Print quality evaluation and applied colour management in coldset offset newspaper print

This article aims to investigate print quality in newspaper print, by considering the appropriate calibration standard and applying colour management. In particular, this article examines the colorimetric properties of eight Norwegian newspaper printing presses, to evaluate the relevant colour separation approach, either by applying custom separation profiles or by using an industry standard profile. The key method underlying the work described here relies on obtaining colour measurements to determine the repeatability of each participant in terms of colour differences. Furthermore, the variation between the eight newspaper printing presses and the variation according to the colorimetric values of the ISO 12647‐3 standard are important parts of the quantitative evaluation. Based on the colour measurements two custom ICC profiles were generated and an industry standard profile “ISOnewspaper26v4.icc” was also used. The first custom profile was generated using averaged colour measurement data set from a test print run, and the second using a data set averaged between measured data and the characterization data set “IFRA26.txt” provided by IFRA. These three profiles were applied to four test images, which were then printed by the eight newspaper printing presses. A psychophysical experiment was carried out to determine the “pleasantness” of the reproductions, which were produced using the three profiles. The results of the study show the performance of the appropriate profile, which is applied to the eight newspaper printing presses to obtain significant best print quality. Eventually the results demonstrate the fact that the print variations in colours between the eight printing presses are larger thanthe difference between the custom and the standard profiles. Hence, the print variations and not the profile selection may have determined the visual print quality. Therefore the study reveals the importance of adopting international standards and methods instead of using insufficiently defined house standards to preserve equal results among different newspaper printing presses. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011     

Instrumental measurement and control of colour

In spite of the fact that the basic method of colour measurement was established more than harf a centuy ago, it is only during the last fifteen years that the application of colour measurement is particularly substantial and significant because of the advancement of computer technology, better understanding of colour science, and the revolution in equipment design. This has brought colour science from a scientific exercise in the research laboratory to a widely used industrial and commercial tool. The present state of the art of colour measurement is such that an analogy can be made to the measurement of linear dimensions at one time by the relatively crude yardstick, but now replaced by the precisely scaled micrometer. Thus with colour measurement now, colour can be measured with a precision unmatched by the human eye. To-day, both the colorant industry and colour dependent commerce (industries such as dyes, textiles, pigments, cosmetics, coatings, paper, plastics etc.) are taking advantage of such techniques since the economic advantages are quite substantial. Furthermore, the techniques involved are, to a large extent, no longer trade secrets. The literature abounds with practical theories and concepts which can be applied directly in the workplace by competent colourists. It is expected that more applications of colour measurement for similar general usage are being developed. This paper is designed to introduce the fundamental concept of colour science and various types of colour measuring instruments and their selection. The value of these colour measuring instruments for practical use in industry and commerce is discussed. Finally, the sources of the technical information and assistance are given.     

Dispense systems target RIM processes

INTERTRONICS, UK, is now offering a line of variable ratio low viscosity gear pump dispensing systems for constant flow resin injection moulding (RIM) processes.This is a short news story only. Visit www.reinforcedplastics.com for the latest plastics industry news.     

Some aspects of the visual scaling of large colour differences

The formulation of a metric to provide numbers that correlate with visually perceived colour differences has proved a very difficult task. Most early experimental work was concerned with just-perceptible colour differences. Later the concept of perceptibility was expanded to acceptability, it being argued that many industrial tolerances were larger than just-perceptible. This led naturally to the concept of large colour differences and the question as to whether the current CIE colour-difference formulae, specified as appropriate for just-perceptible differences, can be applied to larger differences than those concerned with, for instance, colour matches experienced in the fabric dyeing industry. This article investigates the application of four colour-difference formulae to visual scaling of large colour differences between photographically prepared reflection colour samples at approximately constant lightness. It is shown that the scaling of colour differences depends on the directions of hue and chroma differences of a test sample when compared with a reference. It is also shown that, of the four candidate colour-difference metrics, the modified CIE 1976 L*a*b* colour difference, referred to as CIE1994 or , correlates best with visual scaling. © 1997 John Wiley & Sons, Inc. Col Res Appl, 22, 298–307, 1997     

Spectrophotometric colour matching algorithm for top-dyed mélange yarn,based on an artificial neural network

Colour, the first element of quality control of textile products, is a complex subject relating to physical optics, psychology, and the human visual system. Colour matching remains one of the major problems in the textile industry. Mélange yarn is a class of textile product with a specific colour appearance, which colour is mainly affected by colour matching of the dyed fibres and their ratio for spinning rather than by the dyeing process. The existing colour matching models for mélange yarn derived from specific types of fibre or specific spinning processes are restricted by the adopted conditions and parameters of the model, resulting in low universal applicability and low accuracy. In this paper, a spectrophotometric colour matching algorithm based on the back-propagation (BP) neural network and its processes were proposed. The weighted average spectrum was predicted by a BP neural network, followed by recipe prediction from the weighted average with constrained least squares. The results showed that the average colour difference of practical samples, based on the prediction of nine blind testing targets, was 0.79 CMC (2:1) units if more than two a priori training samples were used. This result indicated the capability and practicality of accurate prediction of colour matching for top-dyed mélange yarn by this novel method.     

Degreasing machine refurbishment now available

Ransohoff plc is now offering customers in the UK a refurbishment service for redundant washing or degreasing machines that costs significantly less than the cost of a replacement machine.This is a short news story only. Visit www.filtsep.com for the latest filtration industry news.     

Mastering the shade…a CAD system for colour

Since the introduction of computer-aided design technology into the textile industry, imprecise on-screen colour has become a recognised weak link in the production chain. Colour mismatch between the different media has led to costly modifications, as well as reaffirming many a designer's technophobia. However, a new system has been developed which is user-friendly, versatile and which communicates colour accurately.     

Publication Sponsored by the Society's Fastness Tests Co-ordinating Committee-51 Colour Fastness to Shampooing of Textile Floor Coverings

For over fifteen years the UK carpet industry has used a test method for controlling the colour fastness to shampooing of carpets. The carpet manufacturers, in conjunction with dye makers, originally developed the test for wool carpets of the Axminster type, in which deep colours lay side by side with ecru or pale colours. Later the procedure was extended to wool I nylon mixtures. In many cases at the end of the dyeing stage, the yarn is left in an acid condition, and to predict the effect of repeated shampooing the test solution is buffered in order to show what would happen as the carpet approaches a neutral pH condition. Throughout the use of this test, the laboratory procedure has been compared with domestic and contract shampooing. The following paper clearly shows this relationship and suggests that perhaps the title of the test method is misleading, since the major effect on the dyed carpets tested is due to the retention of the shampoo liquor and not to the method of shampooing.     

Colour Measurement — Present Position and Future Developments

Presented at a Symposium on ‘The Next Fifty Colourful Years’, held by the Huddersfield Region at Huddersfield College of Technology, on 18 October 1968, Mr G. England in the chair The contributions to colour theory and colour measurement which have been made during the last 50 years and which led directly to some industrial end-use are reviewed briefly. Some of the more important applications are discussed and the associated difficulties for extension of use are outlined. The requirements for automated, colour-monitored dyeing processes are considered generally.     

Farbmessung an transparenten Flüssigkeiten

Colour Measurements at Transparent Liquids In the chemical industry, the colours of transparent liquids are still determined by visual comparison of the products with the corresponding series of colour standards. This subjective colour assessment, which is susceptible to faults, was rendered more objective by means of the new DIN-standard set up in 1989 to determine the colour of the products by measuring. This DIN 53995 defines colour measurements at liquids in accordance with DIN 5033 for colour measurements at surfaces which has been in force since 1931. The liquid tester LTM1 by Dr. Lange was developed on the basis of these standards and enables objective colour assessment in compliance with DIN 53995 and iodine, Hazen and Gardner colour scales.     

有色人种护发品市场增长的空间

论述了有色人种护发品市场的现状及未来发展趋势。指出，虽然与有色人种相关的产品大多仅限于美国市场，而且这一市场增长缓慢，但这一市场仍有发展潜力。随着社会就业岗位的增加，有色人种消费者在购买护发产品时变得越来越挑剔，越来越多的非洲女性开始喜炊她们天生的自然卷发，并在市场七寻找可以满足这种需求的创新性优质产品。因此，有色人种护发产品市场将呈现出多样化的趋势。     

Instrumental Assessment of the Staining of Adjacent Fabrics: ISO Test Under Consideration

The UK submitted a proposal to ISO TC 38/SC1 concerning an equation for calculating the staining scale rating from CIELAB values. The document was circulated as 381/N 717 and was discussed by WG7 in the course of the meeting in Copenhagen in June 1981 when it was agreed that it should become a test under consideration. A further report has now been prepared and has been circulated to all members of TC38/SC1 for comment. This is now published in order to obtain comments from a wide section of industry in the United Kingdom.     

Universal models of colour emotion and colour harmony

A new set of quantitative models of colour emotion and colour harmony were developed in this study using psychophysical data collected from 12 regions in the world, including Argentina, China, France, Germany, Hungary, Iran, Japan, Spain, Sweden, Taiwan, Thailand, and the UK. These data have previously been published in journals or conferences (for details see Tables 1 and 2 ). For colour emotion, three new models were derived, showing satisfactory predictive performance in terms of an average correlation coefficient of 0.78 for “warm/cool”, 0.80 for “heavy/light” and 0.81 for “active/passive”. The new colour harmony model also had satisfactory predictive performance, with an average correlation coefficient of 0.72. Principal component analysis shows that the common colour harmony principles, including hue similarity, chroma similarity, lightness difference and high lightness principles, were partly agreed by observers of the same region. The findings suggest that it is feasible to develop universal models of colour emotion and colour harmony, and that the former was found to be relatively more culture‐independent than the latter.     

Biotechnology for industrial sustainability

Until recently waste production was seen as an inevitable outcome of industrial production and processing, and a problem that could be managed by end-of-pipe andin situ biotreatment, disposal, or simply be ignored. However the introduction of clean, or cleaner, technology options now is focussing attention on the minimisation of materials and energy use, and waste generation, and upon recycle. Thus clean technology has emerged as a concept that is compatible with industrial sustainability, and whose environmental benefitsand economic competitiveness have been demonstrable over a range of industrial sectors. Biotechnology is an enabling technology that offers one important route to clean products and processes; it provides powerful and versatile tools that can compete with chemical and physical means of reducing both material and energy consumption, and the generation of wastes and emissions. The wide penetration of biotechnology in industry has still to occur but many examples of its ability to deliver clean and competitive products and processes are now available particularly through the development and application of biocatalysts. The introduction of clean or cleaner processing does not necessarily entail a complete change in manufacturing strategy or the refitting of plant. Upgrading existing manufacturing processes by fitting biotechnology unit stages illustrates the opportunities for such intermediate technology. Nevertheless, for biotechnology to achieve its full potential as a basis for clean industrial products and processes beyond its current applications, innovative R&D will be needed. The successful application of biotechnology as a clean technology is illustrated in this review through a series of case studies, while the innovative nature of biotechnology in this context is demonstrated by the development and application of novel biocatalysts.     

Quantifying colour appearance. Part I. Lutchi colour appearance data

The work described here forms part of a research project entitled Predictive Perceptual Colour Models. The aim of this project is to develop a colour appearance model capable of predicting changes of colour appearance under various different viewing conditions. This will provide industry with a quantitative measure for assessing the quality of colour reproduction and enable more rapid and accurate proofing simulations in the graphic art industry. A large-scale experiment has been carried out in which colour appearance was assessed under a wide range of viewing conditions. The parameters studied were (1) D65, D50, white fluorescent, and tungsten light sources, (2) luminance levels of about 40 and 240 cd/m², (3) five background conditions: white, grey, black, grey with white border, and grey with black border, and (4) two media: luminous colours (displayed on a high-resolution colour monitor) and nonluminous colours (presented in a viewing cabinet). Each colour was assessed by a panel of six or seven observers using a magnitude estimation method. In total, 43,332 estimations were made, and these form the LUTCHI Colour Appearance Data. Data analysis has been carried out to examine the reliability of the experimental results and to understand the effects of the various viewing parameters studied. (Part II of this article describes how the LUTCHI Colour Appearance Data has been used to test the performance of various colour spaces and models.     

Production of protein and metabolites by yeast grown in solid state fermentation: present status and perspectives

Culture conditions for the generation of products using yeast have been optimized for fermentative processes in industry involving predominantly submerged medium (SmF). However, solid‐state fermentation (SSF) is now a realistic alternative system for the production of recombinant proteins and metabolites of interest in the market, with great potential in biofuels production, food, chemical and pharmaceutical industries. One of the main advantages of SSF over SmF is the reduction of downstream expenses. Also, the use of artificial and very cheap solid supports for yeast SSF such as polyurethane foam or amberlite helps with study of the physiology of such systems. This mini‐review makes an overview of previous research and emphasizes the major physiological advantages of yeast SSF that can be used for new processes and product development and stresses the need for integrated approaches between adaptive evolution and high‐throughput genetic analysis. © 2015 Society of Chemical Industry     

Protein soil defoaming in machine dishwashers

The machine washing of dishes that are heavily loaded with proteinaceous soil has been a problem facing consumers and the surfactant industry alike for many years. The rapid growth in the machine dishwasher market and the trend toward the use of lower water temperatures have tended to aggravate the resulting foaming problem for both the household and the industrial consumer of machine dishwashing detergents. Although many surfactants have been recommended for use in defoaming protein soils, no one product which satisfactorily defoams protein soils over a temperature range of 100−160F has been available. A systematic study undertaken with the primary objective of defoaming egg and milk soils in machine dishwashers over wide temperature ranges has now led to the development of an effective protein soil defoaming system. This consists of monostearyl ester of phosphoric acid blended with special nonionic surfactants, in a mixture of alkaline builders, and provides excellent control of protein foam from 100−160F. Studies have been undertaken to show the effects of variations in monoalkyl ester concentration, types of surfactant, soil load, water temperature, water hardness and builder systems. Presented at the AOCS Meeting, Chicago, October 1967.     

Pelletised fuel production from coal tailings and spent mushroom compost — Part I: Identification of pelletisation parameters

This study investigates the technology of manufacturing pellet blends for energy production from two discarded materials in industry. Coal tailings material is the fine discard produced as a result of coal cleaning. Although it still has a significantly high calorific value, over a million tonnes of coal tailings are deposited in lagoons every year in the UK alone. Spent mushroom compost (SMC) consists of fibrous compost substrate and a wet casing layer used during mushroom production. In the form of pellets, these materials become more homogeneous, easily stored and transported, and suitable for use in power plants or gasifiers. The characterisation of the fuel properties shows that the two materials have a complimentary status for pelletisation and energy production in terms of particle types, carbon source, calorific value and volatile matter content.     

吸附理论与吸附分离技术的进展

各种固体界面上发生的吸附现象引起了广泛的关注,基于吸附的分离过程在工业和环保等领域发挥着重要的作用。近年来,涉及吸附现象的许多技术创新领域在不断扩展,改进现有的吸附剂,研发新型吸附剂及新用途;而研究的重点在缩小理论与实际应用的不协调,使吸附由技艺走向科学,由物理、化学、工程等多学科的交叉而形成的界面科学迅速成熟。概述了吸附和吸附分离过程的基础,围绕上述方面体现吸附理论的研究进展和吸附实际应用之间的关系,用实例介绍在吸附与吸附分离过程方面的研究与实践。     

认真分析发展形势 实施知识创新工程 全力推进轮胎产业新型发展战略

一、我国轮胎产业回顾及现状分析 我国轮胎产业从20世纪30年代开始,在较长时期内处在低水平徘徊不前的发展期,始终在低端斜交胎产品领域行走。新中国成立后,伴随民族汽车工业的发展,斜交胎产品逐步由中小规格系列向较大规格的载重胎系列转变。六、七十年代,发达国家子午胎已经占较大比重以后,我国才开始逐渐研发子午胎。