ANSI T 400 SP-2011 Sampling and accepting a single lot of paper paperboard containerboard or related product.pdf

1、T 400 sp-11 OFFICIAL STANDARD 1926 TENTATIVE STANDARD 1962 OFFICIAL STANDARD 1970 REVISED 1975 OFFICIAL TEST METHOD 1985 REVISED 1989 REVISED 1990 STANDARD PRACTICE 1995 REVISED 1997 REVISED 2002 REVISED - 2006 REVISED - 2011 2011 TAPPI The information and data contained in this document were prepar

2、ed by a technical committee 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 determ

3、ining that this document is the most recent edition published. Approved 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

4、 alert the user 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

5、method may require 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 an

6、d maintained 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 a

7、s local, state, and federal authorities for safe use and disposal of these chemicals. Sampling and accepting a single lot of paper, paperboard, containerboard, or related product 1. Scope1.1 This method describes procedures for obtaining a representative sample for testing. It should be recognized t

8、hat in an ideal situation the samples selected should represent a lot of paper or paperboard, container board, or related product, including converted paper products (all hereafter referred to as “paper”). However, in some situations the sample may be as small as a single sheet of paper that has bee

9、n provided to the laboratory for testing and may not represent the lot from which it is obtained. 1.1.1 Procedures are described (see Section 4) for establishing the lot of paper to be sampled. 1.1.2 The rules for selecting a representative sample for testing from this lot are described in Sections

10、5.1 and 5.2. Specific sampling procedures are described (5.3) for large rolls or skids. 1.1.3 Specific procedures are described (5.4) for sampling from a single roll of containerboard for basis weight and burst strength. 1.1.4 A procedure is described (5.5) for the sampling and testing of a continuo

11、us strip of paper. In evaluating the performance of a process there may be advantages in measuring the cross or along machine variation in the product. An example could be the cross machine caliper profile to determine the processing variation caused by calendar roll loadings or crown. The evaluatio

12、n of machine direction strips can provide information of performance of equipment, i.e., a blocked couch roll. 1.1.5 A procedure is described (5.6) for handling a sample that may consist of a limited quantity of paper; or, may be as small as a single sheet of paper. Situations may arise where the te

13、sting laboratory has no control of the quantity of paper that is supplied for testing. An example could be the return of a piece of paper that the customer perceives to be defective and the testing laboratory has been asked to quantify its properties. It must be recognized that in these situations T

14、 400 sp-11 Sampling and accepting a single lot of paper, / 2 paperboard, containerboard, or related product the laboratory may not have control of the sampling procedure; and, the samples supplied and tested may not represent the lot of material from which they came. 1.2 Prior to purchase, there sho

15、uld be agreement between buyer and seller on the size of the lot to be sampled (3.1), on details of the sampling procedure, the required physical and chemical properties, dimensional tolerances, etc., and the testing methods to be employed. 1.3 The appendices, which provide useful, statistical crite

16、ria for accepting individual lots of paper on the basis of the number of defective test units, can assist the buyer and the seller in selecting an agreed upon sampling and acceptance procedure. 2. Significance The significance of this practice is that it provides sampling procedures for a majority o

17、f TAPPI Test Methods, 3. Definitions 3.1 Lot, a quantity of paper of a single type, grade, grammage, thickness, and composition, about which it is desired to make a judgment (usually as to conformance to specification) by examining or testing a small fraction called the sample. 3.2 Sample, a specifi

18、ed number of test units selected according to a prescribed procedure to represent the lot. It should also be recognized that in some situations the sample to be tested may consist of a limited quantity, or be as little as one sheet of paper. 3.3 Sublots, a natural subdivision of a lot consisting of

19、discrete quantities such as carloads, pallets, rolls, etc. 3.4 Test unit, an area of paper sufficient to obtain a single adequate set of test results for all the properties to be measured. 3.5 Test specimen, a test unit, or a portion of a test unit, upon which (for a specified property) a single tes

20、t determination is to be made. 3.6 Test determination, (1) the process of carrying out the series of operations specified in the test method whereby one or more readings (observations) are made on a test specimen and the observations combined to obtain the value of a property of the test specimen, o

21、r (2) the value obtained by the process. 3.7 Test result, the value obtained for one test unit of the sample by carrying out the complete protocol of the test method, the value being (as specified in the test method) either a single test determination or a specified combination of a number of test d

22、eterminations. 3.8 Test strip, cross machine strip, continuous strip of paper that represents the width of either a roll or reel as specified by the buyer/seller. Machine direction strip - continuous strip of paper of a length and machine position to reflect the measurement of interest. 4. Establish

23、ing the lot 4.1 General considerations. Avoid grouping together different manufactures as a lot. Batches of paper are likely to differ significantly from each other in raw materials or manufacture. If the shipment is small or consists of a large number of batches, it may be uneconomical or impractic

24、able to form lots conforming with the definition (3.1). If this is the case, divide the shipment into portions, to be designated “sublots,” in which each portion conforms with the definition of lot. Before starting the sampling, obtain a complete understanding of the paper to be sampled, including t

25、he composition and size of lots and sublots, rolls, skids, etc. 4.2 Location of sampling. 4.2.1 Sampling at the paper mill. When paper is to be delivered in large rolls or skids, if agreed, have the sample taken at the paper mill and delivered to the purchaser for examination and testing. Include in

26、 the purchase agreement a definition of the number of rolls or skids constituting a lot and details of the sampling procedure to ensure compliance with the rules in selecting the sample under Section 5. Specifically indicate whether the sample was taken from mill reels or from the finished rolls or

27、skids. 4.2.2 Sampling in transit or warehouse. It may be necessary to take a sample at a dock or warehouse in route between the supplier and the purchaser, especially for international shipments or in sampling for referee testing. Sampling in transit or warehouse can be quite expensive and should be

28、 avoided whenever possible, because of the problem of resealing. Arranging to inspect the shipment prior to unloading is recommended on inspection in transit. Establish the size of each lot and determine which rolls or skids will be sampled, and arrange to sample and reseal the 3 / Sampling and acce

29、pting a single lot of paper, T 400 sp-11 paperboard, containerboard, or related product rolls or skids as they are loaded or unloaded to minimize additional handling. Obtain the sample in accordance with Section 5. 4.2.3 Sampling after receipt. This type of sampling has the obvious disadvantage of d

30、elaying evaluation of the shipment and of providing the least favorable conditions for disposal of a rejected lot. Other considerations are the same as above for sampling in transit. 4.3 Representativeness of the sample. The test units of the sample usually cannot be taken at random from anywhere wi

31、thin a large roll or skid, but must be taken near the outer layers so as not to destroy the roll or skid. If such test units are regularly taken at the paper mill (4.2.1) and a reasonably uniform quality of production is being maintained, then the test units will, in the long run, be quite represent

32、ative of average production, even though not randomly selected and therefore not “representative” from a statistical viewpoint. Such test units, however, taken when the lot is in transit or warehouse (4.2.2) or after receipt (4.2.3), cannot be said with certainty to be representative of the shipment

33、 for example, rolls shipped to a customer may have been selected because their outer layers met the customers specification, with no knowledge as to whether properties vary from the outer layers to the core of the roll. Such test units therefore may be neither random nor “representative,” but they

34、are all that is available “to represent” the lot, which experience shows they do fairly well unless non-uniform manufacture or aging has occurred. 5. Selecting the sample 5.1 Determine the area of paper required for each test unit (see definition 3.4) and the number of test units required. Take a sa

35、mple consisting of the required number of test units in accordance with a predetermined procedure, designed to eliminate deliberate selection of any particular area of paper, and, as far as practicable, conforming to the following rules: 5.1.1 Rule 1: Take test units in proportion to the sizes of th

36、e sublots. When a lot divides naturally into sublots consisting of discrete quantities such as carloads, pallet loads, rolls, etc., or when certain portions of the lot (3.1) differ from one another and are segregated as “sublots” (3.3), take the test units in such a way that the number of test units

37、 taken from a given sublot is proportional to the size of the sublot. 5.1.2 Rule 2: Take the test units so that each area of paper in the lot or sublot has an equal probability of being selected. It is recognized that difficulties of handling may not permit the taking of test units from locations sc

38、attered throughout the lot, but this should be done to the greatest practicable extent. 5.1.3 Rule 3: Take test units indiscriminately. Take the units without regard to their condition or quality but do not sample the outermost sheets of a roll or skid. Also do not sample from inner sheets which hav

39、e been damaged by handling, abrasion, etc., unless it is evident that similarly damaged areas occur throughout the lot. 5.2 Compliance with rules 2 and 3 may be assured by sampling according to the following plan: Divide the lot or sublot into “locations” (carloads, skids, cartons, etc.) in such a w

40、ay that each location contains an equal quantity of paper. Assign a number to each location and select the locations to be sampled by drawing numbers at random from a hat or from a table of random numbers. Next assign and select the sublocations or areas within a location by the same procedure. In o

41、rder to minimize handling during sampling, observe the precautions of Section 6. 5.2.1 When test units are to be taken from small rolls, reams, bundles, cartons or shipping containers of completed paper products, divide the lot or sublot into “locations,” etc., and proceed as described above. 5.2.2

42、When test units are to be taken from large rolls or skids, divide the lot or sublot into “locations” and “sublocations” no smaller than a roll or unopenable skid (see 5.3.2), assign and select numbers as described above, then proceed as described in 5.3 below. NOTE 1: In ISO and British Standards, t

43、he word “reel” is used for a continuous sheet or board wound on a core and the word “roll” for the same when wound without a core. In the United States, the distinction is between the “reel” at the end of the paper machine and the “rolls” (with or without the cores) made therefrom. 5.3 Large rolls o

44、r skids. 5.3.1 When taking a test unit from a large roll remove all damaged layers from the outside of the roll and, in addition, discard at least three undamaged layers for sheets having a nominal grammage of less than 250 g/m2(51.2 lb/1000 ft2) or at least one undamaged layer for heavier sheets. C

45、ut the roll across its full width and to a sufficient depth to enable the requisite number of sheets to be taken. Let the cut sheets fall to each side and remove the roll. 5.3.2 When taking a test unit from a skid or roll that may not be opened at the time of sampling, cut a window 300 by 450 mm (12

46、 18 in.) or larger if larger test specimens are required. Cut the window with its longer side parallel to the machine direction when this is known, or if not known, cut the window at least 450 by 450 mm (18 18 in.) with sides parallel to those of the skid. For paper that has been sheeted simultaneou

47、sly from several rolls, take a sufficient T 400 sp-11 Sampling and accepting a single lot of paper, / 4 paperboard, containerboard, or related product number of adjacent sheets to assure representation of all the rolls used. Cut the sheets to sufficient depth to enable the requisite number of sheets

48、 to be taken and remove them. Remove all outside sheets that are damaged and, in addition, discard at least the three outermost undamaged sheets for paper having a nominal grammage less than 250 g/m2(51.2 lb/1000 ft2) or at least one outmost undamaged sheet of heavier paper. Vary the position of the

49、 window at random among the skids or rolls from which test units are to be drawn, making sure that the sides of the window are parallel to those of the skid or to the roll edge and axis. 5.3.3 In either of the above, if a test for moisture content is to be made, it may be necessary to discard considerably more than three undamaged sheets of paper and one undamaged sheet of board. In one case reported in the literature (1), it was necessary to discard 40 sheets of manila board to obtain the moisture content of the major portion of the roll. Moisture content sample must