specimens exposed to larvae as the criterion of damage and this is, of course, the most objective result which can be obtained. However, with pile fabrics, if the larvae cut the roots of the pile or nap, significant loss of pile can sometimes be caused before the larvae die. in this case, the loss in mass of the test specimen may be above the generally acceptable limit although no damage is visible to the naked eye, and the fabric may be accepted as adequately proofed. Conversely, fabrics with a smooth milled surface, and fine knitwear, may have a loss in mass below the acceptable limit, but still show enough damage for them to be assessed as insufficiently proofed. Thus although determinations of mass are recorded in this method, subjective visual observations on the condition of the fabric and larvae play an equal part in the assessment. In most cases the losses in mass will reinforce the visual observations.
1 SCOPE AND FIELD OF APPLICATION
This International Standard specifies a method for the determination of the resistance of textiles to the larvae of certain insects. It is applicable to all textiles containing animal fibre In any porportion. Information relating to the breeding of the larvae is given In the annex.
2 PRINCIPLE
Conditioned voracity control specimens and test specimens of known mass are placed in contact with selected larvae for 14 days. The loss in mass of all specimens, the extent of the attack on test specimens and the condition of the test larvae are ascertained to assess the resistance of each test specimen.
3 APPARATUS
3.1 Metal containers, the covers of which are pierced with ventilating holes, shallow, large enough to permit the test larvae to remain in contact with, or move away from, the test specimens. A suitable size is 45 mm diameter, 10 mm height.
3.2 Flexible forceps and camel hair brush with pesticidefree bristles.ISO 3998:1977 pdf download.