446 Novel food packaging techniques Mechanical strength of a package This is determined using a simulated transportation test. For example in the VTT ransportation test, a whole pallet positioned on a vibration table is subjected to a simulated road transportation of about 1000 km. As an example, during this 45- minute test run. the table is vibrated at a constant acceleration of 0.5 g. with the frequency of the table sweeping between 5 and 55 Hz. Since each package type resonates at its own specific frequency, every package tested is exposed to mor or less high accelerations during the test procedure. In general, the packages in the top layer of a pallet are exposed to the highest accelerations, which can be even more than 6 g. After the test, all the possible flaws, such as flexes, fractures, open seals and product disorientation originating from the transportation tests are recorded, and the test packages are scored as follows I point: if even one tested package in the pallet is leaking, the whole sample group is rejected Suitability with respect to packaging standard. This is evaluated by examining the volume occupied by the primary packages tested in a secondary package, which had the dimensions of the pallet area Scores between I and 5 are given on the following basis I point: relatively large empty space left in the secondary package 5 points: primary packages tight together, no empty space in the secondary tio of package weight to product weight score for this ratio(= Sm)is calculated using eqn I Sm=0.444.(1-m/m:100+5 where mp= weight of the empty package and m= weight of the packaged food Equation I was formulated on the following basis I point corresponds to an empty package weighing 10% of the weight of the packaged product, and 5 points correspond to an empty package weighing 1% of the weight of the packaged product ge waste This is scored from 1 to 5 on the following basis I point: a rigid package, e.g. tray, which cannot be scrunched and which would require a large space in a household waste basket 5 points: a package that is made of a thin flexible material, which can easily be put in a household waste basket without the need for stuffing or crunchingMechanical strength of a package This is determined using a simulated transportation test. For example in the VTT transportation test, a whole pallet positioned on a vibration table is subjected to a simulated road transportation of about 1000 km. As an example, during this 45- minute test run, the table is vibrated at a constant acceleration of 0.5 g, with the frequency of the table sweeping between 5 and 55 Hz. Since each package type resonates at its own specific frequency, every package tested is exposed to more or less high accelerations during the test procedure. In general, the packages in the top layer of a pallet are exposed to the highest accelerations, which can be even more than 6 g. After the test, all the possible flaws, such as flexes, fractures, open seals and product disorientation originating from the transportation tests are recorded, and the test packages are scored as follows: • 1 point: if even one tested package in the pallet is leaking, the whole sample group is rejected. • 3 points: there are some minor dents or flexes. • 5 points: no package is affected by the vibration test. Suitability with respect to packaging standards This is evaluated by examining the volume occupied by the primary packages tested in a secondary package, which had the dimensions of the pallet area. Scores between 1 and 5 are given on the following basis: • 1 point: relatively large empty space left in the secondary package. • 5 points: primary packages tight together, no empty space in the secondary package. Ratio of package weight to product weight The score for this ratio (ˆ Sm) is calculated using eqn 1 Sm ˆ 0:444
…1 ÿ mp=mf
100† ‡ 5 …1† where mp ˆ weight of the empty package and mf ˆ weight of the packaged food. Equation 1 was formulated on the following basis: • 1 point corresponds to an empty package weighing 10% of the weight of the packaged product, and • 5 points correspond to an empty package weighing 1% of the weight of the packaged product. Volume of package waste This is scored from 1 to 5 on the following basis: • 1 point: a rigid package, e.g. tray, which cannot be scrunched and which would require a large space in a household waste basket. • 5 points: a package that is made of a thin flexible material, which can easily be put in a household waste basket without the need for stuffing or scrunching. 446 Novel food packaging techniques