The performance o f a retortable semi-rigid aluminium container, o f square shape, net capacity 330ml and w i t h a heat sealable lid, produced in Germany by Alcan, was studied relative t o parameters o f filling, thermal processing and heat sealing. Tests were applied t o packages containing water (275 and 295g) and a solution of carboxymethyl cellulose (CMC) at 1.25% (295 and 306g). The thermal processing was applied under stationary and rotary (at 8, 10 and 12 r.p.m.) conditions. Heat sealing was evaluated by visual aspect, integrity, burst resistance, tensile strength and thickness reduction. The influence o f contamination (presence of water, water vapour, CMC and vegetable fat) on the heat sealing area was also examined.Rotary thermal processing has been proved more advantageous in comparison w i t h a stationary process, mainly for a high viscosity model medium (CMC solution at 10000 CP a t 25°C). as it reduces the sterilization time t o about 50%. The headspace volume measured by the destructive method indicated small variations, significant a t the level o f 5%, when pre-and post-thermal processing values were compared. This is due t o the presence of entrapped air in the test product, which is released during thermal processing. The seal resistance measured by the increase in internal pressure (burst) resistance showed average values o f 26-29 p.s.i. obtained for packages containing water or CMC examined preand post-stationary and rotary (8 r.p.m.) thermal processing. Such average values guarantee the container good performance. A t the 5% level, there was no significant difference i n burst resistance for the container processed with or without rotation, containing either water or CMC, a t any of the filling levels analysed. Contamination of the heat sealing area, evaluated through the burst resistance, indicated the non-existence o f any significant difference at the level of 5% and the minimum value of 25p.s.i. can be said t o be satisfactory for all the treatments studied. For the t w o test products, at S. A. ORTlZ €7 AL. the filling levels studied, the compression resistance measured before heattreatment showed average maximum load values ranging from 84.5 to 87.8kgf (deflection varying from 4.7 to 5.0mm). After both stationary and rotary (8r.p.m.) thermal processing, the minimum crushing yield load value was around 83.5 kgf. Such values are acceptable for this kind of package.

The mechanical performance of lightweight glass packages produced by the NNPB (narrow neck press and blow) process was evaluated by comparison with the same glass packages (regular weight) produced by the conventional process (blow and blow). The temper number (annealing process evaluation), thickness distribution behaviour and mechanical performance (impact, vertical load and thermal shock strength) were analysed before and after line simulation, applied in optimized conditions in the laboratory. The performance of lightweight glass packages under transport simulation (truck envelope) in relation to the regular weight bottles was also evaluated. Both bottles presented residual stress values within the speci®ed limits. The lightweight glass bottles had a more homogenous thickness distribution in comparison with the regular weight bottles and a better performance (about 33% improvement) in relation to the impact strength, especially in the heel, even when evaluated after line simulation. As to the vertical load strength, the lightweight glass bottle also indicated a superior performance to the regular weight bottle, both before and after line simulation. Both bottles withstood the temperature difference of 42°C that such packages are supposed to resist according to thermal shock speci®cation. Due to the better thickness distribution of lightweight glass packages, they withstood a maximum temperature difference (progressive thermal shock) of 5±10°C higher than the regular weight bottles. No restrictions of the lightweight glass packages submitted to the transport simulation were found.