A cartonboard package is often sealed and closed with an adhesive – either a hot-melt adhesive (adhesives that are applied in a molten state on the cartonboard) or a dispersion adhesive (adhesives that are applied as water-based dispersions). This thesis focuses on the process of hot-melt gluing, and how material properties and process conditions affect the performance of the adhesive joint. Requirements vary depending on how the package is to be used. A package that is only supposed to protect the product during transport differs from one that is supposed to attract consumers and facilitate their use of the product. If a package has been opened, due to external or internal forces that cause a fracture in the adhesive joint, the consumer may choose another package instead. A fracture of the adhesive joint may occur in several different ways; for example, a cohesive fracture in the adhesive, an interfacial fracture between the adhesive and one of the cartonboard surfaces, and a cohesive fracture in the cartonboard. The traditional way of testing the adhesive joint is to subjectively evaluate the fibre tear after manually tearing the joint apart. The primary interest of this study has been to find an objective method that can characterise the adhesive joint – that is, its strength and joint characteristics. The work has principally concentrated on physical experiments where the Y-peel method has been evaluated and further developed, including the construction of a laboratory adhesive applicator. Adhesive joint failure is analysed and correlated to the force-elongation curve during Y-peel testing in order to explore various mechanisms of the failure. The force versus elongation curves are transformed into a force versus inelastic deformation curve for the adhesive joint. The inelastic deformation of the adhesive joint is defined as the inelastic opening of the adhesive joint perpendicular to the cartonboard surface. The dissipative descending energy has been used to characterise the adhesive joint. High descending dissipative energy showed high resistance against final failure of the joint. This correlates very well with the manual fibre-tear test. Characteristic force-elongation curves in Y-peel testing – that is, the shape of the curve – have been analysed, and four main failure modes have been identified. The finite element method has been used to predict mechanical behaviour in the ascending part of the force-elongation curve. When it comes to local behaviour, a high stiffness adhesive results in bending behaviour while a low results in shearing, but on a global scale, no big difference was detected on the ascending part of the force-elongation curve. The new laboratory adhesive applicator and finite element method can be used to objectively design the interaction between the adhesive and the cartonboard for a specific application. This can be achieved by modifying the cartonboard, the adhesive or the process parameters.

In which ways can the process of trimming dispersion coated board products be optimized so as to reduce material waste and increase production efficiency? This is the question that this master thesis report seeks to answer. In paper production, alot of waste is generated when cutting production reels into customer reels. Some material waste are necessary in order to ensure good quality, however a large amount of the wastecould be reduced if the cutting process was to be optimized. During this project, carried out at a forest company, a mathematical optimization model was developed in order to reduce waste and save costs. This model is based on a cutting stock problem using column generation approach. It provides as its output cutting patterns and an optimal allocation of rolls for production purposes, which implies minimizing the number production rolls needed.The visualization of the results could also be used to achieve optimal stock levels, and easier keep track on how to use the material available in stock. Findings show that there are potential savings to be done. Simulations suggest an implementation of this model could result in material savings of around 7 %. This could also translateto environmental savings in CO2, where every decrease of one tonne material equals to adecrease in CO2emissions of 500 kg

Biomimetic tactile sensing was previously mostly performed in medical situations, such as when locating tumors in patients’ bodies. This thesis examined the effectiveness of using a biomimetic tactile sensory equipment for examining pressure distribution throughout carton board packages, made in two different carton board qualities. The purpose was to examine to what extent biomimetic tactile sensing was able to mimic the results of a group of human test subjects evaluations. Eight packages, made from two different materials, were tested. There were four packages of each of the materials. Each package had four points where displacement measurements with a force of 6N were conducted. The packages were then measured twice on a single point on the edge of the package, with the force of 12N.  The packages at disposal were compressed using a uniaxial-tensile-testing machine alongside with the aforementioned equipment. The pressure sensitive film was placed on top of the packages and a limit on the maximum force to be applied was set on the testing machine. Two limits on the applied forces were set, the first to see the distribution of pressure within the range of elastic deformation, so that no lasting deformation would have occurred. The second force limit was set to see the moment where the elastic deformation area transformed into the plastic deformation area, to see whether or not there was a difference in the distribution of pressure pre- or post-plastic deformation. From the results from compression tests, it was clear that there was a difference in pressure distribution before and after the plastic deformation had occurred. The experimental diagrams showed that the curves were vastly different in both cases. It was also clear that there was a significant difference in the distribution of pressure, depending on if the pressure was applied closer to the middle compared to closer to the center of the package (single vs multiple concentration of forces, respectively). Inspecting results from packages made in both carton board qualities, there were no clear results as the same trends could be seen throughout the tests.  It was concluded that the BioTac could be used to accurately identify concentrations of forces, differences in pressure distribution and the location of deformation. This means that the BioTac will be useful in future experiments, when objectively evaluating and defining grip stiffness, with the help of methods such as the finite-element method. / Biomimetiskt taktilt avkännande var något som tidigare mestadels utfördes för medicinala syften, såsom för att lokalisera tumörer i patienters kroppar. Detta examensarbete undersökte effektiviteten av att använda en biomimetisk taktil avkännare för att granska tryckfördelningen genom kartongförpackningar, gjorda av material från två olika kartongkvaliteter. Totalt åtta förpackningar, gjorda av två olika material, provades. Det var fyra av varje materialtyp. Varje förpackning mättes på fyra punkter med 6N och sedan två gånger på samma punkt med 12N. Förpackningarna till förfogande trycktes ihop med en enaxlad drag- och tryckprovare samt den tidigare nämnda avkännaren. En tryckkänslig film användes mellan avkännaren och förpackningen för att tydligt se tryckfördelningen på alla förpackningarna. Två gränser på den maximala tillåtna kraften upprättades i tryckmaskinen, 6N och 12N. Den lägre nivån sattes för att undersöka tryckfördelningen inom det elastiska deformationsområdet, utan att en kvarstående plastisk deformation uppstått. Den högre gränsen sattes för att undersöka skedet där det elastiska deformationsområdet övergår till det plastiska. Båda gränsvärdena valdes för att undersöka om det gick att urskilja en skillnad i tryckfördelningen innan och efter plastisk deformation, eller inte.  Från resultaten av dessa kompressionstest var det tydligt att det fanns en skillnad i tryckfördelning före och efter den plastiska deformationen uppstått. De uppställda diagrammen visade att kurvorna var mycket annorlunda i båda fallen. Det var, dessutom, relativt tydligt att det fanns en skillnad i tryckfördelning beroende av om trycket var applicerat närmre mitten av paketet jämfört med om det var applicerat närmre kanten av paketet (enskilda kraftkoncentrationer vid mitten av förpackningarna och multipla koncentrationer vid kanten av förpackningarna). Genom att undersöka resultat från förpackningar gjorda av båda kartongkvaliteter, upptäcktes ingen tydlig skillnad i förpackningarna, då liknande trender uppstod i båda materialen. Slutsatsen drogs att BioTac kunde användas för att finna kraftkoncentrationer, skillnader i tryckfördelning, samt området för deformation. Detta betyder att BioTac-sensorn kan vara nyttig vid framtida experiment, för att objektivt utvärdera och definiera greppstyvhet, med metoder som finita-element-metoden.

This is a thesis project done on behalf of BillerudKornäs in collaboration with Örebro University in a research project investigating grip stiffness of carton board packages. This is of interest because a better understanding of it would allow optimizing of the packaging design and result in a better product. In this thesis the mission has been to develop a setup for a sensor enabling a method of testing on packages. This has been carried out as a product development project. After a preparation study a specification of requirements was written. With the use of this a number of concepts were generated. Through evaluation one concept was chosen for further development and built as a prototype model. The prototype did not work satisfactory at the end of the project but could with some improvements be useful in testing packages with the intended sensor. / Detta är ett examensarbete utfört åt BillerudKorsnäs i samarbete med Örebro universitet inom ett forskningsprojekt där greppstyvhet hos kartongförpackningar undersöks. Det här är intressant eftersom att en djupare förståelse inom området skulle möjliggöra optimering av förpackningsdesignen och resultera i en bättre produkt. Uppgiften i detta examensarbete har varit att utveckla en testrigg för en sensor med syfte att möjliggöra en laborativ metod för att testa förpackningar. Detta har bedrivits som ett produktutvecklingsprojekt. Efter att en förstudie gjorts togs en kravspecifikation fram. Med hjälp utav vad som definierats i denna generades ett antal koncept. Genom utvärdering valdes ett koncept för vidareutveckling och byggdes sedan som prototypmodell. Prototypen fungerade inte tillfredställande vid projektets slut men skulle efter vissa förbättringar kunna vara användbar vid tester av förpackningar med den avsedda sensorn.

The work has been carried out mainly for Tetra Pak within the project "A New Model for Deformation of Carton boardPackages by Manual Handling". Tetra Pak is specialized in food packaging, its processing and distribution. The purpose of this thesis was to implement a new carton board model for the finite element method which describes both the elastic and plastic deformation, this is called Hill’s model.This model is used to describe orthotropic materials, which a carton board is. Next, examine the differences that occurred in terms of principal stress and force-displacement diagram for different carton board packages when loaded with different objects. Simulations were performed in the finite element program Ansys APDL. To start with, a literature study was performed to cover the theory of the problem, problem causes and other work carried out in the same area. Then the material model was constructed and the simulations were performed. After this, all the data was gathered and analyzes performed. The introduction of the new material model was successful. The result shows how the carton board packages act until the maximum force the package can engage, in some cases also what happens after this state. The results also show how the principal stresses develop and the size of these. / Examensarbetet har utförts för i huvudsak Tetra Pak inom projektet "A New Model for Deformation of Carton Board Packages by Manual Handling". Tetra Pak är specialister på livsmedelsförpackningar, dess bearbetning och distribution. Syftet för detta examensarbete var att införa en kartongmodell för finita elementmetoden som beskriver både elastiskt och plastiskt tillstånd, denna kallas Hills modell. Modellen används för att beskriva ortotropa material, vilket kartong är. Därefter undersöka skillnader som uppstod vad gäller huvudspänningar och kraftförskjutningsdiagram för olika kartongförpackningar när dessa utsattes för olika tryckande objekt. Simuleringar utfördes i finita elementprogrammet, Ansys APDL. Till att börja med utfördes en litteraturstudie för att täcka teorin om problemet, problemorsaker och andra utförda arbeten inom samma område. Därefter gjordes materialmodellen var på simuleringarna utfördes. Efter detta samlades all data in och analyser utfördes. Införandet av den nya materialmodellen lyckades. Resultatet visar hur kartongförpackningarna agerar fram till den maximala kraften som förpackningen kan ta upp, i vissa fall även vad som händer efter detta tillstånd. Resultaten visar också hur huvudspänningarna utbreder sig och storleken på dessa.