ASTM D6265-98(2003)
(Practice)Standard Practice for Separation of Contaminants in Polymers Using an Extruder Filter Test
Standard Practice for Separation of Contaminants in Polymers Using an Extruder Filter Test
SIGNIFICANCE AND USE
Presence of paper, metal, gels, incompatible polymer, or other extraneous contamination in polymers, including recycled polymers, may cause problems with extrusion and subsequent processing of the material. This procedure is useful for separating gross contaminants from polymers. For example, the procedure is useful for determining the quality of resins to be used in fiber applications. If desired, the isolated contaminants may be subsequently identified by the appropriate visual or instrumental procedures.
SCOPE
1.1 This practice covers a means to separate the unmolten particles, gels, and impurities contaminating a polymer sample. The procedure may be used to remove gels and incompatible materials that may cause imperfections in the final extruded product. Under pressure, most gels will break up or deform and pass through a wire mesh filter, however high molecular weight gels may not break up or deform.
1.2 If desired, materials isolated on a wire mesh filter can subsequently be identified by spectroscopic or other analytical means.
Note 1—Although not presented as a quantitative method, the procedure presented in this practice may be used to provide quantitative results at the discretion of the user. The user assumes the responsibility to verify the reproducibility of quantitative results. Detection limit depends on the mesh size of the filter screen, but the procedure is generally applicable to the separation of immiscible contaminants present at concentrations greater than 0.1 %.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 This standard does not purport to address 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. For specific hazards statements, see Section 8.
Note 2—There is no equivalent ISO standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D6265–98 (Reapproved 2003)
Standard Practice for
Separation of Contaminants in Polymers Using an Extruder
Filter Test
This standard is issued under the fixed designation D 6265; 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 the Proper Use of Recycled Plastics
E 380 Practice for Use of the International System of Units
1.1 This practice covers a means to separate the unmolten
(SI) (the Modernized Metric System)
particles,gels,andimpuritiescontaminatingapolymersample.
The procedure may be used to remove gels and incompatible
3. Terminology
materials that may cause imperfections in the final extruded
3.1 The terminology used in this practice is in accordance
product.Underpressure,mostgelswillbreakupordeformand
with Terminology D 1600 and Guide D 5033. Units and
passthroughawiremeshfilter,howeverhighmolecularweight
symbols are in accordance with Practice E 380.
gels may not break up or deform.
1.2 If desired, materials isolated on a wire mesh filter can
4. Summary of Practice
subsequently be identified by spectroscopic or other analytical
4.1 As polymer passes through a wire mesh filter of known
means.
2 2
area and porosity (for example, 0.00032 m [0.049 in.]ofa
NOTE 1—Although not presented as a quantitative method, the proce-
325 mesh screen) positioned in line at the end of an extruder
dure presented in this practice may be used to provide quantitative results
barrel, the filter becomes blocked by impurities and gels. This
at the discretion of the user. The user assumes the responsibility to verify
procedure is used to remove gels and contaminants that may
the reproducibility of quantitative results. Detection limit depends on the
result in undesirable imperfections in the extruded product.
mesh size of the filter screen, but the procedure is generally applicable to
This blockage results in a proportional rise in the pressure
the separation of immiscible contaminants present at concentrations
greater than 0.1 %. behind the filter. Although this Practice is not designed to
provideanyquantitativeestimateofthelevelofcontamination,
1.3 The values stated in SI units are to be regarded as the
the rate of this pressure rise may be correlated to the level of
standard.
contamination through appropriate experiments.
1.4 This standard does not purport to address the safety
concerns, if any, associated with its use. It is the responsibility
5. Significance and Use
of the user of this standard to establish appropriate safety and
5.1 Presence of paper, metal, gels, incompatible polymer, or
health practices and determine the applicability of regulatory
other extraneous contamination in polymers, including re-
limitations prior to use. For specific hazards statements, see
cycled polymers, may cause problems with extrusion and
Section 8.
subsequent processing of the material. This procedure is useful
NOTE 2—There is no equivalent ISO standard.
forseparatinggrosscontaminantsfrompolymers.Forexample,
the procedure is useful for determining the quality of resins to
2. Referenced Documents
be used in fiber applications. If desired, the isolated contami-
2.1 ASTM Standards:
nants may be subsequently identified by the appropriate visual
D 1238 Test Method for Flow Rates of Thermoplastics by
or instrumental procedures.
Extrusion Plastometer
D 1600 Terminology for Abbreviated Terms Relating to 6. Apparatus
Plastics
6.1 Extruder, designed to deliver a continuous supply of
D 5033 GuidefortheDevelopmentofStandardsRelatingto
molten resin to a filter at a uniform rate with good temperature
control. An extruder with 25 to 64-mm barrel has been found
to be useful.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.95 on Recycled Plastics.
Current edition approved July 10, 2003. Published September 2003. Originally
approved in 1998. Last previous edition approved in 1998 as D 6265 - 98. Annual Book of ASTM Standards, Vol 08.03.
2 4
Annual Book of ASTM Standards, Vol 08.01. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6265–98 (2003)
6.1.1 Internal Rod Die, to fix the filter area. Fig. 1 shows a
typical 6.4 mm diameter die that gives a filter area of 12.45
mm .
6.1.2 Breaker Plate or Screen Holder—A typical configu-
ration is shown in Fig. 2.
6.1.3 Pressure Transducer, installed in-line before the
screen pack and connected to digital readout and a chart
recorder.
6.1.4 Melt Thermocouple, installed before or after the
screen pack and connected to a chart recorder.
6.1.5 High Pressure Alarm and Rupture Disk.
6.1.6 Split Clamp, to permit ready access to the screens,
sizing die, and breaker plate.
6.1.7 Swing Gate, to support the split clamp (6.1.6) during
screen changes.
NOTE 3—Although desirable, a swing gate is not always available on
NOTE—Drill 25 holes; use #60 drill.
small extruders.
FIG. 2 Schematic of the Breaker Plate
6.2 Screens, 25.4 mm diameter (60 mesh (0.251 mm open-
ing), 100 mesh (0.152 mm opening), 200 mesh (0.076 mm
8.2 Always wear thermally insulated gloves when handling
opening), 325 mesh, or other appropriate sizes).
hot polymer or working directly with the heated areas of the
6.3 Strip Chart Recorder, with a speed of 15 cm/h.
extruder.
6.4 Balance, capable of weighing with accuracy of 6 0.1
kg.
9. Procedure
6.5 Torque Wrench, with ratchet drive attachment.
9.1 Turn on the power to the extruder and turn on the feed
6.6 Thermally Insulated Gloves.
throat cooling water.
6.7 Spatulas and Scrapers, brass, assorted sizes for remov-
9.2 Set extruder temperature controllers to maintain the
ing molten polymer from equipment.
barrelattheappropriatetemperatureforthepolymer(seeTable
1).
7. Materials
9.3 Wait at least 30 min after achieving melt temperature
7.1 Virgin Polymer, free of gels and contaminants, for
before starting the extruder.
purging the extrude
...
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