ASTM D5224-00(2006)

Standard Practice for Compression Molding Test Specimens of Thermosetting Molding Compounds

SIGNIFICANCE AND USE
The conditions at which compounds are molded are known to influence the properties of the specimens. The degree of cure, elimination of knit-lines between particles, density of the part, and degradation of the polymer are among those factors which will be affected by the molding conditions. Thus it is important to hold to a standard set of conditions in order to have a valid comparison of properties between different compounds and different batches of the same compound.
If the molded specimens show evidence of low-density areas due to trapped gases, they should be discarded. A breathe step may be necessary to eliminate this situation. It is critical that the breathe step be as brief as possible to avoid precuring of the compound before full pressure is applied. This would lead to poorly “knitted” areas and lower strength in the molded specimen.
SCOPE
1.1 This practice covers the general principles to be followed when compression molding test specimens of thermosetting molding compounds, such as phenolics, aminoplastics, melamine phenolics, epoxies, and unsaturated polyesters.
Note 1—This standard is similar in content (but not technically equivalent) to ISO 295-1974 (E).
1.2 Molding conditions are given for amino, phenolic, and allyl molding compounds. Materials specification standards should always be consulted to determine whether the material to be molded has any special requirements.
1.3 The values stated in SI units are to be regarded as standard. The values in brackets are given for information only.
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.

General Information

• Status: Historical
• Publication Date: 14-Mar-2006
• ICS: 77.180 - Equipment for the metallurgical industry
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.09 - Specimen Preparation

Relations

• Replaces: ASTM D5224-00 - Standard Practice for Compression Molding Test Specimens of Thermosetting Molding Compounds
• Effective Date: 15-Mar-2006
• Replaced By: ASTM D5224-12 - Standard Practice for Compression Molding Test Specimens of Thermosetting Molding Compounds
• Effective Date: 01-Apr-2012
• Referred By: ASTM D704-99(2020) - Standard Specification for Melamine-Formaldehyde Molding Compounds
• Effective Date: 15-Mar-2006
• Referred By: ASTM D6289-13(2019) - Standard Test Method for Measuring Shrinkage from Mold Dimensions of Molded Thermosetting Plastics
• Effective Date: 15-Mar-2006
• Referred By: ASTM D1636-21 - Standard Specification for Allyl Molding Compounds
• Effective Date: 15-Mar-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D5224–00 (Reapproved 2006)
Standard Practice for
Compression Molding Test Specimens of Thermosetting
1
Molding Compounds
This standard is issued under the fixed designation D5224; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice covers the general principles to be fol- 3.1 Definitions—For definitions of terms pertaining to plas-
lowed when compression molding test specimens of thermo- tics used in this practice, see Terminology D883.
setting molding compounds, such as phenolics, aminoplastics, 3.2 Definitions of Terms Specific to This Standard:
melamine phenolics, epoxies, and unsaturated polyesters. 3.2.1 breathe step, n—in plastics molding, the part of the
molding cycle in which the mold halves are opened momen-
NOTE 1—This standard is similar in content (but not technically
tarily, prior to curing, to release volatiles from the molded part.
equivalent) to ISO 295-1974 (E).
3.2.2 skin, n—in plastics molding, the thin resin-rich layer
1.2 Molding conditions are given for amino, phenolic, and
(skin) on the surface of the molded part.
allyl molding compounds. Materials specification standards
3.2.3 skin effect, n—in plastics testing, the positive or
should always be consulted to determine whether the material
negative effect the skin may have on the results of some
to be molded has any special requirements.
standard tests.
1.3 The values stated in SI units are to be regarded as
standard.Thevaluesinbracketsaregivenforinformationonly.
4. Summary of Practice
1.4 This standard does not purport to address all of the
4.1 Compression molded test specimens are produced by
safety concerns, if any, associated with its use. It is the
loading a mold cavity with some form of the molding material,
responsibility of the user of this standard to establish appro-
applying a specified pressure to the mating surface for a
priate safety and health practices and determine the applica-
specified time and at a specified temperature, and then remov-
bility of regulatory limitations prior to use.
ing the part from the cavity.
2. Referenced Documents
5. Significance and Use
2
2.1 ASTM Standards:
5.1 The conditions at which compounds are molded are
D638 Test Method for Tensile Properties of Plastics
known to influence the properties of the specimens.The degree
D883 Terminology Relating to Plastics
of cure, elimination of knit-lines between particles, density of
D958 Practice for Determining Temperatures of Standard
the part, and degradation of the polymer are among those
3
ASTM Molds for Test Specimens of Plastics
factors which will be affected by the molding conditions. Thus
2.2 ISO Standard:
it is important to hold to a standard set of conditions in order
ISO 295 Plastics—Compression Molding Test Specimens
to have a valid comparison of properties between different
4
of Thermosetting Materials
compounds and different batches of the same compound.
4
ISO 3167 Plastics—Multipurpose—Test Specimens
5.2 If the molded specimens show evidence of low-density
areas due to trapped gases, they should be discarded.Abreathe
1
step may be necessary to eliminate this situation. It is critical
ThispracticeisunderthejurisdictionofASTMCommitteeD20onPlasticsand
is the direct responsibility of Subcommittee D20.09 on Specimen Preparation. that the breathe step be as brief as possible to avoid precuring
Current edition approved March 15, 2006. Published March 2006. Originally
of the compound before full pressure is applied. This would
approved in 1992. Last previous edition approved in 2000 as D5224 - 00. DOI:
lead to poorly “knitted” areas and lower strength in the molded
10.1520/D5224-00R06.
2
specimen.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on 6. Apparatus
the ASTM website.
3 6.1 Molds:
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. 6.1.1 The mold shall be made of steel, able to withstand the
4
ISO Standards Handbook 21, Vol 2, Plastics, 2nd Ed., 1990, available from
molding temperatures and pressures. The mold shall be de-
AmericanNationalStandardsInstitute(ANSI),25W.43rdSt.,4thFloor,NewYork,
signed such that the compressive mold force is transferred to
NY 10036.
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D5224–00 (2006)
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