ISSN:0894-3214    

DOI:10.1002/pts.2770030402

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA simple method for the consolidation of all of the conventional cushion curves for a particular material into a single relationship is discussed. The method requires only one of the usual cushion curves for an arbitrary drop height and cushion thickness to deduce the dynamic stress‐strain curve for the material. The results can then be used to generate all other cushion curves regardless of drop height, cushion thickness, or static loading. The procedure is applied to the published sets of cushion curves for Arcel® 512 and for expanded polystyrene, separately, and the predicted shock values for various drop conditions are then compared with the actual values from the cushion curves. The error incurred in using the consolidated data instead of the cushion curves is shown to fall within the limits of accuracy associated with the cushion curves themselves. The method offers many advantages, such as compactness of information, a continuous range of application, greater compatibility with computer aided cushion design, and a sizeable reduction in the number of drop tests required to generate new cushion performance da

ISSN:0894-3214    

DOI:10.1002/pts.2770030403

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe possible interaction between non‐coated aluminium and foods was studied using the corrosion behaviour of an aluminium household foil under different conditions of acidity, dissolved oxygen and temperature of the contacting phase.The aluminium foil was kept in contact with acetic acid solutions of pH values varying from 2.5 to 3.5 and dissolved oxygen concentrations between 0 and 8 ppm, under different conditions of temperature (from 0.3 to 50 °C) and contact time between 24 and 120 h. Corrosion was always detected and it was shown that all three variables influence the rate, and consequently the extent, of the interaction but pH and temperature have a greater effect since their relationships with rate are of an exponential nature. The relationship between corrosion rate and dissolved oxygen, however, is linear and has a minor accelerating effect on the corrosion rate.By applying the Arrhehius equation it was possible to evaluate the thermal sensitivity of the phenomenon with respect to the different variables.The activation energies vary between 31–635 and 88–471 J mol−1, indicating a higher thermal sensitivity at the lowest pH values and highest dissolved oxygen

ISSN:0894-3214    

DOI:10.1002/pts.2770030404

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe rapid increase in number of elderly persons with greater needs for medical care in future years will influence considerably the growth of medical packaging. A growing importance of disposable medical devices produced, packed and sterilized in manufacturers plants using various form‐fill‐seal (FFS) packaging systems has been observed during several recent years.The present predominance of flexible package thermoformed by a FFS system results from the considerably lower costs of these packages in comparison with rigid packaging. The role of packaging in this area is still not properly appreciated and analyses that were carried out showed that the major part of claims connected with sterility problems resulted for faulty packaging (mainly defective seals, pinholes and holes).The results of the assessment of heat‐seal strength are presented for thermoformed flexible packages processed on a Multivac machine and made of various laminates (mainly polyamide/polyolefine laminates) sealed with different types of sterilizable paper and used for packing disposable syringes and blood transfusion sets.A large scatter of results was found in both the individual packagings and the various packages processed on the same machine and made of the same materials. This spread of results occurred not only when packages were sealed using uncoated paper but also when paper with a grid pattern coating was used. A distinct advantage of the latter is the peelable opening of packages even when maximum seal strength is recorded. The reduction in the seal strength, which is very difficult to avoid, stresses the importance of selecting such combinations of materials giving distinctly higher average seal values while simultaneously maintaining the requirement for a peelable separation of the sealed layers during opening. An assessment of thickness distribution in the laminate and the PA layer shows that, because of the presence of areas of drastic thinning, the saving achieved by using a PA layer, increases the risk of package puncture, and therefore, may not be worthwhile.The substitution of polyproplyene for polyamide in laminate destined for thermoformed packages for medical devices must take account of the greater local thinning with simultaneous lower puncture resistance of polyprop

ISSN:0894-3214    

DOI:10.1002/pts.2770030405

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractWhen packaging technology reaches a certain level, it should be prepared for a variety of demands from the packed‐side about how to be packed. Knowledge of physical properties of food will be of importance to solve problems for controlling the food quality both during and after packaging. In this review paper, first the importance of controlling the water activity of the food is explained in relation to chemical and biochemical reactions.The significance of hysteretic in the process of drying and wetting is also indicated. Second, progress in the prediction of the thermal properties of food is reviewed. Special attention is paid to the systematic understanding of the effective thermal conductivity of various foods. Third, the seemingly irregular archeological behaviour of food materials is presented with recent theoretical explanations. Development in computational techniques helps to solve problems that have previously been left unsolve

ISSN:0894-3214    

DOI:10.1002/pts.2770030406

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770030407

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractAn experiment was performed to measure the oxygen transmission rate through the Gamma squeeze bottle for tomato ketchup and to determine the permeability constant for the Gamma material itself. Another experiment was carried out to study the change in the co lour of ketchup after long‐term exposure to an oxygen‐rich environment and to establish a minimum acceptable redness level for ketchup as measured by a standard Chroma Meter®. (Minolta Camera Co). The combined results were then used to determine the reaction rate between oxygen and ketchup and to predict the shelf‐life for co lour stability of ketchup packaged in the Gamma bottle. The predicted shelf‐life is at least

ISSN:0894-3214    

DOI:10.1002/pts.2770030408

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770030409

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0894-3214    

DOI:10.1002/pts.2770030401

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY