Gloss and gloss variations inelectrophotographic print = Glans och glansvariationer i elektrofotografiskt tryck

This degree project was performed at M-real Technology Centre in Örnsköldsvik. The perpose was to investigate thedifferences in gloss and gloss variations between chemical and ground toner and different paper grades in electrophotographicprints. Gloss is a property that gives the impression of a higher quality of a product. Therefore it is of great importance toaccomplish high gloss in advertising print.A test chart was printed on three different uncoated paper grades on three different printers. Thereafter, gloss, glossvariation, surface topography, print mottle and density were measured. A visual evalution was also performed. A multivariateanalysis was acheived of the data in order to find correlations between the measured variations.The results showed that paper grades with large surface roughness gave more variations in surface topography and glossvariations (both visual and measured) in print. A rough surface also gave more print mottle. Ground toner gave moresurface topography variations and mottle which increased with the amount of silicone used.

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.

Studie av web to print samt kartläggning av kunders behov för tillämpning av systemet CiPublisher

Customers put their printing suppliers to severe claims for shorter production time and faster deliveries.Printers always look for new solutions to increase the satisfaction of their customers. Oneexample of such a solution is web to print, where the customers book their printed matters atInternet.The solution involves design of printed matter by using templates that are made unique for thecustomer's printed matter. Web to print is suitable for reiterated printed matters. By using templatesthe customer doesn´t have to redo their layout for every new edition. Bromma tryck AB hasinvested the system CiPublisher, which is applied for the customer to make their printed matter atInternet.The purpose of the examination work is to investigate the needs of the customers of Brommatryck for a web to print solution and how such a system should be adapted.The result shows that the customer who is in need of a web to print solution wish such a system tobe easy managed and also usable. The customer inquiry also shows that most of the customers primarydesire for start using such a solution is that it will save time and also simplify the process formanufacturing of printing matters.

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.

Processanalys vid Color Print Sweden AB med fokusering på prepressavdelningen

This thesis work has introduced process orientation at the printing company Color Print Sweden AB. The outcome ofthis work is a survey of the work flow at the prepress department. To visualise the production process at the companya comprehensive mapping of the main process, order-to-delivery, has been made. The work has detected a couple ofcritical elements in the existing process. These elements are the following: initial check of material delivered to the prepressdepartment as well as the control made of the plotter print-out, digital test print and plate. To guarantee the qualityof the prints it is very important that the work made in the prepress department is optimized. This survey can thereforebe used as a basis for continuous improvement in the processes at Color Print Sweden AB. This work has alsoresulted in a template that Color Print Sweden AB can use to design routine descriptions to ensure that specific worktasks are performed the right way by everyone and all the time.

Study of ink mileage and print through

This report contains a study of ink mileage, show through and other mechanisms that are important inthe study of substrate printability. These mechanisms have an impact on how ink will react on paper.To develop a substrate that provides good ink mileage and less show through requires a closer studyof substrate characteristics.Substrates with different characteristics have been tested by a technique developed for this projectcalled modified ink mileage. Ink mileage is a method to determine how much ink that is required for acertain target density. Further tests on the same substrates have been done including print throughand surface roughness measurements.