Introduction

Cellulose containing textiles are considered as resistant against the attack of microorganisms living in the soil, provided that their structure, appearance and maximum tensile strength have not been altered essentially after a soil burial test.

The assessment of damage resistance takes into account the structure, the aspect and the changes in the maximum tensile strength, compared to untreated specimens of the same material quality. It is assessed by comparing the relative decrease of maximum tensile strength of buried specimens, with that of unburied control specimens.

A long-term rot retardant finish or an increased long-term resistance meets with the requirements for cellulose containing textiles if the maximum tensile strength of a buried specimen, compared with an unburied specimen, does not decrease by more than 25 %.

The soil burial intervals for long-term retardant finishes take twice the time needed for control specimens to lose 80 % of their maximum tensile strength. The soil burial intervals for increased long-term resistant finishes takes four times the time needed for the controls to lose 80 % of their maximum tensile strength.

 

1   Scope

This European Standard describes a test procedure for identification of the long-term resistance of a rot retardant finish against the attack of microorganisms in the soil.

It allows distinction to be made between rot retardant finishes with no long-term resistance, with regular long-term resistance and with increased long-term resistance, in order to assess the suitability for use in the tropics.

As the soil burial test is a biological process and the test soil not accurately defined, this European Standard only covers the comparison of finished and unfinished specimens.

 

2   Normative references

This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments).

EN ISO 11721-1:2001, Textiles — Determination of the resistance of cellulose-containing textiles to micro-organisms — Soil burial test — Part 1: Assessment of rot-retardant finishing (ISO 11721-1:2001).

EN ISO 13934-1, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and elongation at maximum force using the strip method (ISO 13934-1:1999).

ISO 7218, Microbiology of food and animal feeding stuffs — General rules for microbiological examinations.