| Title | Istraživanje čvrstoće ambalaže od valovitog kartona u kondicioniranim uvjetima |
| Title (english) | The research strength of the
packaging of corrugated cardboard
in terms of conditioned |
| Author | Denis Jurečić |
| Mentor | Darko Babić (mentor) |
| Committee member | Vilko Žiljak (član povjerenstva) |
| Committee member | Branka Lajić (član povjerenstva) |
| Committee member | Zvonimir Sabati (član povjerenstva) |
| Granter | University of Zagreb
Faculty of Graphic Arts
Zagreb |
| Defense date and country | 2015-12-23, Croatia |
Scientific / art field,
discipline and subdiscipline | TECHNICAL SCIENCES
Graphic Technology |
Universal decimal classification
(UDC) | 655 - Graphic industries. Printing. Publishing. Book trade |
| Abstract | Kutije od valovitog kartona za pakiranje voća i povrća susreću se na svom
distribucijskom putu od proizvođača do potrošača s vrlo promjenljivim vremenskim uvjetima.
Distribucijski put podrazumjeva najčešće dulji boravak u različitim hladnjačama pri prijevozu
i skladištenju te kratkotrajno izlaganje vanjskim atmosferskim uvjetima pri pretovaru. U
hladnjačama, radi očuvanja kvalitete i kvantitete voća i povrća, vladaju definirani uvjeti
temperature i vlažnosti dok u vanjskoj okolini oni variraju. Izloženost tim promjenama ima
nepovoljan utjecaj na mehanička svojstva valovitog kartona a posljedica je značajno
smanjenje vijeka trajanja kutije.
Cilj ovog istraživanja je razviti model ambalaže od valovitog kartona za predviđanje
njene čvrstoće na tlačno opterećenje, bazirano na kondicioniranim uvjetima relativne
vlažnosti i temperature okoline. Kako je agrokulturnoj industriji primarna briga težina i
kvaliteta voća i povrća dok je ambalaža nužan izdatak koja mora opstati u datim uvjetima uz
minimalan trošak. Cilj je otkriti informacije kojima ćemo odrediti donju granicu kvalitete
kutije od valovitog kartona a kod koje postoji minimalna mogućnost njenog loma.
Ispitivano je šest kvaliteta peteroslojnog valovitog kartona sa različitim
kompozicijama slojeva papira različitih gramatura. Ispitivani su papiri od kojih je izrađen
valoviti karton te kutije izrađene od tog valovitog kartona. Ispitivana je gramatura, debljina,
otpornost na prskanje po Mullenu, otpornost horizontalne površine valovitog kartona na
tlačnu čvrstoću, otpornost vertikalne površine valovitog kartona na tlačnu čvrstoću, sadržaj
vlage u valovitom kartonu, otpornost valovitog kartona na dinamičko probijanje, otprnost
kutije od valovitog kartona na tlačnu čvrstoću, relativna vlažnost zraka u hladnjači, relativna
vlažnost zraka u okolini, temperatura hladnjače i temperatura okoline. Brojna mjerenja su
interpretirana regresijskom analizom.
Rezultati pokazuju velika odstupanja temperature i relativne vlažnosti zraka hladnjače
i okoline. Prosječna razlika u temperaturi između hladnjače i vanjske okoline iznosi 23,88°C,
dok je prosječna razlika relativne vlažnosti zraka u odnosu na okolinu 22,58%. Toplinska
šokiranja kojima su bili izloženi uzorci kutija pokazuju velika odstupanja u tlačnoj čvrstoći.
Uzorcima 2KŠ i 2KŠ-E tlačna čvrstoća pala je za 40% i nakon samo dva dana došlo je do urušavanja kupova na paleti. Ostali uzorci izdržali su ove drastične promjene. Mjeranja
pokazuju da pad tlačne čvrstoće kod svih uzraka prati istovremeno veliko povećanje sadržaja
vlage.
Zaključak. Cikličke promjene relativne vlažnosti zraka uz zanemarivi utjecaj vremena
trajanja opterećenja drastično smanjuju nominalnu tlačnu čvrstoću kutija od valovitog
kartona. Skladištenje voća u hladnjači zahtjeva upotrebu visokokvalitetnih kartona
proizvedenih od visokokvalitetne nereciklirane sirovine.
Preporuke. Predlaže se analiza mjerenja kontrole kvalitete papira za ravni i valoviti
sloj u samom proizvodnom procesu njegove izrade. Ovi podaci mogli bi se iskoristiti za
određivanje utjecaja na graničnu tlačnu izdržljivost svakog sloja valovitog kartona kao i
graničnu tlačnu izdržljivost kutije. Predlaže se i postavljanje barijere za vlagu na površinu
valovitog kartona ali ta odluka trebala bi se bazirati na studiji o veličini i stupnju kruženja
vlage. |
| Abstract (english) | Boxes made from the corrugated board for packing the fruit and vegetables meet very
changeable weather conditions on their distribution way from the producer to the consumer.
Longer stay in different cold storage plants during the transport and storage as well as
the short exposition to the outer atmospheric conditions during the reloading is understood
under the distribution way. In the cold storage plants, for preserving the quality and the
quantity of the fruit and vegetable, there are defined conditions of temperature and humidity
while in the outer environment they vary. The exposition to these changes has an
unfavourable influence on the mechanical properties of the corrugated board and the
consequence is the considerably decrease of the boxes lifespan.
The aim of this investigation is to develop the model for prediction the box strength on
the compression load, based on the conditioned state of relative humidity and the temperature
in the environment. As the weight and the quality of fruit and vegetables is the primary care in
the agricultural industry, the packaging is necessary expense which must survive in the given
conditions with minimal costs. The aim is to find out the information which will determine
the lower boundary of the corrugated box quality and the minimal possibility of its
breakdown.
Six qualities of the double – wall corrugated board with different composition of paper
layers of different grammage were investigated. The papers used for the production of the
corrugated board and the boxes produced from that corrugated board were investigated. The
grammage, the thickness, the burst resistance per Mullen, the resistance of the horizontal
surface of the corrugated board to compression strength, the resistance of the vertical surface
of the corrugated board to compression strength, the humidity content in the corrugated board,
the resistance of the corrugated board to dynamic penetration, the resistance of the corrugated
board to compression strength, relative humidity of the air in the cold storage plant, relative
humidity of the air in the environment, temperature of the cold storage plant and the
temperature of the environment were tested. Numerous measurements were interpreted by the
regression analysis. The results show great aberrations of temperature and relative humidity of the air in
the cold storage plant and in the environment. The average difference in temperature between
the cold storage plant and the outer surroundings was 23,88oC, while the average difference of
the relative humidity of the air in regard to the environment was 22,58%. The thermal shock
to which the box samples were exposed showed great aberrations in the compression strength.
The compression strength of the samples 2KŠ and 2KŠ-E was decreased for 40%, and after
only two days the stacks on the pallet imploded. The rest of the samples survived these drastic
changes. Measurements show that the decrease of the compression strength of all the samples
follows the simultaneous great humidity content increase.
Conclusion: The cyclic changes of the relative humidity in the air, with the negligible
influence of the time duration drastically decrease the nominal compression strength of the
corrugated boxes. The storage of the fruit in the cold storage plants demands the usage of the
high quality boards produced from the high quality non recycled raw material.
The analysis of the paper quality control measurements for the flat and wall layer is
suggested in its production process. These data could be used for determining the influences
on the boundary compression durability of each layer of the corrugated board as well as the
boundary compression durability of the boxes. The setting of the humidity barrier on the
surface of the corrugated board is also suggested. This decision however should be based on
the size and on the degree of the humidity circulation. |
| Language | croatian |
| URN:NBN | urn:nbn:hr:216:173426 |
| Study programme | Title: Graphic engineering and graphic product design
Course: Graphic technology
Study programme type: university
Study level: postgraduate
Academic / professional title: doktor/doktorica znanosti u području tehničkih znanosti (doktor/doktorica znanosti u području tehničkih znanosti) |
| Type of resource | Text |
| File origin | Born digital |
| Access conditions | Open access |
| Terms of use |  |
| Created on | 2024-04-24 22:06:10 |
