Packaging methods barrier

Microbial ChaUenge/Product Sterility Test Methods. There are really two types of microbial barrier test those performed on materials and those performed on whole packages. Microbial barrier... 

The male barrier contraceptive device is known as the condom, or mbber, and is widely available in most countries. The condom is a mbber or latex sheath, sometimes packaged with a lubricant and spermicide, which serves as a cover for the penis and a receptacle for semen. The method is very effective if the condom is of good quaUty, remains on, and is replaced for each subsequent intercourse. It was reported that 6 biUion condoms were used in 1990 (101). Usage appears to be increasing as adjunctive use with other methods of contraception for prevention of HIV or other sexually transmitted diseases. By rough estimate, condoms may have been used in more than 13 biUion acts of sexual intercourse that risked unwanted pregnancy, HIV, and/or other sexually transmitted diseases (101). 

A description is given of the initiatives carried out within the European Community for the harmonization of fire testing. The technical and economic reasons are explained for such initiatives, which are taken in order to remove barriers to trade from the European internal market. Of the various fire aspects, only fire reaction testing is taken into consideration here, because it appears as a major technical obstacle to the free circulation of construction materials. All possible approaches are considered for the attainment of such a harmonization and one, the so called interim solution, is fully described. The proposed interim solution, is based on the adoption of three fundamental test methods, i.e. the British "Surface Spread of Flame", the French "Epiradiateur" and the German "Brandschacht", and on the use of a rather complicated "transposition document", which should allow to derive most of the national classifications from the three test package. 

To determine the suitability of fluorinated HDPE containers as packaging material for the solvent-based formulations, the containers were placed in well-ventilated ovens at 50°C for 28 days. During this period the mass loss of the contents was monitored. To date more than 130 liquid crop protection chemical formulations have been evaluated at the AEC by this method with at least 91 of them having serious permeation problems through the untreated HDPE containers. In only two cases fluorinated containers did not have acceptable barrier properties. 

The above results suggest a potential for utilizing surface fluorinated plastics for modified atmosphere and vacuum packaging applications. If needed, the barrier properties can be improved further by vacuum metalization. Excellent adhesion was found for vacuum-deposited aluminum on this new fluorinated layer, achieving an adhesion index of 10 using the classical cross-hatch method. With this treatment method it was also possible to heat-seal PP or PE onto PET. 

T. Penttinen, K. Nevalainen, and J. Jarvinen, Method for manufacturing heat-sealable packaging material having barrier layer containing cycloolefin copolymer, US Patent 7 344 759, assigned to Stora Enso Oyj (Helsinki, FI), March 18, 2008. 

UHT milk differs from pasteurized milk mainly in the heat treatment employed for sterilization. Usually UHT milk is heated at 130° to 150°C for 2 to 8 seconds and is then aseptically packaged. In the final heating stage, steam is injected directly into the milk, or the milk is infused into a steam chamber, followed by flash evaporation to remove added water (steam). An alternative procedure, the indirect method, involves heating milk across a stainless steel barrier, using high-pressure steam as the heating medium (Mehta 1980). 

This test is intended to detect channels, open pathways, or discontinuity in a sealed area specified as a critical primary barrier. Pinholes in nonporous materials are also detected. This method is suitable for both flexible and rigid packages and with porous and nonporous materials. 

NBS s involvment in SRM s for gas transmission studies arose out of activities within ASTM Committees D-20 (Plastics) and F-2 (Flexible Barrier Materials) that were aimed at standardizing a new instrumental method employing a coulometric oxygen detector for the measurement of oxygen gas transmission rates in materials used for various kinds of packaging (4 ). A subsequent reevaluation of the precision data for the classical manometric and volumetric methods (5) for gas transmission measurements showed that there are serious problems with the reproducibility and repeatability these methods. The use of SRM 1470 to verify the calibration is currently being written into ASTM standards D-3985 and D-1434. 

EVOH have superior gas barrier properties.80 89 They are often used as the internal layer in multilayer food packaging films, blow molded rigid containers, gasoline tanks for automobiles for a variety of purposes, etc. EVOH can be fabricated by the usual melt processing methods. The barrier properties of films decrease in the presence of moisture, so multilayer with protective polypropylene (especially biaxially oriented material), low-density polyethylene, nylons, or other moisture barrier films provides films or products that are useful even with liquids. The... 

Debeaufort, F., Quezada-Gallo, J.A., and Voilley, A. (2000). Edible barriers A solution to control water migration in foods. In Food Packaging Testing Methods and Applications. American Chemical Society, Washington, DC, pp. 9-16. 

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