ANSI T 259 OM-2015 Species identification of nonwood plant fibers.pdf

1、TAPPI/ANSI T 259 om-15 SUGGESTED METHOD 1941 OFFICIAL STANDARD 1978 OFFICIAL TEST METHOD 1983 REVISED 1988 REVISED 1993 STANDARD PRACTICE 1998 REVISED 2005 REAFFIRMED 2009 REVISED AS AN OFFICIAL METHOD 2015 2015 TAPPI The information and data contained in this document were prepared by a technical c

2、ommittee of the Association. The committee and the 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 doc

3、ument is the most recent edition published. Approved by the Standard Specific Interest Group for this Standard Practice 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 us

4、er of the method to safety issues related to such use. The 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 re

5、quire the use, disposal, or both, of chemicals which may 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

6、by all distributors of potentially hazardous chemicals. Prior 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, stat

7、e, and federal authorities for safe use and disposal of these chemicals. Species identification of nonwood plant fibers 1. Scope The fibrous elements of the nonwood plant species, which are commonly encountered in papermaking or that are expected to have the potential of being used for this purpose,

8、 may be identified on the basis of their morphology as revealed by the microscope. The purpose of this method is to provide some of the details, which are useful in making an identification of an unknown nonwood plant specimen. This method can be used whether a coarse undefibered specimen is present

9、 or samples of pulp, paper or other paper products are provided. 2. Apparatus The only special equipment required for this method is a compound microscope equipped with a calibrated micrometer eyepiece. 3. Significance To assist an analyst in determining what type of commercially available nonwood f

10、iber is present either in the rough form or present in a pulp, paper or other paper product. 4. Reagents The majority of the specimens depicted in this method were delignified with an acidified sodium chlorite solution. The required reagents are: 50% acetic acid (CH3COOH), sodium chlorite (NaClO2),

11、1.0% NaOH, 0.5N HC1, and Graffs C-Stain or Sellegers stain. A second, and more rapid, procedure requires: 1% sodium hydroxide (NaOH) solution and 1% methylene blue solution. The solutions need only be of the approximate strengths indicated. As an additional reference, TAPPI T 401 “Fiber Analysis of

12、Paper and Paperboard” for information on Graffs C-Stain and Sellegers stain. 10% sodium hydroxide (NaOH) solution can be used to defiber specimens of reference fibers. T 259 om-15 Species identification of nonwood plant fibers / 2 5. Sample preparation Caution: Use safe laboratory practices in handl

13、ing hot chemicals. The sodium chlorite procedure should be handled with extreme care. If the reaction is carried out too rapidly this mixture could react violently. Use of a vented fume hood with sash and a personal protection face shield are necessary. 5.1 A fibrous suspension may be prepared by th

14、e acidified sodium chlorite procedure as follows: 5.1.1 Place 1 g of a stalk or coarse specimen in a 170 x 20 mm test tube and wet with 30 mL of H2O. 5.1.2 Add 5 g of solid NaClO2. 5.1.3 Add 10 mL of 50% CH3COOH at 60C and lower test tube into a water bath heated to 60C. 5.1.4 Lightly swirl the cont

15、ents, stopper, and allow to react for 1 h. 5.1.5 At the end of 1 h, stir contents with a glass rod and let stand for 24 h at 60C. The stoppers should be kept in place to prevent the loss of reaction liquor. 5.1.6 At the end of the 24 h period, drain off the reaction liquor, wash the mat three times

16、in distilled water, and shake vigorously to insure uniform fiber separation. 5.1.7 The 24 h reaction period, steps 2 to 6, may have to be repeated as many as three times depending upon the ease of fiber separation of the material. 5.1.8 If the fiber mat was removed for washing, place it back in the

17、test tube. Add 10 mL of 1.0% NaOH, heat to 60C and hold for 1 h, drain liquor, macerate, and wash pad in water three times. 5.1.9 Treat the fibrous pad with 10 mL of 0.5NHCl for 0.5 h at 20C and wash three times. 5.1.10 Place a few drops of the suspension on a microscope slide, stain in the normal m

18、anner with C-Stain or Sellegers stain, cover, and examine. (See TAPPI T 401 for proper staining technique.) 5.2 The rapid hot alkali procedure may alternatively be employed as follows: 5.2.1 A 1 g sample of the specimen pulp or paper is boiled for a few minutes in a 1% NaOH solution. 5.2.2 Wash the

19、sample with water and shake to insure complete separation. 5.2.3 Place a few drops of the fibrous suspension on a microscope slide, stain with a drop of methylene blue, Graffs “C” stain or Sellegers stain solution, cover, and examine. NOTE 1: The 1941 and 1947 versions of this method contained only

20、the rapid procedure detailed in section 5.2. The more rigorous procedure detailed in 5.1 was added in the 1978 revision of the method. Analysts are referred to Reference 5 and 6 for further information on the use of the stains specified in this method. Depending on the application, analysts may find

21、 other stains useful in the identification of fibers. 6. Reference standards When authentic specimens of commercial fibrous materials are available, it is highly desirable that known fibrous suspensions be prepared for purposes of comparison with tentatively identified samples. A coarse material may

22、 be defibered by boiling a small amount of the commercial fiber in 10% NaOH solution for approximately 30 min, followed by washing and vigorous shaking in water. A pulp or paper reference can be defibered and prepared using 5.18 through 5.1.10. 7. Procedure 7.1 A thorough microscopical examination o

23、f the fibrous suspension includes an enumeration of the cell types present, their characteristic markings, and a measurement of cell dimensions. The micrographs included in this method have been prepared mostly at the same magnification to facilitate direct comparisons. A tentative identification ma

24、y be made through the use of the dichotomous key in Table 1. In using the key, select from the pair numbered 1 the description that best fits the material under consideration. If a number is found at the right-hand end of the line, refer next to the pair of descriptions bearing that number and repea

25、t the procedure. By this method of selection, a description will ultimately refer to a species, or group of species, which possesses the required characteristics. Analysts should keep in mind that not all non-woody fibers can be covered in this method. Unknowns will be encountered. 7.2 Reference sho

26、uld next be made to the description, fiber dimensions, and the photomicrographs of this particular species as a further check upon the identification. A final comparison of the unknown with authentic material as previously mentioned should provide conclusive proof as to the identity of the sample. 3

27、 / Species identification of nonwood plant fibers T 259 om-15 Table 1. Species identification of nonwood plant fibers; key to nonwood plant papermaking fibers 1. Fibers long, averaging more than 15 mm in length; complete fibers rarely seen under an ordinary microscope . 2 1. Fibers comparatively sho

28、rt, averaging less than 10 mm in length, complete fibers frequently seen by moving the glass slide about the stage of the microscope 5 2. Fiber flat, ribbonlike; usually twisted about its longitudinal axis Cotton 2. Fiber cylindrical, not twisted; prominent transverse fractures in the cell wall . 3

29、3. Individual fibers variable in width, up to 80 m in width at their broadest portions Ramie 3. Individual fibers quite uniform in diameter; the broadest fibers not more than 50 m wide 4 4. Narrow lumen clearly defined within thick fiber walls; fibers pointed at their ends . Flax 4. Cell cavity rath

30、er obscure but often wider than the fiber wall; fiber ends blunt Hemp 5. Fibers isolated or accompanied by occasional cells of other types 6 5. Vessel segments and parenchyma cells abundant together with fibers . 9 6. Fiber unusually variable in diameter, a central segment averaging about twice as w

31、ide as the rest of the fiber Mitsumata 6. Diameter of fiber relatively uniform throughout nearly its entire length 7 7. Fiber lumen irregularly constructed at intervals to an extremely narrow canal Jute 7. Fiber lumen uniform in diameter . 8 8. Fiber lumen broad, distinct; cell walls thin to moderat

32、ely thick . Manila hemp 8. Fibier lumen narrow; often indistinct; cell walls thick . New Zealand flax 9. Individual epidermal cells or fragments of epidermal tissue abundant; margins of these cells rather distinctly toothed 10 9. Epidermal cells infrequent; their margin undulating rather than distin

33、ctly toothed 12 10. Parenchyma cells relatively narrow, none present more than 20.5 m wide, epidermal cells narrow (less than 14 m) accompanied by numerous erect trichomas, hooked at their apices . Esparto 10. Parenchyma cells narrow to barrel-shaped; up to 130 m in width; epidermal cells usually gr

34、eater than 14 m in width occur together with straight trichomes, the latter appressed to the surface of epidermal cells or comparatively spare and erect 11 11. Trichomes in conspicuous and erect; dermal cells as fattened, spurlike projections; epidermal cells profusely pitted; stomata of the epiderm

35、is accompanied by dentate guard cells; fiber diameters 5.1 to 13.6 m . Rice 11. Trichomes in conspicuous and erect; epidermal cells rarely pitted; guard cells surrounding the stomata with entire margins; fiber diameters 6.8 to 23.8 m Barley, oat, rye, wheat 12. Fibers relatively long (up to 4.3 mm i

36、n length; averaging 2.7 mm) accompanied by thin-walled, ribbon-shaped fibers up to 40 m in width . Bamboo 12. Fibers relatively short (up to 2.9 mm in length; broadest fibers not ribbon-shaped (34 m wide) . 13 13. Vessel segments long (1350 m); maximum fiber diameter 34 m, parenchyma cells as long a

37、s 850 m Sugar Cane 13. Vessel segments comparatively short (600 m maximum); maximum fiber diameter 24 m, parenchyma cells as long as 325 m Corn 8. Structure of the plant stem 8.1 Although the pulping process so destroys the original tissue of the plant stem that the individual cells are more or less

38、 completely separated and appear as isolated units, a general introduction to the structure of the plant is essential to an understanding of the cell types to be described. The true fiber of the nonwood plant, which is the only cell type contributing in any degree to the strength of the paper, is ac

39、companied by other types of cells which frequently are important aids in identification. 8.2 The plants from which the commercial fibers described herein are obtained may be divided into two general classes according to their botanical characteristics: monocotyledons and dicotyledons. The monocotyle

40、dons are the plants having parallel-veined leaves such as the grasses, lilies, and palms. The dicotyledons have net-veined leaves and include such plants as kenaf, hemp, okra, flax, and the common broadleaf trees. The two classes may be separated by an examination of the internal structure of the pl

41、ant stem. 8.3 The transport of water and food through the plant is accomplished in both monocotyledons and dicotyledons by a system of cells arranged in a long series known as sieve tubes and vessels. The thin walls, frequently modified by openings known as sieve areas and pits, together with the la

42、rge lumens of these cells, are commonly explained on the basis of their evolutionary adaptation for the conduction of liquids. As though to compensate for these weak conducting cells, they are accompanied by another cell type, the fiber, which contributes strength and rigidity to the T 259 om-15 Spe

43、cies identification of nonwood plant fibers / 4 plant. Fibers are long, slender cells characterized by relatively thick, infrequently pitted walls and a narrow cell cavity or lumen. 8.4 The arrangement of the conducting or vascular tissue in the plant stem is characteristically different in the mono

44、cotyledons and the dicotyledons. In the former group the conducting tissue and the accompanying fibers are arranged in vascular bundles which are generally distributed at random throughout the greater part of the plant stem (Fig. 1). The vascular tissue of the dicotyledons, conversely, are arranged

45、in a definite ring pattern, or frequently an unbroken ring of vascular tissue without distinct bundles may serve for purposes of conduction and mechanical support (Fig. 2). The inner portion of this ring of vascular tissue is the xylem, composed chiefly of xylem fibers and vessels. Just outside of t

46、he xylem is a narrow layer of living meristematic cells known as the vascular cambium and beyond this lies the phloem, consisting for the most part of sieve tube elements, parenchyma, and phloem fibers. Surrounding the vascular tissue are successive protective layers known as the pericycle, cortex,

47、and epidermis. The fibers used in papermaking may be vascular bundle fibers from the stem or leaf of the monocotyledons, or, if derived from the dicotyledons, they may be from the phloem, pericycle, cortex, or xylem of the stem. The dicotyledonous phloem fibers are commonly designated as bast fibers

48、. 8.5 The cotton fiber illustrates still another source of commercial fiber. This is the seedhair, a cell that originally was attached to the seed of the plant. In contrast to the structural fibers, which are separated only by disintegration of the plant tissue which they constitute, the seedhairs a

49、re individual units in nature. 8.6 The fibers to be described in the ensuing paragraphs may be classified in the following manner: 8.6.1 Structural or stem fibers 8.6.1.1 Vascular bundle fibers - monocotyledons (Gramineae): reed, arundo donax; oat, Avena barbata; barley, Hordeum sp.; rice, Oryza sp.; elephant grass, Napier grass, Pennisetum purpureum; reed, Phragmites communis; rye, Secale sp.; Columbum grass, Sorghum alum; broomcorn, Sorghum bicolor; Piper sudan, Sorghum sudanense; esparto, Stipa tenacissima; triticale; wheat, Triticum sp.; emmer