ANSI T 277 SP-2014 Macro stickies content in pulp the pick-up method.pdf

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1、TAPPI/ANSI T 277 sp-14 PROVISIONAL METHOD 1999 OFFICIAL METHOD 2007 REVISED AND RECLASSIFIED AS A STANDARD PRACTICE 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

2、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. Approved by the Standard Specific Interest

3、 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. The user is responsible for determini

4、ng 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 present serious health hazards to h

5、umans. 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. Prior to the use of this method, the

6、 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 these chemicals. Macro stickies cont

7、ent in pulp: the “pick-up” method 1. Scope1.1 This standard practice describes removing and preparation of a test specimen that can be analyzed for determining heat-set area and number of macro stickies in a specified amount of pulp screened. The method applies to a wide range of pulps, typically, r

8、ecycled pulp. 1.2 The standard practice does not quantify content of micro stickies. 2. Definitions 2.1 Stickies are defined as tacky particles, which soften and form a thin film at 90-95C (194-203F) and 0.8 bar (11.6 psi) in a heated press. 2.2 The standard practice describes a procedure for the co

9、llection and removal of the macro stickies content remaining on a slotted screen plate of 0.15 mm (0.006 in.) or 0.10 mm (0.004 in.) when applying controlled screening conditions. Slot width of 0.15 mm is typically used for pulp made from Old Corrugated Container (OCC), whereas 0.10 mm is used for M

10、ixed Office Waste (MOW), Old Newsprint (ONP), Old Magazine (OMG), etc. 2.3 The stickies passing the slotted screen plate under 1 bar are considered micro stickies, and are not quantified in this method. 3. Significance 3.1 Stickies testing procedures practiced currently in the industry vary enormous

11、ly. This procedure provides a consistent format to separate for analysis stickies in a reasonable amount of time and with acceptable precision. 3.2 Stickies present in a papermaking mill system can deposit on wires, felts, dryers, and calender stacks. Therefore, when carried onto the dry end, these

12、stickies frequently cause sheet breaks and downtime for fabric cleaning. This method satisfactorily measures the macro stickies content, thus providing a means to determine the efficiency of stickies removal across various process modules in the recycle process and quantifying the final macro sticki

13、es content in the recycled pulp. T 277 sp-14 Macro stickies content in pulp: the “pick-up” method / 2 3.3 The quantification of stickies allows paper producers and recovered paper traders to identify the contaminant sources and characterize the quality of recovered paper. 4. Summary 4.1 Pulp samples

14、 are screened using a laboratory screening device. The rejects from the screen are transferred to a black filter paper. A coated paper is placed on top of the filter paper, and then heated and pressed under controlled conditions. Once the coated paper is removed from the filter paper, the coating wi

15、ll be picked up by the stickies and create a contrast on the black filter paper, which readily allows the measurement of area and number of the heat-set stickies with an image analyzer or by hand using the transparent defect size measurement chart. The manufacturer and type of image analyzer and the

16、 parameters of measurement are not specified in this standard practice, but an example of an analysis procedure can be found in the appendix of this standard practice. 5. Applicable documents 5.1 TAPPI T 275 “Screening of Pulp (Somerville-Type Equipment).” 5.2 TAPPI T 274 “Laboratory Screening of Pu

17、lp (MasterScreen-Type Instrument).” 5.3 TAPPI T 278 “Pulp screening (Valley-type screening device)” 5.4 TAPPI T 564 “Transparent chart for the estimation of defect size.” 6. Apparatus 6.1 A laboratory screening device, with 0.15 or 0.10 mm slotted screen plate. 6.2 Glass-fritted filter (15 cm in dia

18、meter). 6.3 Black wet-strength filter paper (15 cm in diameter). Maximum pore size 25 microns. 6.4 Coated paper with the following specifications: size 320 mm 210 mm, plybond resistance of 2 0.5 kN/m per DIN 54516, or 5.5 1.5 kPa per TAPPI T 541 “Internal Bond Strength of Paperboard (z-Direction Ten

19、sile),” 70 g/m2basis weight of wood-free sized base paper, one-side coated 50 55 g/m2, ISO brightness 85 3%. 6.5 A heated press or sheet making system with heated press with temperature and pressure control. The pressure should be set at 0.8 bar (11.6 psi) and temperature at 90C. 6.6 Silicone releas

20、e liner paper. 6.7 Water-resistant black felt pen. 6.8 Filter washing device, as illustrated in Figure 1. 6.9 Image analysis system with a minimum of optical resolution of 42 microns/pixel (600 ppi) and 256 grey levels. Speck counting starts at 100 m (0.0078 mm2) in diameter. 6.10 Standard disintegr

21、ator, as described in TAPPI T 205 “Forming Handsheets for Physical Tests of Pulp,” Appendix A. 7. Sampling 7.1 Sample size. 7.1.1 An initial sample size of 100 g o.d. is recommended. If a pulp contains high stickies content, the sample size may be reduced. 7.1.2 In the event the test results do not

22、fulfill the desired statistical requirements per Figures 2 and 3, a second sample with the same sample size is tested and the test numbers are added up until the statistical requirements are fulfilled. 7.2 Sampling schedule 7.2.1 Screening of the samples must take place within 24 hours after the sam

23、ples are collected from the recycle process. When comparing samples, similar elapsed time after sampling has to be applied; otherwise the potential agglomeration of micro stickies into macro stickies will skew the results. 3 / Macro stickies content in pulp: the “pick-up” method T 277 sp-14 8. Testi

24、ng procedure 8.1 Disintegration 8.1.1 Predetermine the pulp consistency according to TAPPI T 240 “Consistency (Concentration) of Pulp Suspensions.” 8.1.2 If the debris content is high, disintegrate the sample for 15000 rev. (5 min) at room temperature and 1.0% or less consistency according to TAPPI

25、T 205. 8.2 Screening 8.2.1 Screen a pulp sample according to TAPPI T 274, TAPPI T 275 or TAPPI T 278 when using a different screening device. At the end of screening, carefully collect all materials retained on the screen plates and rinse them off into a beaker containing about 250 mL water. 8.3 Fil

26、tering 8.3.1 Place a filter paper on a glass-fritted funnel. Pour the contents into the 250 mL beaker and apply slight vacuum. In the case of high stickies and debris concentration, the contents in the beaker may be divided into two or more portions in order to prevent overlapping of stickies. When

27、a pressure screen reject sample collected from a recycling plant is tested, fiber flakes should be picked out before filtering to avoid covering of stickies. 8.3.2 When automated filtration device is used, place a black filter paper on filtering plate before screening. 8.4 Heat-setting 8.4.1 After f

28、iltering, place a coated paper described in 6.4 on top of the moist black filter paper and then sandwiched between two blotters. The “sandwich” is placed between the lower and upper heated plates of a press. Press the “sandwich” at 0.8 bar (11.6 psi) for 10 minutes at 90C (194F). 8.5 Filter washing

29、8.5.1 After heat-setting the stickies, the coated paper is removed from the black filter paper. Flakes, shives, grit, and other non-tacky contaminants are washed off under controlled conditions with a flat spray nozzle for 20 - 25 s (see Fig. 1). The water pressure is about 1 bar (14.5 psi) at a flo

30、w rate of 9.6 1/min (2.6 gal/min). Distance between the spray nozzle and the filter paper is approximately 180 mm (7 in.). 8.6 Post drying 8.6.1 Cover the washed black filter paper with a silicon paper and is dried in the automated press for 10 min. Temperature and pressure are the same as in 8.4 8.

31、7 Marking 8.7.1 Identify the white coating pigments on the black filter paper. If any light colored fibers or other light colored non-tacky contaminants remain on the black filter, a black felt pen is used to dye them black. 8.8 Determine the stickies content by hand or by use of image analysis equi

32、pment. Fig. 1. Spray washer. T 277 sp-14 Macro stickies content in pulp: the “pick-up” method / 4 9. Report 9.1 Sampling/testing data. 9.2 The elapsed times between sampling, screening snd specimen preparation if greater that 24 hours. 9.3 Sample ID and pulp specification 9.4 Sample size in (g) o.d.

33、 9.5 Reference screening device used and size of slotted plate 10. Precision A precision statement is not required for a standard practice. 11. Keywords Stickies, Impurities, Hot melts, Newsprint, Mixed waste papers, Reclaimed fibers, Old corrugated containers, Pulps, Screening, Image analysis 12. A

34、dditional information 12.1 Effective date of issue: April 30, 2014 12.2 During the 2013 revision the method was rewritten as a standard practice. This was done to better fit its use as a sample preparation procedure and to permit different automated and non-automated procedures for the stickies “siz

35、e” estimation content. 12.3 Required sample size 12.3.1 Figure 2 reveals the required sample size (g) o.d. as a function of the anticipated stickies area (mm2/g). The chart is based on statistics and paper mill/pilot plant data. 12.3.2 Figure 3 is solely based on statistics. This chart reveals the r

36、equired sample size (g) o.d. as a function of the anticipated number of stickies (1/kg). 12.3.3 Applying Fig. 3 will ensure that with an 80% probability, the test results will fall within 20% of the true stickies number. 10,0001,0001001010.110 1,000100 10,000Specific Stickies Area (mm/kg)O.D.Sample

37、Mass(g)ConfidenceIntervalI = 20%Fig. 2. Minimum sample size as a function of anticipated specific stickies area. 5 / Macro stickies content in pulp: the “pick-up” method T 277 sp-14 11010010001000010 100 1000 10000Specific Stickies Count l/kgSampleSizegConfidence IntervalI = 20%Fig. 3. Minimum sampl

38、e size as a function of anticipated number of stickies. 12.4 Statistical fundamentals 12.4.1 For a desired 80% probability and a sample size larger than 100 g the mean stickies number of the complete sample population will fall in the following confidence interval: nx1.282 + x nx1.282 - x where: x =

39、 number of stickies (test result) n = sample size 12.4.2 Incorporating the sample size unit (g) and the anticipated specific stickies number x (stickies/kg o.d. pulp) we utilize equation m = 4.11 104/x to calculate the necessary sample size m (g) based on a 20% confidence interval. References 1. Hei

40、se, O., Holik, H., Schabel, S., Cao, B., Kriebel, A., Dehm, J., “A New Stickies Test Method- Statistically Sound And User-Friendly,” 1998 TAPPI Product each size class states the stickies number and the stickies area. Based on these numbers, the logarithmic area density for each size class is calcul

41、ated. Further, the total stickies number and area is stated. Stickies diameter range (m) Measured stickies number (-) Measured stickies area (mm2) Logarithmic area density (mm2) 100 - 200 200 - 300 300 - 400 400 - 500 500 - 600 600 - 700 700 - 1000 1000 - 2000 2000 - 5000 5000 TOTALS Measurement Are

42、a Logarithmic Area Density = 2.303 Average Size of Class Range Size Class Range A.2.2 Calculate the specific stickies area using the following equation: MA= Sain which, Sa = Specific stickies area, mm2/kg A = Total area of stickies, mm2 M = Total o.d. mass of pulp screened, kg. A.2.3 Calculate the s

43、pecific stickies number using the following equation: Sn= N / M in which, Sn= Specific stickies number, kg-1 N = Total stickies count M = Same as aforementioned A.2.4 Calculate average stickies size using the following equation: D = Sz/ Sx7 / Macro stickies content in pulp: the “pick-up” method T 27

44、7 sp-14 D = Average stickies size, mm2 Sa = Same as aforementioned Sn = Same as aforementioned. A.2.5 Find out the minimum sample mass required from Figure 2 and 3. If the amount of pulp used for screening is larger than the minimum sample mass, then follow section 10 to report the results. Otherwis

45、e, increase the amount of pulp screened until the minimum sample mass is reached. A.3. Report section covering the analysis procedure A.3.1 Report the average specific stickies area of two determinations. A.3.2 Report the average specific stickies number of two determinations. A.3.3 Report the avera

46、ge stickies size of two determinations A.3.4 Graphical charting: logarithmic area density vs. stickies size (optional) A.3.5 Reference screening device used and size of slotted plate A.4 Example precision statement A.4.1 For the maximum expected difference between two test results: Repeatability (wi

47、thin a laboratory) = 28% Reproducibility (between laboratories) = 101% A.4.2 The repeatability and reproducibility are in accordance with the definitions specified in TAPPI T 1200 “Interlaboratory Evaluation of Standards to Determine TAPPI Repeatability and Reproducibility.” A.4.3 The repeatability

48、and reproducibility data are based on results obtained from three laboratories on the same sample of old newsprint pulp sample. A.4.4 Good repeatability and reproducibility can only be achieved with a consistent type of laboratory screening device screen plate and similar operating conditions. For a pulp that contains concentrated debris, precision of the test method will be lowered. Your comments and suggestions on this procedure are earnestly requested and should be sent to the TAPPI Standards Department.