1、CEN PREN+iSbS 93 3404589 0045599 171 Edition approved for publication 1993-05-10 AECMA STANDARD NORME AECMA AECMA NORM Comments should be sent within six months after the date of publication to AECMA Technopolis - 175, rue Jean-Jacques Rousseau 921 38 Issy-les-Moulineaux Cedex - FRANCE prEN 2565 Edi
2、tion P 2 May 1993 UDC : EDITE PAR LASSOCIATION EUROPEENNE DES CONSTRUCTEURS DE MATERIEL AEROSPATIAL Technopolis - 175, rue Jean-Jacques Rousseau - F-92138 Issy-les-Moulineaux Cedex - Tl. (1) 47.36.98.76 Key words : ENGLISH VERSION Aerospace series Preparation of carbon fibre reinforced resin panels
3、for test purposes Srie arospatiale Prparation de panneaux base de rsine et fibres de carbone destins llaboration dprouvettes Supersedes issue P 1 June 1987 Luft- und Raumfahrt Herstellen von CFK- Prf platten This “Aerospace Series “ Prestandard has been drawn up under the responsibility of AECMA (As
4、sociation Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the neds of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this prestandar
5、d, 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 signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Memb
6、er countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Nota - Extra copies can be supplied by B.N.A.E. - Technopoli 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LESMOULINEAUX CEDEX C7 Chairman M. Bezaud I I 0 aecma 19C - C
7、EN PRENu25b5 93 m 3404589 0045b00 713 m prEN 2565 Page 2 - Contents 1 Scope 2 Principle 3 References 4 Equipment and mate for the preparation of 5 Working procedure -6 Report of preparation of test panel . : ., , . . _. . CEN PRENx25b5 93 m 3404589 0045bOL b5T m prEN 2565 Page 3 1 Scope This standar
8、d describes the preparation of panels with any desired fibre orientation of unidirectional orientated carbon fibre or fabric with thermosetting resins. The purpose of this standard is to describe recommended processes for the preparation of the panels from which test specimens subsequently are machi
9、ned. Standard specimens prepared in this manner may be used either for evaluating the components .e. the carbon reinforcement, finishes, resins, catalysts, curing agents, etc. or for verifying the overall quality of the finished products. 2 Principle Preparation of the laminates or panels by one of
10、the following methods : 2.1 The carbon fibre reinforcement impregnated with liquid resin containing a suitable catalyst or curing agent is moulded under conditions of temperature and pressure appropriate for the resin and curing system. Method A (wet lay-up technique) 2.2 Method B (prepreg) The carb
11、on fibre reinforcement impregnated with resin (prepreg) is moulded under conditions of temperature higher than room temperature and pressures appropriate for the resin system. 3 Normative references EN 2564 Aerospace series - Carbon fibre laminates - Test method for the determination of the fibre an
12、d resin fractions and porosity content EN 2743 Aerospace series - Reinforced plastics - Standard procedures for conditioning prior to testing 4 Equipment and materials recommended for the preparation of panels by methods A and B 4.1 Equipment 4.1 .I Press of any hydraulic or mechanical type, with th
13、e following requirements a) Temperature measuring and controlling devices to maintain the curing temperature between the specified limits. b) Moulding force with an accuracy of 5 % over the period of time required for curing of the resin. ci The pressing tool 1 (see figure 1) consists of frame il),
14、ram (2) and base (3). The height of the frame shall be large enough to provide a moulding chamber where the reactive resin composition can be put in place in one operation. By means of appropriately constructed guides, e.g. centering pins (41, a gap between the ram and the frame of 0.20 mm minimum s
15、hall be ensured. 1) Published as AECMA Prestandard at the date of publication of this standard - CEN PRENt2565 93 m 3404589 0045602 59b m prEN 2565 Page 4 d) The tool 2 (see figure 2) consists of two flat plates, which shall be guided only at the four corners (open pressing tool). By placing distanc
16、e pieces between the guides, a specific thickness of the test panel can be obtained. 4.1.2 Autoclave of any dry heat type with the following requirements : a) as 4.1.1 (a). b) a heat up speed of at least 3 OC/min. c) capable of maintaining the required pressure to an accuracy of 10 kPa over the peri
17、od of time required for curing of the resin. d) vacuum pumps capable of applying a vacuum equal to at least 80 kPa. 4.1.3 Ruler for measuring length and width to an accuracy of 0,5 mm 4.1.4 Micrometer screw type with an accuracy of 0,Ol mm for measuring the thickness 4.1.5 Balance With an accuracy o
18、f 0,Ol g 4.1.6 Cutting device such as a knife with a sharp blade 4.2 Materials 4.2.1 between the parties concerned. Metal lay-up plate of 500 mm x 500 mm x 7 mm or any other suitable dimensions agreed upon 4.2.2 When necessary, metal cover plate of 300 mm x 300 mm x 7 mm or any other suitable dimens
19、ions agreed upon between the parties concerned. 4.2.3 Where required, rubber pressure retaining rings resistant to a temperature at least 20 OC higher than the actual curing temperature. 4.2.4 Release film resistant to a temperature at least 20 OC higher than the actual curing temperature, such as p
20、olyvinylfluoride (PVF), polytetrafluoroethylene (PTFE) or PTFE coated fabric. 4.2.5 When necessary, perforated release film resistant to a temperature at least 20 OC higher than the actual curing temperature, such as PTFE or PTFE coated fabric. 4.2.6 Pressure blanket material with the capacity of fo
21、rmability, resistant to polymerisation products and resistant to a temperature at least 20 OC higher than the actual curing temperature, such as PVF, PTFE or PTFE coated fabric. 4.2.7 Breather material such as aluminium gauze and glass fabric. 4.2.8 Absorption material for absorption of excess resin
22、. Examples are : 1) Woven glass fibre fabric having a surface mass of 100 g/mz capable of absorbing approximately 60 g/m2 resin, 2) Woven glass fibre fabric having a surface mass of 300 g/mz capable of absorbing approximately 115 g/m2 resin, 3) Polyamid fibre fabric having a surface mass of 60 g/m2
23、capable of absorbing approximately 40 g/m2 resin. - li- CEN PREN*:2565 93 w 3404589 O045603 422 W prEN 2565 Page 5 4.2.9 Metal edge surrounding material strips or other suitable material with a length of 300 mm and a width of 15 mm, or any other dimensions agreed upon between the parties concerned.
24、The thickness depends on thickness of plate or panel to be produced. 4.2.10 Sealing tape resistant to a temperature at least 20 OC higher than the actual curing temperature. 5 Working procedure The materials to be used for preparing the test panels, including the material from which the test panels
25、have to be made, shall be conditioned at a temperature of (23 f 2) OC and a relative humidity of (50 k 5) % as specified in EN 2743 for at least 2 h. 5.1 5.1.1 The carbon fibre or carbon fibre fabric shall be conditioned during 6 h to the standard atmosphere as specified in EN 2743 and then impregna
26、ted with the required resin containing a suitable catalyst or curing agent. Method A (wet lay-up technique) 5.1.2 The resin content of the impregnated carbon fibre assembly shall not be in excess of 45 % by weight. 5.1.3 From the prepared impregnated carbon fibre assembly the required number of laye
27、rs to produce the final cured thickness of panel (see note in 5.1.5) are cut to the width and length required and placed on the lay-up plate (4.2.1) to produce a panel of the required dimensions. 5.1.4 Unless otherwise specified in the materials data sheet, not more than 50 % of the gel time of the
28、resin at the temperature of the impregnation may elapse before the start of the cure cycle. 5.1.5 The assembly laminated on the metal lay-up plate (4.2.1) shall be made ready for curing as presented in figure 1 or figure 2 for pressing tools and figure 3 or figure 4 for bladder press method or autoc
29、lave method. The total number of absorption layer material (4.2.8) for excess resin absorption depends on the actual resin content required for the cured laminate or panel (see figure 5 as an example). The laminate or panel thickness and resin content are also a function of pressure, temperature and
30、 other factors, depending upon the properties of the carbon fibre and of the resin system (see note). NOTE : It will be necessary, before marking the number of panels required for preparing the test specimens, to determine by experiment the number of layers from the prepared resin impregnated carbon
31、 fibre tape or sheet and number of absorption layers for excess resin combined with the pressure necesSan/ to obtain panels of the required cured thickness and resin content. 5.1.6 The temperature, pressure and time of curing are stipulated by agreement or specified in the material data sheet, depen
32、ding on the type of resin, catalyst or curing agent. The temperature stipulated shall be maintained during the curing cycle such that the temperature values indicated by the temperature measuring device will remain within the ranges required for the particular resin system (see figure 6). The temper
33、ature of any point on the active surface of the plate or panel shall not differ by more than f 2 OC from the value indicated by the temperature measuring device (4.1.1.(a) and 4.1.2 (a). 5.1.7 After completion of the curing process the test panel has to be taken from the press or autoclave and coole
34、d if necessary in such a way that any deformation, damage, etc. is avoided. 5.1.8 The carbon fibre orientation(s) relative to the length direction of the panel shall be indicated on a pressure sensitive paper tag or other suitable means agreed upon and applied to the panel. CEN PRENx25b5 93 3404589
35、0045b04 369 prEN 2565 Page 6 5.1.9 Where no other treatment is specified the panels may be used, in this condition, to produce test specimens. If not specified in the relevant standard on testing the types, sizes and orientations of the specimens with respect to the orientation of the carbon fibre r
36、einforcement within the panel shall be stipulated by separate agreement. The margins of the panels up to at least 10 mm from its edges shall be discarded. 5.2 Method B (prepreg) 5.2.1 If the material is stored at temperature lower than the standard specified temperature of EN 2743, it shall be retai
37、ned in an airtight bag to prevent moisture pick-up. The required material shall be conditioned at a temperature of (23 k 2)OC and relative humidity of (50 f 5) % as specified in EN 2743. After conditioning the material required for the preparation of the test panels shall be cured within 6 h, unless
38、 otherwise specified. 5.2.2 The carbon fibre prepreg is cut to the width and length required to prepare a laminate of the required dimensions. 5.2.3 A lay-up to produce a cured test panel shall be prepared as described in clause 5.1.3 through clause 5.1.9. 5.3 5.3.1 Measure the length (4.1.3) of eac
39、h of the four sides to an accuracy of 0,5 mm after having trimmed at least 10 mm from its edges (5.1.8). Calculate the arithmetic mean of the four measurements rounded off to the nearest mm. Determination of the quality of the panels 5.3.2 Measure the thickness (4.1.4) at each of the four corners bu
40、t not closer than 25 mm to the edges and in the centre to an accuracy of 0,05 mm. Calculate the arithmetic mean of the five measurements rounded off to the nearest 0,l mm. 5.3.3 If required, take a test specimen from two diagonally opposite corners with the dimensions of 20 mm x 10 mm at the thickne
41、ss of the panel. From both test specimens the carbon fibre content by volume and weight shall be determined by resin digestion in accordance with EN 2564-A. 5.3.4 Determine the porosity and other defects by means of ultrasonic inspection method using the procedure agreed between the parties concerne
42、d. 6 Report of preparation of test panel The report of preparation of the test panel shall include the following : 6.1 Place and date of production of test panel. 6.2 Details of number of plies, stacking sequence and ply orientation. 6.3 Description of materials including batch, roll numbers used fo
43、r preparing the test panel (nature and type of resin, catalyst, curing agent or other additives including the amounts used, nature and type of carbon fibre, nature of finish, etc.). CEN PRENr25b5 93 D 3404589 O045605 2T5 D prEN 2565 Page 2 6.4 temperatures and pressures, etc.). Description of produc
44、tion equipment (type of press, autoclave, mould, method of checking 6.5 force), temperature, curing-time, post-curing, etc.). Working procedure (designation of method as given in this standard, moulding pressure (or 6.6 Length and width of panel (individual measurements and average value in mm). 6.7
45、 Thickness of panel (individual measurements and average value in mm). 6.8 percent by volume and by weight. Fibre content of panel (when measured) - individual measurements and average value in 6.9 Porosity level shown by ultrasonic scan picture (when measured) 6.10 Special notes CEN PRENt2565 93 34
46、04589 0045606 L3L m prEN 2565 Page 8 P I /o centeringpins 1 6af t oll around II Figure 1 Pressing tool 1 for the production of test laminates or panels Distance pieces of variable thickness Figure 2 Pressing tool 2 for the production of test laminates or panels , I - i CEN PRENS2565 93 3404589 00456
47、07 O78 m prEN 2565 Page 9 Build-up see fig. 5 Lower press plates /- - - - Metal edge (42.9) - Metal plate (4.2.11 - Release film (4.2.4) - Breathermat.(4.2.7) I Pressure blanket (4.2.6) Rubber presswe retaining rings (4.2.3) To air pressure “Y - To vacum supply 3a. Pressure and vacuum method I I I T
48、o air pressure SuPpiY - Build-up see fig. 5 I I L / 1 / / 3b. Pressure method I Build-up see fig. 5 I- / 3c. Vacuum method Figure 3 Schematic example of press curing CEN PREN*25b5 93 = 3q04589 00q5b08 TO4 9 prEN 2565 Page 10 - Sealing tape (4.2.10) rPressure blanket (4.2.6) -Breather ma teria1 (42.7
49、) Metal edge surrounding (4.2.9) Release film (4.2.4) atmosphere outside Ventilation to normal autoclave such as temp. and Attachment measuring purpose, for 1 pressure 1 Figure 4 Schematic example for autoclave curing CEN PRENx25b5 93 = 340Y589 0045609 940 prEN 2565 Page 11 t I I Laminate lay-up - Perforated release film (4.2.5) I Absorption material (4.2.8) - Metal cover plate (4.2.2) Figure 5 Example of build up of laminate with resin absorption layers, perforated release film and pressure plate to obtain the required panel quality CEN PREN*25b5 93 3404589 O
