AS 4758.2:2015 pdf download.Lifejackets Part 2: Materials and components——Requirements and test methods.
SECTION 2 SEWING THREAD
2.1 CONSTRUCTION Sewing thread shall not consist wholly of natural fibres or be monofilament. Where natural fibre is used as a component of the thread, it shall be treated to resist rotting.
2.2 PERFORMANCE Sewing thread shall comply with the requirements specified in Table 2. 1.
2.3 LOOP BREAKING STRENGTH The loop breaking strength shall be determined using a constant rate of extension tensile testing machine described in ISO 2062 as follows: (a) Secure both ends of one piece of sewing thread in one clamp of the testing machine so that the length of the loop equals half the distance between the jaws. (b) Pass one end of the second piece through the loop formed by the first and secure both ends in the other clamp of the testing machine. (c) Operate the tensile testing machine at a constant rate of extension of 500 ±10 mm/mm. (d) Record the breaking strength.
SECTION 5 STRUCTURAL ZIPPERS
5.1 CONSTRUCTION A hole shall be provided on the zipper pull. A zipper pull shall be at least 24 mm long. Projections (i.e. raised material) on the end of the zipper pull shall be provided to make the zipper pull easier to grasp. The slider of the zipper shall he of the automatic locking type.
5.2 PERFORMANCE Structural zippers shall comply with the requirements specified in Table 5.1. NOTE: Non-structural zippers should not he closed during the test of a lifejacket.
SECTION 6 WEBBING CLOSURES AND ADJUSTERS
6.1 CONSTRUCTION Closures and adjusters, such as buckles and slide adjusters shall comply with the criteria specified in Table 6.1 when subjected to the tests specified in that table.
6.2 PERFORMANCE 6.2.1 Tensile strength The assembly shall consist of the hardware component with two lengths of webbing 150 mm in length attached as they are for use. A constant rate-of-extension tensile testing machine with a rate of extension of 300 ±10 mm/s and jaws not less than the width of the webbing shall be used. A tensile load shall be applied until breakage, disengagement, slipping in excess of 75 mm or a similar condition occurs. The tensile load at failure shall be reported. 6.2.2 Strength/slippage An assembly consisting of the hardware component with webbing attached as for use shall be subject to a tensile load for 10 mm using either the fixed straight-length method or the loop assembly methods as follows:
(a) Fixed Straight— length in ct/i oct Two lengths of webbing not less than 600 mm in length shall be used to make up the assembly as shown in Figure 6.1(a).One end of the assembly shall be secured to a fixed point and a steady load shall be applied to the other. (b) Loop assein b/v method The assembly shall be made up with a single piece of webbing not less than 1200 mm in length as shown in Figure 6.1(b). The assembly loop shall be supported vertically over a cylinder and a second cylinder shall provide the means for applying a steady load [see Figure 6.1(b)]. 6.2.3 Tab disengagement The assembly shall consist of the hardware component with two lengths of webbing not less than 600 mm in length attached as for use. One end of the assembly shall be secured to a rigid fixture and a mass of 2.25 kg shall be attached to the other end. The mass shall be raised 300 mm above the attachment point and shall be released to apply a shock load to the assembly.
SECTION 7 WHISTLES
Whistles shall be non-metallic and robust in construction, free from all burrs, and not rely on any moving part for the production of sound. Three specimens shall be tested by being blown as hard as possible by a subject of between 20 and 30 years of age and free from all known impairments to pulmonary function, in an outside and open area during calm clear weather. When measured at a distance of 5 ±0.1 m directly in front of the whistle, the sound generated by the whistle exceeds at least for an instant 100 dB(A) at a predominant frequency of 2 ±0.1 kHz.
The whistle shall also be shown to be capable of producing sound in air immediately following immersion in fresh water. The whistle shall be attached to cord or line of a length sufficient to permit its use, which shall in turn be attached securely to the lifejacket or buoyancy aid. It shall be stowed on the device in such a way that the performance of the lifejacket is not affected, but so that they can be removed from use with either hand of the wearer, and can be stowed by the wearer.AS 4758.2 pdf download.