1、 The following commercial specification is an original Parachute Industry Association specification. CURVATURE TEST METHOD FOR NARROW FABRIC TAPES AND WEBBING The Parachute Industry Association makes this document available for use by Industry and Government organizations that wish to apply this spe
2、cification to their products. 1. SCOPE 1.1 Scope. This method is intended for determining the curvature of narrow fabric tapes and webbings. 2. TEST SPECIMEN 2.1 Specimen. The specimen shall be a length of webbing, full width, measuring a minimum of 40 inches. The specimen shall not be stretched, sm
3、oothed, or otherwise changed from its original condition prior to testing (see FIGURE A). 3. NUMBER OF DETERMINATIONS 3.1 Number of Determinations. Unless otherwise specified in the procurement document, five determinations shall be tested from each sample unit. 4. APPARATUS 4.1 Apparatus. Plexiglas
4、 or equal - Plexiglas weighing approximately 35 ounces with dimensions of 45 inches by 5 inches by 1/4 inch Straight edge - A rigid straight edge measuring 36 inches in length Roller - A roller 1 inch in diameter and weighing 1 1/2 pounds 5. PROCEDURE PIA-TEST METHOD-504 28 October 2015 DISTRIBUTION
5、 STATEMENT: All Rights Reserved. No Part of this publication may be reproduced without prior written permission from Parachute Industry Association. Additional copies may be purchased on-line from PIA Specifications and Products at: . Copyright Protected: Do Not Copy! PIA-TEST METHOD-504 Page 2 of 3
6、 5.1 Preparation of specimen. Unless otherwise specified in the procurement document, material testing shall be performed under standard conditions as specified in ASTM D 1776. 5.2 The specimen. The specimens shall be placed flat, on a smooth, horizontal flat surface without tension and allowed to r
7、each moisture equilibrium as defined in the standard textile conditions as specified in ASTM D 1776. After equilibrium is reached a weight shall be placed at one end of the webbing. The roller shall be placed on the specimen at the end of the webbing where the weight is located. The specimen should
8、be approximately in the center of the roller. The roller shall be rolled along the length of the specimen, care being taken to keep the specimen in the center of the roller and not to exert any pressure on the roller. When the roller has passed the length of the webbing, the Plexiglas shall then be
9、placed on the specimen for a period of 1 hour. Without moving the Plexiglas on the specimen, the straight edge shall be placed on the Plexiglas so that both ends of the straight edge are aligned perpendicularly with the outermost edge of the specimen. Determine the highest degree of curvature of the
10、 specimen from the straight edge by measuring to the nearest 1/32 of an inch perpendicularly from the straight edge. Record the highest measure (see FIGURE A). 6. CALCULATION6.1 Curvature. The maximum curvature, utilizing the above procedure (see 5.2), shall be not more than 3/4 of an inch. 7. REPOR
11、T7.1 Report. The average of five determinations from each sample unit shall be recorded. FIGURE A Lateral curvature diagram. * Notices: This document is being maintained as a commercial specification by the Parachute Industry Association. Orders, inquiries, and comments should be addressed to PIA, S
12、pecification Committee via email at: or to our website at: . Copyright Protected: Do Not Copy! PIA-TEST METHOD-504 Page 3 of 3 Disclaimer: This document is published by the PIA to provide technical and engineering standards that can be used as reference by all those who may benefit from them. The u
13、se of this document is entirely voluntary, and its applicability and suitability for any particular use, including any patent or trademark infringement arising there from, is the sole responsibility of the user. The PIA reviews each technical publication periodically, at which time it may be reaffirmed, revised, or cancelled. The PIA invites your written comments and suggestions. Copyright 2015 Parachute Industry Association. Copyright Protected: Do Not Copy!
