ANSI TAPPI T401 OM-2015 Fiber Analysis of Paper and Paperboard.pdf

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1、TAPPI/ANSI T 401 om-15 OFFICIAL STANDARD 1926 OFFICIAL TEST METHOD 1982 CORRECTION 1983 REVISED 1988 REVISED 1993 REVISED 2003 REAFFIRMED 2008 REVISED 2015 2015 TAPPI The information and data contained in this document were prepared by a technical committee of the Association. The committee and the

2、Association assume no liability or responsibility in connection 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. Approve

3、d by the Standard Specific Interest Group for this Test 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. Th

4、e user is responsible for determining that the safety precautions 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

5、present serious health hazards to humans. Procedures for 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. P

6、rior to the use of this method, the user must determine 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 t

7、hese chemicals. Fiber analysis of paper and paperboard 1. Scope1.1 This method provides a procedure for the identification of the kinds of fibers present in a sample of paper or paperboard and their quantitative estimation. This method requires the analyst be skillful and experienced in the field of

8、 pulp and paper microscopy. 1.2 The analyst must make frequent use of standard samples of known fiber composition or of authentic fiber samples and must become thoroughly familiar with the appearance of the different fibers and their behavior when treated with the various stains. 1.3 Morphological c

9、haracteristics help identify special fibers such as straw, flax, esparto, soft woods, such as southern pine, Douglas fir, western hemlock, and various species of hardwoods, so that the correct weight factors may be applied. A knowledge of morphological characteristics of the different fibers is esse

10、ntial for their identification. More information on this subject is given in the Appendices. 1.4 It is reported that fiber analysis in highly refined or secondary fiber sheets is very difficult to perform. 2. Summary Details are presented for the disintegration of differing grades of paper, staining

11、, preparation of slides, and fiber identification by specific staining techniques. Provision is made for both qualitative identification and quantitative analysis of furnishes. 3. Significance Many types of paper, particularly bonds, ledgers, index, and book papers are bought on the basis of fiber c

12、omposition. This method is used to quantitatively and qualitatively identify the fibers in paper. It will also show whether the composition is free from fibers which the specifications particularly prohibit. T 401 om-15 Fiber analysis of paper and paperboard / 2 4. Apparatus and materials 4.1 Micros

13、cope1, compound, preferably of the binocular type, equipped with a mechanical stage and Abbe condenser. A magnification of approximately 100 times is recommended for observation of fiber colors; a higher magnification may be desirable for studying morphological characteristics. If an apochromatic ob

14、jective is used, it is desirable to have a compensating eyepiece and an achromatic condenser. A field of approximately 6 mm is desirable. The eyepiece should have a cross hair, pointer, or dot for counting the fibers passing under it. Such an eyepiece can be supplied by the manufacturer, or it may b

15、e prepared by the technician, positioning the point in the eyepiece so as to obtain its image in focus. 4.2 Slides and cover glasses, standard slides 25 by 75 mm (1 by 3 in.) of clear, colorless glass, and No. 2 cover glasses (25 mm square). 4.3 Dropper, a glass tube about 100 mm (4 in.) long and 8

16、mm (5/16 in.) internal diameter with one end carefully smoothed, but not constricted, and the other end fitted with a rubber bulb. The tube shall be graduated to deliver 0.5 mL. 4.4 Warm plate, a plate with a plain, level top having black matte finish and provided with a control to keep the temperat

17、ure of the surface between 50 and 60C. 4.5 Dissecting needles, two needles mounted in handles. Steel needles may be used but are subject to corrosion by some of the stains. Needles made from an alloy of platinum and iridium are preferred. 4.6 Glass-marking equipment, either a glass-marking pencil or

18、 an aluminum stearate solution (see Appendix G) for marking lines on the slide. 4.7 Light source, a 15-W “daylight” fluorescent tube or equivalent daylight source. 4.8 Camels hair brush, small. 4.9 Counter, a device that counts the number of times a button is pressed. This can be used to assist in t

19、he counting of the fibers. 4.10 Miscellaneous, 50- or 100-mL beaker; test tube; glass beads; hot plate blotter paper; and, depending on the specimen, stains, reagents, and apparatus as described in the appropriate section of the procedure. A good dissecting knife may be helpful to separate the plies

20、 of cylinder board. 5. Reagents 5.1 Graff “C” stain, suggested for general analysis. Other stains, listed below, could be used for specific purposes or to confirm results obtained with the “C” stain. 5.2 Herzberg stain, especially useful to differentiate between rag, groundwood, and chemical wood pu

21、lps. 5.3 Sellegers stain or Alexanders stain, used to differentiate between softwood and hardwood pulp. Sellegers stain is also helpful in differentiating between bleached softwood sulfite and bleached softwood sulfate. 5.4 Wilsons stain, used in place of, or to confirm results with, the “C” stain.

22、5.5 Green and Yorston stain, very useful for the detection of unbleached sulfite fibers. 5.6 Directions for preparing these stains are given in Appendix E, and the directions for preparing and using other stains are given in Appendix F. 6. Sampling and test specimens Select a single composite test s

23、pecimen of approximately 0.2 g so as to be representative of all the test units of the sample obtained in accordance with TAPPI T 400 “Sampling and Accepting a Single Lot of Paper, Paperboard, Containerboard or Related Product.” 7. Procedures 7.1 Disintegration 7.1.1 Ordinary papers 1Names of suppli

24、ers of testing equipment and materials for this method may be found on the Test Equipment Suppliers list, available as part of the CD or printed set of Standards, or on the TAPPI website general Standards page. 3 / Fiber analysis of paper and paperboard T 401 om-15 7.1.1.1 (Method A) CAUTION: It is

25、recommended to handle paper with gloves as metallic salts on fingers may give reactions with stain. Tear the specimen into small pieces and place in a small beaker. Cover with distilled water and bring to a boil on the hot plate. Decant the water from the beaker. Then roll the individual pieces into

26、 small pellets between the fingers and place in a large test tube. Add a little water and shake vigorously until the water is thoroughly absorbed by the paper. Add a little more water, shake well, and again add some water and shake. Repeat this procedure until the paper has been thoroughly disintegr

27、ated. When the paper has been completely defibered, dilute the suspension by discarding part of it and adding water to the remainder until the suspension has a final consistency of about 0.05%. Shake vigorously between these operations to prevent fiber stratification. If the specimen is difficult to

28、 disintegrate, glass beads may be used in the test tube, and should be so stated in the report. Glass beads should not be used if the fibers are to be examined for degree of beating. Ultrasonic disintegration is helpful in dispersing fibers. If most of the fibers have separated but a few undefibered

29、 areas remain, various methods can be used that have shown no noticeable fiber cutting or damage effect. In situations where incomplete separation of fibers occurs, an agitation method (proven not to cut the fibers) can be used. 7.1.1.2 (Method B) If the paper cannot be disintegrated by shaking in w

30、ater (Method A), return the specimen to the beaker, cover with 1% NaOH solution and bring to a boil. Decant the alkaline solution. Wash the specimen twice with water. Cover the specimen with approximately 0.05N HCl; let stand several minutes. Decant the acid and wash the specimen several times with

31、water (a fritted glass filter funnel is recommended to minimize small fiber loss). Roll into pellets and proceed as in Method A. Caustic will swell the fibers and may affect the subsequent stain shade. 7.1.1.3 (Method C) Some analysts prefer to start disintegrating the specimen in a heated 5% alum s

32、olution. After boiling 15 mins, the specimen is washed, rolled into a pellet, and suspended in a test tube of water. 7.1.1.4 If the specimen cannot be disintegrated by Method A, B, or C, use one of the special methods given below. 7.1.2 Specially treated papers. Standardized methods cannot be specif

33、ied for the disintegration of papers containing tar, asphalt, rubber, viscose, etc., or parchment papers, because the needs vary according to the material, the amount present, and the nature of the treatment. The following methods are given as guides: 7.1.2.1 Tar and asphalt-treated papers Method 1:

34、 Place the specimen in a dish. Cover with kerosene and digest on a steam bath for 1 h. Next, remove and press the specimen between blotters. Repeat the kerosene extracting and blotting. Extract the specimen with cold toluene or hexane until the solution is clear. No NaOH should be used in the final

35、disintegration of these papers because of the possible presence of wool fibers (1). Method 2: CAUTION: Vapors from this solvent are toxic. Work should be done under a hood. Fill several convenient containers (250-mL beakers) about one-half full with 1,1,1-trichloroethane. Cut the specimen into conve

36、nient squares and immerse in the first container. After several minutes in the first container, transfer the squares to the next container, using forceps. Do not allow the squares to dry. In the case of laminated papers, the sheets may be separated easily after the first or second soaking and this s

37、hould be done, removing any fabric scrim which can be treated separately, if desired. Continue moving the specimen into fresh solvent until the liquid remains clear after the specimen has been agitated in it for several minutes, then remove the specimen and allow to air dry. After drying, disintegra

38、te the specimen in the usual manner. Method 3: Place the specimen in a Soxhlet or similar extractor and extract with 1,1,1-trichloroethane or 1,1,1,- trichloroethylene. 7.1.2.2 Rubber-treated papers. Extract the paper for 6 h in a Soxhlet extractor with toluene, dry, and then boil in water to which

39、a little wetting agent has been added. In very rare cases, a 1% NaOH solution may be necessary. With most specimens, the toluene will extract about 98% of the rubber (2). 7.1.2.3 Parchment papers Method 1: To 25 mL of water, slowly add 25 mL of concentrated H2SO4 and cool it to 50 to 60C. Place the

40、specimen in the acid. When the specimen begins to disintegrate, stir quickly while emptying into a 1000-mL beaker two-thirds full of water (3). Method 2: Soak the specimen for about 5 mins in concentrated HCl. Wash, boil in 0.5% NaOH solution, and repeat this sequence if necessary. Then wash, acidif

41、y with dilute HCl, again wash, and then boil in a little water and a wetting agent, and disintegrate (3). 7.1.2.4 Pyroxylin-treated papers. Extract or remove the pyroxylin with ethylene glycol monoethyl ether, acetone, or amyl acetate. T 401 om-15 Fiber analysis of paper and paperboard / 4 7.1.2.5 W

42、et-strength papers Method 1: Tear the specimen into small pieces and place in a beaker. Cover with 5% aluminum sulfate solution and boil from 5 to 20 mins depending upon the amount of wet strength present. Decant the solution, wash, and proceed as in 7.1.1.2. Method 2: When an estimation of the degr

43、ee of beating of the fibers is not required, the specimen may be disintegrated in water in a high-speed electric mixer for a period of less than 60 seconds. Method 3: Alkaline-cured resin papers are repulped at a pH of 10 obtained with caustic soda at 38C. As little as 0.1% of sodium hypochlorite on

44、 a fiber basis is effective in accelerated broke disintegration, as the amidochloride formed apparently hydrolyzes readily. Information on papers treated with polyethylene imide (PEI) (also considered to be an alkaline-curing resin) indicates that broke recovery is most satisfactory under acid condi

45、tions. 7.1.2.6 Highly colored papers. If the paper is highly colored (the treatment selected depends on the characteristics of the dyes), remove the dye by one of the following methods (a) By solution: use alcohol, NH4OH, acetic acid, or HCl. (b) By oxidation: use nitric acid or bleach liquor (sodiu

46、m hypochlorite). (c) By reduction: Use hydrosulfite, stannous chloride, or HCl and zinc (1) and then disintegrate by method A. 7.2 Preparation of slides 7.2.1 It is desirable to keep the slides and cover glasses in a 50% alcohol/water solution. After a slide has been dried and polished, draw lines 2

47、5 mm (1 in.) from each end, using the glass-marking pencil or aluminum stearate solution. This will keep the fiber suspensions inside the square at each end of the slide. (A repellent-type label tape may be used to cover the center square portion of the slide, in which case lines need not be made on

48、 the slide.) Remove any dust or lint from the slide with a small camels hair brush. Place the slide on the warm plate, shake the test tube containing the defibered specimen, and withdraw a portion of the fibers by inserting the dropper and expelling two or three bubbles of air. Deposit 0.5 mL of the

49、 fiber suspension on the square on one end of the slide. Withdraw another 0.5-mL portion from the test tube and deposit it on the other end of the slide. Allow the water on the slide to evaporate until there is just sufficient left to float the fibers, then gently tap the suspension with a dissecting needle to distribute the fibers evenly inside the squares. Leave the slides on the warm plate until completely dry. NOTE 1: A few drops of an acrylamide-type deflocculating agent added to the fiber suspension is very effective in many cases. 7.3 Staining 7.3.1 To use the