1、TAPPI/ANSI T 831 om-14 OFFICIAL TEST METHOD 1993 REVISED 1999 REVISED 2005 REVISED 2009 REVISED 2014 2014 TAPPI The information and data contained in this document were prepared by a technical committee of the Association. The committee and the Association assume no liability or responsibility in co
2、nnection with the use of such information or data, including but not limited to any liability under patent, copyright, or trade secret laws. The user is responsible for determining that this document is the most recent edition published. Approved by the Standard Specific Interest Group for this Test
3、 Method TAPPI CAUTION: This Test Method may include safety precautions which are believed to be appropriate at the time of publication of the method. The intent of these is to alert the user of the method to safety issues related to such use. The user is responsible for determining that the safety p
4、recautions are complete and are appropriate to their use of the method, and for ensuring that suitable safety practices have not changed since publication of the method. This method may require the use, disposal, or both, of chemicals which may present serious health hazards to humans. Procedures fo
5、r the handling of such substances are set forth on Material Safety Data Sheets which must be developed by all manufacturers and importers of potentially hazardous chemicals and maintained by all distributors of potentially hazardous chemicals. Prior to the use of this method, the user must determine
6、 whether any of the chemicals to be used or disposed of are potentially hazardous and, if so, must follow strictly the procedures specified by both the manufacturer, as well as local, state, and federal authorities for safe use and disposal of these chemicals. Water absorption of corrugating medium:
7、 water drop penetration test 1. Scope and summary 1.1 The water absorptivity of corrugating medium is measured by dropping a drop of water on the surface of a specimen and determining the time in seconds for the drop to penetrate through the sheet and wet the lower surface. 1.2 This method is applic
8、able to corrugating medium as it is commercially produced by all processes. It is generally applicable to relatively unsized (water leaf) containerboards but may not be applicable to more highly sized boards or to grades produced in different grammage (basis weight) than those normally used in corru
9、gating medium. 1.3 Alternative methods which can be performed in the same general time period with equal repeatability do not give the same numerical results, but, in general, will rank the materials in the same order as this method (see Section 9.2). 2. Significance In the past, medium was produced
10、 with semichemical pulp, and water drop could be found to correlate with the medium to liner bondability on a corrugator Todays mediums are made primarily from recycled and kraft fiber. Water drop can vary widely when using these fiber types with no detrimental effects on bondability. 3. Apparatus a
11、nd materials 3.1 Burette, syringe or dropper, which will deliver 20 1 drops/ml of distilled or deionized water. 3.2 Rack or ring stand, to support test specimen. 3.3 Mirror, to place under the rack to observe lower side of specimen. 3.4 Distilled water or deionized water, pH 6.5 to 7.5, 23.0 1.0C (7
12、3.4 1.8F). 3.5 Stopwatch or timer. T 831 om-14 Water absorption of corrugating medium: water drop penetration test / 2 4. Sampling and test specimens 4.1 Select sample according to TAPPI T 400 “Sampling and Accepting a Single Lot of Paper, Paperboard, Containerboard, or Related Product.” 4.2 Precond
13、ition and condition according to TAPPI T 402 “Standard Conditioning and Testing Atmospheres for Paper, Board, Pulp Handsheets, and Related Products.” Conduct test in atmosphere corresponding to T 402. 4.3 From each test unit of the sample, select at least ten specimens. 5. Procedure 5.1 Place the sp
14、ecimen on a rack so that its lower side can be observed. A ring is satisfactory. The specimen should be flat and the area to be wetted should not be allowed to touch anything on the top or bottom. 5.1.1 Ensure that the bottom of the specimen is visible. The test can be facilitated by placing the sta
15、nd over a mirror to make observations easier. 5.2 Fill the burette, syringe or dropper with distilled or deionized water. 5.3 Position the burette or dropper 25 mm (approximately 1 inch) above the top surface of the specimen. 5.4 Drop a drop of water on the upper surface of the specimen and immediat
16、ely start the stopwatch or timer. 5.5 Record the time in seconds for the penetration of the drop through the sheet to the lower side of the specimen as noted by the first visual indication of wetting of the lower surface. Complete absorption of the drop as viewed from the top of the sheet is not req
17、uired. 6. Report For each test unit, report as the test result the average penetration time for ten test specimens. Also report the penetration time for each individual test specimen. 7. Precision 7.1 The precision of this method was determined by a round-robin evaluation of this and several other m
18、ethods by eight laboratories on samples of corrugating medium from eight different mills made by a variety of processes with a wide range of absorptivity levels. Tests were made both before and after aging. 7.2 The following estimates of precision are based on these results. 7.2.1 Repeatability = 18
19、% of average according to definitions of TAPPI T 1200 “Interlaboratory Evaluation of Test Methods to Determine TAPPI Repeatability and Reproducibility.” 7.2.2 Reproducibility = 85% of average, computed from the Coefficient of Variation, as described in T 1206 “Precision Statement for Test Methods.”
20、8. Keywords Corrugating medium, Absorptivity, Water absorption, Water drop tests, Sizing 9. Additional information 9.1 Effective date of issue: April 30, 2014 9.2 There are two official methods and one classical method which can be performed in the same general time period and provide equal repeatab
21、ility. These methods are TAPPI T 832 om-07 “Water Absorption of Corrugating, Medium: Float Curl Method;” TAPPI T 835 om-03 “Water Absorption of Corrugating Medium: Water Drop Absorption;” and TAPPI T 819 cm-07 “Water Absorption of Corrugating Medium: Boat Method.” The various methods do not all reac
22、t similarly to artificial aging (see appendix), but do typically maintain the rank-order of absorptivity among different samples. 3 / Water absorption of corrugating medium: water drop penetration test T 831 om-14 9.3 TAPPI T 432 cm-99 “Water Absorbency of Bibulous Papers” has also been used to meas
23、ure the water absorptivity of corrugating medium, but the study which led up to the development of this method indicates that it lacks the repeatability of this method and most certainly takes more time to conduct, especially on more water-resistant samples. 9.4 Revision history. In the 2009 revisio
24、n, minor edits were made for language and clarity, information on parallel methods from one of the appendices was moved into the additional information section, and information on aging in the other appendix was reorganized. In the 2014 edition, Appendix A was eliminated, the Significance was rewritten, the requirement to identify the wire and felt side was deleted, and minor editorial changes were made. Your comments and suggestions on this procedure are earnestly requested and should be sent to the TAPPI Standards Department.
