Buy ASTM D TEST METHODS FOR CARBON BLACK – DISPERSION IN RUBBER from SAI Global. However, unvulcanized compounds should be compressed in a mold for 5 minutes at °C to remove the air holes before testing. ASTM D , Method B , is a. ASTM D Standard Test Methods for Carbon Black-Dispersion in Rubber.
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Rubbers that contain relatively high amounts of inorganic pigments are particularly prone to cause knife chipping and may require a fresh knife for each different specimen. For specimens that are too soft to be microtomed at liquid CO2 temperatures, pour a little liquid nitrogen onto the specimen block while it is in position on the freezing stage. However, before using either of these latter methods, astmm stock should be pressed out to eliminate most asstm the air holes.
ASTM D – 14 Standard Test Methods for Carbon Black—Dispersion in Rubber
The tear may be initiated aastm a small cut. The black clumps of carbon are easily distinguished from the background usually brown in tone and from the knife marks, which appear as long streaks.
Count all squares that are at least half covered by an agglomerate of carbon black. Lenses should include two wide? The immersion time depends, primarily, on the type of polymer and the type and loading of carbon black. The test is applicable to the analysis of carbon black dispersion in compounds that contain other? No other units of measurement are included in this standard. The section will be curled up in a small tight roll.
Refreeze during the sectioning operation whenever necessary. It is the responsibility of the user of atm standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Next, reimmerse the specimen mount in liquid nitrogen for the required amount of time. If the section tends to slip on the s2663, hold one axtm lightly with a mounted needle. This constant eliminates high frequency electronic or vibrational noise which may be dependent on the location of the instrument.
Standard Test Methods for Carbon Black-Dispersion in Rubber
This setting will remain constant for subsequent specimens which can ast be mounted in place by gently lifting the stylus with a? The upper jaw of the pliers should have raised pressure points at both ends of the gripping surface, while the lower jaw should have a raised area in the center.
Then proceed as in 7. The time increases with decreasing black loading, increasing particle diameter, and decreasing second-order transition temperature of the polymer.
Position the drive unit on the vibration isolator slab prior to this procedure. D enough subsequently to form buttons about 10 mm in diameter and about 2 to 3-mm deep thoroughly atsm dicumyl peroxide.
Prior to fracture, it is also important that the glass be free of dirt. Then cover the sections with cover glasses, and seal with tape, or a bit of zstm at each corner. This applies only to vulcanized specimens.
For each letter rating the amount of undispersed black is the same throughout the six agglomerate size categories.
Lower or higher values for C may be used at the discretion of the operator.
Standard Test Methods for Carbon Black—Dispersion in Rubber
S 5 area swelling factor from the action of the solvent used to uncurl the sections a ratio of the section area after swelling to the area before swellingand L 5 volume percentage of black in the compound. Also, if too much time is taken, the rubber specimen will soften and will have to be refrozen. Asm test result range measured dispersion d6263 was from approximately 35 to To accomplish this, press the rubber into a slab between thin sheets of plastic in a mold at a pressure of about 1.
Test Method A—Visual Inspection. Record this asstm along with the sample area before swelling. These instances would include in particular the evaluation of compounds at very low dispersion levels which are known to be of poor quality by simple visual inspection of the sections. Then assign the most closely matched numerical rating to each compound being rated.
Standard – Standard Test Methods for Carbon Black-Dispersion in Rubber ASTM D –
More detailed information atm freezing times is best compiled by individual operators on their own particular specimens. A large sheet of glass should? Summary of Test Method Careful manipulation of the solvent wet brush will unroll and spread the section out?
Each measurement was made as a 2.
This is best prepared by individual operators, since dispersion requirements may vary greatly for different types of compounds. However, as a safety precaution, it is recommended that the stage be specially reinforced to withstand the high vapor pressure of liquid carbon dioxide.
Fracture in this manner is preferred over simply breaking off mm sections one at a time. Record the values for these two points. Cure in accordance with Practice D If you feel that your comments have not received a fair hearing you should make d266 views known to the ASTM Committee on Standards, at the address shown below.
Thickness should be preferably about 6 mm. If convenient, more than one operator should rate the samples.
Next, fracture along the score line using the glass pliers. Ratings are made against a set of standard photographs Fig. If the surface is uneven or contains any severe cutting artifacts, repeat the cutting operation with a new razor blade. Then, score the resultant mm square of glass across the diagonal, keeping the mark a bit off center so that the potential knife edge will be formed slightly away from the FIG.
Certain compounds for example, NR and IR are particularly prone to very small black agglomerations which are difficult to resolve by the Visual Inspection Method. With a brush dipped in FIG.