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Application of derivat Determination of Miner Determining the water Difference between IEC A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Such extraction test methods are described herein. They are applicable to crosslinked ethylene plastics of all densities, including those containing?
They have been particularly useful for electrical insulations since specimens may be selected from those portions of the insulation most susceptible to insufficient crosslinking. The inch-pound units in brackets are for information only.
Referenced Documents 2. Terminology 3. Summary of Test Methods 4. After extraction, the specimens are removed, dried, and reweighed as directed. The amount of material extracted is calculated and, if desired, swell 1.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applica- 1 These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Subcommittee D Current edition approved April 1, Published April Originally approved in Last previous edition approved in as D — Hence, determination of the gel content provides a means of both controlling the process and rating the quality of?
Any test specimen preparation, conditioning, dimensions, or testing parameters, or a combination thereof, covered in the materials speci? If there are no material speci? Precautions 6. Conditioning 7. Apparatus 8. For one or two determinations at one time, a 2 mL? For several determinations at one time, but not exceeding six, a mL? A bench-top laboratory mill4,5 is satisfactory, although any procedure which will produce a sample of the required?
The extraction thimble, with extra-coarse fritted glass disk sealed in; Kontes , mm body diameter, mm height or equivalent height must subsequently be cut to 75 mm. The fritted disk is extra-coarse with fused edge; Kontes , mm diameter or equivalent. Glass wool 13 to 19 mm thick [1? The extraction thimble assembly rests upon the mm portion of the thimble previously cut off, the latter inserted into the modi?
Reagents 9. Safety Precautions Use only in a ventilated hood. Check the effectiveness of the hood before starting the tests. Do not inhale the vapors. Excessive inhalation of the vapors may cause dizziness or headache, or both. In the event of excessive inhalation, seek fresh clean air. Test Specimens Your comments will receive careful consideration at a meeting of the responsible technical committee,1 which you may attend. D — 01 A—Identi? C—Ring stand clamp.
D—Water inlet. E—Ground-glass or cork joint. F—Large-mouth round-bottom? G—Variable transformer. H—Water outlet. I—Ring stand. J—Decahydronaphthalene or xylene. K—Heating mantle. L—mesh wire cage containing the specimen. Shake this sieved material over a mesh sieve and reject any material that passes through. Procedure Fold this to form a square measuring approximately 40 mm [11?
Fold two sides of this square closed by folding the cloth at the edges about 6 to 7 mm [1? In that manner, a pouch open at the top is obtained. Weigh this pouch W1. Weigh the pouch and specimen W2. Fold over the open side of the pouch and staple the edge to form a cage. Weigh the cage and sample W3. Three hundred? Suspend the cage and specimen in the solvent so that the bottom edge of the cage is almost touching the bottom of the?
A small wire, attached to the cage and extending through the re? Extract the specimen for 6 h in decahydronaphthalene or for 12 h in xylenes. NOTE 3—Since most of the extraction occurs within less than the speci? If this is done, the time of extraction must be reported. For referee tests, extraction time is to be as speci? Cool and weigh W4. If the compound absorbs moisture, cool the specimen in a desiccator before weighing.
NOTE 4—It has been reported that drying time sometimes can be materially shortened if the cage and sample are cooled for 15 min and then are placed either on a suspended screen or on lint-free absorbent material to remove excess solvent before being put into the vacuum drying oven. Scope The test strip used for extraction should be taken next to the conductor only when strand shielding tapes or compounds are not employed.
In high-voltage cable employing strand shielding tapes or compounds, the strip should be shaved as closely as possible along the shielded surface, being careful not to include any of the semiconducting compound see Fig. The outer sections of this strip are discarded, thus leaving only a sample of the material closest to the conductor or shielded surface.
This sample then is cut or diced into pieces measuring approximately 6 by 6 mm [1? For Size 2 AWG and smaller, the dimensions should be proportionately less. Close the pouch by folding over the open side and stapling it to form a cage. However, if there is any doubt about the values obtained with reused extractant, the test should be repeated with fresh extractant.
NOTE 5—If the modi? Calculation NOTE 6—If the fraction of? Report B—Semiconducting strand shield. C—Area most susceptible to insufficient crosslinking. D—Crosslinked polyethylene insulation. E—Specimen for solvent extraction shaded area.
Both measurements are obtained in one test. The degree of crosslinking is not expressed as a percent of total crosslinkability or similar expression, but is judged from swell ratio and percent extract based on experience with the particular polymer-solvent system under consideration. However, this test method permits swell ratio to be determined.
Summary of Test Method The swell ratio and percent extract are calculated from these weight measurements. In the presence of xylene, polyethylene in the density range from 0. Provided that no chemical degradation occurs, the greater the degree of crosslinking the lower the amount of extract lower percent extract. Provided that no chemical degradation occurs, 5 the lower the swell ratio the greater the crosslinking and the lower the molecular weight between crosslinks.
Apparatus Reagents and Materials In case of excessive inhalation, seek fresh clean air.
Application of derivat Determination of Miner Determining the water Difference between IEC
EP2256158A1 - Polymer composition for crosslinked articles - Google Patents
Many important properties of crosslinked ethylene plastics vary with the gel content. Hence, determination of the gel content provides a means of both controlling the process and rating the quality of finished products. Extraction tests permit verification of the proper gel content of any given crosslinked ethylene plastic and they also permit comparison between different crosslinked ethylene plastics, including those containing fillers, provided that, for the latter, the following conditions are met:. Since some oxidative degradation of the material can occur at the reflux temperature of the extractants, a suitable antioxidant is added to the extractant to inhibit such degradation. Before proceeding with this test method, reference should be made to the specification of the material being tested.
Determination of Gel Content and Swell Ratio of Crosslinked Ethylene Plastics
Active view current version of standard. Other Historical Standards. More D The methods described herein are applicable to crosslinked ethylene plastics of all densities, including those containing fillers, and all provide corrections for the inert fillers present in some of those compounds. Test Method B differs from the referee test method only in sample preparation; that is, it requires use of shavings taken at selected points in cable insulation, for example, rather than the ground sample required by the referee test method. They have been particularly useful for electrical insulations since specimens may be selected from those portions of the insulation most susceptible to insufficient crosslinking. The inch-pound units in brackets are for information only.
ASTM D2765 + REDLINE
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