Optimizacija kolorimetrijskih vrijednosti fleksibilne ambalaže nakon postupka sterilizacije i obrade visokim hidrostatskim tlakom = Optimization of colorimetric values of flexible packaging after sterilization process and processing with high hydrostatic pressure

Tomerlin, Renata (2019) Optimizacija kolorimetrijskih vrijednosti fleksibilne ambalaže nakon postupka sterilizacije i obrade visokim hidrostatskim tlakom = Optimization of colorimetric values of flexible packaging after sterilization process and processing with high hydrostatic pressure. Dissertation (PhD) thesis. Grafički fakultet. [Mentor: Tomiša, Mario].

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Sastavni dio svakog prehrambenog proizvoda čini ambalaža koja je jedan od ključnih faktora pri donošenju odluke o kupnji. Cilj je da kroz čitav grafičko-tehnološki proces i proces obrade gotovog proizvoda ambalaža ostane nepromijenjena u svim svojim karakteristikama. Ambalažni materijal koji je predmet istraživanja višeslojna je fleksibilna ambalaža, koja se sastoji od ukupno četiri sloja, od čega su tri sloja polimerni materijali (poliester, orijentirani poliamid i polipropilen), a jedan sloj je aluminij. Za potrebe istraživanja pripremljeni su uzorci s apliciranim dizajnom dvije tekuće juhe (Vegeta – Krem juha od šparoge i Podravka – Krem juha od koprive). Krem juha od šparoge otisnuta je u dominantno Vegeta plavoj boji, a Krem juha od koprive u dominantno Podravka crvenoj boji. Navedene spotne boje i njihova kolorimetrijska odstupanja tijekom grafičkotehnološkog procesa i procesa obrade gotovog proizvoda predmet su istraživanja. Za obje boje predefinirano je područje tolerancije u CIE L*a*b* prostoru boja. Mjerenja su izvršena na uzorcima dva dizajna za fazu tiska, kaširanja, sterilizacije i obrade visokim hidrostatskim tlakom. Kolorimetrijska odstupanja u tisku za obje boje unutar su definiranog tolerantnog područja (Podravka ΔECMC = 0,38; Vegeta ΔECMC = 0,23). Kaširanjem transparentnog polimernog materijala na sloj aluminija dolazi do neželjenih kolorimetrijskih odstupanja kod obje boje (Podravka ΔECMC = 3,21; Vegeta ΔECMC = 1,56), dok procesom sterilizacije Podravka crvena ima neznatan povrat prema vrijednostima standarda, a Vegeta plava raste u kolorimetrijskom odstupanju (Podravka ΔECMC = 2,99 za rominjanje, ΔECMC = 2,94 za zrak-paru; Vegeta ΔECMC = 1,69 za rominjanje, ΔECMC = 1,69 za zrak-paru). Kod obrade visokim hidrostatskim tlakom Podravka crvena opada u odstupanju i dolazi do još jednog povrata vrijednosti prema standardu, a kod Vegeta plave zabilježen je rast vrijednosti odstupanja (Podravka ΔECMC = 2,47; Vegeta ΔECMC = 1,94). Na temelju dobivenih rezultata vidljivo je da se u fazi kaširanja transparentnog poliestera na sloj aluminija događa najveće i neprihvatljivo odstupanje za zaštićene boje robnih marki koje su predmet istraživanja. Dvije se boje ne ponašaju identično kroz grafičko-tehnološki proces i svaka faza uzrokuje različita kolorimetrijska odstupanja. Prevenciju kolorimetrijskih odstupanja potrebno je odraditi u fazi grafičke pripreme i recepturi spot boja.

Item Type: Dissertation (PhD) thesis
Mentor name: Tomiša, Mario
Thesis Committee: Mrvac, Nikola and Pap, Klaudio and Vusić, Damir
Defence date: 25 July 2019
Abstract in english: Packaging is an integral part of the food product and it has become one of the most influential factors in the purchase decision. Aside from aesthetic graphic parameters, which enhance the attractiveness of the product and affect the purchase process, packaging must meet various other functional parameters. Accordingly, food packaging is often subjected to the finished product processing such as various sterilization processes or Hydrostatic Pressure Processing treatment (HPP). The main objective is to keep the food packaging characteristics unchanged throughout the entire graphic technology process and the processing of the final product. Since all these procedures affect the colorimetric color values and stability, they also inevitably affect the aesthetic graphic parameters and the behavior of the package container and packaging material in general. Hence, it is necessary to examine and control for the graphic procedure influence during the packaging production process and processing of the final food product. This study aims to examine behavior of a multilayer flexible composite packaging consisting of a total of four layers, of which three layers are polymer materials (polyester, oriented polyamide and polypropylene), and one layer is aluminum. Aforementioned combination is used to form a self-contained bag, also known as retort stand - up pouch. This type of packaging is gradually entering the market, taking over the glass and metal packaging dominance in the sterilized food products sector. Combination of several different layers of material provides an adequate protection and barrier for the final product, and allows necessary physical mechanical packaging properties that are subjected to the sterilization process and Hydrostatic Pressure Processing treatment. Global companies usually strive to standardize and enhance recognition of their main visual attributes. Given that, Podravka is no exception, investing great efforts in quality, repeatability and uniformity of all visual materials, including packaging. The most significant brands are Podravka and Vegeta. Making precisely the protected spot colors for these two brands the aim of this research. In cooperation with their suppliers (packaging producers), Podravka defined the recipe and composition for Podravka red and Vegeta blue, with defining areas as the toleration within which colors can have colorimetric deviation. The Podravka red tolerance is: ΔE ≤ 2, while Vegeta blue tolerance is: ΔE ≤ 1. For the research purpose, samples were prepared with the experimental design of two liquid soups applied (Vegeta - Asparagus Cream Soup and Podravka - Nettle Cream Soup).Asparagus Cream Soup is printed in the dominant Vegeta blue color, and Nettle Cream Soup in the dominant Podravka red color. The subject of this research are the aforementioned spot colors and their discrepancy during the graphical technological process and the final product processing. The samples were printed using rotogravure printing technique at the Aluflexpack Novi printing house in Umag, while prepress and printing forms were made in Anilox company. The lamination, forming and sealing of self-contained bags was also carried out at the Aluflexpack Novi. For the purpose of this research, processing of the finished product was simulated using water at the Podravka Pilot Laboratory for applying the sterilization process and the Faculty of Food Technology in Zagreb for Hydrostatic Pressure Processing treatment. This paper has studied the impact of the graphic process by phase (printing, lamination) on the colorimetric deviation of Vegeta blue and Podravka red spot colors, and their behavior after the sterilization process and processing with high hydrostatic pressure. The aim of this research was to define a process phase where the greatest deviation in the colorimetric values is present, while also offering guidelines for the prevention of color spot deviation from the set, prescribed values. Measurements were performed on 25 samples for each design, for phase of printing, lamination and sterilization. After applying the Hydrostatic Pressure Processing treatment, 24 samples were measured. Statistical methods were applied to analyze the measurement results, and they are expressed by the median as the core result of the set of measured samples. Colorimetric deviations in printing values for Podravka red are ΔECMC = 0.38 for light source D65./10 ° and are therefore found acceptable. For Vegeta blue, colorimetric deviation under the same printing conditions is ΔECMC = 0.23. By lamination the transparent polymeric material on the aluminum layer, undesirable colorimetric variances occur in both colors - Podravka red is more distinct with value ΔECMC = 3.21, while Vegeta blue value amounts half less ΔECMC = 1.56. Applying sterilization, there is a slight improvement in colorimetric deviation of Podravka red color, while CIE L*a*b* color values return to the default standard (ΔECMC = 2.99 for resurfacing, ΔECMC = 2.94 for air vapor). After sterilization, colorimetric values of Vegeta blue remain virtually identical as after the phase of lamination, with slightly increased deviation (ΔECMC = 1.69 for the resurfacing, ΔECMC = 1.69 for the air vapor). After applying the Hydrostatic Pressure Processing treatment to the product, Podravka red color is returned to its default and standard values (ΔECMC = 2.47), while Vegeta blue deviation increases (ΔECMC = 1.94).The obtained research results reveal that the largest and unacceptable colorimetric deviation of the trademark brand colors are present in the lamination phase. Therefore, it is necessary to redefine the color recipe before the printing phase, considering the colorimetric deviation that occurs during the lamination phase. If the final product is subjected to a sterilization process or treated with Hydrostatic Pressure Processing, these deviations must be taken into account. It has also been noted that after lamination, smaller difference in Vegeta blue color is visibly stronger than the difference in Podravka red color. For this reason, the tolerant area is not identical for both colors - Podravka red tolerance is twice larger as the tolerance for Vegeta Blue color. The study and definition of colorimetric deviations in spot colors of protected brands are of particular interest to global companies such as Podravka. The goal of almost every global company is to achieve and maintain recognition. In particular, protected and defined spot colors must be kept within the prescribed standard and tolerance, throughout the complete graphical technological process and prepress processes of the final product. Spot colors can be precisely measured and the area in which the colorimetric deviations will occur can be recognized for a particular type of packaging material and a particular printing technique.
Uncontrolled Keywords: CIE L*a*b*, fleksibilna ambalaža, kolorimetrijsko odstupanje, obrada visokim hidrostatskim tlakom, samostojeća vrećica, spot boja, sterilizacija
Keywords in english: CIE L*a*b*, flexible packaging, Hydrostatic Pressure Processing treatment, stand up pouch, spot color deviation, sterilization
Subjects: TECHNICAL SCIENCES > Graphic Technology
Institution: Grafički fakultet
City: Zagreb
Number of Pages: 144
Callnumber: 535.6:621.798:655
Inventory number: 10318
Depositing User: Nina Jelača
Status: Unpublished
Date Deposited: 09 Apr 2024 09:02
Last Modified: 09 Apr 2024 09:02
URI: http://eprints.grf.unizg.hr/id/eprint/3638

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