MFHPB-05 Method for the Determination of Micro-leaks in Hermetically Sealed Metal and Glass Containers
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CA4469743EC74C459514AB300FABD5D9 |
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文件大小(MB)： |
0.22 |
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页数： |
9 |
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文件格式： |
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日期： |
2012-3-2 |
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文本摘录（文本识别可能有误，但文件阅览显示及打印正常，pdf文件可进行文字搜索定位）：
Published on the Food Directorate’s (Health Canada's) website at http://www.hc-sc.gc.ca/food-aliment.,Government of Canada Gouvernement du Canada,HPB Method MFHPB-05,May 2003,HEALTH PRODUCTS AND FOOD BRANCH,OTTAWA,METHOD FOR THE DETERMINATION OF MICRO-LEAKS IN,HERMETICALLY SEALED METAL AND GLASS CONTAINER,Dev C. Nundy,Food Laboratory,Ottawa Laboratory (Carling),Canadian Food Inspection Agency,Ottawa, Ontario K1A 0C6,E-mail: dnundy@inspection.gc.ca,1. APPLICATION,The purpose of the method is to detect micro-leaks in containers by application of a known vacuum or,pressure. The method is applicable to all two and three-piece hermetically sealed metal cans and glass,containers. The vacuum micro-leak test is the preferred method. Alternatively, special dyes can be used to,also detect micro-leaks. These tests can be used to determine the presence of defects on the double seam,side seam, scoreline, pull-tab and the can body, and their severity if they are present, whether they are hidden,or visually apparent. In glass containers with caps the failure of enamel on the inside of the cap, gasket,improper formation of or depth of lugs on “twist-off” caps, smears, dirt or foreign material on caps and possible,fractures in the glass are some of the defects that could be detected by the micro-leak test. This revised,method replaces MFHPB-25E, dated October 1991.,2. PRINCIPLE,The method employs the application of a known vacuum or pressure to an emptied, cleaned and dried metal,cans or glass containers. Leaks are detected by observing the formation of air bubbles at the site of leakage.,The application of special dyes allows for the detection of leaks through the test site and observed visually.,3. DEFINITION OF TERMS,See Appendix A of Volume 2.,4. COLLECTION OF SAMPLES,See Appendix B of Volume 2.,MFHPB-05,- 2 - May 2003,5. MATERIALS AND SPECIAL EQUIPMENT,Vacuum micro-leak test:,1) Micro-leak detector,Preparation of the vacuum testing system is described in Appendix A.,2) Sealing gaskets,One sealing gasket for each container size (diameter) or shape (big enough to accommodate the,largest containers expected to be tested) are required and can be cut from ?inch (6.35 mm) sheet,of gum or neoprene rubber. The inside diameter of each gasket should be approximately ?inch,(12.7 mm) smaller than the container diameter and have an outside diameter approximately ?inch,(12.7 mm) greater. "O" rings of similar construction and size can be purchased to fit all of the popular,container diameters.,3) Vacuum source,A laboratory vacuum and pressure pump or its equivalent capable of maintaining a constant vacuum,head of 25 ± 1 inches of mercury.,3.1 Calibration of the vacuum source is to be performed yearly, or as required, using a calibrated,NIST (National Institute of Standards and Technology) certified calibrator.,4) Valves and piping,The valves and piping can be arranged as shown in Figure 2. The piping should be ?inch,(6.35 mm) R.P.T. withc inch (3.175 mm) nipples at either end to accept rubber pressure tubing to,connect the valve system to the vacuum source and the detector plate. The arrangement may vary,slightly depending on the equipment available.,5) Light source,A 100 Watt, quartz/iodine lamp attached to a 1-?foot (45 cm) flexible tube (fibreglass tube has been,found to be adequate) or a commercially available halogen lamp source for observations can be used.,6) Bacti-Disc Cutters (Wilkens-Anderson Co., Dixie Canner Equipment Co.).,7) Round Glass tank or rectangular Fish tank.,Pressure micro-leak test :,List of materials and preparation of the pressure testing system as described in Appendix B.,Micro-leak test with dyes :,1) Ardrox liquid dye (Ardrox P134D, Water Washable Fluorescent Penetrants. Oakite Ltd., 115 East,Drive, Bramlea, Ont., L6T BI7, 1-800-668-4318),2) Developer (Ardrox 9D1B, Oakite Ltd., 115 East Drive, Bramlea, Ont., L6T BI7, 1-800-668-4318),3) Magnaflux zyglo liquid green fluorescent dye (ZL-4B Magnaflux Corporation, Chicago, IL),4) Erythrosin B (Sigma Ltd. Cat. No. E886),5) Rodamine B (Sigma Ltd. Cat. No. R662),6. PROCEDURE,MFHPB-05,- 3 - May 2003,SAFETY PRECAUTIONS: Follow all safety procedures outlined in MFHPB-01 and MFHPB-06 for food in,hermetically sealed containers.,6.1 Preparation of sample units,6.1.1 Ensure that the identification of the container has been done as described in MFHPB-06.,6.1.2 Remove and identify the label as described in MFHPB-06.,6.1.3 Select the end to be opened. Usually this will be the uncoded end (can manufacturer’s end).,6.1.4 Locate and clearly mark any visible defects using the Metal Can Defects, Identification and,Classification Manual, Canadia……
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