Keresés

Keresési eredmények

• PVC/LDPE Blends: Relationship Between Thermal/Mechanical Properties, Structure and Blend Behaviour

  162-165

  Román Krisztina

  Zsoldos Gabriella

  Megtekintések száma:

  194

  In this paper the effect of LDPE content in PVC foams are examined on the structure of both the foam and the LDPE. We attempt to understand how LDPE content affects the structure of PVC in blends and how it changes the glass-transition (Tg). These parameters often provide important information related to the overall macromolecular structure of the polymer blend. Thermal analytical techniques such as differential scanning calorimetry (DSC) often used to determine the structural transformation of samples. The effect of the miscibility and composition of the PVC/LDPE foam blends on the thermal stability were also investigated.

• Synthesis of Polylactic Acid (PLA) by Polycondensation Method

  286-293

  Horváth Tibor

  Szabó Tamás József

  Marossy Kálmán

  Megtekintések száma:

  359

  The Polylactic acid (PLA) is compostable and natural renewable sourced plastic type. Its mechanical properties quite similar to the PET, therefore the PLA is a good alternative for strongly ruled food industrial application. The PLA only has one critical attribute – the relatively low glass transition temperature. According to the relevant literature the glass transition of PLA is in the range of 40-70°C. In light of this fact, this material can be used only in that segments of food industrial field where the packaging process temperature are under of the lower limit of Tg range. The actual Tg of a material is highly depends on the molar mass and material structure, therefore the molar mass and the structure of material should be designed according to the future requirements of application and procedures.

• The Effect of the Excess Titanium Content on the Microstructure of Al – Si Foundry Alloys

  12-20

  Bubenkó Marianna

  Fegyverneki György

  Molnár Dániel

  Tokár Mónika

  Megtekintések száma:

  135

  Grain refining is an important technological step for the nucleus growth of the melt, in order to increase the number of nuclei, to improve mechanical properties (tensile strength, yield strength, hardness, elongation), feeding conditions and to decrease the tendency of hot tearing and the degree of sintering. [1][2] The aim of the experiments was the determination of the grain refining effects of titanium (Ti) addition in the form of AlTi5B1 master alloy to the examined alloys (AlSi7MgCu0.5 – AC 42 000, AlSi9Cu3Fe0.5 – 46 500; AlSi9Cu1 – AC 46 400). The results prove that the addition of small amount of master alloy has a favourable effect on the foundry practice.

• The Effect of Fluxes on the Melt Quality of AlSi7MgCu Alloy

  372-380

  Gyarmati Gábor

  Fegyverneki György

  Mende Tamás

  Tokár Mónika

  Megtekintések száma:

  209

  The presence of inclusions such as oxides, carbides or refractory particles can be harmful to the mechanical and surface characteristics of castings. Inclusion-rich metals result in lower fluidity and feeding capability during casting. Nowadays, solid fluxes are widely used in foundries in order to reduce the inclusion content of aluminium melts. In this study, the effect of four different fluxes on the melt quality was studied. First, the inclusion content of the flux-treated melt, and then the properties of the fluxes (i.e. chemical composition and melting temperature) were examined.

• Polylactic Acid as a Potential Alternatives of Traditional Plastic Packagings in Food Industry

  123-129

  Horváth Tibor

  Szabó Tamás József

  Marossy Kálmán

  Megtekintések száma:

  372

  Huge quantity of synthetic polymers is used as packaging materials in different fields of food industries. A significant part of these polymers applied as a primary, direct food contact construction. The scoped application area is the sweet industry. In this field Polystyrol (PS), Polypropylene (PP) and Polyethylene terephthalate (PET) have used but during the last fifteen years the usage of PET has been grown. In one hand the price of this material is efficient, form other hand the PET is the one of the most safe (for food industrial applications) petrol chemical plastic that can be used as primary or secondary food contact packaging material. To maximize the customer safety and minimize the environmental impact of traditional PET, a new bio-sourced and bio-degradable alternative polymer aimed to be used in this special food industrial segment. One of the potential alternatives is the Polylactic acid (PLA) that would be a possible substitute as it is compostable and produced from renewable sources and has good physical and mechanical properties [1].

• Pin on disc vizsgálatok zártcellás alumíniumhabokon

  353-357

  Gábora András

  Kalácska Gábor

  Keresztes Róbert

  Beke Sándor

  Géresi Zoltán Gergő

  Megtekintések száma:

  219

  A fémhabok cellás szerkezetük és kiváló mechanikai és fizikai tulajdonságaik révén előtérben vannak a jármű és egyéb iparágak anyagfejlesztéseiben. Ugyan a különböző típusú fémhabok közkedveltek, a bonyolult szerkezetük miatt továbbra is kutatások tárgyai. Jelen kutatás célja különböző gyártástechnológiával készült és különböző cellaméretű zártcellás fémhabok tribológiai vizsgálata. A cikkben bemutatásra kerülnek a vizsgálat tárgyai, azaz a direkt habosítással és gázinjektálással készült zártcellás alumíniumhabok és azok mátrixanyagai. Részletezésre kerül továbbá a kísérletekhez használt Pin on Disc vizsgálóberendezés, valamint a kísérletek legfontosabb paraméterei.