1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication prEN 4243 Edition P 1 August 2001 Comments should be sent within six months after the date of Dublication to Material Domain PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES - STANDARDIZATION (AECMA-STAN) Guiledelie
2、94 - 8-1200 BRUXELLES - Tel. (+32) 2 775 81 10 - Fax. (+32) 2 775 81 I1 ICs: Descriptors: Srie arospatiale Feuilles dacrylique Spcification technique ENGLISH VERSION Aerospace series Cast acrylic sheets Technical specification Luft- und Raumfahrt Platten aus Acrylglas Technische Lieferbedingungen Th
3、is %Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA-STAN (The European Association of Aerospace Industries - Standardization). It is published on green paper for the needs of the European Aerospace Industry. It has been technically approved by the experts of the con
4、cerned Domain following member comments, Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and fo
5、rmal agreement of AECMA-STAN it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. 2001-08-31 AECMA-STAN Gulledelle 94 Mr Pays 8-1200 BRUXELLES 0 aecma 20C 1 Page 2 prEN 4243: 2001 Blank page Page 3 prEN 4243: 2001 1 Scope This standard sp
6、ecifies the inspection for cast acrylic sheets (blocks) used for aerospace glazing applications. 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 an
7、d 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. I
8、S0 62 IS0 75 (ait parts) IS0 179 IS0 306 IS0 489 Plastics - Determination of the refractive index IS0 527-2 Plastics - Determination of tensile properties - Part 2: Test conditions for moulding and extrusion plastics IS0 554 Standard atmospheres for conditioning and/or testing - Specifications IS0 I
9、1 83 (all parts) Plastics - Methods for determining the density of non-cellular plastics Plastics - Determination of water absorption Plastics - Determination of temperature of deflection under load Plastics - Determination of Charpy impact strength Plastics - Thermoplastic materials - Determination
10、 of Vicat softening temperature IS0 2818 IS0 8402 EN 2000 EN 2155-4 EN 2155-5 EN 2155-6 EN 2155-7 EN 2155-8 EN 2155-9 EN 21 55-1 2 EN 21 55-1 9 EN 21 55-20 EN 2155-21 EN 21 55-22 Plastics - Preparation of test specimens by machining Quality management and quality assurance - Vocabulary Aerospace ser
11、ies - Quality assurance - EN aerospace products - Approval of the quality system of manufacturers Aerospace series - Test methods for transparent materials for aircraft glazing - Part 4: Determination of ultraviolet light transmission over the wavelength range 280 nm to 360 nm 1) Aerospace series -
12、Test methods for transparent materials for aircraft glazing - Part 5: Determination of visible light transmission Aerospace series - Test methods for transparent materials for aircraft glazing - Part 6: Determination of optical defects 1) Aerospace series - Test methods for transparent materials for
13、 aircraft glazing - Part 7: Determination of optical deviation Aerospace series - Test methods for transparent materials for aircraft glazing - Part 8: Determination of optical distortion Aerospace series - Test methods for transparent materials for aircraft glazing - Part 9: Determination of haze A
14、erospace series - Test methods for transparent materials for aircraft glazing - Part 12: Determination of linear thermal expansion Aerospace series - Test methods for transparent materials for aircraft glazing - Part 19: Determination of craze resistance Aerospace series - Test methods for transpare
15、nt materials for aircraft glazing - Part 20: Determination of retention of strength after crazing for as-cast acrylics 1) Aerospace series - Test methods for transparent materials for aircraft glazing - Part 21: Determination of resistance to crack propagation (K factor) Aerospace series - Test meth
16、ods for transparent materials for aircraft glazing - Part 22: Determination of thermal relaxation of stretched acrylic sheet 1) Page 4 prEN 4243: 2001 EN 3042 EN 3844-2 EN 4367 ASTM-D 1925 Standard Test Method for Yellowness Index for Plastics (Discontinued 1995, no Aerospace series - Quality assura
17、nce - EN aerospace products - Qualification procedure Aerospace series - Flammability of non-metallic materials - Part 2: Small burner test, horizontal - Determination of the horizontal flame propagation 1) Aerospace series - Cast acrylic sheets - Dimensions 2) replacement 3) 3 Terms and definitions
18、 For the purposes of this standard, the terms and definitions given in IS0 8402 and the following apply. 3.1 production batch 3.1 .I sheets, as cast a production batch of as cast acrylic sheet represents the quantity of material manufactured in one continuous production run according to an establish
19、ed manufacturing process using identical batches of raw materials, additives, etc. 3.1.2 sheets, stretched a production batch of multi-axial orientated (stretched/pressed) acrylic sheet represents the quantity of sheets of one specific thickness produced according to an established manufacturing pro
20、cess using one batch of as cast acrylic sheet 3.2 qualification testing a test or a series of tests to demonstrate that the product sample submitted for qualification satisfies the requirements specified in the standard 3.3 acceptance testing testing to demonstrate that the quality characteristics o
21、f a product batch conform to the quality characteristics of a qualified type 4 Requirements 4.1 Materials The requirements are specified in the relevant EN material standards. The acrylic material shall be cast polymethyl methacrylate, modified by means of a cross-linking agent, if applicable, and p
22、olymerised in a casting process. Stretched acrylic material shall be produced by subsequent multi-axial stretching or pressing. 4.2 Dimensions In accordance with EN 4367 1) Published as AECMA Prestandard at the date of publication of this standard 2) In preparation at the date of publication of this
23、 standard 3) Published by: American Society for testing and Materials (ASTM), 1916 Race Street, Philadelphia, PA 19103, USA Page 5 prEN 4243: 2001 Optical deviation according to EN 2155-7 130“ max. 3 max. I 6 max. l IO max. i 4.3 Colour 4.3.1 Colourless material The material shall be of colourless a
24、ppearance when viewed through the cast surface. 4.3.2 Coloured material Coloured material will be supplied subject to agreement between user and manufacturer. Optical defects Optical distortionlgradient according to EN 21 55-8 1 : 17 Angle of optical incidence: 60“ Discontinuity: d = 0,5 mm max. In
25、accordance with 4.4.2,4.4.3 and 4.4.3.1 I : 12 Angle of optical incidence: 45“ Discontinuity: d = 0,5 mm max. Angle of optical incidence: O“ Discontinuity: d = 0,5 mm max. In accordance with 4.4.2,4.4.3 1:12 and 4.4.3.2 4.4 Optical properties 4.4.1 Optical quality classification See table 1. Table 1
26、 -Optical quality classification 4.4.2 General requirements The sheets shall have a high finish and be free from crazes and significant scratches. However, light scratches which are easily removed by hand polishing are acceptable. 4.4.3 Optical defects a) Minor - bubbles, foreign matter and surface
27、defects from 0,15 mm2 to 0,4 mm2 b) Major - bubbles, foreign matter and surface defects from 0,4 mm2 to 0,5 mm2; - hairs and fibres from 0,5 mm to 3 mm in length. 4.4.3.1 Sheets containing major or minor defects, inspected as in EN 2155-6, shall be acceptable provided that: I) any area of the sheet
28、enclosed by a circle of 150 mm radius contains no more than one major defect and or 2) any area of the sheet enclosed by a circle of 150 mm radius, without a major defect, contains no more Optical defects for classifications A and B no minor defects, than 3 minor defects. Page 6 prEN 4243: 2001 Any
29、accumulation of defects smaller than those defined in clause 4.4.3 a) or individual defects greater than those defined in 4.4.3 b) shall be subject to agreement between user and manufacturer. 4.4.3.2 The frequency of all defects for classifications C and D shall be subject to agreement between the u
30、ser and manufacturer. Optical defects for Classifications C and D 4.4.4 Optical defects after heating The above optical tests shall normally be carried out on sheet that has not been heated. However, when required by the purchaser, the optical quality of unstretched sheet can be assessed as follows:
31、 One sheet per batch shall be suspended for a period of time T4) in an oven preheated to a temperature of (145 f 5) OC unless otherwise specified following which it will be cooled to ambient and inspected for optical defects as per EN 2155-6 (according to table 1 of EN 4243). Should the first sheet
32、fail to satisfy the above acceptance criteria, the test shall be repeated on a second sheet. Should the second sheet fail to satisfy the acceptance criteria, the batch shall not be accepted against this clause. 4.4.5 Yellowness index after heating When required by the purchaser, one sample per batch
33、 of unstretched sheet shall be heated as described in clause 4.4.4. and Yellowness Index determined according to ASTM-D 1925. 4.5 Weathering When required by the purchaser weathering conditions (natural or artificial), test methods and requirements after weathering shall be subject to agreement with
34、 the supplier. 4.6 Required characteristics The required test methods and frequency of testing are specified in table 2. 5 Quality assurance See EN 2000 and EN 3042. 5.1 Qualification testing For material qualification, all the required values of the material standard shall be demonstrated and docum
35、ented by the manufacturer performing all the tests to the test methods given in table 2. The number of batches to be tested shall be in accordance with the material standard. These tests shall be performed before the first delivery. No changes shall be made to the composition of the material and the
36、 manufacturing process, otherwise further qualification testing is required. Should the manufacturer not be in a position to perform the required tests, due to the lack of test facilities, they may be carried out by an approved materials testing facility. Separate qualification testing is required f
37、or materials supplied in the following thickness bands: As cast: I 10 mm; 10 mm to 20 mm; 20 mm to 35 mm; 35 mm. 4) T = 1 O + (3 x a, where d = thickness of sheet in mm, and T = time in minutes Page 7 prEN 4243: 2001 Stretched: I7 mm; 7 mm to 12 mm; 12 mm to 20 mm; 20 mm. Qualification of any one th
38、ickness within each band qualifies the material for the whole of this thickness band. 5.2 Acceptance testing 5.2.1 Sampling and testing Samples for acceptance testing according to table 2 shall be taken at the frequency as defined in the material standard and tested against the requirements of 4.1 t
39、o 4.5. , 5.2.2 Certificate of conformity For each delivery, the manufacturer shall confirm compliance to the requirements of the material standard by means of a Certificate of Conformity (for example, see Annex A) for each production batch. 6 Protection and packaging Each sheet shall be provided wit
40、h a suitable protective covering (plastic film or paper) on both sides, which is easily removable without damaging the surface. This covering shall protect the surfaces against damages during delivery, storage, handling and cutting to size and shall not cause any degradation. Unless otherwise agreed
41、 with the customer, sheet shall be packed separated according to thickness and size. The packaging shall be such that the material retains its original condition whilst protected. 7 Marking 7. I Sheets Sheets shall be appropriately marked on the protective covering with the following information: -
42、designation according to EN 4367, - name of manufacturer or manufacturers identification mark including colour reference, if applicable (as agreed at qualification), - production batch number or manufacturers reference. 7.2 Packages Packages shall be marked with the following information: - designat
43、ion according to EN 4367, - name of manufacturer or manufacturers identification mark (as agreed at qualification). Page 8 prEN 4243: 2001 Column 1 2 3 Table 2 - Tests 4 Line No. Properties Tensile stress at yield/at break Tensile strain at yield/at break bc Modulus of elasticity e Number of test sp
44、ecimens for qualification testing acceptance testing a Test to IS0 527-2 Specime; Type 1B IS0 179/1fU I I - 5 5 5 10 - - - 1.4 2 Impact strength I Thermal properties IS0 75-2Ae Temperature of deflection under load 2.1 - 3 2.2 2.3 2*4 2.5 2.6 2.7 Vicat softening temperature IS0 306 3 3 /lo Vicat soft
45、ening temperature 9 50 “Clh 3 3 Coefficient of linear thermal expansion Method B - EN 2155-12 2 3 3.1 Optical properties - Refractive index n; IS0 489 2 3.2 3.3 Visible light transmission Optical defects 3.6 I Haze _ - EN 2155-5 EN 2155-6 3.7 1 UV transmission 3 3 Each Sheet 3.8 1 3.4 3.5 EN 2155-7
46、I Optical deviation Optical distortion Each Sheet EN 2155-8 EN 2155-9 Each Sheet 2 - EN 2155-4 I I continued 3 - I I I Page 9 prEN 4243: 2001 Column 1 2 3 Table 2 - Tests (concluded) 4 Line No. Properties I I I Number of test specimens for qualification testing acceptance testing Test to 4.1 I Flamm
47、ability 4 1 EN 3844-2 I Behaviour under external effects 5 EN 2155-5 Visible light transmission Resistance to weathering - 3 Tensile stress at yield/break Terisile sirairi at yield/break Haze I EN 2155-9 I 2 - IS0 527-2 5 Specimed type 16 5 - K factor 1 EN2155-21 I 3 4.7 Optical defects after heatin
48、g 4.8 Yellowness index after heating See 4.4.4. I 1 See 4.4.5. 2 2 4.9 - 3 IS0 62 Water absorption Method 1 4.1 O I Craze resistance 5 5.1 5.3 s4 5.5 5.6 I EN 2155-19 I _ Other properties Density i - 2 IS0 1183 Method A Retention of strength after crazing EN 2155-20 10 - EN 2155-21 10 3 Resistance t
49、o crack propagation (K factor) Thermal relaxation at I 1 O OC EN 21 55-22 3 3 Thermal relaxation at 145 OC EN 2155-22 3 3 6 I 3 Page 10 prEN 4243: 2001 Required values according to material standard EN Annex A (informative) Minimum values from production batch Certificate of Conformity for Acrylic Sheets Customer . Contract or order No. Product standard . Technical specification EN 4243 . Name and addre . Manufacturers materia Quantity delivered . Production batch No. Test report No. . Properties Vicat softening temperature Light transmission in as-received condi
