BS 684-1 7-1976 Methods of analysis of fats and fatty oils - Physical methods - Determination of surface-drying time《脂肪和油脂的分析方法 物理法 表面干燥时间的测定》.pdf

《BS 684-1 7-1976 Methods of analysis of fats and fatty oils - Physical methods - Determination of surface-drying time《脂肪和油脂的分析方法 物理法 表面干燥时间的测定》.pdf》由会员分享，可在线阅读，更多相关《BS 684-1 7-1976 Methods of analysis of fats and fatty oils - Physical methods - Determination of surface-drying time《脂肪和油脂的分析方法 物理法 表面干燥时间的测定》.pdf（8页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARD CONFIRMED APRIL 1993 BS684-1.7: 1976 Methods of analysis of Fats and fatty oils Part1: Physical methods Section1.7: Determination of surface-drying time IMPORTANT NOTE. It is essential that this Section be read in conjunction with the information in the “General introduction” to BS6

2、84, which is published separately. UDC665.1.014:543:667.612.82BS684-1.7:1976 This British Standard, having been prepared under the directionof the Oils and FatsStandards Committee, waspublished under the authorityof the Executive Boardon 29October1976 BSI11-1999 The following BSI references relate t

3、o the work on this standard: Committee reference OFC/24 Draft for comment74/50396 DC ISBN 0 580 09135 X A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Stand

4、ard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 and2 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicat

5、ed in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS684-1.7:1976 BSI 11-1999 i Contents Page 1 Scope 1 2 References 1 3 Definitions 1 4 Principle 1 5 Apparatus 1 6 Sampling and preparation of sample for analysis 1 7 Procedure 1 8

6、Expression of results 2 9 Test report 2ii blankBS684-1.7:1976 BSI 11-1999 1 1 Scope This Section describes a method for determining the surface-drying characteristics of a film of oil and is similar to that described in BS3900-C2. The method may be carried out either as a “go/no go” test by determin

7、ing the surface-drying state after a specified time to assess compliance with a particular requirement, or by determining the surface-drying state at suitable intervals until the surface-drying time is obtained. 2 References The following standards publications are referred to in this Section: BS245

8、, White spirit. BS410, Test sieves. BS458, Xylenes. BS1796, Methods for the use of British Standard fine-mesh test sieves. BS3900, Methods of test for paints PartC2:Surface-drying time (ballotini method). 3 Definitions For the purposes of this Section of BS684 the following definitions apply. 3.1 su

9、rface-drying state general term describing the state of the surface of a film of oil, i.e.whether “surface-dry” or not 3.2 surface-dry surface-drying state of a film of oil when ballotini can be lightly brushed away without damaging the surface of the film 3.3 surface-drying time period of time betw

10、een that at which a film of oil is applied to a prepared test panel, and that at which the film is assessed as just surface-dry by the procedure described in clause7 4 Principle Ballotini are poured on the film under specified conditions, then brushed away and the film examined visually. 5 Apparatus

11、 The following items of apparatus are required (see also BS684: General introduction). 5.1 Test panel, of polished plate glass approximately100mm 150mm. 5.2 Ballotini (transparent solid glass spheres), graded so that none passes a sieve of nominal aperture1254m, all pass a sieve of nominal aperture3

12、354m, and at least75% (m/m) pass a sieve of nominal aperture2504m but are retained on a sieve of nominal aperture1804m. (The test sieves used shall comply with BS410 and the testing shall be carried out in accordance with BS1796.) 5.3 Camel-hair brush 5.4 Stopwatch or stopclock 6 Sampling and prepar

13、ation of sample for analysis See BS684: General introduction. 7 Procedure 7.1 Preparation of test panel. Prepare the test panel by one of the following methods. 7.1.1 Solvent wash. Wash the panel three times with an excess of a suitable solvent. (e.g.white spirit complying with BS245 or xylene compl

14、ying with BS458) using a clean piece of cloth soaked in the solvent. Allow the clean panel to dry either by evaporation of the solvent or by lightly wiping with a clean linen cloth, if necessary warming very slightly to remove traces of condensed moisture. 7.1.2 Detergent wash. Wash the panel thorou

15、ghly in aqueous non-ionic detergent solution and then rinse thoroughly with distilled water. Dry by wiping with a clean linen cloth, if necessary warming very slightly to remove traces of condensed moisture. 7.2 Application. Brush the oil on to the surface of a prepared test panel(5.1). 7.3 Drying.

16、Place the panel in a vertical position in a well ventilated room at a temperature of16 C to21 C and a relative humidity of60% to70% so that the surface of the panel is illuminated by diffused daylight for at least6h during each day of the drying period. In order to avoid interference through deposit

17、ion of moisture on the oil film, take care that throughout the drying process the temperature of the room is above the dew point. NOTEThe temperatures stated are applicable to temperate climates. In the case of a test carried out in tropical or subtropical climates (or on material intended to be use

18、d in tropical or subtropical climates), any higher temperatures up to35 C may be substituted. The actual temperature and humidity at which the test is to be carried out should be the subject of agreement between purchaser and vendor.BS684-1.7:1976 2 BSI 11-1999 7.4 Assessment of surface-drying time

19、after a specified time. On completion of the specified period of drying, place the test panel in a horizontal position. Pour approximately0.5g of ballotini(5.2) from a height of150mm on to the surface of the film. NOTEIt is convenient to pour the ballotini down a glass tube of appropriate length and

20、 with an internal diameter of approximately25mm, in order to avoid undue spreading of the ballotini and thus to enable further tests to be made, if necessary, on other areas of the same panel. CAUTION. Ballotini split on to the floor can constitute a hazard. After1min hold the panel at an angle of20

21、 to the horizontal, brush lightly with the camel-hair brush(5.3) and examine the film using normal corrected vision. The film is surface-dry if all the ballotini can be brushed away without damage to the surface of the film. 7.5 Determination of surface-drying time. Prepare a number of similarly coa

22、ted test panels as described in7.2 and allow to dry as described in7.3. At appropriate intervals, starting shortly before the oil film is expected to be surface-dry and using a different panel for each test (or an untouched area of the same panel if the tube described in the note to7.4 is used), car

23、ry out the test as described in7.4 until the test shows the coating to be surface-dry. 8 Expression of results 8.1 Assessment of surface-drying time after a specified time. Express the result as “surface-dry” or “not surface-dry” as appropriate after a drying period of x, where x is the drying perio

24、d (in hours) used in the test procedure. 8.2 Determination of surface-drying time. Record the time taken for the oil film to become just surface-dry. 9 Test report See the general instructions and recommendations given in BS684: General introduction, and state the temperature and humidity if differe

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