1、MIL-S-90dlB SUPERSEDG MIL-S-O+A 19 March 197$ 28 December 1953 MILJTARY SPECIFICATION SANDWICH CONSTRUCTION; PLASTIC RESIN, GLASS FABRIC BASE, LAMINATED FACINGS AND HONEYCOMB CORE FOR AIRCRAFT STRUCTURAL AND ELECTRONIC APPLICATIONS This specification is approved for use by all Depart- ments and Agen
2、cies of the Department of Defense 1. SCOPE 1.1 Scope. This specification covers the requirements for plastic molded sandwich construction using glass fabric base plastic laminate facings and glass fabric base plastic honeycomb core materials for aircraft structural applica- tions, including aircraft
3、 exterior parts, such as radio and radar antenna housings, and other parts. 1.2 Classification. 1.2.1 Class. The sandwich construction shall be of the following classes, as specified (see 6.2) : Class I - Radar purpose (Electrical) - “._ Class II - General purpose (Nonelegtrical) 1.2.2 Types The mol
4、ded sandwich construction; libbeycomb core X. , ) material shall be of the following types, as specified (see 6 .2): Type I-A, 3/16 inch cell size; 4. O lbs. /CU. ft., nominal dehsity Type I-B, 3/16 inch cell size; 5,5 lbs. /CU. ft., nominal density Tspe I-C, 3/16 inch cell size; 8. O lbs. /CU. ft.,
5、 nominal density Type II-A, 1/4 inch cell size; 3.5 lbs. /CU. ft., nominal density Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-S-904lB Type II-B, 1/4 inch cell size; 4.5 lbs. /CU. ft., nominal density Type II-C, 1/4 inch cell size; 6.5 lbs.
6、/CU. B., nominal density Type II-D, 1/4 inch cell size; 8.5 lbs. /CU. fe., nominal density Type III-A, 3/8 inch cell size; 2.2 lbs. /CU. ft., nominal density Type III-B, 3/8 inch cell size; 3.2 lbs. /CU. ft., nominal density Type III-C, 3/8 inch cell size; 4.5 lbs. /CU. ft., nominal density Type III
7、-D, 3/8 inch cell size; 6. O lbs. /CU. ft., nominal density 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent specified herein. SPECIFICATIONS Military MIL-C-8073 Core Ma
8、terial, Plastic Honeycomb, Laminated Glass Fabric Base, For Aircraft Structural and Electronic Applications MIL-P-9400 Plastic Laminate Materials and Sandwich Construc- tion, Glass Fiber Base, Low Pressure Aircraft Structural Process Specification Requirements STANDARDS Military MIL-STD- 105 Samplin
9、g Procedures and Tables for Inspection by Attributes MIL-STD-401 Sandwich Constructions and Core Materials, General Test Methods (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions should be obtained from the procur
10、ing activity or as directed by the contracting officer.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-7OLILB Sb m 9777906 02LOOLB O MIL-S-904lB 2.2 Other publications. The following document forms a part of this specification to the extent s
11、pecified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply. Aerospace Industries Association of America, Inc. ATC Report No. ARTC-4; Electrical Test Procedures for Radomes and Radome Materials (Application for copies should be
12、addressed to the National Standards Association, hc., 1321 Fourteenth Street NW, Washington, DC 20005). 3. REQUlREMENTS 3.1 Precedence of requirements. The products furnished under this specification shall be as specified herein and in accordance with the drawings, specifications, or contract requir
13、ements for the specific sheet or part. In the event of discrepancy between this specification and the requirements of the applicable drawings, specifications, or contract for the specific sheet or part, the requirements of the latter shall govern. 3.2 First article inspection. The sandwich construct
14、ion furnished under his specification (see 1.2) shall be a product(s) which has been inspected and has passed the first article inspection specified herein (see 4.3). The material supplied under contract shall be identical within manufacturing tolerances with the product receiving first article insp
15、ection approval. Any change in the use ;of materials or processes will necessitate its resubmittal for first article inspection. 3.3 Materials. The materials comprising the sandwich construction shall conform to applicable specifications and shall be as specified herein. Materials which are not cove
16、red by applicable specifications, or which are not specifically described herein, shall be subject to the approval of the procuring activity (see 6.2). 3.3.1 Sandwich construction. The sandwich construction shall consist of faces of glass fabric base laminated plastic material bonded to a core of la
17、minated glass fabric base plastic honeycomb materTa1. 3.3.2 Face material. The face material shall consist of a glass fabric base laminated with plastic material capable of meeting the requirements of this specification for use up to 350F. All materials used in the facings shall be specified in the
18、manufacturing and fabricating process specification of the sandwich construction. 3“ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.3.3 Core material. The core material shall conform to all require- ments of MIL-C-8073. Type I, It and III sandwich
19、 construction shall be made with Type I, II and III core materials respectively of MIL-C-8073. Bonding of pieces of core material together shall be made with the same resin used in the construction of the core or with an approved compatible resin adhesive. The resins shall not be corrosive to metals
20、, Process specification. A detailed description of the manufacturing and fabricating process and methods of control of manufacturing variables in the form of a titled, numbered, and dated process specification shall be prepared by the prime contractor, or obtained from a subcontractor (see 6.3), and
21、 approved by the prime contractor. The process specification shall conform to MIL-P-9400, and follow its format as closely as possible. The process specification shall be made available by the prime contractor at the time of first article inspection (see 4.3) and, thereafter, during the course of pr
22、oduction for use by authorized Govern- ment and industry representatives in the facilities of the prime contractor, his subcontractors, or his vendors. It shall also be made available, on request, for review by engineers of the procuring activity. The prime contractor shall certify that compliance w
23、ith such process specification will produce material meeting all the contract requirements. Mechanical and physical properties. Unless otherwise specified by the procuring activity (see 6.2), the mechanical and physical properties of each type of honeycomb core sandwich construction shall conform to
24、 all the applicable requirements of Table I. Reference areas for the “L“ and rrWfl direction of the cells for the plate shear strength and the ffT“ direction of the cells for the compres- sive strength shall be in accordance with Figure 1. Electrical properties (Class I only). The electrical propert
25、ies of the sandwich construction, fabricated as specified in 4.3.1, shall conform to the values listed in Table JI (see 4.6.6). Dimensions and weight. The face thickness, overall sandwich construction thickness, and maximum weight in pounds per square foot, shall be as specified in the speczications
26、, drawings, or contracts for the molded sandwich construction parts (see 6.2). Workmanship. 3.8.1 Faces, Except as otherwise specifically approved (3.8.1. l), the plastic material shall be uniform, smooth, and free from uncured or unbonded areas, gaps, cracks, holes, blisters, resin pockets, areas l
27、acking resin, tacki- ness, excess surface resin, incorrect laps, wrinkles, delamination, air or gas pockets, patches, porosity, and other similar defects as defined in MIL-P-9400. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-9041B ommm wm 2:
28、 moom NmmN A m 4 .B oom mrlt- ANm momo rlm*w omw mwrl d . :G the sandwich thickness dimension shall be in the IIT“ core thickness direction (see Figure 1). 4.6.4.1 Sandwich flatwise compressive strength at elevated temperature. Five stabilized specimens, prepared in accordance with MIL-STD-401, shal
29、l be heated at 350 rt 10 “F for 1/2 hour and tested as in 4.6.4 at this temperature. 4.6.5 Sandwich shear strength and shear modulus. Plate shear strength and modulus of rigidity shall be determined in accordance with MIL-STD-401. Five sandwich specimens in both TL and TW directions shall be prepare
30、d and tested at standard conditions and the results averaged. Tensile or compressive loading shall be employed. The modulus of rigidity shall be obtained by computing the slope of the initial straight line portion of the stress-strain curve. 4.6.5.1 Sandwich shear at elevated temperature. Five speci
31、mens in each direction, prepared in accordance with MIL-STD-401, shall be heated at 350 k 10F for 1/2 hour and tested as in 4.6.5 at this temperature. 4.6.6 Electrical properties (Class I only). The electrical power trans- mission efficiency shall be determined on a minimum of 3 test panels prepared
32、 from 4.6.6.1 at standard conditions (4.5) and after environmental conditioning (4.6.6.2) in accordance with ATC Report No. ARTC-4, and checked for conformance to Table II. 4.6.6.1 Electrical test specimens. For each process described in the manufacturerrs process specification, three sandwich panel
33、s 2 feet by 3 feet using any one type of core shall be furnished. The outside border of these panels shall be a solid laminate having a width of 1 inch rt 1/4 inch. The core shall be O. 330 f O. 005 inch thick and other dimensions shall be as specified in Table I. The panels shall be fabricated in c
34、onfqrmance with this specification and the applicable approved process specification. They shall be accompanied by a description of the resin, fabric, and core used, and identification of the process when more than one process is described in the manufacturers process specifi- cation. 4.6.6.2 Enviro
35、nmental conditioning. Environmental conditioning of the test panels prepared from 4.6.6.1 shall consist of 25 cycles of temperature variation from 71C to -55C (160F to -67“F), with the panels attaining the extreme temperatures during each cycle, after which they shall withstand 50 cycles of simulate
36、d altitude changes from 8,000 to 50,000 feet while maintaining an atmosphere saturated with water vapor (sufficient for condensation to form on the faces of the panel) from a steam supply, and having room air temperature metered into the chamber on the descent phase of each cycle to preclude drying.
37、 il Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-“I_- “ NIL-S-SOLILB 56 M 777770b 62L0027 1 a MIL-S-9041B Upon completion of the environmental conditioning, the panels shall be subjected to the electrical power transmission efficiency test of 4.6.
38、6. 4.7 Destructive testing. All material, specimens, or parts destroyed in making tests required by this specification to determine compliance with the specification shall be in addition to the quantity specified in the contract or purchase order, and shall be furnished without increasing the cost o
39、f the contract or purchase order (see 6.2). 4. a Preservation, packaging, packing and marking. Preservation, packaging, packing and marking of the materials covered by this specification shall be in accordance with the requirements of Section 5. 5. PREPARATION FOR DELIVERY 5.1 Application. The packi
40、ng, packaging, and marking requirements shall be as specified in the specifications, drawings, or contracts for the parts fabricated from the plastic material. 6. NOTES 6.1 Intended use. Class I sandwich material may be used for air- craft radar antenna housings as well as for applications as indica
41、ted for Class II. Class II sandwich material may be used for general aircraft structural parts and other applications. Class I and II materials may be used for application where temperatures will not exceed 350F. 6.2 Ordering data. Procurement documents should specify the following: a. Title, number
42、, and date of this specification. b. Class required (see 1.2.1). c. Type required (see 1.2.2). d. Dimensions and make-up of the sandwich construction (see 3.9). e. Exceptions, if any, to the optional provisions of this specification including: (1) Waiving of the compression strength and plate shear
43、strength requirements at 350F when not required (see 3.5 and Table I). Determination should be based on the temperature limitation of the type laminate facing used in the sandwich construction. 12 “-F E“- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
44、-,-MIL-S-SOLILB 5b m 7779706 0210028 3 i- MIL-S-9041B (2) Allowable plastic laminate defects (see 3.8.1.1) (3) Laminate thickness and make-up of thickness including number of plies and lay-up. (4) Identification of laminate plies as to type, fabric and number. (5) Type of resin. f. Allowance of quan
45、tity for destructive testing (see 4.7). g. Type, class and dimensions of core under MIL-C-8073. h. Quantity required (see 4.6) i. Level of packaging, packing and markings when required (see 5.1). j. Responsibility for the performance of first article inspection (see 6.2.1). 6.2.1 Contracts or orders
46、 shall specify the following provisions for first articIe inspection, 6.2.1.1 Whether first article inspection is required. When a contractor is in continuous production of the sandwich construction from contract to contract, consideration should be given to waiving the first article inspection. If
47、inspection is required, indicate: - - a. Where the first article inspection is to be conducted (at the Contractors plant or Government or commercial laboratory). b. Where the contractors process specification is to be for- warded and the number of copies required. c. That the approval of first artic
48、le samples or the waiving of the first article inspection shall not relieve the contractor of his obligation to fulfill all other requirements of the specifications and contract. 6.3 Definitions. 6.3.1 Prime contractor. A prime contractor is a contractor fabricating components under direct contract
49、with the Government, or subcontracting the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-9041B fabrication of part or all such C( direct to the Government. 6.3.2 Subcontractor. nents to a prime contractor. Custodians : Army - AV Navy - AS Air Force - 11 Review activities: Army - AV Air Force - 84 User activities: Army - ME, Mu 3mponents; or a fabricator
