Test sheet

Physical Requirements for the Liquid Polymer and Cured Compounded Test Sheet... 

Plasticized PVC is tested by covering both sides of the pigmented test sheet with white plasticized PVC films, which are placed between glass or aluminum plates. With a certain weight on it, this sandwich is exposed for 24 hours at a temperature of 80°C (or for 15 hours at 100°C) [41], The thickness of the test sample does not affect the test results. 

The Avesta cell was originally used for testing sheet material as shown here. However, with a few changes, tubes and welds can be tested as well without preparatory machining. ... 

In testing sheet, welded, and pipe material, the specimen is placed as a part of the bottom plate of the Avesta cell. Especially at higher temperatures there will be a difference between the temperature of the solution and the temperature of the specimen. This can be corrected for by calibration. When the modified ASTM G5 electrode holder is used, the specimen is totally immersed in the solution and no correction is needed. 

Often the protocol will incorporate test sheets or sections for recording data. In this way, once the protocol has been executed, the document constitutes a record of the results and conclusion [3]. It must describe the activities to be performed in a validation, including the acceptance criteria for the approval of a manufacturing process or a part thereof for routine use [1]. 

OQ tests are very commonly used in the ongoing performance verification or calibration of the system. Test templates should be used for OQ. An example is shown in Figure 17.2. Most important is that acceptance criteria should be defined before the test, and both acceptance criteria and test results should be documented in the test sheet. 

Except for work on complete products, a test piece must be formed before the test can be carried out. In many cases, the test piece can be directly moulded but, particularly when tests on finished products are concerned, the specimens need to be cut and/or buffed to some particular geometric shape (Figure 4.1). It is convenient to consider separately, first the mixing and moulding leading up to a vulcanised (or thermoplastic) test piece or test sheet, and secondly the preparation of test pieces from moulded sheets or products. The preparation of test pieces for tests on raw rubber and unvulcanised compounds will be considered integrally with those tests in Chapter 6. 

Provide the calibration test sheet(s), applicable to the instrument under test, that should be used to record all test data necessary to satisfy the specified calibration requirements. 

The calibration test sheets form the evidence necessary to demonstrate the accuracy of data gathered during product manufacture and as such are key inspection documents. Critical instruments must be provided with a calibration test sheet/certificate that details both the test results and their limits of uncertainty. Calibration test sheets must be checked and approved by an authorized person. 

These films can be based on Teflon (DuPont, Wilmington, Delaware) film, polypropylene, or Mylar (DuPont, Wilmington, Delaware) polyester film. These release materials are normally used where the surface of the material must be free of any contamination and defects. An example of the application is in the preparation of test sheets for determining mechanical properties. 

The preparation of the sample is important. There should be no gas bubbles or other imperfections in the test sheet. The cutting knife must be sharp and free from any nicks. The sides of the sample must not be concave or have any fine ridges. Tensile samples from hard grades may be milled out. 

These preliminary studies to evaluate the potentially damaging effects of the direct exposure to test sheets to visible and near-ultraviolet radiation employed exposures tens of times greater than those customarily used in "light bleaching" procedures. Moreover, the test sheets have been exposed directly to the radiation in contrast to the customary exposure of the papers in an aqueous bath to achieve bleaching. Experiments to be reported elsewhere show that the damage to the paper is very much reduced when the sheets are immersed at less than a centimeter... 

To determine the penetration of the radiation through the sheet of aluminum a number of measmrements of the ionization current due to the radiation from the mercury vapor with and without the test sheet of aluminum in the path of the rays were made. The test sheet was placed close to the pin-hole, K, so that a negligible amount of the scattered radiation from it entered the ionization chamber. 

In order to calculate the theoretical amount of radiation that should pass through the test sheet of aluminum, if the distribution in the spectrum follows the above inverse square law, it is necessary to determine accurately the absorption of x-rays of different wave-lengths by the mica windows and the sheets of aluminum. This has been done as described in the previous note by measuring the absorption of a few mono-... 

After the experiments reported in the previous note (loc. dt.) had been finished, the tube was purposely broken and the absorption of the glass window determined for homogeneous rays in the x-ray spectrometer. Calculations similar to those described above show that in the earlier experiments, 56% of the radiation coming through the glass window theoretically should have passed through the test sheet of aluminum, whereas, as previously reported, 57.5% passed through it. The results of. the earlier experiments, therefore, indicate that the theoretical penetration of the radiation is approximately that observed. 

Several years ago we began to express the results of our thermal and photochemical degradation experiments in terms of Equation 4. Figure 1 shows some of the initial data obtained, relating to exposure of test sheets in the Fade-ometer. Just as Daruwalla and Narsian (16) observed, there seems to be a break in the curve. If the first stage indeed represents weak links, about 3 such bonds per 10,000 in the original cellulosic chain (0.03 ) are apparent, a figure similar to the fraction of labile acid-sensitive links determined by Sharpies (21) and labile photochemically sensitive links reported by Daruwalla (16) when radiation at 2540 A was used. 

Test sheets were prepared principally from Whatman No. 42 filter... 

Extraction of HemiceUuloses from Various Pulps. The extraction procedure followed was that of Giertz and McPherson (6). Fifteen grams of unaged pulps [four kinds in all bleached kraft pulp (BP), unbleached kraft pulp (UBP), unbleached groundwood pulp (GP), and chlorited UBP] was treated with 290 mL of 10.9 lithium hydroxide solution for 1 h at room temperature and was stirred intermittently (see Table I for the characteristics of the pulps). After the samples were diluted to about 1 L, the insoluble material was filtered off. The extract (filtrate) was neutralized to pH 6 with 2 M phosphoric acid (300 mL) and was allowed to stand overnight. The precipitated lithium phosphate and /3-cellulose were separated by filtration. The filtrate was then concentrated to about 175 mL under reduced pressure at 30-40 °C. Salts present in the system were further precipitated with methanol and separated by filtration. The filtrate was again concentrated to about 60 mL. The filter paper was immersed into this concentrate to saturate the test sheets. 

Filter Paper with Hemicellulosic Fractions Added On. Hemicellu-lose fractions were isolated from unaged and thermally aged papers by extraction with LiOH, following the procedure described by Giertz and McPherson (6). The changes in postcolor number [100(K/S) — (K/S)0] (7) for various test sheets during exposure to visible and UV radiation and to heat are shown in Figures la, lb, and lc for material extracted from... 

Figure 1. Changes in postcolor number of filter-paper sheets with 15% add-on of hemicellulose fractions derived from various pulps. For comparison, the thermal discoloration of a test sheet of groundwood pulp, gp, is shown. The initial postcolor number represents the increase in color over that of the untreated filter paper a, daylight fluorescent lamps b, black-light fluorescent lamps c, heat (90 °C and 50% rh). Key O, blank filter paper , BP A, GP V, UBP 0, chlorited UBP.

In contrast, marked and very similar darkening occurred upon the thermal aging of added-on test sheets at 90 °C and 50 rh, regardless of the particular hemicellulosic extract (Figures lc and 2c). For comparison, the behavior of handsheets made solely from groundwood pulp (gp), notorious for its tendency to discolor, is shown in each figure. 

Figure 5. Postcolor number of test sheets of various contents of y-cellulose that were prepared from UBP by extraction with alkali The 10.5% sample is the starting material Key (percent y-cellulose) 0,0,10.5 8.8 A,A,...

Acetylxylan and arabinogalactan added-on test sheets, postcolor number changes, 383-84... 

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