ASTM_D_1916_-_93_1997.pdf

Designation:D 1916 93(Reapproved 1997)Standard Test Method forPenetration of Adhesives1This standard is issued under the fixed designation D 1916;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the pen-etration under pressure of adhesives used in systems where atleast one of the adherends is porous.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with 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:D 907 Terminology of Adhesives23.Terminology3.1DefinitionsMany terms in this test method are de-fined in Terminology D 907.3.1.1 adhesive penetration,nthe entering of an adhesiveinto a porous adherend.4.Significance and Use4.1 This test method is useful in selecting adhesive systemsfor a particular application,and in modifying adhesive systemsto obtain maximum performance without excessive penetrationof the adhesive into the substrate of the adherends.It isparticularly adaptable to use with starch or starch-base adhe-sives commonly used in the paper converting industry.Furtherdevelopment may well result in its usefulness with other typesof adhesives.5.Apparatus5.1 Penetration Tester,as shown in Fig.1,constructed so asto allow a section of round steel bar stock 25 mm(1 in.)indiameter and weighing 700 g(the hammer),to fall freelythrough a distance of 0.8 m(31 in.)upon a steel disk(the anvil)6 mm(14in.)thick and 51 mm(2 in.)in diameter,in such amanner as to strike the anvil at right angles.Dimensions of theguiding tube and of the section of bar stock,as shown in Fig.1,permit free fall of the bar stock without undue sidewaysmovement.Cut the bottom end of the bar stock at right anglesto the longitudinal axis,within 0.051-mm(0.002-in.)tolerance,and finish to 32 microfinish.5.2 Filter Paper,coarse,rapid-filtering type,cut into51-mm(2-in.)disks.5.3 Syringe,hypodermic,1-mL capacity,without needle.5.4 Densitometer.35.5 Compensating Planimeter,unit range 0.01 in.2(6.5mm2).6.Reagent6.1 Staining Reagent,suitable for the adhesive being tested.For adhesives containing starch,an iodine solution containing2.0 g of potassium iodide and 0.20 g of iodine in 3 Lof distilledwater is appropriate.Some adhesives that are basic in pH mustbe stained with phenolphthalein or other suitable indicatorsolution.1This test method is under the jurisdiction of ASTM Committee D-14 onAdhesives and is the direct responsibility of Subcommittee D14.10 on WorkingProperties.Current edition approved July 15,1993.Published September 1993.Originallypublished as D 1916 61 T.Last previous edition D 1916 88.2Annual Book of ASTM Standards,Vol 15.06.3A MacBeth-Ansco Color Densitometer,Model 12,has been found satisfactoryfor this purpose.Metric Equivalentsin.11116231mm252751787(0.8 m)FIG.1 Penetration Tester1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.7.Procedure7.1 Place five disks of filter paper,stacked one on top ofanother,upon the anvil at the bottom of the tube.Apply 0.1 mLof the adhesive to be tested to the center of the bottom end ofthe hammer(bar stock)using the 1-mL syringe(Note 1).If thehammer has been inverted for this purpose,reinvert thehammer so that the adhesive is now on the bottom and place inthe testing apparatus with the handle of the hammer resting inthe notch provided for it(Note 2).NOTE1The hammer may be inverted for this purpose.NOTE2Inversion of the hammer without loss of adhesive may requiresome practice.If any adhesive is lost during this step,restart the test.7.2 Thirty seconds after the adhesive is applied to thehammer,release the hammer from this position,allowing it tofall freely and strike the anvil.NOTE3Application of the adhesive to the hammer and release of thehammer is accomplished quickly in order to reduce loss of solvent.7.3 Immediately raise the hammer,remove and separate thestack of filter papers,then clean the hammer with a damp clothor sponge.7.4 Stain the filter papers by applying a slight excess of anappropriate staining solution.Allow the stained papers toair-dry for 1 h prior to evaluating density with the densitometer.A minimum of five different tests of each adhesive is recom-mended to obtain significant and checkable results.NOTE4Variables making multiple readings necessary include differ-ences in porosity and direction of fibers in filter paper.These factors causesome distortion of color intensity within a spot and spot contour from levelto level.7.5 Carefully outline the stained areas on each level with avery sharp No.2 lead pencil.Do not indent the paper,andavo