ASTM D5687/D5687M-95(2002)
(Guide)Standard Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation
Standard Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation
SCOPE
1.1 This guide provides guidelines to facilitate the proper preparation of laminates and test specimens from fiber-reinforced organic matrix composite prepregs. The scope is limited to organic matrices and fiber reinforcement in unidirectional (tape) or orthagonal weave patterns. Other forms may require deviations from these general guidelines. Other processing techniques for test coupon preparation, for example, pultrusion, filament winding and resin-transfer molding, are not addressed.
1.2 Specimen preparation is modeled as an 8-step process that is presented in and Section . Laminate consolidation techniques are assumed to be by press or autoclave. This practice assumes that the materials are properly handled by the test facility to meet the requirements specified by the material supplier(s) or specification, or both. Identification and information gathering guidelines are modeled after Guide E 1309. Test specimens shall be directly traceable to material used as designated in Guide E 1434. Proper test specimen identification also includes designation of process equipment, process steps, and any irregularities identified during processing.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D5687/D5687M–95 (Reapproved 2002)
Standard Guide for
Preparation of Flat Composite Panels with Processing
Guidelines for Specimen Preparation
This standard is issued under the fixed designation D5687/D5687M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. Within the text the
1.1 This guide provides guidelines to facilitate the proper
inch-pound units are shown in brackets. The values stated in
preparation of laminates and test specimens from fiber-
each system are not exact equivalents; therefore, each system
reinforced organic matrix composite prepregs. The scope is
must be used independently of the other. Combining values
limited to organic matrices and fiber reinforcement in unidi-
from the two systems may result in nonconformance with the
rectional(tape)ororthagonalweavepatterns.Otherformsmay
standard.
require deviations from these general guidelines. Other pro-
1.4 This standard does not purport to address all of the
cessing techniques for test coupon preparation, for example,
safety concerns, if any, associated with its use. It is the
pultrusion, filament winding and resin-transfer molding, are
responsibility of the user of this standard to establish appro-
not addressed.
priate safety and health practices and determine the applica-
1.2 Specimen preparation is modeled as an 8-step process
bility of regulatory limitations prior to use.
that is presented in Fig. 1 and Section 8. Laminate consolida-
tion techniques are assumed to be by press or autoclave. This
2. Referenced Documents
practice assumes that the materials are properly handled by the
2.1 ASTM Standards:
test facility to meet the requirements specified by the material
C297 Test Method for Flatwise Tensile Strength Sandwich
supplier(s) or specification, or both. Identification and infor-
Constructions
mation gathering guidelines are modeled after Guide E1309.
D123 Terminology Relating to Textiles
Test specimens shall be directly traceable to material used as
D792 TestMethodsforDensityandSpecificGravity(Rela-
designated in Guide E1434. Proper test specimen identifica-
tive Density) of Plastics by Displacement
tion also includes designation of process equipment, process
D883 Terminology Relating to Plastics
steps, and any irregularities identified during processing.
This guide is under the jurisdiction of ASTM Committee D30 on Composite
Materials and is the direct responsibility of Subcommittee D30.04 on Lamina and Annual Book of ASTM Standards, Vol 15.03.
Laminate Test Methods. Annual Book of ASTM Standards, Vol 07.01.
Current edition approved March 15, 1995. Published May 1995. Annual Book of ASTM Standards, Vol 08.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5687/D5687M–95 (2002)
D2734 Test Method for Void Content of Reinforced Plas- 3.2.6 dam, n—asolidmaterial(suchassiliconerubber,steel
tics or aluminum) used in the autoclave bag to contain the matrix
material within defined boundaries during laminate consolida-
D3163 Test Method for Determining Strength of Adhe-
tion.
sively Bonded Rigid Plastic Lap-Shear Joints in Shear by
Tension Loading 3.2.7 debulk, v—process of decreasing voids between
laminabeforelaminateconsolidationthroughuseofvacuumor
D3171 Test Method for Constituent Content of Composite
by mechanical means. Laminae can be debulked at ambient or
Materials
elevated temperatures.
D3531 TestMethodforResinFlowofCarbonFiber-Epoxy
3.2.8 doubler, n—an unbonded tab used to hold the lami-
Prepreg
nate specimen in a grip or fixture. See tab.
D3878 Terminology for Composite Materials
3.2.9 fiber washing, n—the tendency of fibers to change
D3990 Terminology Relating to Fabric Defects
orientationduetoresinflowfromtheoriginallay-updirection.
D4850 Terminology Relating to Fabric
Fiber washing may occur during the laminate consolidation
D5229/D5229M Test Method for Moisture Absorption
process mainly at the sides of a laminate.
Properties and Equilibrium Conditioning of Polymer Ma-
3.2.10 fill, n—(1) Fiber inserted by the shuttle during
trix Composite Materials
weavingalsodesignatedasfilling.SeeTerminologyD123.(2)
E 1237 Guide for Installing Bonded Resistance Strain
8 The direction of fiber running perpendicular to the warp fibers.
Gages
3.2.11 flip/flop, v—the process of alternating plies through
E1309 Guide for Identification of Fiber-Reinforced Poly-
an angle orientation of 180° during laminate lay-up. This
mer Matrix Composite Materials in Databases
practice is commonly used if material of the same width as the
E1434 GuideforRecordingMechanicalTestDataofFiber-
laminate has a reoccurring flaw. The process changes the
Reinforced Composite Materials in Databases
location of the flaw so that it does not unduly affect the
laminate structure.
3. Terminology
3.2.12 flaw, n—a material defect, typically occurring in the
3.1 Definitions—TerminologyD3878definestermsrelating
discrete fiber reinforcement, but possible in the matrix.
to high-modulus fibers and their composites. Terminology
3.2.13 flow, n—the movement of uncured matrix under
D883 defines terms relating to plastics. Terminology D123
pressure during laminate consolidation.
defines textile related terms. Terminology D4850 defines
3.2.14 harness, n—a weaving designation of how many fill
terms relating to fabric. In the event of a conflict between
fibersawarpfloatcrossesinasatinweave.Typicalweavesare
terms, Terminology D3878 shall have precedence over the
5-Harness and 8-Harness.
other standards.
3.2.15 joint, n—a location where two edges of prepreg
3.2 Description of Trems Used in This Standard—Theterms
meet. Two common types of joints used in lay-up are a butt
usedinthisguidemayconflictwithgeneralusage.Thereisnot
joint (where 2 plies are aligned edge to edge) and an overlap
yetanestablishedconsensusconcerningtheuseoftheseterms.
joint (where the edge of each ply is overlapped some specified
The following descriptions are intended only for use in this
width with another ply).
guide.
3.2.16 lay-up, n—the finished product of ply stacking and
3.2.1 bag, v—the process of enclosing the ply layers within
bagging operations.
a flexible container. See lay-up.
3.2.17 matrix, n—thecontinuousconstituentofacomposite
3.2.2 base plate, n—a flat plate on which a laminate is laid
material.
up [usually made of aluminum and 6 mm [0.25 in.] or thicker
3.2.18 mold, n—the support structure that holds the lami-
with a flatness requirement of 0.05 mm [0.002 in.] or less].
nate or lay-up during the laminate consolidation process.
3.2.3 breather string, n—a glass string connected from the
3.2.19 non-perforated TFE, n—a non-porous tetrafluoroet-
laminate to a breather in the autoclave bag. It is used as a
hylene film.
degassing aid; providing a path for gasses to be transferred
3.2.20 panel, n—a uniformly contoured composite lami-
from the laminate.
nate, typically flat.
3.2.4 caul plate, n—aflatplateusedtoprovideaflatsurface
3.2.21 peel ply, n—aclothwithreleasecapabilities.Usually
to the top of the laminate during laminate consolidation
used in conjunction with laminates requiring secondary bond-
[usually made of aluminum and 3 mm [0.125 in.] thick or
ing.
thicker with a flatness requirement of 0.05 mm [0.002 in.] or
less]. 3.2.22 perforated TFE, n—aporoustetrafluoroethylenefilm
usedinthebaggingprocessthatallowsgassesorexcessmatrix
3.2.5 cloth, n—a piece of textile fabric containing woven
materials to escape from a laminate during laminate consoli-
reinforcement without a load transferring matrix.
dation, while protecting the laminate from physical bonding to
other items such as base plates or caul plates.
3.2.23 ply, n—a single layer of prepreg used in lay-up.
Annual Book of ASTM Standards, Vol 08.02.
3.2.24 press, n—equipment consisting of heated, flat [usu-
Annual Book of ASTM Standards, Vol 15.06.
allywithinatoleranceof0.3mm[0.01in.]orless]platensthat
Annual Book of ASTM Standards, Vol 07.02.
Annual Book of ASTM Standards, Vol 03.01. supply pressure against a surface.
D5687/D5687M–95 (2002)
3.2.25 satin, adj—aweavepatterninwhichwarpfloatspass 5.3 Steps 3 through 8 of the 8-step process may not be
over several yarns before crossing under a single yarn. It is required for particular specimen or test types. If the specimen
characterized by parallel fibers and no diagonal pattern. or test does not require a given step in the process of specimen
3.2.26 sealant, n—a high temperature material used to seal fabrication, that particular step may be skipped.
the edges of a vacuum bag to the base plate during a 5.4 A test specimen represents a simplification of the
consolidation or debulking cycle. structural part. The test specimen’s value lies in the ability of
several sites to be able to test the specimen using standard
3.2.27 staggered, adj—the description of ply placement
wherethejointsarenotpositionedinthesameinplanelocation techniques. Test data may not show identical properties to
those obtained in a large structure, but a correlation can be
through some specified thickness of the laminate.
3.2.28 tab, n—a piece of material used to hold the laminate made between test results and part performance. This may be
due, in part, to the difficulty of creating a processing environ-
specimen in a grip or fixture for testing so that the laminate is
not damaged, and is adequately supported. It is bonded to the mentfortestspecimensthatidenticallyduplicatesthatoflarger
scale processes.
specimen. An unbonded tab is termed a doubler.
3.2.29 TFE coated cloth, n—a cloth coated with a tetrafluo- 5.5 Tolerancesareguidelinesbasedoncurrentlabpractices.
Thisguidedoesnotattempttogivedetailedinstructionsdueto
roethylenecoating.Thisisusedinthebaggingprocesstoallow
the variety of possible panels and specimens that could be
gases or excess matrix material to escape during the laminate
made. The tolerances should be used as a starting reference
consolidation. It differs from perforated TFE in that it gives a
from which refinements can be made.
textured surface to the laminate.
3.2.30 traveler, n—a coupon with the same nominal thick-
nessandwidthasthetestspecimen,madeofthesamematerial 6. Interferences
andprocessedsimilarlytothespecimenexceptusuallywithout
6.1 Specimenpreparationpracticesshouldreflectthoseused
tabs or gages. The traveler is used to measure mass changes
onanapplicablepart,tothegreatestextentpractical.However,
during environmental conditioning when it is impractical to
due to scaling effects, processing requirements for test lami-
measure these changes on the actual specimen.
nates may not exactly duplicate the processes used in larger
3.2.31 vacuum bag, n—a low gas permeable material used
scale components. The user should attempt to understand and
to enclose and seal the laminate during a consolidation or
control those critical process parameters that may produce a
debulking cycle.
differenceinmaterialresponsebetweenthetestcouponandthe
3.2.32 vacuum couple, n—the mechanical connection that
structure. Critical process parameters are material, application,
sealsthevacuumsourcetothelay-upduringaconsolidationor
and process dependent and are beyond the scope of this guide.
debulking cycle.
6.2 Laminate quality is directly related to the prevention of
3.2.33 warp surface, n—the ply surface which shows the
contamination during lay-up and processing.
larger area of warp tows with respect to filling tows. Fabrics
where both surfaces show an equal area of warp tows with
7. Apparatus and Materials
respect to filling tows do not have a warp surface.
NOTE 1—Thissectionprovidesalistingofapparatusandmaterialitems
3.2.34 warp nested, n—warp plies alternated in the pattern
that have been shown to be acceptable. The list is not meant to be all
warp surface up, warp surface down.
inclusive, but may be helpful to novice users.
7.1 Equipment:
4. Summary of Guide
7.1.1 Lay-up Environment/Tools:
4.1 This guide describes the general process flow for prepa-
7.1.1.1 Tables—Tables should be1m[3ft]in height (or
ration of flat composite panels and provides specific recom-
adjustable tables) with ample area for lay-up. The table should
mended techniques that are generally suitable to laminated
be accessible from all sides. The table surface should have a
fibrous organic polymer matrix composites for each of the
fully supported metal or wood undersurface. The table surface
process steps to test specimen fabrication.
shouldbeof(1)safetyglasswithedgesprotectedbyaluminum
4.2 The specific techniques included in this guide are the
angle plate or (2) A toughened transparent plastic sheet.
minimum recommended for common composite material sys-
7.1.1.2 Convenient accessibility of lay-up materials—Wall
tems as represented in the scope of this guide. For a given
racks hold bulk cloth, TFE, and other expendable bagging
application other techniques may need to be added or substi-
materials.Theserackstypicallyconsistofasteelrodwhichcan
tuted for those described by this guide.
hold a roll of material. The rods should be able to accommo-
date material rolls up to 1.5 m [60 in.] wide. The spacing
5. Significance and Use
between racks should be a minimum of 0.4 m [15 in.] spacing
5.1 The techniques described in this guide, if properly used
between rods with the bottom rod being no closer than 0.6 m
in conjunction with a knowledge of behavior of particular [25 in.] to the floor and the top rod being no higher than 2.2 m
material systems, will aid in the proper preparation of consoli-
[85 in.] from the floor. Cabinets and drawers hold other lay-up
dated laminates for mechanical property testing. materials such as sealants, spare tape, vacuum couples, hoses,
5.2 The techniques described are recommended to facilitate caul plates, thermocouple wire, and so forth. These should be
the consistent production of satisfactory test specimens by compartmentalized for easy access.
minimizing uncontrolled processing variance during specimen 7.1.1.3 Vacuum Supply—Overhead piping for vacuum with
fabrication. a flexible hose reel over the table has been found to be
D5687/D5687M–95 (2002)
satisfactory. The vacuum pump should be located within 45 m applications above 230°C [450°F]. Peel plies are generally
[150 ft] of the lay-up site. used when secondary bonding is required.
7.1.1.4 Cleanliness and Airborne particulates—Controlling
7.2.2.2 TFE co
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