Production and Investigation of Polylactic and Foils Modifed with Montmorillonite and Polyethylene Glycol
Poly(lactic acid) (PLA) which is a synthetic linear aliphatic polyester produced by the polymerization of lactic acid is one of the most promising members of the bioplastics. PLA is a versatile polymer and has been already used in many various applications. Behind the several good properties of the PLA its applications in the packaging industry are limited due to some weak properties (brittleness, thermal and barrier properties). In order to improve the properties of the poly(lactic acid) organically modified montmorillonite (MMT) (Closite 30B) as reinforcement and poly(ethylene glycol) (Mw= 400g/mol) as plasticizer, compatibilizer and as dispersion helper were used. After the drying process the PLA granulates, the MMT and the PEG (were mixed in a four zoned twin screw co-rotating extruder. Four different types of foils were made: PLA + 10 wt% PEG, PLA+1 wt% MMT+10 wt% PEG, PLA+3 wt% MMT+10 wt% PEG, PLA+5 wt% MMT+10 wt% PEG. The modified PLA based foils were prepared on a single screw extruder in the thickness of 80-90 microns. Neat poly(lactic acid) processed in same conditions as reference sample. Differential scanning calorimetry (DSC), thermogravimetry (TGA), UV-VIS spectrophotometry, tensile test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were done to evaluate the properties of the materials. The results gave that homogenous structure was achieved by using PEG, intercalated and ex-foliated strucures formed thus the material kept its transparency. The thermal properties were not changed significantly, a little enhancement (with 5%) in the onset temperature of the degradation was detected. Remarkable improvement (up to 2534% compared to the neat PLA) was observed at strain at brake in cross and in process directions as well when using 3 wt% and 5 wt% MMT with 10 wt% PEG.
Kulcsszavak: politejsav, csomagolóipar, nanokompozit, motmorillonit, spektrofotomteria
Cardboard Boxes Printed by Digital Technology at STI Petőfi Nyomda Kft.: a Case Study
Digital printing is now a commonly used technic for cardboard boxes as well. However when producing consumer packagings, it is important to consider beside the applied technics the balance of logistical questions, the high tech quality and expenses. It is especially true for low sales when the ordering number of packaging materials and boxes are limited. To combat these problems, during 2010 the STI Petőfi Nyomda Kft. conducted a study to test the quality of their digital prints, to find solutions to printing cardboard boxes, and mapping the compatibility between offset and digital printing technologies. In this paper one can read about printing technologies applied by STI Petőfi Nyomda Kft. and a study of reproductivity in cardboard box printing.
Kulcsszavak: digitális nyomtatás, csomagolóanyag, kartondoboz gyártás, piaci igény, nyomtatási tesztsorozat, Xerox iGen 4, Hewlett Packard Indigo 5500
Investigation of Factors Influencing the Quality of Screen Prints
Screen printing is one of the oldest printing processes. Its theory and tools did not change significantly, however the technology underwent a considerable improvement during its history and continues to develop in the 21st century as well. Screen printing allows the deposition of a thick layer of ink onto the substrate, enabling the use of ideally any kind of substrate. In case of this technology it is increasingly important to choose the right screen ruling according to the estimated viewing distance. Despite the significant technological development halftone screen printing remains a challenge. Factors influencing quality are in close interaction with each other. For the optimal output it is necessary to control these factors more or less independently to produce high density screen prints in high quality. Tone values of the screen print are primarily influenced by the density of the mesh and thread weight. In practice the smallest dot will determine the usable highest screen ruling. In our research we investigated the effect of screen ruling on print quality. Test charts were printed on PVC and PE substrates using 36 l/cm and 60 l/cm screens ruling. Optical measurements were performed to determine density values, TVI curves, gamut volume to investigate the factors influencing tone reproduction quality. Magnified images were used to evaluate substrate-ink interaction.
Kulcsszavak: szita nyomtatás, denzitás, kitöltési arány növekedés
Bindery for the Future – Binding Without Glue, Book Binding and Conservation, Practical Approaching
Workshop about how to bind books with soft pergamenbindings was held in Ljubljana November 2008 by Christopher Clarkson from Oxford. On this two-week long program his knowledge in conservation was utilised to teach thoroughly the basics and specialities of bookbindery and patternery as well for those interested in special technical questions and solutions to them.
Kulcsszavak: konzerváló kötések, firenzei puhapergamenkötés, régi papírkötések, fűzések, fűzőanyagok
Does the Product Fee Law Change?
The first version of product fee law was issued in 1995. It was changed every year except the years of election. Last year, after the election, the new envi-ronmental government announced, the product fee law will be changed soon. In the news a lot of reasons were issued why the actual product fee law need to be modified. In June 2011 the new draft of product fee law was submitted to the Parliament by a MP (not Ministry). In the draft we could read: – the exception system will be abolished, – the rate of product fee will be lower, but the obligation of companies will be grown.