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Factors affecting the Relative Crease Strength of paperboard

Smedman, Oskar LU (2017) In ISRN LUTFD2/TFHF-17/5218-SE(1-61) FHL820 20171
Solid Mechanics
Abstract
Paperboard is frequently used as a base material in packages. There is folding involved in the conversion process, where a package is formed from a paperboard sheet. However, because direct folding causes undesirable effects such as wrinkles, it must first be creased. The creasing procedure consists of intentionally damaging the material, creating an indentation on the piece, after which the material may be folded as desired.

Constitutive models for paperboard require a large number of parameters to precisely reflect the material behaviour during strongly nonlinear processes such as creasing and folding. In order to increase understanding of the connection between the parameters and the material's behaviour, a parameter study has been... (More)
Paperboard is frequently used as a base material in packages. There is folding involved in the conversion process, where a package is formed from a paperboard sheet. However, because direct folding causes undesirable effects such as wrinkles, it must first be creased. The creasing procedure consists of intentionally damaging the material, creating an indentation on the piece, after which the material may be folded as desired.

Constitutive models for paperboard require a large number of parameters to precisely reflect the material behaviour during strongly nonlinear processes such as creasing and folding. In order to increase understanding of the connection between the parameters and the material's behaviour, a parameter study has been conducted and documented in this thesis. Simulation of the procedure is performed in Abaqus/Standard with the help of its scripting tools. Specifically, the tendency of the material to fold along the crease lines will be measured using the relative crease strength (RCS): the force required to fold a piece of paperboard is considered, and the ratio between the force for a creased and an uncreased package defines the RCS.

Besides the primary goal of studying the RCS, other output data will be extracted to evaluate the material parameters' influence on other responses, as well as the material model itself. Correlations between different responses will also be sought for.

The statistical tool iSight will determine the parameter configurations in each run in order to maximise the amount of information gained from a given number of simulation runs for efficiency; the entire parameter space can not be explored due to the unrealistic amount of time that it would take. When results have been generated, another program, MODDE, statistically analyses the results and determines which factors out of the selected set have a significant effect on the folding procedure.

It is finally concluded that one can get meaningful information by modelling the responses as polynomial functions in terms of the material parameters. It is then discovered that the most important factors are the yield stresses in MD compression and tension, as well as the compressive behaviour in ZD. (Less)
Popular Abstract (Swedish)
Kartong kan framställas för att få fram olika egenskaper. En kartongförpackning har
någon gång i tiden vikts fram av en bit kartong. Men hur viker man utan att få
oönskade skador och veck, och hur påverkas detta av materialets egenskaper?
Please use this url to cite or link to this publication:
author
Smedman, Oskar LU
supervisor
organization
course
FHL820 20171
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
paperboard, paper mechanics, creasing, solid mechanics, design of experiments, simulation
publication/series
ISRN LUTFD2/TFHF-17/5218-SE(1-61)
report number
5218
language
English
id
8910315
date added to LUP
2017-06-12 14:42:56
date last changed
2017-06-12 14:42:56
@misc{8910315,
  abstract     = {Paperboard is frequently used as a base material in packages. There is folding involved in the conversion process, where a package is formed from a paperboard sheet. However, because direct folding causes undesirable effects such as wrinkles, it must first be creased. The creasing procedure consists of intentionally damaging the material, creating an indentation on the piece, after which the material may be folded as desired.

Constitutive models for paperboard require a large number of parameters to precisely reflect the material behaviour during strongly nonlinear processes such as creasing and folding. In order to increase understanding of the connection between the parameters and the material's behaviour, a parameter study has been conducted and documented in this thesis. Simulation of the procedure is performed in Abaqus/Standard with the help of its scripting tools. Specifically, the tendency of the material to fold along the crease lines will be measured using the relative crease strength (RCS): the force required to fold a piece of paperboard is considered, and the ratio between the force for a creased and an uncreased package defines the RCS.

Besides the primary goal of studying the RCS, other output data will be extracted to evaluate the material parameters' influence on other responses, as well as the material model itself. Correlations between different responses will also be sought for.

The statistical tool iSight will determine the parameter configurations in each run in order to maximise the amount of information gained from a given number of simulation runs for efficiency; the entire parameter space can not be explored due to the unrealistic amount of time that it would take. When results have been generated, another program, MODDE, statistically analyses the results and determines which factors out of the selected set have a significant effect on the folding procedure.

It is finally concluded that one can get meaningful information by modelling the responses as polynomial functions in terms of the material parameters. It is then discovered that the most important factors are the yield stresses in MD compression and tension, as well as the compressive behaviour in ZD.},
  author       = {Smedman, Oskar},
  keyword      = {paperboard,paper mechanics,creasing,solid mechanics,design of experiments,simulation},
  language     = {eng},
  note         = {Student Paper},
  series       = {ISRN LUTFD2/TFHF-17/5218-SE(1-61)},
  title        = {Factors affecting the Relative Crease Strength of paperboard},
  year         = {2017},
}