BS 4060:2006 pdf download – Pressed wool felts – Specification
fabric characterized by the entangled condition of most, or all, of thefibres of which it is composed 3.2general purpose felt
felt used for packaging, clothing, decorative and similar purposes3.3precision felt
felt used in engineering applications, where close tolerances arenecessary
3.4 pressed felt
felt formed from a web or batt containing animal hair or wool,consolidated by the application of heat and mechanical action thatcauses the constituent fibres to mat together
3.5white felt
felt that has the colour of natural,unpigmented wool
NOTE White felts are used where visual appearance is important.3.6grey felt felt, the colour of which has been obtained from using mixtures ofcoloured wools and other fibres
4 Material requirements
Felts shall be manufactured from wool, or mixtures of wool with naturalor man-made fibres. The minimum wool content shall be as specified inTable 1 and Table 4.
NOTE The fibres should be blended, carded and felted to form a uniformproduct substantially free from permanent ridges and cveases. The procluct should be fvee from all non-fibrous agents, e.g. stiffening, loadingor reinforcing agents of any kind.
5 Designation
Felts shall be designated by a condensed technical description (seeTable 1 and Table 4) containing the following:
a) a first letter to indicate whether the felt is general purpose (A) or
precision (B);
b) a number, consisting of two digits, to indicate the minimum
percentage wool content;
c) an oblique stroke;
d)a single digit number, 1 to 8, to indicate the hardness or density grade;
e) a letter to indicate the colour white (W), grey (G) or dyed (D).NOTE If appropriate,interested parties can agree to inclde the additional designations in Table 6 and Table 7 in order to indicate thatparticular chemical and/or phgsical recuirements have been conformedto (see 6.4 and 6.5).
EXAMPLE 1: The designation, A75/1W, indicates that the felt is general purpose, with 75% wool content, extra hard and white.
EXAMPLE 2 The designation, B97/1G6.1–6.6, indicates that the felt is a precision felt with 97% wool content, extra hard, grey, having a minimum breaking strength of 5.5 MPa and having chemical properties conforming to 6.1 to 6.6 of Table 6.
6 Performance requirements 6.1 General purpose felts General purpose felts, including packaging felts, shall conform to Table 1 and Table 2.
NOTE Commonly manufactured thicknesses are 1 mm, 3 mm, 5 mm, 10 mm, 15 mm, 20 mm and 25 mm but other thicknesses may be specified by the customer.
6.2 Decorative felts Decorative felts shall conform to 6.1 and shall meet the minimum colour fastness ratings detailed in Table 3.
6.3 Precision felts Precision felts shall conform to Table 4 and Table 5.
6.4 Chemical properties If felts are required to have particular chemical properties, the felts shall conform to the relevant requirements of Table 6. NOTE 1 The manufacturer should query the purchaser as to whether there are any particular chemical properties that are required (see Annex A).
NOTE 2 For MOD purposes, general purpose felts and felts for aerospace purposes should conform to 6.1, 6.3 and Table6. The tests outlined in Annex C shall be used to determine the wool content of felts.
6.5 Physical properties If felts are required to have particular physical properties, such as breaking strength and oil retention, they shall conform to the relevant requirements of Table 7. NOTE The purchaser should specify whether any particular physical properties are required (see Annex A). The tests outlined in Annex D shall be used to determine the physical properties of the felts.
6.6 Special finishes Felts shall be manufactured either with or without special finishes imparting, for example, rot, mildew, moth, flame or water resistance, or a combination of these properties.
NOTE The purchaser should specify whether any special finishes are required (see Annex A).
7 Inspection, sampling, conditioning and testing atmosphere
7.1 Inspection Each manufactured piece shall be visually inspected for defects, e.g. permanent ridges and/or creases and holes.