ASTM C782-2018 pdf free download

ASTM C782-2018 pdf free download.Standard Test Method for Softness of Preformed Tape Sealants
1. Scope
1.1 This test method describes a laboratory procedure for determining the softness of preformed tape sealants. N OTE 1—Cone penetration methods applicable to greases and to petrolatum are described in Test Methods D217 and D937. Test Method D2451 also uses a penetration technique for determining the degree of set in sash glazing compounds. 1.2 The values stated in SI units are to be regarded as standard. Temperature values are also provided (in parenthe- ses) in degrees Fahrenheit. 1.3 The subcommittee with jurisdiction is not aware of any similar ISO standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 The preformed tape sealant specimen is allowed to equilibrate at standard conditions. A standard needle under a defined load is placed on the specimen for 5 s. The penetration of the needle into the preformed tape sealant is measured. Multiple readings are recorded and averaged.
5. Significance and Use
5.1 Preformed tape sealants are tacky, deformable solids that are used under compression between two substrates in a variety of sealing applications. This procedure measures the softness of a preformed tape sealant and gives an indication of the preformed tape sealant’s ease of compression during installation. The resistance to penetration may also give an indication of the toughness of the preformed tape sealant.
6. Apparatus
6.1 Needle Penetrometer, as described in Test Method D5, with a certified needle. N OTE 2—Test Method D5 describes the needle method for determining the penetration of bituminous material; Test Method D1321 describes a similar method for use with petroleum waxes, but a different needle is used. 6.2 Stop Watch or Timing Mechanism, for the penetrometer. 6.3 Thermometer, to measure the temperature of the test specimen in the vicinity ofthe temperature ofthe test. For tests at 23 6 0.5°C (73 6 1°F) a thermometer conforming to the requirements prescribed in Specification E2251 is recommended, such as ASTM Saybolt Viscosity Thermometer 17C (or 17F) having a range from 19 to 27°C (66 to 80°F).
10. Procedure
10.1 Place the penetrometer in a level position with the shaft set up so that there is a total moving load of 100 g. This load is comprised of the 2.5-g needle, the 47.5-g shaft, and an extra weight of 50 g placed atop the shaft. 10.2 Raise the penetrometer shaft until the pointer on the dial reads exactly zero. Lightly tap the indicator dial control lever to ensure that this reading is maintained. 10.3 Position the test specimen on the penetrometer so that it is approximately centered under the needle. Then lower that part of the apparatus consisting of the dial gage and shaft with the needle point until the needle point just makes contact with the top surface of the specimen. N OTE 4—Ifthe specimen is made from preformed tape sealant less than 13 mm wide, care should be taken to see that the needle is not placed in the joint between two abutting strips of preformed tape sealant. 10.4 Quickly release the needle for 5 s. 10.5 Adjust the apparatus to measure the distance through which the needle penetrated the specimen. Record the amount of penetration to the nearest 0.1 mm. 10.6 Wipe the penetrometer needle clean. Following the same procedure, take at least two additional penetration read- ings for the same preformed tape sealant specimen. If readings are taken on the same specimen surface, the penetration should be made at points at least 7 mm from other readings. The amount of penetration for each reading should be recorded separately and the needle should be wiped clean after each reading. N OTE 5—Unusually low readings, caused by the needle striking an embedded core or other hard material, and unusually high readings caused by penetrating a void or air pocket shall be considered invalid and disregarded.