Neinvazivni postupak mjerenja deformacija u mikrostrukturi peteroslojnog valovitog kartona

Denis Jurečić, Branka Lajić, Tigran Jokić, Aleksandra Bernašek Petrinec

Sažetak

Valoviti karton je kombinacija vanjskih papirnih ravnina i unutarnjih valovitiha struktura, međusobno slijepljenih. Ta struktura omogućuje otpornost na savijanje i deformaciju. U radu se proučavaju povezanosti oblika kartona pod utjecajem vlage i mehaničkih deformacija. Namjera je utvrditi povezanost transformacija materijala i stupanj deformacije valovitog kartona prema različitim utjecajima. Uvodimo neinvazivni postupak kvantitativnog mjerenja deformacija u mikrostrukturi valovitog kartona. Presjek valovitog kartona snimi se digitalnom kamerom koja omogućuje preciznost od preko tisuću dijelova na jednom milimetru. Makro fotografija presjeka valovitog kartona rasčlanjuje se na piksel strukturu visoke rezolucije. Budući da se snimanje odvija u različitim bližim ili daljnjim pozicijama, snima se i tvrdi talon. Taj talon je kovanica od 5 kuna. I za njega se određuje debljina kao broj piksla na istoj snimci, u isto vrijeme. Svako mjerenje će dati drugačiji broj piksla. Pojedini sloj mjeri se na desetak mjesta kako bi se utvrdila njegova debljina i nastala deformacija. Rezultati se prezentiraju kroz srednje vrijednosti i standardne devijacije svakog pojedinog sloja peteroslojnog valovitog kartona.

Ključne riječi: Valoviti karton, stupanj deformacije, piksel

Non-Invasive Procedure of Measuring Deformations in Micro-Structure of Five-Layer Corrugated Cardboard

Denis Jurečić, Branka Lajić, Tigran Jokić, Aleksandra Bernašek Petrinec

Abstract

Corrugated cardboard is a combination of external paper planes and internal corrugated structures, pasted together. This structure allows the resistance to bending and deformation. The paper investigates the connection between the forms of cardboard under the influence of humidity and mechanical deformation. The intention is to determine the relationship between the transformation of the material and the degree of deformation of the corrugated cardboard under various influences. A non-invasive procedure of measuring the quantity of deformation in the microstructure of corrugated cardboard was applied. The cross-section of corrugated cardboard was recorded by a digital camera, that allows the precision of the more than one thousand parts per one millimetre. The macro photo of the cross-section of corrugated cardboard was analysed in the pixel structure of high resolution. Since the recording took place in different, closer or further positions, the hard talon was recorded. The talon was a 5 kuna coin. The talon was used as the reference for determining the thickness as the number of the pixels on the same photo at the same time. Each measuring resulted in a different number of pixels. Specific layers were measured at ten sites in order to determine its thickness and create deformation. The results are presented in the mean values and standard deviations of each layer of the five-layer corrugated cardboard.

KeyWords: corrugated cardboard, level of deformation, pixel