C-M605.pdf

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FA8202-15-D-0001-0002

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C D O C C-M605

U GLASS PREPREG 250 CURE

11/07/2017

T A 3 4 9 0 0 1 4 A 1 2 9

C-M605 Revision C A-10 Aircraft Material Specification for Glass Fabrics Preimpregnated with Epoxy

Resin, 250°

Dated 07 November 2017

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WEIR

11/07/2017

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NONE

Update IAW ASIP Legacy VI

DO 0002

WEIZENECKER

2017-11-07 2017-12-20

PCO LETTER REQUEST

A-10 TLPS

Legacy VI 12/20/2017

Contract/Delivery Order Number: FA8202-15-D-0001

Program Manager: Edie Messina

Letter Number: A10-CDM-0001-E-17-0091

Date of Letter: 12/5/2017

CDRL Number: A129

Document Title:

Material Specification Glass Fabrics Preimpregnated with Epoxy Resin, 250° F (121°C) Curing

Document/ Drawing Number: C-M605 Rev C

NOT APPROVED (See comment below)

X APPROVED

APPROVED Subject to inclusion of attached comments

OTHER (please identify below)

Notes:

Program Manager Signature and Date:

X

MESSINA.CARRI

E.E.1023771388

Digitally signed by

MESSINA.CARRIE.E.1023771388

Date: 2017.12.21 13:00:49 -07'00'

CAGE 77751 C-M605

Revision C

07 November 2017

Data contained on this sheet is subject to the restrictions on the title page of this document.

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TABLE OF REVISIONS

Revision Changes Reason for Change

Original Issue 06/11/1981

Amendment 1 06/22/1985

No change to spec requirements. Authorize use on T-46 aircraft.

Amendment 2 09/18/1986

Add Qualified Product List (Appendix I).

Use of qualified sources.

Update Applicable Documents.

Revision A 04/18/1988

Incorporate Amendment 2 (Amendment 1 not applicable to A-10 Aircraft).

Incorporation of changes.

Remove all revision letters from

2.0 and delete MIL-Y-1140 and AMS 3824. Add MIL-C-9084.

Update applicable documents.

Revision B 03/05/1997

NOTE: This specification has been reviewed for hazardous air pollutants (HAPs) and ozone depleting substances (ODSs) and found not to specify these materials.

Added Foreword describing the review of this specification for toxins, pollutants and other hazardous materials, and establishing user responsibility for following all laws and regulations involving their use.

To comply with requirements of contract.

Reformatted all tables and redrew Figure 1.

To improve clarity.

In Section 4.4.3.2.b, changed reference from Figure 3 to Figure 2.

To correct error.

iii

Revision Changes Reason for Change Approved by

Revision C 11/07/2017

Incorporated Revision B, Attachment 1; redrew figures;

added numbers to previously unnumbered tables (renumbered subsequent tables as necessary), corrected typos and made minor grammatical changes.

Specification update; to improve clarity.

M. Kassinger

Air Force Engineering Order 06A1617 superseding Northrop Grumman specification C-M605 with Boeing material specification BMS 8-79 was purposely not incorporated.

The Air Force continues to purchase fiberglass prepreg to Northrop Grumman material specification C-M605 for A-10 parts.

Throughout document, replaced “refrigeration” or “refrigerated storage” with “cold storage.”

To recognize the use of non-refrigerated means of cold storage, e.g., dry ice.

Throughout document, replaced “shelf life” with “storage life.”

Consistency of terminology.

In Sec. 1.2.1, added reference to and type designations per AMS- C-9084; deleted Type 1582.

To specify defining document for material types and list those types;

material is no longer available.

In Para. 1.2.2.a, deleted “or as pre-cut patterns or kits.”

These are no longer

In Para. 1.2.2.b, deleted first sentence in its entirety.

Material is no longer available in different degrees of tack.

In Sec. 2.0, updated applicable documents; updated all references and callouts throughout; deleted documents not referenced in this specification.

Specification requirement, to reflect the latest documents; documents not cited in this specification are not required in Sec. 2.0.

Added Sec. 3.0, Definitions;

adjusted subsequent numbering.

To provide definitions of uncommon terms used in this document.

In Sec. 4.1.1 [was 3.1.1], added 4.1.1.c and 4.1.1.d.

Additional uniformity requirements.

iv

Revision Changes Reason for Change Approved by

Revision C (Continued)

In Sec. 4.1.1.b [was 3.1.1.b], modified defect definitions as follows: in first sentence, added “as noted in 4.1.1.c and 4.1.1.d”;

in second sentence, changed “both ends” to “one end”; in third sentence, deleted “or three defects per roll” and replaced with “with a maximum defect limit of 15% of the roll length.”

Clarity.

In Table I, deleted Type 1582. Material is no longer

In Sec. 4.1.3 [was 3.1.3], deleted “(no pigment added).”

Not required.

In Table II, converted units to msi or ksi as appropriate; for tensile ultimate test, changed Type 7781 values to agree with those of Type 1581; added new Note 1/ and re-designated existing Note 1/ as Note 2/.

Clarity; to agree with material supplier’s data; to clarify basis of mechanical values.

In Para. 4.1.5 [was 3.1.5], rewrote in entirety.

To more adequately describe environmental resistance requirements.

Retitled 4.1.6 [was 3.1.6] as “Storage Life and Out Time.”

To clarify the purpose of this section.

In Sec. 4.1.6 [was 3.1.6], rewrote Paras. 4.1.6.a, 4.16.c, and 4.1.6.d.

To more clearly define storage times, out time, and re-test limits, respectively.

In Para. 4.1.7.1 [was 3.1.7.1], added powder-free nitrile gloves.

To permit use of nitrile gloves.

In Para. 4.1.8.1 [was 3.1.8.1], modified required information;

deleted “PERISHABLE” from container legend.

To conform to supplier practices.

v

Revision Changes Reason for Change Approved by

Revision C (Continued)

In Table IV [was unnumbered], deleted Type 1582; updated parting film colors; changed “7881” to “7781.”.

Material is no longer available; to reflect current colors; to correct typo.

In Sec. 4.2.d [was 3.2.d], in first sentence, deleted “in duplicate.”

No longer required.

In Sec. 4.2.e [was 3.2.e], replaced end of second sentence with “A-10 System Program Office (SPO) Engineering or their representative”; was “A-10 Material, Materials Engineering, and Quality Control.”

Per Air Force direction.

In Sec. 4.2 [was 3.2], added Item l.

To require written approval by the A-10 SPO of any deviations from test method requirements.

Deleted Sec. 4.3 [was 3.3]. Moved type-defining document reference to Sec. 1.2.1.

In Sec. 5.2 [was 4.2], retitled as “Supplier Test Requirements”;

rewrote Para. 5.2.a.

To clarify supplier test requirements.

In Para. 5.2.a [was 4.2.a], changed beginning of second sentence to “Test percent resin solids...” (was “Test resin solids content...”);Table V, changed “Percent Resin Content” to “Percent Resin Solids”; changed title of Sec. 5.4.2.1 to “Percent Resin Solids” (was “Resin Solids Content”).

Consistency; per Air Force direction.

In Para. 5.2.b [was 4.2.b], rewrote in entirety.

Clarity.

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Revision Changes Reason for Change Approved by

Revision C (Continued)

In Table VI, changed Section reference for Laminate Compression Ultimate to 5.4.4.1.b; was 5.4.4.3.a(2); for Laminate Compression Ultimate, under Specimen Requirements, deleted “and a minimum of five specimens at 160°F.”

To correct typo; elevated temperature testing is no required.

In Sec. 5.3.1 [was 4.3.1], added records retention requirement.

To define material supplier record retention requirements for processing prepreg.

In Sec. 5.4.2 [was 4.4.2], added Item c.

To permit alternative test methods with written approval of the A-10 SPO.

In Para. 5.4.3.1.b [was 4.4.3.1.b], reworded requirement for two test panels, one at minimum heat-up rate, one at maximum heat-up rate; added “and as shown in Figure 1.”

Clarified qualification laminate test panel requirements; Figure 1 is the appropriate cure cycle.

In Para. 5.4.3.2.a [was 4.4.3.2.a], corrected table reference to Table III (was Table II).

To correct typo.

In Para. 5.4.3.2.b, changed references to Section 5.4.3.3.d (was 5.4.3.3).

Appropriate item within the paragraph.

Added Note beneath Para.

5.4.3.2.b.

To ensure the proper orientation of the skins relative to the core.

In Para. 5.4.3.3.d [was 4.4.3.3.d], changed pressure at which to vent vacuum bag and temperature at which to release autoclave pressure; added “as shown in Figure 1”.

To permit venting over a range of pressures and ensure a positive pressure when venting;

venting temperature now agrees with supplier’s recommendation; to ensure that curing would be per Figure 1.

vii

Revision Changes Reason for Change Approved by

Revision C (Continued)

In Para. 5.4.4.1.c [was 4.4.4.1.c], changed reference to ASTM D638 [was FTMS 406, Method 1011].

To reflect current document.

In Para. 5.4.4.1.d [was 4.4.4.1.d], changed reference to ASTM D3846 [was FTMS 406, Method 1042A].

To reflect current document.

In Para. 5.4.4.1.e(1) [was 4.4.4.1.e(1)], added single-place decimals to dimensions.

Consistency with tolerances; per Air Force direction.

In Para. 5.4.4.2.a(1) and (2) [were 4.4.4.2.a(1) and (2)], added single-place decimals and ± 0.1 tolerances to dimensions.

Consistency; per Air

In Para. 5.4.4.2.a(3) [was 4.4.4.2.a(3)], changed “Osnaberg” to “Osnaburg”; in first sentence, between “Osnaburg cloth” and “and determine” added “or the peeled skin of the test specimen.”

To correct typo; clarity.

In Para. 5.4.4.2.a(4) [was 4.4.4.2.a(4)], changed Peel strength formula as follows: is “(avg. peel load – avg. peel drum rewind load) (torque arm)”; was:

“(avg. peel drum rewind) (torque arm)”

Per Air Force direction; to correct error.

In Para. 5.4.4.2.c(3) [was 4.4.4.2.c(3)], in the second sentence, changed “strength” to “ultimate load and P/Y.”

Per Air Force direction.

In Para. 6.1.b [was 5.1.b], changed minimum bag thickness to 6 mils [was 4 mils]; added desiccant requirement; and requirement that bags be free of defects.

To clarify prepreg shipping requirements to minimize material rejection.

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Revision Changes Reason for Change Approved by

Revision C (Continued)

In Para. 6.1.c [was 5.1.c], deleted “in red letters.”

Supplier request.

In Para. 6.2.a [was 5.2.a], changed section reference to

4.1.8 (was 3.1.8).

To correct typo.

In Para. 6.2.b [was 5.2.b], deleted Items (2) through (5).

Supplier request (this information is provided on the certificate of conformance accompanying each container).

In Para. 7.0.b [was 6.0.b], added that material width as ordered shall be ± 1 inch and shall not include selvages.

To define useable prepreg width.

In Table IX [was unnumbered], deleted Type 1582; relabeled “Roll Length” as “Roll Length (Nominal)” and deleted “± 5” from each length value.

Material is no longer available; supplier request.

In Para. 7.0.c [was 6.0.c], at end of first sentence, changed to “A- 10 System Program Office (SPO)”; was “SPO and a copy sent to the A-10 Program.”

Per Air Force direction.

In Appendix, QPL, updated supplier name, contact information, and product designations; deleted Type 1582 material; added C3 finish equivalents for each material.

To reflect current corporate and product identities; material is no longer available; per Air ix

TABLE OF CONTENTS

TABLE OF REVISIONS ....................................................................................................... i

LIST OF TABLES .............................................................................................................. xi

LIST OF FIGURES ............................................................................................................ xii

FOREWORD .................................................................................................................... xiii

1.0 SCOPE

1.1 Scope

1.2 Classification

1.2.1 Type

1.2.2 Form

2.0 APPLICABLE DOCUMENTS

2.1 Government Documents

2.1.1 Federal

2.1.2 Military

2.2 Non-Government Documents

2.2.1 Industry

2.2.2 A-10 Program

3.0 DEFINITIONS

4.0 MATERIAL REQUIREMENTS

4.1 Composition

4.1.1 Uniformity

4.1.2 Formulation – Prepreg Physical Requirements

4.1.3 Color

4.1.4 Mechanical Properties

4.1.5 Environmental Resistance

4.1.6 Storage Life and Out Time

4.1.7 Toxicity and Safety

4.1.8 Material Identification and Marking

4.1.9 Workmanship

4.2 Qualification

5.0 QUALITY ASSURANCE PROVISIONS

5.1 Responsibility for Inspection

5.2 Supplier Test Requirements

x

5.3 Quality Conformance Inspection

5.3.1 Supplier Quality Control

5.3.2 Supplier Certification and Test Reports

5.3.3 Purchaser Quality Control

5.4 Material Test Methods

5.4.1 Sampling for Prepreg Physical Property Requirements

5.4.2 Prepreg Material Test Methods

5.4.3 Test Panel Fabrication

5.4.4 Specimen Preparation and Test

6.0 PREPARATION FOR DELIVERY

6.1 Packaging

6.2 Material Identification

7.0 NOTES

APPENDIX I: QUALIFIED PRODUCTS LIST

xi

LIST OF TABLES

Table I: Prepreg Physical Property Requirements

Table II: Laminate Mechanical and Flammability Resistance Requirements

Table III: Sandwich Test Panel Mechanical Property Requirements

Table IV: Prepreg Backing Color Coding

Table V: Supplier Prepreg Physical Specimen Requirements

Table VI: Supplier Laminate Mechanical Specimen Requirements

Table VII: Minimum Purchaser’s Quality Control Test Frequency

Table VIII: Laminate Test Panel Dimensions

Table IX: Prepreg Roll Lengths xii

LIST OF FIGURES

Figure 1: Cure Cycle – Laminate and Sandwich

Figure 2: Sandwich Test Panel Configuration xiii

FOREWORD

This specification has been reviewed for EPA 17 toxic chemicals, SARA 313-listed pollutants, as well as ozone depleting substances. No ozone depleting substances were found. No hazardous air pollutants and toxic materials were found. This specification is in compliance with the Air Force Pollution Prevention Program, AFI 32-7080.

It must be understood that the materials, methods, applications and processes can contain toxic and hazardous materials. It is the responsibility of the user to ensure safe and proper use in accordance with all applicable OSHA, EPA, Federal, state and local regulations.

The intent of this report is to explain why chemicals known as the EPA 17 are still required by this specification and the effort that was made to find a substitute. Contract F04606-96-D- 0021, Delivery Order 0016, did not include provisions or require a test program(s) to replace these materials. The materials below could not be replaced with alternate environmentally acceptable materials due to the lack of test data or qualified environmentally acceptable alternative materials. Aerospace industry practice requires that only fully qualified materials be used to assure high reliability or safety of flight considerations.

Material EPA 17 F04606-96-D-0021-0016

Effort Made to Find a Substitute

MIL-R-9300 TT-S-735

Multiple constituents

The updating of Federal specifications goes beyond the scope of Contract F04606-96-D- 0021, Delivery Order 0016.

JP-5 Fuel Multiple constituents The updating of JP-5 goes beyond the scope of Contract F04606-96-D-0021, Delivery Order 0016.

MIL-H-5606 Multiple constituents The updating of Military specifications goes beyond the scope of Contract F04606-96-D- 0021, Delivery Order 0016.

MIL-H-83282 Multiple constituents The updating of Military specifications goes beyond the scope of Contract F04606-96-D- 0021, Delivery Order 0016.

1.0 SCOPE

1.1 Scope

a. This specification establishes the material requirements for 250°F curing, fire-resistant, epoxy resin preimpregnated glass fabrics to be used in fabricating structural reinforced solid glass laminates and glass-laminate-faced honeycomb sandwich parts.

b. Only qualified products from qualified sources may be supplied in accordance with this specification (see Appendix I).

1.2 Classification

1.2.1 Type

Types are based upon fabric reinforcement used and are defined per AMS-C-9084:

Fiberglass Designation

AMS-C-9084

Designation

Type 120 Type III

Type 1581 Type VIIIA

Type 7781 Type VIIIB

Type 1584 Type XIA

1.2.2 Form

a. Prepreg materials may be purchased as a single ply of prepreg with polyethylene parting film.

b. The acceptable level of tack should be determined as a function of layup conditions and agreed to with each supplier.

2.0 APPLICABLE DOCUMENTS

The following documents of the issue in effect on the effective date of contract shall form part of this specification. In the event of conflict between the contractual documents referenced herein and the requirements of this specification, the contractual documents referenced herein shall govern.

2.1 Government Documents

2.1.1 Federal

FAR 25 Appendix F Airworthiness Standards, Transport Category Airplanes, Federal Aviation Administration

2.1.2 Military

MIL-DTL-5624 Turbine Fuel, Aviation, Grades JP-4 and JP-5

MIL-PRF-5606 Hydraulic Fluid, Petroleum Base; Aircraft, Missile, & Ordnance

MIL-PRF-83282 Hydraulic Fluid, Fire Resistant, Synthetic Hydrocarbon Base, Aircraft, Metric, NATO Code Number H-537

MIL-PRF-87257 Hydraulic Fluid, Fire Resistant; Low Temperature, Synthetic Hydrocarbon Base, Aircraft and Missile

MIL-R-9300 Resin, Epoxy, Low-Pressure Laminating

2.2 Non-Government Documents

2.2.1 Industry

AMS-C-9084 Cloth, Glass, Finished, for Resin Laminates

AMS-STD-401 Sandwich Construction and Core Materials; General Test Methods

ASTM D638 Standard Test Method for Tensile Properties of Plastics

ASTM D695 Standard Test Method for Compressive Properties of Rigid Plastics

ASTM D1781 Standard Test Method for Climbing Drum Peel Test for Adhesives

ASTM D3846 Standard Test Method for In-Plane Shear Strength of Reinforced Plastics

2.2.2 A-10 Program

S-F502 Process Specification for the Fabrication of 250°F Curing Epoxy Resin Composite Laminate and Honeycomb Sandwich Parts

3.0 DEFINITIONS

The following definitions apply to terms that are uncommon or have special meaning as used in this specification:

Crease – A condition of the surface of the material in which the nominal thickness is not appreciably changed, but the material is permanently formed into a ridge.

Date of manufacture – The date when the fiberglass reinforcement is impregnated with one resin mix in one continuous operation.

Dry (boardy) areas – Portions of the prepreg that do not drape easily or exhibit an unnatural drape or exhibit very little tack.

Fabric warp face – That side of the fabric on which the majority of the area is composed of yarns running parallel to the selvage.

Fill – The yarns running perpendicular to the longer dimension or selvage of the fabric reinforcements.

Fill face – That side of the fabric on which the majority of the area is composed of yarns running perpendicular to the selvage.

Fold – A condition in which the fabric is laid back over itself.

Manufacturing and Quality Assurance Plan (MQAP) – A document that describes the raw materials, manufacture and testing of a material to ensure product quality and consistency.

Mill roll – An uninterrupted roll of glass fabric cut from a loom and subjected to all subsequent fabric inspection, heat cleaning, and finishing operations as a single unit.

Out-time – The maximum (cumulative) time that a prepreg may be kept at ambient conditions and still retain properties within the limits of this specification.

Prepreg batch – Prepreg containing fabric meeting the requirements of AMS-C-9084, impregnated with resin in one continuous manufacturing operation.

Prepreg lot – Prepreg from one prepreg batch submitted for acceptance at one time.

Puckers – Areas on prepreg material in which the material has locally blistered from the carrier (separator film or release paper).

Resin rich area – An area with more than the maximum allowable resin content.

Roll – Any section from a batch of prepreg furnished as a continuous roll of material.

Selvage – The edge of woven fabric of different threads or weave from the body of the fabric.

Storage life – The period of time for which the material may be kept under cold storage so that it retains the properties within the limits of this specification.

Warp – The lengthwise parallel yarns of the fabric reinforcements running parallel to the selvage.

Wrinkle – A condition in which one or more plies of prepreg are formed into a ridge.

4.0 MATERIAL REQUIREMENTS

4.1 Composition

a. The glass fabric shall conform to the requirements of AMS-C-9084. Fabric styles shall be limited to those types listed in Section 1.2.1.

b. The glass finish used in a qualified system shall be listed with that material on the Qualified Products List (Appendix I) to this specification. The glass fabric finish is considered an integral part of a qualified system, and a change of finish requires requalification of the material.

c .Resin shall meet the requirements of MIL-R-9300.

4.1.1 Uniformity

a. The material shall be clean and free from foreign material and shall not exhibit characteristics that are detrimental to handling, fabrication, appearance, and performance of the laminate in which it is used.

b. Material containing preimpregnation defects, as noted in Sections 4.1.1.c and 4.1.1.d shall be allowed if each defect is flagged and an additional yard of material is added to the roll for every defect occurring in that roll. The flag shall consist of a strip of polyethylene backing material extending out one end of the roll at the location of the defect. Additionally, no more than one defect may occur in any 10 yards of material with a maximum defect limit of 15% of the roll length. Materials that do not meet the quality requirements specified herein will be returned to the supplier at the supplier’s expense.

c. The impregnated material shall be free from visible indications of moisture, puckers, cured resin, foreign material, unwetted fibers, resin rich areas, and dry or boardy areas.

d. The impregnated material shall be free from curled or folded selvages that overlap non-selvage areas, wrinkles, creases, tears or other permanent distortions.

4.1.2 Formulation – Prepreg Physical Requirements

a. Prepreg materials supplied in accordance with this specification shall meet the requirements of Table I.

b. All prepreg property values listed in Table I are average acceptable values for the types indicated (see Section 4.2).

Table I: Prepreg Physical Property Requirements

Property Type

Type

Type

Type

Resin Solids Content Test, percent Sec. 4.4.2.1

45 ± 3 38 ± 2 38 ± 2 36 ± 3

Gel Time Test, minutes Sec. 4.4.2.2

4 ± 2 4 ± 2 4 ± 2 4 ± 2

Flow Percent at 50 psi and 275°F Test Sec. 4.4.2.3

14 ± 6 14 ± 6 14 ± 6 14 ± 6

Volatiles Test, maximum percent Sec. 4.4.2.4

1.5 1.5 1.5 1.5

4.1.3 Color

Unless otherwise specified, the color of the prepreg material and the laminate cured in accordance with Section 5.4.3.3 shall be natural and uniform.

4.1.4 Mechanical Properties

4.1.4.1 Laminate Mechanical and Flammability Resistance Requirements

a. Laminates fabricated in accordance with Section 5.4.3 shall meet the requirements listed in Table II.

b. All mechanical strengths listed in Table II are minimum acceptable values for the average of five specimens.

Table II: Laminate Mechanical and Flammability Resistance Requirements

Property – Test Type 120 Type 1581 Type 7781 Type 1584

Number of Plies Compression and Tension Interlaminar Shear Flammability

Mechanical Properties Compression Ultimate Test, ksi 1/ Section 5.4.4.1.b

Room temperature 160 ± 5°F 200 ± 5°F

50.0 37.5 25.0

60.0 45.0 30.0

60.0

40.0

20.0

Compression Modulus Test, msi 1/ Section 5.4.4.1.b

Room temperature

3.00 2.25 1.50

3.40 2.55 1.70

3.40 2.55 1.70

1.50

Tensile Ultimate Test, ksi 1/ Section 5.4.4.1.c

Room temperature

33.75 22.5

54.0 40.5 27.0

54.0 40.5 27.0

50.0 37.5 25.0

Tensile Modulus Test, msi 1/ Section 5.4.4.1.c

Room temperature

2.80 2.10 1.40

1.50

3.20 2.40 1.60

2.80 2.10 1.40

Interlaminar Shear Test, ksi Section 5.4.4.1.d

Room temperature

3.50 2.63 1.75

1.75

Flammability Properties Test Section 5.4.4.1.e

60-second vertical

30-second 45-degree angle

2/ Material shall be self-extinguishing within 15 seconds of flame removal, shall burn for no more than 6 inches, and resin drips shall extinguish within 3 seconds.

2/ Material shall be self-extinguishing within 15 seconds of flame removal, afterglow shall cease to be visible within 10 seconds of flame removal, and there shall be no complete penetration of the material.

1/ Normalized mechanical values are based on the cured ply thickness of each fabric type as follows:

• Type 120 = 0.0041” cured ply thickness.

• Types 1581 and 7781 = 0.0095” cured ply thickness.

• Type 1584 = 0.0236” cured ply thickness.

2/ FAR 25.853.

4.1.4.2 Sandwich Mechanical Property Requirements

Sandwich panels fabricated in accordance with Section 5.4.3 shall meet the requirements listed in Table III.

Table III: Sandwich Test Panel Mechanical Property Requirements

Property – Test Type

Type

Type

Number of Face Plies 3 2 2

Drum Peel Test, lb.-in./3-in. width Section 5.4.4.2.a

Room temperature test only

Flatwise Tensile Test, psi Section 5.4.4.2.b

Room temperature 160 ± 5°F after 1/2 hour at temperature 200 ± 5°F after 1/2 hour at temperature

Long Beam Flexure Ultimate Test, lb.

Section 5.4.4.2.c

Room temperature

P/Y Test, lb./in. 1/ Section 5.4.4.2.c

Room temperature

1/ P/Y is the slope of the tangent to the initial portion of the load-deflection curve.

NOTES:

1. Peel strength values listed are minimum acceptable averages of at least four specimens equally divided between bag-side and tool-side facings.

2. Flatwise tensile and long beam flexure values listed are minimum acceptable values for the average of four specimens.

4.1.5 Environmental Resistance

Material supplied to this specification shall meet the interlaminar shear requirements of Table II for all test environments after exposure to JP-5 fuel per MIL-DTL-5624 and hydraulic oil per MIL-PRF-5606, MIL-PRF-83282 or MIL-PRF-87257 for 7 days at 160°F. Test panels shall be cured within the prepreg out time requirements of Paragraph 4.1.6.c using one of the heat-up rates noted in Paragraph 5.4.3.3. Exposed specimens shall be wiped dry and tested within 8 hours of removal from the test fluids.

4.1.6 Storage Life and Out Time

a. The prepreg shall meet the requirements of this specification after storage for 180 days (calculated from the date received) at 10°F or lower. The supplier shall store prepreg within 72 hours after manufacture at 10°F or below for a maximum of 30 days prior to shipment.

b. The material shall be kept at or below 10°F during shipment and storage. However, storage temperature at or below 0°F is recommended.

c. The prepreg shall meet the requirements of this specification after exposure to a temperature of 70 ± 10°F for an accumulated period of 200 hours. The prepreg shall meet the requirements of this specification after exposure to temperatures between 81° and 100°F for an accumulated period of 70 hours. Material exposed to temperatures above 100°F shall be rejected.

The cumulative “out of freezer” exposure shall be tallied using the following unit times:

• 1 hour at 10 to 80°F = 1 unit hour

• 1 hour at 81 to 100°F = 3 unit hours

The cumulative “out time” exposure shall not exceed 200 units. All materials must be stored in sealed moisture-proof bags with proper identification.

d. After the initial 180-day storage life, the prepreg may be revalidated for two additional 90-day storage lives. Retest shall include flow and gel time per Table I and room temperature long beam flexure per Table III. The maximum time for storage at 10°F or below, which includes supplier storage, shall be 390 days from date of receipt.

4.1.7 Toxicity and Safety

4.1.7.1 Certain resins and catalysts can cause sensitization of the skin. Clean surgical cotton, polyethylene or powder-free nitrile gloves should be worn at all times while handling these materials in the uncured state.

4.1.7.2 Resin flash of newly cured laminates may contain some fibers that migrated during the resin flow stage. This flash is very sharp and should be handled with care.

4.1.8 Material Identification and Marking

4.1.8.1 Legibly identify each roll in the prepreg core and the container for each roll with the following information:

(1) Specification number including revision letter, and type

(2) Purchase order number

(3) Manufacturer and manufacturer's number (including designation of reinforcement, i.e., glass)

(4) Batch and roll number

(5) Quantity and width

(6) Date of impregnation

(7) Date of shipment (on container only)

(8) Storage life

(9) Legend:

STORE AT OR BELOW 10°F (–12°C)

DO NOT STAND ON END

4.1.8.2 All prepreg material shall have a backing layer of diamond-embossed polyethylene parting film. The polyethylene shall be placed on the prepreg surface with the long dimension of the diamond pattern parallel to the fabric warp direction and in contact with the warp face, color coded as follows:

Reinforcement Type Color of Polyethylene

120 Red

1581 Red

7781 Red

1584 Green

Table IV: Prepreg Backing Color Coding

4.1.9 Workmanship

4.1.9.1 To ensure the highest quality workmanship, the prepreg manufacturer shall establish a system for record keeping as required to produce prepreg material consistent with the requirements of this specification. This system and the records shall be made available for inspection by the procuring activity or representative of the A-10 Program upon request.

4.2 Qualification

a. Qualification will require submittal of test data indicating compliance with the material requirements of this specification for the type of material to be qualified.

b. All requests for qualification shall be directed to A-10 Program Engineering, which will request data and samples when desired for qualification purposes.

c. The qualification sample shall consist of three representative production sample rolls (at least 50 yards), one roll each from three different batches, of the particular type under which the vendor elects to qualify. The qualification samples must also have a specific glass finish with which the vendor elects to qualify. Each type must be qualified individually.

d. The qualification samples submitted for approval shall be accompanied by a certified test report showing that the samples supplied meet the requirements of this specification at the minimum and maximum heat-up rates described in Section 5.4.3.3.d, both on “as received” material and after aging for 200 hours at 70–80°F, and that a laminate made from this material meets the requirements of Table II and a sandwich panel (Type 120, Type 1581 or Type 7781) meets the requirements of Table III. A vendor must also certify that his qualification material will meet the requirements of Tables II and III material. The vendor qualification report must contain:

(1) Supplier product designation

(2) Glass finish

(3) Type in accordance with this specification, and latest revision letter of the specification.

e. All suppliers shall have test facilities capable of testing in accordance with this specification. The adequacy of test facilities may be verified, as deemed necessary, by a survey team including representatives of A-10 System Program Office (SPO) Engineering or their representative.

NOTE: A manufacturer may qualify a new facility or glass finish to all types of their material of a given resin system already appearing on the QPL by qualifying Types 120 and 1581 or 7781 of that resin system at that facility.

f. Requalification may be required at any time as deemed necessary by A-10 Program Engineering and Quality.

g. No change in approved product formulation, critical raw materials, basic methods of manufacture, or geographic location shall be made without notification and prior approval in writing from A-10 Program Engineering. Requalification of the revised material may be required and a revised supplier designation may be requested.

h. Vendor Quality Control shall run an infrared (IR) analysis and a gel permeation chromatogram on each qualification sample and supply the results with the other qualification data.

i. Any or all of the qualification tests may be repeated at any time by the purchaser and the material must pass the qualification requirements.

j. The manufacturing activity shall evaluate the acceptability of all materials for handling characteristics in the shop environment and shall recommend either full or conditional acceptance.

k. The supplier shall submit an approved Manufacturing and Quality Assurance Plan (MQAP) containing baseline chemical and in-process test information.

l. Deviations from the physical and mechanical test method requirements of this specification shall not be permitted without prior written approval from the A-10 SPO.

5.0 QUALITY ASSURANCE PROVISIONS

Fabric preimpregnated material covered by this specification shall be inspected to ensure conformance to the requirements of Section 4.0 of this specification.

5.1 Responsibility for Inspection

Unless otherwise specified in the contract or order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified, the supplier may utilize his own facilities or any commercial laboratory acceptable to the A-10 Program. The program reserves the right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to ensure supplies and services conform to the prescribed requirements.

5.2 Supplier Test Requirements

a. Physical specimen requirements are shown in Table V. Test percent resin solids on material taken from each mill roll at intervals not exceeding 250 yards within the mill roll. Test gel time, percent flow and volatile content on the first and last roll in the prepreg batch at a minimum.

Test Section Specimen Requirements Per Roll

Percent Resin Solids 5.4.2.1 Minimum of two specimens

Gel Time 5.4.2.2 Minimum of two 20-gram specimens

Percent Flow 5.4.2.3 Minimum of two 0.10-inch-thick specimens

Percent Volatile Content 5.4.2.4 Minimum of two specimens

Table V: Supplier Prepreg Physical Specimen Requirements

b. If any test results of the sample fail to meet the requirements of Table I, then one retest of the failing property is allowed. If the retest test results fail to meet the requirements, then the roll shall be rejected. If the retest test results meet the requirements, then a referee test is required. Both the retest and referee test results must meet the requirements of Table I for the roll to be accepted.

c. Supply mill roll or splice identification with each batch.

d. Mechanical tests per Table VI shall be performed on at least one representative roll of prepreg per batch, and results included with the supplier test report:

Test Section Specimen Requirements

Laminate Tensile Ultimate

5.4.4.1.c Minimum of five specimens at room temperature

Laminate Compression Ultimate

5.4.4.1.b Minimum of five specimens at room temperature

Table VI: Supplier Laminate Mechanical Specimen Requirements

5.3 Quality Conformance Inspection

5.3.1 Supplier Quality Control

Supplier Quality Control shall provide a system of in-process records that assure product integrity. These records shall be made available to authorized representatives of purchaser on request. The supplier shall maintain, for a period of 7 years, all records pertaining to raw material receiving inspection and certification, in-process records, and product testing in accordance with an approved manufacturing and quality assurance plan.

5.3.2 Supplier Certification and Test Reports

With each production shipment, the supplier must state that the materials and methods of manufacture have not changed from those used in the qualification sample (Section 3.2). A test report on the production batch shall also be supplied that contains test values demonstrating conformance of the prepreg to the requirements of this specification.

5.3.3 Purchaser Quality Control

a. Quality control tests shall include, as a minimum, those tests listed in Table VII. Any other test listed in this specification may be performed to ensure that materials meet requirements.

b. Additional tests such as IR analysis, gel permeation chromatography, or thermal analysis may be performed as deemed necessary to ensure that no formulation changes have been made to production shipments since initial qualification.

c. All test data and records must be kept on file and be readily available for review.

Table VII: Minimum Purchaser’s Quality Control Test Frequency

Test

Test Frequency 1/

No. of Rolls in Shipment

No. of Rolls to Test

Prepreg Tested at Room Temperature (See Table I):

1. Resin Solids

2. Volatiles

3. Flow

4. Gel Time

1–10 11–60

61–100 101–160

160 and up

1 additional roll for each additional

100 rolls

Laminate Tested at Room Temperature (See Table II):

1. Compression Ultimate

2. Compression Modulus

3. Tensile Ultimate

4. Tensile Modulus

Sandwich Tested at Room Temperature (See Table III):

1. Drum Peel

2. Flatwise Tensile

3. Long Beam Flexure

4. P/Y

1/ Test frequency applicable for all tests.

5.4 Material Test Methods

5.4.1 Sampling for Prepreg Physical Property Requirements

a. Before taking a sample, warm the material as necessary to above the ambient dew point to ensure that no condensation will occur on the sample or the unused prepreg when the protective bag is removed.

b. Discard any dried, moisture-affected, or contaminated material from each roll to be sampled. Remove sufficient material from each roll to perform all required tests, and repackage the roll and sample(s) in moisture-proof bags before returning the unused prepreg to storage. Minimize out-time from refrigerated storage.

5.4.2 Prepreg Material Test Methods

a. Cut 4 x 4-inch specimens as required for resin solids content, percent flow, and percent volatiles tests and 2 x 2-inch specimens as required for gel time test.

b. Cut these specimens at 45 degrees to warp in a pattern so that the samples for each test will be representative of the swatch. Do not cut any specimens within 2 inches of the selvage.

NOTE: Allow prepreg to attain room temperature prior to debagging and sampling.

c. The material supplier may use alternative test methods when approved in writing by the A- 10 System Program Office (SPO).

5.4.2.1 Percent Resin Solids

a. Test a minimum of two specimens from each sample.

b. Remove polyethylene backing from each specimen and place specimens in an air-circulating oven at 275 ± 5°F. Heat soak for 8 minutes ± 5 seconds, then remove from oven, cool in a desiccator, and immediately weigh to nearest 10 milligrams. Place each specimen in a muffle furnace at 1,050 ± 50°F until resin is completely burned away (white glass cloth with no dark areas). Cool in a desiccator and weigh burnout product. Calculate percent resin solids:

Percent resin solids content = A – B

A × 100

Where A = weight of devolatilized specimen

B = weight of burnout product

c. Test average shall meet Table I requirements.

5.4.2.2 Gel Time

a. Remove polyethylene backing from 2 x 2-inch specimens cut in accordance with Section

5.4.2 and stack to make two laminates weighing approximately 20 grams each.

b. Place the stack between aluminum foil or suitable* 2-mil plastic film and place between the heated platens of a press regulated at 275 ± 5°F. Position the specimen at least 1 inch from the edge of the platen. Platen opening should be the minimum required for specimen insertion so that pressure can be applied as soon as possible.

* Suggested suitable film is Tedlar.

c. Immediately apply sufficient pressure to create a bead of resin around the edge of the panel. Start a stopwatch as soon as pressure is applied. Probe the resin bead with a wooden or glass rod until the specimen has gelled. Gelling will be preceded by the appearance of “stringiness”—long strands of resin can be drawn out from the bead with the probe. When stringiness ceases and the bead has a rubbery feel, gelation has occurred. Stop the watch and immediately remove the specimen from the press and examine it. If the material is hard and brittle while still hot, the gel point has been exceeded and the test must be repeated. If the specimen is soft, tacky, and stringy, when probed while still hot, then the gel point has not quite been achieved and the test must be repeated.

d. Run duplicate test with the second stack of prepreg.

e. Each gel time shall meet Table I requirements.

5.4.2.3 Percent Flow

a. Remove polyethylene backing from 4 x 4-inch specimens cut in accordance with Section

5.4.2 and stack with all edges aligned. Lay up two laminates, each at least 0.10 inch thick.

b. Weigh each specimen to the nearest milligram.

c. Place each specimen between sheets of aluminum foil or any suitable* plastic film and position in the center of a heated platen (275 ± 5°F). Apply pressure (50 ± 5 psi) and cure for at least 5 minutes longer than the gel time measured in accordance with Section 5.4.2.2.

* Suggested suitable film is Tedlar.

d. Remove specimen from press, cool, and remove parting film. Scrape the flash from the edge of the panel with a scraper. Take precautions to prevent removal of glass with the scrapings. Reweigh the clean specimen and calculate flow:

Percent flow = A – B

A × 100

Where A = weight of specimen prior to cure

B = weight of specimen after cure

e. The average percent flow shall meet the requirements of Table I and two consecutive flow determinations shall not vary more than 3 percent. Tests must be rerun if the spread is greater than 3 percent.

5.4.2.4 Percent Volatiles

a. Select a minimum of two representative 4 x 4-inch specimens cut in accordance with Section 5.4.2. Remove polyethylene backing and weigh each specimen to the nearest milligram. Preweigh the hook used to hold each specimen in the oven and weigh a sheet of aluminum foil for each specimen.

b. Suspend each specimen in an air-circulating oven regulated at 275 ± 10°F and place the weighed aluminum foil below each specimen to catch any resin runoff.

c. Close the oven door and start a stop watch. The oven door shall not be open more than 10 seconds to suspend the specimens. After 8 minutes ± 5 seconds, remove the specimens and allow them to cool. Reweigh the specimen, hook, and aluminum foil. Calculate volatile content:

Percent volatile content = A – B

A × 100

Where A = weight of specimen prior to test

B = weight of specimen after test plus any increase in weight of the hook and the aluminum foil due to resin pickup

d. The volatile content of each specimen shall meet the requirements of Table I.

5.4.3 Test Panel Fabrication

5.4.3.1 Laminate Test Panels

a. Use the number of plies specified in Table II for the test panel being fabricated and the type of prepreg being tested.

b. Initial qualification will require duplicate test panels fabricated for each property listed in Table VIII and cured using both heat-up rates specified in Section 5.4.3.3.d and as shown in Figure 1. After qualification, only one test panel shall be fabricated and tested per property, with the heat-up rate being within the rates specified in Section 5.4.3.3.d.

c. Each laminate must be large enough to accommodate test specimens so that no tested area is within 2 inches of any edge bleeder. The sizes per Table VIII are recommended.

Test Panel Property Length, inches

(Warp Direction) Width, inches

Compression and Tension 14 20

Interlaminar Shear 10 20

Flammability 24 26

Table VIII: Laminate Test Panel Dimensions

d. Position plies with warp face up and warp direction parallel within ± 1.0 degree.

5.4.3.2 Sandwich Test Panels

a. Use the number of facing plies specified in Table III for the type of prepreg being tested.

b. Initial qualification will require duplicate test panels—laid up in accordance with Figure 2 and cured using both heat-up rates specified in Section 5.4.3.3.d. After qualification, only one panel need be fabricated and tested with the heat-up rate within those rates specified in Section 5.4.3.3.d used in the cure.

NOTE: Sandwich test panels fabricated per Figure 2 shall be inspected during layup and documented on the work order to verify that both bag and toolside skins have the “warp face” of the fabric placed facing toward the core. Sandwich test panels that do not have skin “warp face” direction documented on the work order shall be set aside and new test panels shall be fabricated with the required skin layup. Improper skin layup can result in non-conservative test values that are inaccurate.

Figure 1: Cure Cycle – Laminate and Sandwich

1/ The prepreg shall be oriented so that the “warp face” of the fabric is against the core on both sides.

2/ Panel dimension shall be such as to allow machining of the number and kinds of test coupons specified in Table III.

3/ No splices are allowed in test panel core.

4/ All test panel cores shall be chamfered 25 ± 10 degrees.

NOTE: Square edge is optional to chamfered edge.

* Product of Hexcel Corp.

Figure 2: Sandwich Test Panel Configuration

5.4.3.3 Test Panel Processing

a. Edge bleed only. The bleeder material may overlap the layup a maximum of 0.5 inch.

b. Apply nonbondable Tedlar, FEP, or TFE release film between the layup and bag (do not use bondable Tedlar).

c. Vacuum bag each test panel. Draw full vacuum and test each assembly for leaks. When vacuum line is disconnected, vacuum shall not drop more than 5 inches of mercury in 5 minutes.

d. Cure one set of test panels as shown in Figure 1 at a heat-up rate of 2 +1.5 / –0.5 °F/minute. Cure a duplicate set at a heat-up rate of 8 +0 / –2 °F/minute.

(1) Place test panels while under vacuum into autoclave and apply 45 ± 5 psi positive pressure. When autoclave pressure reaches 20 +10 / –0 psi, vent assemblies to atmosphere.

(2) Heat to 260 ± 10°F at the designated heat-up rate. Hold at temperature for 90 +15 / –0 minutes. Cool to or below 140°F before releasing autoclave pressure.

5.4.4 Specimen Preparation and Test

5.4.4.1 Laminate Test Specimens

a. General Requirements

(1) Machine all mechanical test specimens at 0 ± 1.0 degree to warp (parallel to warp).

(2) Heat soak all elevated-temperature specimens for a minimum of 30 minutes at the specified temperature just prior to test.

(3) Report individual and average values.

b. Compression Ultimate – ASTM D695

(1) Machine and test a minimum of five specimens from each test panel at each temperature. Cut the specimens randomly to make them representative of the panel.

(2) Use a compressometer to obtain the load-strain curve. Do not use a deflectometer.

(3) Compression ultimate test averages shall meet the requirements of Table II.

c. Tensile Ultimate and Modulus – ASTM D638

(1) Machine and test a minimum of five Type II-configuration specimens from each set at each temperature. Cut the specimens randomly to make them representative of the panel.

(2) When testing each specimen, use a crosshead rate of travel of 0.05 inch/minute until the initial straight-line portion of the stress-strain curve is obtained for modulus calculation. The rate may then be increased to 0.20–0.25 inch/minute until failure occurs.

(3) Tensile ultimate and modulus averages shall meet Table II requirements.

d. Interlaminar Shear – ASTM D3846

(1) Each test specimen shall be in accordance with ASTM D3846, except that the distance between the notches is to be 0.375 ± 0.015 inch.

(2) Machine and test a minimum of five specimens from each test panel at each temperature (i.e., 15 total specimens/panel). Cut the specimens randomly to make them representative of the entire panel.

(3) Interlaminar shear test averages shall meet Table II requirements.

e. Flammability Properties

(1) The 60-second vertical test specimens shall be 3.0 ± 0.1 inches wide and 12.0 ±

0.1 inches long (warp) and the 30-second, 45-degree specimens shall be 10.0 x 10.0 ±

0.1 inches.

(2) Cut three specimens for each test from each set of panels and test to the procedure listed in FAR 25 Appendix F.

(3) Flammability properties shall meet requirements listed in Table II.

5.4.4.2 Sandwich Test Specimens – Cut test specimens from each test panel and test as follows (see Figure 2):

a. Sandwich Peel Test

(1) Each test specimen shall be 3.0 ± 0.1 x 12.0 ± 0.1 inches with the 12-inch dimension 0 degree (parallel) to the warp direction.

(2) Cut and test a minimum of two specimens for each face of each panel. Use the climbing drum peel apparatus (see ASTM D1781). Use a head speed of 1.0 ± 0.1 inch per minute. Determine peel curve average.

(3) Rewind the drum using a loose material such as Osnaburg cloth or the peeled skin of the test specimen and determine rewind curve average. Determine rewind value at least once each day that peel testing is being conducted. This average rewind value shall be subtracted from the average peel value.

(4) Determine average peel strength for bag-face skins and average peel strength for tool-face skins.

Peel strength = (avg. peel load – avg. peel drum rewind load) (torque arm)

= lb.-in./3-in. width

Torque = radius of flange minus radius of drum

= 0.5 inch.

(5) Peel strength averages shall meet Table III requirements.

(6) Report individual and average values.

b. Flatwise Tensile Test

(1) Each test specimen shall be 2 x 2 inches square.

(2) Cut, bond, and test a minimum of 12 specimens from each test panel (four specimens each at each temperature as listed in Table Ill) in accordance with AMS-

STD-401.

(3) Average flatwise tensile strength shall meet Table III requirements.

(4) Report individual and average values.

c. Long Beam Flexure

(1) Each test specimen shall be 3 x 24 inches with the 24-inch dimension in the warp direction. Exception: Elevated temperature specimens may be reduced in length if required to fit equipment used, provided an 18-inch span is maintained.

(2) Cut and test a minimum of 12 specimens from each panel (four each at each temperature as listed in Table III) in accordance with AMS-STD-401, except testing shall be single-point loading on an 18-inch span. Use a 1-inch-wide by 3-inch-long steel block with a 60D (durometer) rubber pad 1/8 inch thick at the center load point.

Test all specimens bag side up.

(3) Report ultimate load and P/Y for each specimen. Average long beam flexure ultimate load and P/Y shall meet Table III requirements.

6.0 PREPARATION FOR DELIVERY

6.1 Packaging

a. Package in a manner to ensure safe delivery of the material and to retain the properties required by this specification. Each roll shall be stored in a horizontal position.

b. Seal each roll in a polyethylene bag of 6-mil minimum thickness. A suitable desiccant shall be placed in the bags prior to sealing. The bags shall be free of defects such as holes, cuts, or tears that would allow free passage of moisture or other contaminants.

c. Each packaged roll must contain the following information at least 2 inches high:

TEMPERATURE MUST BE MAINTAINED BELOW 10°F

DO NOT STAND ON END

6.2 Material Identification

a. Legibly identify each roll in the prepreg core and on each container of prepreg in accordance with Section 4.1.8.

b. Include the date of shipment on each roll container.

7.0 NOTES

a. Intended Use – The materials identified and controlled by this…