Time filter

Source Type

Stepien K.,Politechnika LLodzka
Przeglad Papierniczy | Year: 2011

The aim of the work was to perform tests of ink transfer on printing substrates in flexographic Inking unit. It shows the impact of technical and technological parameters on ink transport in the inking unit. Methods and results of measurements of printing materials properties as well as methodology olink transfer tests are presented. The research tests of ink transfer were performed with IGT F1 testing appliance and a Mark Andy laboratory flexographic printing machine.

The article presents the results obtained using several analytical methods. Each of the methods used were a source of additional information on the analyzed samples. This results in a more complete assessment of the suitability of packaging in terms of health security.

This article provides an introduction to a series of publications concerning research and prediction of mechanical properties of paper cores. On the basis of available literature and results of author's tests, the measurement methods of paper cores properties were presented. Among other things, the author described, in which loads are applied bending moments and compressive forces. Also discussed the reasons why it is difficult to identify the theoretical strength of the sleeve in various states of load, indicating the possibility ot simplifying the theoretical description of the mechanical properties of the sleeve, where it is possible to treat the fibrous material as the elastic body.

Izabela W.,Politechnika llodzka | Karski S.,Politechnika llodzka | Frajtak M.,Politechnika llodzka
Przemysl Chemiczny | Year: 2011

Te was added (2% by mass) to the SiO2 Al2O 2 TiO2, mol. sieve 13X and C-supported Pd (5% by mass) catalysts during their prodn. by impregnation of supports with aq. solns. of PdCI2 or/and H6TeO6 The Te-modified Pd catalysts were used for liq. phase oxidn. of glucose to CH2OH(CHOH) 4COOH and showed higher activity and electivity than the monometallic Pd catalysts. The pres-ence of PdTe intermetallic was evidenced in the catalysts by temp.-programmed redn., X-ray diffraction and secondary ion mass spectrometry with time of flight anal.

The paper presents the principle of so-called ratio methods used in the diagnosis of gases dissolved in transformer oil. An analysis of these methods showing the reasons why it is not always possible to obtain a correct diagnosis was given. The extension of the algorithms to the elements of fuzzy logic which enhance their effectiveness was proposed. Several studies of the actual defects of transformers were also included.

Article concerns the problem of electrical discharges developing in transformer oil under lightning impulse of both polarities. The results of experimental studies performed for two setups: HV electrode - grounded plane, of different electrical field distribution, were discussed. For both setups, two types of HV electrodes with identical outer dimensions: bare and paper insulated, were used.

Kosmalska A.,Politechnika LLodzka | Zaborski M.,Politechnika LLodzka | SokolLowska J.,Politechnika LLodzka
Polimery/Polymers | Year: 2010

The modification of silica performed by mechanical frictioning of dyes into its surface occurring during intensive mixing has led to stable composite pigments (Table 1). Azo dye, antraquinone, perylene and indigothiazyne derivatives were used as dyeing agents. "crayoning" of silica reduces its specific surface area, parride aggregation tendency, and the formation of structures. It also lowers the filling activity towards silicon rubber thereby altering the interphase interaction resulting in an uneven dispersion of the composite pigments in the elastomer (Table 2, 3, Fig. 2, 3). Vulcanizates filled with the modified silica exhibited an increased resistance to color changes caused by weathering, however, their mechanical resistance decreased in comparison with rubber filled with unmodified silica (Table 4,5).

Wojtas A.,Politechnika LLodzka | Zaborski M.,Politechnika LLodzka | Kosmalska A.,Politechnika LLodzka
Polimery/Polymers | Year: 2010

The blends of methylvinylsilicone rubber with fumed silica additionally filled with particles of cellular silsesquioxanes (POSS) (Table 1) were prepared. The compositions were cured with dicumyl peroxide. Particle size and particle size distribution of POSS used were characterized (Fig. 1, 2) as well as Zeta potential as a function of pH of aqueous dispersion (Fig. 3) and rheological properties (Table 2). The effect of addition of oligosilsesquioxane on the characteristics of the material prepared was evaluated on the basis of crosslinking density (Table 3), tensile strength (Table 4) and hysteresis (Table 5) and relaxation (Table 6) properties of vulcanizates. It was found that monovinyl(isobutyl)-POSS increased the tensile strength and crosslinking density of the rubber obtained.

Loading Politechnika llodzka collaborators
Loading Politechnika llodzka collaborators