ISSN:0894-3214    

DOI:10.1002/pts.2770040102

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040103

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040104

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractIn principle, an aseptic package should protect against any type of microbe penetration. It means that each microhole must be less than about 0.5μm in diameter. In practice this critical limit may be much higher, owing to various factors, and consequently a controlling system does not necessarily have to have such a sensitivity.Controlling systems based on gas leakage detection have been suggested. In this report the basic validity range of such systems, including either mass spectrometer detection or an infra‐red spectrometer, is analysed and various crucial factors are clarified as a basis for technical development.The actual control principle assumes that transmission of gases through the package originates only from microholes and cracks and that gas permeation through the packaging material is negligible.However, in practice the gas permeation may be considerable. For example, a package having a polyethylene (LDPE) barrier layer of 50μm in thickness has a gas permeation comparable to what is coming out through a pinhole of 10μm in diameter, and accordingly only much bigger microholes can be determined, with reference to calculations presented. If the barrier is improved by a Saran® layer (PVDC) of 25μm the gas permeation is still disturbing and only holes bigger than about 5μm in diameter may be detected. If instead the barrier is improved by an aluminium layer, gas permeation is negligible in most cases, and the basic principle of the gas leak detection systems is valid.Infra‐red spectrometer based systems theoretically need at least a test time of 0.5 min and in practice much more to detect a microhole of 10μm in diameter‐to collect a sufficient quantity of trace gas. Mass spectrometer based systems are in principle not testing time limited assuming a rapid enough vacuum pump can be arranged and that moisture interferences do not arise from the packaging material or from the packaged contents.Further, some aspects on the necessity of introduction a 100% control system,vis‐a‐ visa statistical control system, are given in terms of producer's and consumer's risks. About 100 packagings/h must be tested at ordinary production speed (1000–3000 packagingslh−1) to check accepted quality levels of 0.1% defectives. At higher quality levels, i.e. less than 0.1% defectives, the sample size needed increases rapidly towards 100% of

ISSN:0894-3214    

DOI:10.1002/pts.2770040105

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040106

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractGlass containers are relatively heavy. Also, glass is fragile, and breakage sometimes occurs during handling and transport. Therefore, glass bottles must be constructed to achieve maximum strength at minimum weight (wall thickness). To our knowledge, about 85% of all breakage is caused by external impact.The purpose of the present paper is to study the relationship between the shape and thickness of glass bottles and the impact loads they can resist by using linear multivariate statistical/mathematical regression (or calibration) techniques (UN‐SCRAMBLER), in order to compute minimum required thickness of the bottle as a function of impact strength and vice versa.The study was based on 10 different types of bottles. Moreover, we have concentrated on measurements related to the heel of the bottle. The set of bottles used are described as follows: returnable, round body, straight side wall and without metal oxide coating. All the bottles were given a standard abusement before the impact tests.The following conclusions were reached:ithere are strong relations between glass thickness and the resistance to external impact (as expected);iimultivariate calibration gave much better results than using only one variable at a timeiiithe predictive ability is not good enough (accuracy of ±10–15%). But provides useful information that would be difficult to obtain by other methods(i

ISSN:0894-3214    

DOI:10.1002/pts.2770040107

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractPotential migrants were isolated by Soxhlet extraction from plastic laminates used to make a single‐use injection system. The concentrated extracts were then subjected to GCIMS analyses and about 22 compounds were identified. The majority of these appeared to be oligorners derived from polyethylene. Other compounds included monomers, oligomers. cross‐linking agents, processing aids such as fatty acids, plasticizers and anti‐slip agents. Three major new compounds were identified in the Soxhlet extract of gamma‐irradiated test laminates, all of which were considered to be reaction products of nonanedioic acid with alkoxy radicals. The effect of irradiation on the profile of potential migrants and the permeabilities of the laminates were also evaluated. The amount of extractives was determined using food simulating solvents such asn‐heptane, 8% alcohol and water. Minimal changes were observed in the extractives from gamma‐irradiated laminates compared with non‐irradiated laminates. The oxygen permeability was significantly reduced after gamma irradiation, while the average water vapour transmission rate was not significantly changed afte

ISSN:0894-3214    

DOI:10.1002/pts.2770040108

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040109

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040110

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770040112

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY