1、Designation: D6336 11 (Reapproved 2017)Standard Practice forEvaluation of Flushing Vehicles for Pigment Wetting Using aVacuum Modified Sigma Blade Mixer1This standard is issued under the fixed designation D6336; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers guidelines for the evaluations offlushing vehicles for p
3、igment dispersion using a vacuummodified sigma blade mixer, or vacuum flusher.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with
4、its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile
5、Under the Test Conditions) in PigmentsD387 Test Method for Color and Strength of ChromaticPigments with a Mechanical MullerD1316 Test Method for Fineness of Grind of Printing InksBy the NPIRI GrindometerD2066 Test Methods for Relative Tinting Strength of Paste-Type Printing Ink DispersionsD2067 Test
6、 Method for Coarse Particles in Printing InkDispersionsD4017 Test Method for Water in Paints and Paint Materialsby Karl Fischer MethodD4040 Test Method for Rheological Properties of PastePrinting and Vehicles by the Falling-Rod ViscometerD4361 Test Method for Apparent Tack of Printing Inks andVehicl
7、es by a Three-Roller Tackmeter3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 additives, nvarious materials that are used in rela-tively small quantities to condition the pigment or vehicle.3.1.2 break, nthe action that takes place when water isseparated from the pigment in a
8、presscake.3.1.3 flushed color, na color base in paste form preparedby flushing.3.1.4 flusher, na mixing device that has two sigma shapedagitator blades parallel to each other, turning in opposingdirections at different speeds.3.1.4.1 DiscussionThe mixing action of a flusher is that ofkneading.3.1.5
9、flushing, na method of transferring pigments fromdispersions in water to dispersions in oil by the displacement ofthe water by oil.3.1.5.1 DiscussionThe resulting dispersions of flushingare known as flushed colors.3.1.6 pigment, nthe fine solid particles of colorant used togive color to printing ink
10、s.3.1.6.1 DiscussionThe pigment particles are substantiallyinsoluble in the vehicle and in water.3.1.7 presscake, na mixture of pigment and water formedinto a cake by passing through a filter press under pressure.3.1.8 vacuum cycle, nthe time a flush is under vacuum toremove entrapped water.3.1.9 ve
11、hicle, nthe liquid portion of an ink that holds andcarries the pigment, provides workability and drying propertiesand binds the pigment to the substrate after the ink has dried.4. Summary of Practice4.1 Vehicle, pigment presscake, and additives are added intoa sigma blade mixer and mixed until the w
12、ater is displacedfrom the pigment presscake.4.2 Step 4.1 is repeated two or three times until the capacityof the flusher has been reached.4.3 The flusher is then sealed and a vacuum applied until thedispersion (flush) is free of moisture.NOTE 1Lithol rubine pigment undergoes a color conversion when1
13、This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.37 on Ink Vehicles.Current edition approved Feb. 1, 2017. Published February 2017. Originallyapproved in 1998. Last previous edi
14、tion approved in 2011 as D6336 11. DOI:10.1520/D6336-11R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Co
15、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Interna
16、tional Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1essentially all water is removed.4.4 Vehicle solvent and additives are added to adjust thestrength, shade and body of the dispersion (flush) to that of astandard dispersio
17、n (flush).5. Significance and Use5.1 By following this practice it is possible to make repro-ducible flushes when using the same raw materials. Therefore,if someone wishes to evaluate the effect a different rawmaterial has on a flush, it is possible to evaluate this effect bynoting the change that o
18、ccurs from a control flush to theexperimental flush. This change can be, but is not limited to;such things as strength after vacuum, grind, grit, gloss etc. Thispractice can be used by ink companies, pigment companies orvarnish companies. This practice is not meant to give absolutevalues but is mean
19、t to be used as a relative practice in which acontrol flush is made using a standard formula and theexperimental flush is compared to the control flush. Thispractice is not meant to determine the absolute performance ofa formula in production. Again it can be used to give a relativeidea of how a for
20、mula will perform in production when acorrelation has been established between laboratory flushingand production flushing.6. Apparatus6.1 Laboratory Sigma Blade Flusher, typically 1-L (1-qt) to4-L (1-gal) capacity.6.2 Vacuum Pump, capable of obtaining a vacuum in theflusher of 69 cm (27 in.) to 76 c
21、m (30 in.).6.3 Wide Blade Spatula, typically 5 by 10 cm (2 by 4 in.).6.4 Spatula, typically 2.5 by 7.5 cm (1 by 3 in.).6.5 Scale, capable of weighing up to 3 kg accurate to 1 g.6.6 Scale, capable of weighing up to 1 kg, accurate to 1 g.7. Materials7.1 Presscake.7.2 Flushing Vehicle(s).7.3 Experiment
22、al Vehicle.7.4 Flushing Additives.8. Procedure8.1 Fig. 1 illustrates a typical formula for a 1-L laboratoryflusher.NOTE 2It is common practice for formulas to be based on the amountof pigment calculated on a dry basis and not on the weight of presscake,since the amount of water in the presscake will
23、 vary from batch to batch.For example, a presscake can be referred to as 25 % dry or 25 % solids.This means that for every 100 kg of presscake there are 25 kg of pigmentand 75 kg of water. Usually the entire quantity of presscake to be flushedwill not fit in the flusher at one time. If this is the c
24、ase, it is necessary toflush the required amount of pigment in a succession of breaks (see Fig.1).NOTE 3Many formulas call for two or more kinds of oil or varnish orresin solution etc. Directions are usually very specific as to how muchshould be used, when the various items should be added, and the
25、order inwhich they are added. It is normal practice to add these items in the sameorder as shown on the formula. The vehicle having the best pigmentwetting property is usually added first. In some formulas, however,judgment is left to the operator, as predictions cannot be made.NOTE 4Flushing aids a
26、re very effective and should be used with careand good judgment.8.2 First Break:8.2.1 Add prescribed quantity of presscake to the flusher.8.2.1.1 The presscake should be analyzed for dry weight orsolids according to Test Methods D280.8.2.1.2 All presscake should be weighed before it is chargedto the
27、 flusher.8.2.2 Agitate for 2 to 5 min. If using a multispeed flusher,agitate at low speed for 1 to 2 min then at high speed for 2 to5 min.8.2.3 Add flushing additive(s) if required.8.2.4 Add vehicle in small quantities until break occurs.Remember you can always put vehicle in but never take it out.T
28、herefore, always work the vehicle into the presscake wellbefore adding more.8.2.5 When the flush mass begins to form (water is flushedout) continue to mix until the water clears, then drain.8.2.6 Run the flusher on high speed for 30 to 45 s and drainagain. Do this until no more water is flushed from
29、 the system.NOTE 5First breaks generally use 45 to 55 % of the pigment and 55to 60 % of the vehicle. First breaks are usually soft so it is very importantto drain well. Also it is important that the mixers sides should be scrapeddown thoroughly during the first break and all subsequent breaks, to ma
30、kesure all pigment and presscake are mixed in properly. Proper draining willshorten the vacuum cycle.8.3 Other Breaks:8.3.1 Charge the required amount of presscake and mixthoroughly. No vehicle is to be added until the presscakecharged has been mixed in well. The flush should have a dryappearance be
31、fore any vehicle is added.8.3.2 When the charged presscake has been thoroughlymixed, add the vehicle in small amounts until the break occurs.Use the minimum amount of vehicle to obtain the break.8.3.3 After the break occurs run the batch with a stiff body(high viscosity) for 10 to 15 min. When the w
32、ater clears drainonce or twice.8.3.4 Repeat 8.3.1 8.3.3 until all the required amount ofpresscake has been added.NOTE 6Typically subsequent breaks will take about 20 to 25 %pigment per break. The second break will take more pigment than the thirdbreak and, if needed, the fourth break will take less
33、pigment than the thirdbreak etc.NOTE 7Typically the second break will take about 20 to 25 % of thevehicle and the third and all subsequent breaks will take little or novehicle.D6336 11 (2017)2FIG. 1 Development Flushing FormD6336 11 (2017)38.4 Reduction:8.4.1 Add vehicle or solvent, or both, to the
34、flush until theflush is just soft enough to mix in the flusher. If the flush tendsto ride above the sigma blades of the flusher, the flush is tooheavy. If the flush appears too soft when mixing, it is too lowin viscosity.8.4.2 Drain any water that appears during the reduction ofthe batch.NOTE 8Reduc
35、tion is the reducing of the body of the batch so it mixesproperly under vacuum. A poor reduction can affect the grind and strengthwhen the batch is held under vacuum. It is not always necessary to reducea batch if it mixes properly under vacuum.8.5 Vacuum:8.5.1 Seal the flusher so it is airtight, pr
36、eferably in such away the flush can be observed while mixing under vacuum.8.5.2 Apply vacuum until 60 to 70 cm of mercury isobtained. The higher the vacuum the better, but make sure that635 mm of mercury is the minimum used.NOTE 9The dryness of a flush can usually be determined by the lackof condens
37、ation on the walls and cover inside the flusher. If there is anydoubt about the dryness of a batch, determine the moisture content inaccordance with Test Method D4017. For a flush to be considered drythere should be less than 2 % water remaining.8.6 Standardization:8.6.1 After the flush is thoroughl
38、y dried, take a sample anddetermine the strength in accordance with Test Method D387.8.6.2 Based on the after vacuum strength, blend the flush soit is comparable to the control for strength, viscosity, and tack.Determine strength in accordance with Test Methods D2066,viscosity in accordance with Tes
39、t Method D4040, and tack inaccordance with Test Method D4361.NOTE 10It is suggested that a small sample of the batch be blended todetermine the proper combination of vehicles or solvent, or both, neededto achieve a comparable product to the control. Then use this formula toblend the batch in the flu
40、sher. The formula of the experimental flushshould be as close to the formula of the control as possible.9. Report9.1 Report the following information:9.1.1 After Vacuum Strength:9.1.1.1 In accordance with Test Methods D2066, determinethe strength of the flush after the vacuum cycle has beencompleted
41、. Report the after vacuum strength of the controlflush and the after vacuum strength of the experimental flush.Report the difference of these two flushes by subtracting theafter vacuum strength of the control flush from the aftervacuum strength of the experimental flush. This is the relativeafter va
42、cuum strength.9.1.1.2 Calculate the true strength of the experimental flushas follows:True Strength 5 percent strength experimental flush 3 (1)percent pigment in controlpercent pigment in experimental flushNOTE 11The use of 9.2 9.5 is left to the discretion of the operator.Other tests may be substit
43、uted for these tests if the operator feels they aremore appropriate.9.2 Grind:9.2.1 Determine the grind of the standardized control flushand the grind of the experimental flush in accordance with TestMethod D1316. Report both grinds.9.3 Grit:9.3.1 Determine the grit of the standardized control flush
44、and the standardized experimental flush in accordance withTest Method D2067. Report both grit results.9.4 Tack:9.4.1 Determine the tack of the standardized control flushand the standardized experimental flush in accordance withTest Method D4361. Report both tack readings.9.5 Viscosity:9.5.1 Determin
45、e the viscosity of the standardized controlflush and the standardized experimental flush in accordancewith Test Method D4040. Report both viscosities.NOTE 12Comparing the true strength of the experimental flush givesan indication of the wetting efficiency of the experimental flush. If theexperimenta
46、l flush is stronger than the control, the formula change causedbetter pigment wetting. If the experimental flush is weaker than thecontrol, the formula did not wet the pigment as well.10. Keywords10.1 dispersion; flush; flusher; flushing; pigment; presscake;sigma blade; vehicleASTM International tak
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