Utvärdering av ICC-profiler och profil-inställningar för HP Indigo Press 1000

Det nystartade digitaltryckeriet Digaloo planerar att inom en snar framtid införa ICC-hantering i sittarbetsflöde. Med anledning av detta har en studie utförts där antalet erfordrade ICC-profiler undersöktssamt vilka akromatiska inställningar som bäst lämpar sig för tryckeriets HP Indigo Press 1000.Testtryckning utfördes på sex av Digaloos mest använda papperskvaliteter. Genom inläsning av testkartorhar de olika papperskvaliteternas reproducerbara färgrymder åskådliggjorts. Grundat på resultatetfrån denna testtryckning framställdes ICC-profiler för valda papperskvaliteter. Dessa genereradesmed olika inställningar för akromatisk repro och TIC (Total Ink Coverage). Vid en andra testtryckninganvändes dessa ICC-profiler för konvertering av mellanton-, natt- och snöbilder, vilka trycktespå olika papperskvaliteter.Resultatet från den första testtryckningen visar att HP Indigo Press 1000 återger störst förgrymd påpapperskvaliteten Silverblade Silk, tätt följd av Silverblade Art. De minsta färgrymderna reproduceraspå Lessebo Linné Gultonat och Lessebo Linné Naturvit.Vid perceptuell bedömning av de olika bilderna blev resultatet att bäst tryckresultat uppnås medpappersspecifika ICC-profiler. Detta gäller dock endast i två av tre fall. Vid bedömning av bäst lämpadTIC ansågs den idag på Digaloo använda nivån som mycket dålig. Genom att antingen sänka eller höjadenna nivå bedömdes tryckresultatet öka i kvalitet.Slutligen visar studien även att akromatik i form av UCR ger bäst bildåtergivning i mellanton- ochnattbilder på de valda papperskvaliteterna. De olika graderna av GCR i snöbilder anses dock passaolika bra beroende på vilken papperskvalitet som används.

Print quality study of a laboratory offset press

PAPRO operates within the Forest Research company and their mission is to develop value-addingindustry solutions. At present there are no good ways for mills to easily test the printing quality on newsprintpaper. There is a great need for a fast way to do this on different paper qualities; with a laboratory-offset press this can be both a time and money saving method. At PAPRO Forest Research, NewZealand, a laboratory offset press has been developed and designed, during the past seven years, concerningthis issue. Earlier projects were made concerning the press, e.g. to establish the optimal settings.The mission with this project was to partly determine the present variability of the print quality andto evaluate if the fountain solution, distilled water and 2% Diol green concentrate, used at the momentmixed with different percentages of Isopropanol could decrease the variability and contribute to morestabile results. Throughout the whole project the print quality showed a high variation and was evenmore variable when the Isopropanol was added. All in all 50 print rounds times twelve printed paperstrips was carried out through the project divided into three parts. To analyse the print quality, amicroscope with an image capture camera has been used. Data from the taken images was analysedand inserted into charts to see the variations.The conclusions of the whole project are not satisfying because no final evaluations were possible tomake. Main conclusions are that the additive of Isopropanol to the ordinary fountain solution, used atpresent, only contributed to more unstable results of the print quality. And it seems to be difficult toget some stable results from the lab press as long as the room where it is placed is not fully conditionedas required for the process of offset printing. And the fact that the airbrush which applies theamount of fountain solution is also variable, as shown in earlier projects, which contributes to unstableresults as well. For further work more exact parameters as a conditioned room are required and thepossibility to further design the laboratory press to use waterless offset printing instead.

Print quality study of newsprint : Further development of the laboratoryoffset press at PAPRO

A laboratory offset press has been developed over the last five years at PAPRO for testing print qualityon newsprint, as at present, there is no good way for the mills to test this issue. In this project a comparisonhas been made between a laboratory offset press and a commercial press to see if the laboratoryoffset press can be used as a reliable test method or if a further development is needed.To evaluate the method, similar papers have been printed in both presses and compared using imageanalysis techniques. All together eighteen samples were tested which is enough to give comparableresults. The print quality showed a high variation, the values from the laboratory offset press and thecommercial press were not following the same trends. At present time the laboratory offset press needsome further development before it can be used as a reliable test method for halftone prints. Even sosome conclusions were made.The newsprint that has been used came from Norske Skog Tasman Mill (Kawerau), since the otheraim of this project was to do a repeatability study of their three existing paper machines to distinguishpossible differences in the production. The paper samples were taken from each paper machine on sixdifferent dates to give a representative result. This also gave the opportunity to compare the machinesbetween themselves. Comparison between the machines shows that the wire side gives a better andmore even result than the topside on the prints from the laboratory offset press. According to the resultfrom the commercial press the wire side shows a higher degree of variability. Samples from papermachine 2 and 3 were less variable and had the lowest standard deviation of grey level for solid areas.This suggests that newsprints from PM 2 and PM 3 give a more even print quality with a better inkcoverage.

3D roll-forming of hat-profile with variable depth and width

The use of roll-formed products in automotive, furniture, buildings etc. increases every year due to the low part-production cost and the complicated cross-sections that can be produced. The limitation with roll-forming until recent years is that one could only produce profiles with a constant cross-section in the longitudinal direction. About eight years ago ORTIC AB [1] developed a machine in which it was possible to produce profiles with a variable width (“3D roll-forming”) for the building industry. Experimental equipment was recently built for research and prototyping of profiles with variable cross-section in both width and depth for the automotive industry. The objective with the current study is to investigate the new tooling concept that makes it possible to roll-form hat-profiles, made of ultra high strength steel, with variable cross-section in depth and width. The result shows that it is possible to produce 3D roll-formed profiles with close tolerances.

Hårdare tag i arbetslivet? : Åtgärder mot arbetsrelaterat våld i facklig press 1978–2004

Preventing violence at work: A study of descriptions of safety measures in Swedish trade union journals 1978–2004 The purpose of this study is to examine if perceptions of interventions aimed at violence in the workplace have changed since the 1970s. In the beginning of the study period, structural factors are seen as the dominating explanation for workplace violence. The crime perspective rises in the 1990’s and methods of intervention becomes the control- and justice functions of larger society. The result shows search for accountability to be a salient factor for understanding the development towards an increasing use of penal sanctions.

Experimental and computational investigation of the roll forming process

One of the first questions to consider when designing a new roll forming line is the number of forming steps required to produce a profile. The number depends on material properties, the cross-section geometry and tolerance requirements, but the tool designer also wants to minimize the number of forming steps in order to reduce the investment costs for the customer. There are several computer aided engineering systems on the market that can assist the tool designing process. These include more or less simple formulas to predict deformation during forming as well as the number of forming steps. In recent years it has also become possible to use finite element analysis for the design of roll forming processes. The objective of the work presented in this thesis was to answer the following question: How should the roll forming process be designed for complex geometries and/or high strength steels? The work approach included both literature studies as well as experimental and modelling work. The experimental part gave direct insight into the process and was also used to develop and validate models of the process. Starting with simple geometries and standard steels the work progressed to more complex profiles of variable depth and width, made of high strength steels. The results obtained are published in seven papers appended to this thesis. In the first study (see paper 1) a finite element model for investigating the roll forming of a U-profile was built. It was used to investigate the effect on longitudinal peak membrane strain and deformation length when yield strength increases, see paper 2 and 3. The simulations showed that the peak strain decreases whereas the deformation length increases when the yield strength increases. The studies described in paper 4 and 5 measured roll load, roll torque, springback and strain history during the U-profile forming process. The measurement results were used to validate the finite element model in paper 1. The results presented in paper 6 shows that the formability of stainless steel (e.g. AISI 301), that in the cold rolled condition has a large martensite fraction, can be substantially increased by heating the bending zone. The heated area will then become austenitic and ductile before the roll forming. Thanks to the phenomenon of strain induced martensite formation, the steel will regain the martensite content and its strength during the subsequent plastic straining. Finally, a new tooling concept for profiles with variable cross-sections is presented in paper 7. The overall conclusions of the present work are that today, it is possible to successfully develop profiles of complex geometries (3D roll forming) in high strength steels and that finite element simulation can be a useful tool in the design of the roll forming process.

Våld på jobbet : Beskrivningar av våld i arbetslivet 1978–2004 i facklig press

Violence at work as a social problem: a study of the media coverage on workplace violence in Swedish trade union journals 1978–2004 The main purpose of this study was to find out the extent of the unions media coverage on workplace violence and the ways in which the topic was framed. The study shows that the reporting of violence in the workplace described in journals is on a stable level during the period 1978–98. However from the year 2000 and onwards, there is a clear increase in the attention. Four categories of workplace violence were used to identify and recognize different types of violence: intrusive-, consumer-, relationship-and organizational violence. This shows that much of the attention over time has shifted from intrusive violence to organizational violence and consumer violence. What seems to have happened is that workplace violence has become more than just robberies and assaults in the retail business. The stereotypical image of the criminal is challenged by non-traditional criminals like nurses, elderly people and companies. Certain groups, e.g. care workers, come to account for an increasing proportion of attention, both as perpetrators and victims of violence. This study is an important step in understanding the increased reports of workplace violence in Sweden.