1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2013 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR1490BAEROSPACEINFORMATION REPORT AIR1490 REV. BIssued 1978-07 Revised 1995-08 R
5、eaffirmed 2013-08 Superseding AIR1490A Environmental Degradation of Textiles RATIONALE AIR1490B has been reaffirmed to comply with the SAE five-year review policy. FOREWORDThe intent of this SAE Aerospace Information Report (AIR) is to make available information concerning the environmental degradat
6、ion of textiles as used in unit load device (ULD) equipment common to the air cargo community.1. SCOPE AND FIELD OF APPLICATION:Since the ULD device containing textiles should have a predictable service life, there should be data available so that predictions can be made. This document compiles avai
7、lable information on textiles of the types used in air cargo ULD devices and reviews the degradation characteristics of each.Textiles are used primarily in cargo restraint nets on air cargo pallets and nonstructural containers, restraint nets installed in cargo aircraft, and similar applications.2.
8、REFERENCES:2.1 Applicable Documents:The following publications form a part of this specification to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event o
9、f conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained from the appropriate agency.2.1.1 SAE Publications: Availa
10、ble from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.AS1131 Air and Air/Surface (Platform) Cargo Pallet NetsAS1492 Interline Air Cargo Pallet Nets2.1.2 U.S. Government Publications: Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-
11、5094.MIL-W-4088 Webbing, Textile, Woven NylonMIL-W-19078 Webbing, Polyester, Textile, Latex ImpregnatedMIL-W-25361 Webbing, Textile, Polyester, Low ElongationMIL-W-27265 Webbing, Textile, Woven Nylon, Impregnated2.1.3 ANSI Publications: Available from ANSI, 11 West 42nd Street, New York, NY 10036-80
12、02.ISO 4115 Air Cargo Equipment - Air/Land Pallet NetsISO 4170 Air Cargo Equipment - Interline Pallet NetsISO 8647 Environmental Degradation of Textiles Used in Air Cargo Restraint Equipment2.1.4 IATA Publications: Available from International Air Transport Association, IATA Building, 2000 Peel Stre
13、et, Montreal, Quebec, Canada H3A 2R4IATA, Unit Load Devices (ULD) Technical Manual2.2 Applicable References:2.2.1 Sunlight Exposure of Nylon Webbing, Technical Note WCRT 54-249; Wright Air Development Center, ARDC, United States Air Force, Wright-Patterson AFB, Ohio, December 19542.2.2 Comparative C
14、hemical Resistance of Fibers, Bulletin X-48. E.I. DuPont de Nemours nevertheless, prolonged exposure can cause a loss in breaking strength, breaking elongation, and toughness. These properties are especially important in industrial fiber products.4.1 Influence of Wavelength:Test conducted by Du Pont
15、 as well as experience show the primary cause for light degradation of fibers is ultraviolet rays with wavelengths between 290 and 400 millimicron. Radiation of shorter wavelengths, including gamma rays, damages fibers; however, this radiation is seldom encountered by fiber products. Radiation of lo
16、nger wavelengths (that is, the visible and infrared rays), also damages some fibers, but this damage is minor compared to that from ultraviolet rays. Such radiation could, however, cause an increase in fiber temperature, which might result either in heat degradation or in accelerated ultraviolet deg
17、radation of the fiber.The spectral distribution of the energy of the suns radiation reaching the earth is about 5% in the ultraviolet region, 40% in the visible, and 55% in the infrared. These percentages vary with the seasons, time of day, atmospheric conditions, latitude, and altitude.4.2 Influenc
18、e of Other Factors:The deterioration of a fiber by sunlight or other radiation depends on a number of factors. A brief discussion of some of these factors follows:4.2.1 Geographical Location of Exposure: Sunlight deterioration of fibers is more rapid at certain geographical locations than at others.
19、 This is due to differences in the duration and intensity of radiation in the particular wavelengths that damage fibers.4.2.2 Time of Year When Exposed: The rate of sunlight deterioration of fibers also varies with the time of year of exposure. At most locations, deterioration is considerably more r
20、apid in summer than in winter because of the relatively higher amount of ultraviolet radiation during the summer months.SAE INTERNATIONAL AIR1490B Page 3 of 22_ 4.2.3 Type of Exposure: Window glass filters out part of the ultraviolet rays from the sun; thus, the deterioration of fibers exposed behin
21、d glass is generally less rapid than that of fibers exposed outdoors. Fluorescent lamps having appreciable radiation in the ultraviolet range of wavelengths can cause deterioration of fibers, especially when unprotected fiber products are stored in close proximity to such lamps for long periods of t
22、ime. Accelerated light deterioration tests are often made by exposing fiber products to radiation from carbon-arc lamps or xenon-arc lamps. Xenon-arc lamps produce a spectral distribution much more closely resembling natural sunlight than do carbon-arc lamps. When interpreting the results of such te
23、sts it should be recognized that:a. The critical wavelengths differ for different fibers.b. The spectral distribution, temperature, and moisture conditions are likely to be quite different from those encountered in actual use of fiber products.4.2.4 Size or Thickness of Fiber Structure: The light re
24、sistance of a single filament or single fiber increases with denier because less of the damaging radiation penetrates into the interior of the filament or fiber. This same principle applies to most cords and ropes since the outer fibers protect the inner fibers.4.2.5 Materials Added in Fiber Manufac
25、ture: The amount of delustrant present in a fiber may greatly increase the rate of light deterioration. Bright fibers usually have better light resistance than semi-dull fibers which, in turn, usually have better resistance than dull fibers. Other pigments and additives incorporated in the polymer c
26、an be quite effective in improving the light and heat resistance of fibers.4.2.6 Effect of Dyes, Finishes and Other Agents: The effect of agents (coatings, dyes, finishes, etc.) applied to a fiber was not evaluated in the later Florida outdoor-exposure test; however, this effect is significant enoug
27、h to warrant comment in the Du Pont report (see 2.2.5).The rate of deterioration of fibers may be affected appreciably by the presence of dyes; hence, this effect should be investigated whenever light durability is important. Dyes can have a positive, negative or nearly-neutral effect on nylon stren
28、gth retention under ultraviolet exposure - it depends on the specific characteristics of the dyestuff used. Some dyes adversely affect the light resistance to fibers. Others, including many of the “Capracyl“ dyes and some of the “Pontamine“ dyes, are very effective in increasing the light resistance
29、 of nylon 6-6. For instance, a 12.7 mm (1/2 in) diameter rope of Du Pont nylon dyed with 5% “Capracyl“ yellow NW retained 80% of its original strength after 18 months of direct exposure to Florida sunlight and weather, while the same rope in the undyed state retained only 50% of its strength during
30、exposure under exactly the same conditions.SAE INTERNATIONAL AIR1490B Page 4 of 22_ 5. CONCLUSIONS BY THE WRIGHT AIR DEVELOPMENT CENTER ON “SUNLIGHT EXPOSURE TEST OF NYLON WEBBING“ - TEST CONDUCTED DECEMBER 1954 (See 2.2.1):5.1 Olive drab color webbing has better ultraviolet resistance than natural
31、colored webbing.5.2 Strength retention of olive drab resin-treated webbing was superior to that of olive drab untreated webbing.5.3 Resin-treated natural color webbing and natural color untreated webbing lost approximately the same amount of strength.5.4 Latex-treated, olive drab color webbing lost
32、more breaking strength at most exposure times than resin-treated olive drab color webbing.6. OUTDOOR EXPOSURE TEST - 1975-1976:6.1 The samples of webbing and thread used in the tests were representative samples of materials used in the construction of cargo nets, tie-down straps and barrier nets.6.2
33、 Exposure Conditions:6.2.1 Geographical Location: United States of America, Torrance, CA6.2.2 Season of Year: May 22, 1975 to August 22, 1976 (15 months)6.2.3 Type of Exposure: Out-of-doors in direct sunlight. No attempt was made to measure radiation. Torrance, CA, is a light industrial complex whic
34、h emits an indeterminate amount of pollutants into the atmosphere. Although near the Los Angeles County smog area, Torrance is relatively free from noticeable smog because of prevailing sea breezes.6.2.4 Exposure Period: Continuous exposure 24 h per day for a period of 15 months. One rope exposure t
35、est was, however, for 12 months.6.2.5 Weather Conditions: A stochastic analysis of the weather conditions was made from U.S. Department of Commerce weather summaries for the Los Angeles-Long Beach area.About 95% of the days were overcast in the mornings until approximately 11:00 a.m. About 4% of the
36、 days experienced rain, and about 7% of the days were mostly or completely overcast.6.3 Test Condition:6.3.1 A broad sampling of commercially available webbing and thread were used in this test. A total of 29 different webbings and 3 thread samples were included. All specimens were suspended vertica
37、lly and faced due north when mounted on the exposure stand.6.3.2 No weights were attached to the ends of each specimen.SAE INTERNATIONAL AIR1490B Page 5 of 22_ 6.3.3 Breaking strength of the specimens was determined at 21 C (70 F) 65% relative humidity using a 27 272 kg (60 000 lbf) tensile tester.6
38、.3.4 Percent strength retained after exposure was calculated from the breaking strength of the unexposed specimens.6.4 Analysis of Test Results:The percent of original breaking strength retained by the specimens after exposure is a measure of the outdoor durability of the test items.Data for percent
39、 strength retained is tabulated in Tables 1, 2, and 3. The progressive rates of strength loss are shown in graphs in Figures 1 through 5.6.4.1 Color: Generally, the most weather resistant webbings are those dyed with darker colors such as olive drab.6.4.2 Weave: Webbings and the rope in the heavier
40、strength ranges were also much more weather resistant. This can be explained by the webbing weave patterns, which hide many fibers from direct exposure. As an example, some heavy webbings have a stiffer weave with parallel strength members buried under a top and bottom warp. This type of weave weake
41、ns less than a plain weave where strength members weave from top to bottom and are directly exposed to sunlight.6.4.3 Material: Generally, the polyesters retained their strength far better than nylon. The exception was the 4000 lb capacity nylon rope.7. OUTDOOR EXPOSURE TESTS - 1978-1980 (See 2.2.8)
42、:7.1 More recent tests, or trials, than those previously reported, were conducted in south England to compare the “weathering“ of nylon and polyester braids and webbing.7.1.1 Braid and webbing was manufactured by Bridport to their own or British, or both, specifications. Some MIL-W-4088 webbing was
43、used in the tests.7.1.2 The test samples were treated with different finishes to establish the amount of degradation occurring against the original strength of the material, and also to establish the efficiency of selected stitch patterns under the same conditions.7.2 Test results indicate the natur
44、al or anti-abrasive treated polyester braid retains a greater proportion of its strength than its nylon equivalent (Figure 6). Although dyeing of the braids causes an initial loss of strength to the nylon, both materials show a similar degradation after 30 months indicating that the dyeing of braid
45、is more effective on nylon than on polyester in reducing the effect of UV degradation.SAE INTERNATIONAL AIR1490B Page 6 of 22_ TABLE 1 - Ultraviolet and Corrosive Atmosphere TestsWebbingDescription ColorControl SampleStrengthlbf (kg)Strength in lbf(kg) after 450 DaysExposure%RetentionType 25 nylonre
46、sin treatedType 25 nylonresin treatedType 25 nylonresin treatedType 25 nylonresin treatedType 25 nylonresin treatedWhiteOliveDrabBlueRedBlack4540(2064)5120(2327)5320(2418)5100(2318)4940(2245)2000(909)2800(1273)2400(1091)1960(891)2690(1223)4454453854Polyester Type 25resin treatedPolyester Type 25resi
47、n treatedPolyester Type 25resin treatedBlueWhiteOliveDrab4700(2136)4700(2136)4500(2045)2860(1300)2500(1136)3080(1400)605368Type 17 nylonresin treatedType 17 nylonresin treatedType 17 nylonresin treatedType 17 nylonresin treatedType 17 nylonresin treatedWhiteOliveDrabRedBlackBlue3600 (1636) 3600(1636
48、)3130(1423)3300(1500)3560(1618)1180(536)1940(882)1230(559)1200(555)1060(482)3254393729Polyesterresin treated (spec)Polyesterresin treated (spec)Polyesterresin treated (spec)WhiteBluePink3260(1482)2760(1255)2920(1327)1240(564)1940(882)1600(727)387055Nylon Type 18resin treatedNylon Type 18resin treatedOliveDrabWhite7040(3200)7000(3182)3300(1500)2000(909)4728SAE
