Transmission properties of high barrier coated paperboard packages

High barrier materiaaleilla pyritään pidentämään pakattujen elintarvikkeiden hyllyikää. Barrierin tärkein tehtävä on elintarvikkeen suojaaminen hapelta ja kosteudelta. Alumiinin käyttöä barriermateriaalina pyritään vähentämään korvaamalla alumiini polymeereillä, jotka täyttävät elintarvikkeiden asettamat korkeat säilyvyysvaatimukset. Etyylivinyylialkoholin (EVOH) hapenläpäisevyys on kuivissa olosuhteissa alhaisin kaupallisista muovilaaduista. EVOH tarjoaa myös erinomaisen suojan muita kaasuja, rasvoja, hajuja ja aromeja vastaan ja sitä on helppo prosessoida. Polyamideilla on erinomainen kaasutiiveys sekä hyvä lujuus ja sitkeys. Eri muovilaatuja sekoittamalla voidaan vähentää hapenläpäisyä ja parantaa prosessointia. Polyolefiineja käytetään yleisesti päällystysmateriaaleina, koska ne suojaavat tuotetta erinomaisesti kosteudelta. Hapenläpäisyllä tarkoitetaan hapen kulkeutumista materiaalin läpi joko permeaation kautta tai reikien ja vuotojen läpi. Kaasun permeoitumiseen materiaalin läpi vaikuttavat materiaalin vapaa tilavuus, kiteisyysaste, orientaatio, substituointi, suhteellinen kosteus, lämpötila, barrierkerroksen paksuus, paine-ero ja permeoituvan molekyylin ominaisuudet. Kokeellisessa osassa analysoitiin ja vertailtiin kartonkipohjaisia mehutölkkejä, joissa käytettävät high barrier materiaalit olivat EVOH ja PA. Kartonkipohjaisia alumiinitölkkejä käytettiin referenssinä. Pakkausten hapenläpäisevyysmittauksissa saatiin samasta näytteestä toistettavia tuloksia, vaikka vuotomittauksissa saadut tulokset eivät olleet vertailukelpoisia hapenläpäisytulosten kanssa. Tölkkien valmistus vaikutti oleellisesti pakkausten tiiveysominaisuuksiin. Hapenläpäisy vuotojen ja reikien läpi oli merkittävämpää kuin hapenläpäisy materiaalin läpi. Pakkausten tiiveysominaisuuksia analysoitiin mittaamalla appelsiinimehun askorbiini-happopitoisuus. Askorbiinihapon hajoaminen mitattiin koetölkkeihin pakatusta appelsiinimehusta, ja lämpötilan, valon ja hapen vaikutusta askorbiinihapon hajoamiseen tutkittiin 12 viikon ajan. Lämpötilalla oli suurin vaikutus askorbiinihapon hajoamiseen huolimatta käytetystä pakkausmateriaalista.

Methods to test gas tightness of packages

One of the primary goals for food packages is to protect food against harmful environment, especially oxygen and moisture. The gas transmission rate is the total gas transport through the package, both by permeation through the package material and by leakage through pinholes and cracks. The shelf life of a product can be extended, if the food is stored in a gas tight package. Thus there is a need to test gas tightness of packages. There are several tightness testing methods, and they can be broadly divided into destructive and nondestructive methods. One of the most sensitive methods to detect leaks is by using a non destructive tracer gas technique. Carbon dioxide, helium and hydrogen are the most commonly used tracer gases. Hydrogen is the lightest and the smallest of all gases, which allows it to escape rapidly from the leak areas. The low background concentration of H2 in air (0.5 ppm) enables sensitive leak detection. With a hydrogen leak detector it is also possible to locate leaks. That is not possible with many other tightness testing methods. The experimental work has been focused on investigating the factors which affect the measurement results with the H2leak detector. Also reasons for false results were searched to avoid them in upcoming measurements. From the results of these experiments, the appropriate measurement practice was created in order to have correct and repeatable results. The most important thing for good measurement results is to keep the probe of the detector tightly against the leak. Because of its high diffusion rate, the HZ concentration decreases quickly if holding the probe further away from the leak area and thus the measured H2 leaks would be incorrect and small leaks could be undetected. In the experimental part hydrogen, oxygen and water vapour transmissions through laser beam reference holes (diameters 1 100 μm) were also measured and compared. With the H2 leak detector it was possible to detect even a leakage through 1 μm (diameter) within a few seconds. Water vapour did not penetrate even the largest reference hole (100 μm), even at tropical conditions (38 °C, 90 % RH), whereas some O2 transmission occurred through the reference holes larger than 5 μm. Thus water vapour transmission does not have a significant effect on food deterioration, if the diameter of the leak is less than 100 μm, but small leaks (5 100 μm) are more harmful for the food products, which are sensitive to oxidation.

The modular forming press for paperboard packages

In this master’s thesis the structural and functional features of a forming tool are developed to meet the needs of modern packaging production for paperboard packaging are studied. The goal of the study is to develop a new type of machine for the manufacture of the paperboard package by pressing. In the structure of the developed forming press the possibility to modify the packaging as well as the requirements of industrial production, food hygiene and other operational matters are accounted for. The press has been sized based on the main dimensions of a single food-grade paperboard tray. In the LUT Packaging Laboratory the forming press is designed suitable for on-line operation. In addition, suggestions for further development of packaging line and equipment have been made based on the information gathered during this thesis study.

Looking beneath Dalí's paint: non-destructive canvas analysis

A new analytical method was developed to non-destructively determine pH and degree of polymerisation (DP) of cellulose in fibres in 19th 20th century painting canvases, and to identify the fibre type: cotton, linen, hemp, ramie or jute. The method is based on NIR spectroscopy and multivariate data analysis, while for calibration and validation a reference collection of 199 historical canvas samples was used. The reference collection was analysed destructively using microscopy and chemical analytical methods. Partial least squares regression was used to build quantitative methods to determine pH and DP, and linear discriminant analysis was used to determine the fibre type. To interpret the obtained chemical information, an expert assessment panel developed a categorisation system to discriminate between canvases that may not be fit to withstand excessive mechanical stress, e.g. transportation. The limiting DP for this category was found to be 600. With the new method and categorisation system, canvases of 12 Dalí paintings from the Fundació Gala-Salvador Dalí (Figueres, Spain) were non-destructively analysed for pH, DP and fibre type, and their fitness determined, which informs conservation recommendations. The study demonstrates that collection-wide canvas condition surveys can be performed efficiently and non-destructively, which could significantly improve collection management.

Vaahtoamisen estäminen vesiohenteisissa sisäseinämaaleissa

Maalit ovat hyvin komplekseja seoksia, jotka sisältävät erilaisia pinta-aktiivisia aineita. Erilaisia pinta-aktiivisia apuaineita käytetään varsinkin vesiohenteisissa maaleissa veden korkean pintajännityksen takia. Nämä maalin komponentit saat-tavat kuitenkin aiheuttaa maaliin vaahtoamisongelmia. Maalien vaahtoaminen aiheuttaa esimerkiksi erilaisia pintavikoja maalikalvossa ja epäotpimaalista tuo-tantosäiliöiden ja pakkausten täyttöä. Joissain tapauksissa myös maalin funktio-naalisuus saattaa häiriintyä. Maalien vaahtoamista pyritään vähentämään pääasiassa vaahdonestäjiksi kutsu-tuilla apuaineilla. Tärkeimmät vesipohjaisissa maaleissa käytettävät vaahdonestäjät ovat mineraaliöljyjä sekä silikonipohjaisia vaahdonestäjiä. Tässä työssä tutkitaan kolmen eri vesiohenteisen sisäseinämaalin vaahtoamista ja mahdollisia keinoja vähentää sitä. Laboratoriossa kokeillaan nykyisten vaahdonestäjien tilalle mahdollisia korvaavia apuaineita. Lisäksi kullekin maalille luodaan koesuunni-telma, jonka mukaan toteutetaan tehtaalla sarja koeajoja, joilla pyritään löytämään sopiva vaahdonestäjän annostus sekä lisäystapa kullekin maalille, siten että maalien vaahtoaminen vähenee. Laboratoriokokeiden perusteella korvaavaa vaahdonestäjää nykyisten tilalle ei löydetty. Valmistusprosessin yhteydessä sen sijaan havaittiin, että vaahdonestäjän lisäystapaa muuttamalla voisi olla mahdollista vähentää maalien vaahtoamista merkittävästi lisäämättä käytettävää vaahdonestäjän annostusta.

A method to determine volatile contaminants in polyethylene terephthalate (PET) packages by HDC-GC-FID and its application to post-consumer materials

A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.

Dynamics of gas levels inside packages containing minimally processed Pera orange

The purpose of this study was to evaluate the changes in concentrations of O2 and CO2 inside packages of minimally processed Pera orange. Previously selected oranges that were washed, sanitized, and chilled were peeled using hydrothermal treatment (immersion of fruits in water at 50 °C for 8 minutes). The peeled oranges were then packed in five different plastic packages under passive and active modified atmosphere (5% O2 + 10% CO2 + 85% N2). The fruits were stored at 6 °C and 12 °C. The package headspace gas composition was evaluated for twelve days at 6 °C and nine days at 12 °C. The polypropylene film (32 µm) promoted modified atmosphere similar to that initially injected (5% O2 + 10% CO2 + 85% N2) at 6 °C and 12 °C. With regard to the atmosphere modification system, the injection of a gas mixture anticipated achieving an equilibrium atmosphere inside the packages at 12 °C. At 6 °C, the gas composition inside the packages was kept close to that of the injection, but the equilibrium was not verified.

Post-harvest conservation of camu–camu fruits (Myrciaria dubia (Kunth) Mc Vaugh) using different temperatures and packages

Abstract The camu-camu tree (Myrciaria dubia (Kunth) Mc Vaugh) is fruit-bearing tree belonging to the family Myrtaceae. This work was conducted with the purpose of evaluating the type of storage temperature and package which allow better conservation of the quality attributes of camu-camu. The experimental design utilized was the completely randomized with three replications in a factorial arrangement (3x3x8), constituted of three different storage temperatures (laboratory ambiente or 25 ± 2 °C, 15 °C and 20 °C), three types of packages (no package, PET and PVC) and fourteen days’ storage, the fruits being analyzed every two days. The fruits were evaluated as to fresh mass loss, pH, soluble solids contents, titrable acidity, ascorbic acid, carotenoids, anthocyanins, chlorophylls A and B and maturation index (SS/AT). According to the results obtained, the quality attributes and ascorbic acid content were conserved for longer time in the fruits stored on PVC-film covered expanded polystyrene trays at 15 °C. It follows that the best temperature for the storage of camu-camu is 15 °C and the package that best keeps its quality attributes is the PVC-film covered expanded polystyrene tray.

Structural analysis of the Paint Lake Deformation Zone, Northern Ontario /

The Paint Lake Deformation Zone (PLDZ), located within the Superior Province of Canada, demarcates a major structural and lithological break between the Onaman-Tashota Terrane to the north and the Beardmore-Geraldton Belt to the south. The PLDZ is an east-west trending lineament, approximately 50 km in length and up to 1 km in width, comprised of an early ductile component termed the Paint Lake Shear Zone and a late brittle component known as the Paint Lake Fault. Structures associated with PLDZ development including S-, C- and C'-fabrics, stretching lineations, slickensides, C-C' intersection lineations, Z-folds and kinkbands indicate that simple shear deformation dominated during a NW-SE compressional event. Movement along the PLDZ was in a dextral sense consisting of an early differential motion with southside- down and a later strike-slip motion. Although the locus of the PLDZ may in part be lithologically controlled, mylonitization which accompanied shear zone development is not dependent on the lithological type. Conglomerate, intermediate and mafic volcanic units exhibit similar mesoscopic and microscopic structures where transected by the PLDZ. Field mapping, supported by thin section analysis, defines five strain domains increasing in intensity of deformation from shear zone boundary to centre. A change in the dominant microstructural deformation mechanism from dislocation creep to diffusion creep is observed with increasing strain during mylonitization. C'-fabric development is temporally associated with this change. A decrease in the angular relationship between C- and C'-fabrics is observed upon attaining maximum strain intensity. Strain profiling of the PLDZ demonstrates the presence of an outer primary strain gradient which exhibits a simple profile and an inner secondary strain gradient which exhibits a more complex profile. Regionally metamorphosed lithologies of lower greenschist facies outside the PLDZ were subjected to retrograde metamorphism during deformation within the PLDZ.

Letter to S.D. Woodruff from William Leary, steward, endorsing G. Fish to paint the new building

Letter to S.D. Woodruff from William Leary, steward, endorsing G. Fish to paint the new building (1 ½ pages, handwritten), June 7, 1875.

Printed blank from the New York Central and Hudson River Railroad Express Freight Line, New York for shipping packages of brackets and racks to S.D. Woodruff of St. Catharines

Printed blank from the New York Central and Hudson River Railroad Express Freight Line, New York for shipping packages of brackets and racks to S.D. Woodruff of St. Catharines. This document is signed by R.L. Crawford, agent, Aug.11, 1876.

Attention to health cues on product packages

The objectives of the study were (a) to examine which information and design elements on dairy product packages operate as cues in consumer evaluations of product healthfulness, and (b) to measure the degree to which consumers voluntarily attend to these elements during product choice. Visual attention was measured by means of eye-tracking. Task (free viewing, product healthfulness evaluation, and purchase likelihood evaluation) and product (five different yoghurt products) were varied in a mixed within-between subjects design. The free viewing condition served as a baseline against which increases or decreases in attention during product healthfulness evaluation and purchase likelihood evaluation were assessed. The analysis revealed that the only element operating as a health cue during product healthfulness evaluation was the nutrition label. The information cues used during purchase likelihood evaluation were the name of the product category and the nutrition label. Taken together, the results suggest that the only information element that consumers consistently utilize as a health cue is the nutrition label and that only a limited amount of attention is devoted to read nutrition labels during purchase likelihood evaluations. The study also revealed that the probability that a consumer will read the nutrition label during the purchase decision process is associated with gender, body mass index and health motivation.

A comparative study of the creative expressions in paint and clay of deaf and hearing children

This paper discusses the results of study to determine differences in artwork done by hearing impaired and normal hearing children.