Vpliv dielektričnih lastnosti lepila in lesa na selektivnost VF segrevanja

diplomsko delo (univerzitetni študij)

Matija Kranjc (Author), Jože Resnik (Reviewer), Milan Šernek (Mentor)

Abstract

Raziskovali smo vpliv dielektričnih lastnosti lepila in lesa na selektivnost segrevanja preskušanca. Eksperimentalni del je potekal v 2 fazah. Najprej smo izmerili dielektrične lastnosti tekočega PVA lepila in furnirja bukve (Fagus sylvatica L.). Pri lepilu smo ugotavljali odvisnost dielektričnih lastnosti od temperature (22-80 °C) in frekvence (79,4 kHz-25,1 MHz), pri lesu pa samo odvisnost od frekvence na enakem območju kot pri lepilu. Meritve smo opravili z napravo Agilent 4285A Precision LCR Meter in pripadajočima sondama za merjenje dielektričnih lastnosti. V drugi fazi smo pripravili preskušance in jih v stiskalnici segrevali na posreden (klasično) in neposreden (VF) način. Med segrevanjem smo ugotavljali vpliv časa segrevanja na spreminjanje in porazdelitev temperature znotraj lepljenca. Ugotovili smo, da dielektrična vrednost in izgubni faktor lepila naraščata z naraščajočo temperaturo. Lepilo ima bistveno višje dielektrične lastnosti kot les, zato se je lepilni spoj v polju VF segreval hitreje kot les. Razlike v segrevanju so bile bolj očitne v začetni fazi segrevanja. V primerjavi hitrosti neposrednega in posrednega segrevanja nismo ugotovili bistvenih razlik.

Keywords

les;tekoče PVA lepilo;dielektrične lastnosti;visoka frekvenca;segrevanje;selektivnost;

Data

Language:	Slovenian
Year of publishing:	2006
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL BF - Biotechnical Faculty
Publisher:	[M. Kranjc]
UDC:	630*824.87
COBISS:	1445001
Views:	1304
Downloads:	305
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	ǂThe ǂeffect of dielectric properties of adhesive and wood on HF heating selectivity
Secondary abstract:	The effect of the dielectric properties of adhesive and wood on heating selectivity of test pieces was analysed. The experiment was carried out in 2 phases. First the influence of temperature (22-80 °C) and frequency (79.4 kHz-25.1 MHz) on the dielectric properties of liquid PVA adhesive, and the influence of frequency on the dielectric properties of beech wood (Fagus sylvatica L.) were measured. The measurements were performed with the Agilent 4285A Precision LCR Meter and the according test fixtures. In the second phase test pieces were made and heated indirectly and directly (HF). The test pieces were heated in a press, and the growth and distribution of temperature in the boards were monitored. It was determined that by increasing the temperature the dielectric properties of the adhesive increase. Adhesives have considerably higher dielectric properties than wood, and therefore, heat faster. The differences in heating were more obvious in early stages of heating. No differences in speed of indirect and direct heating were found.
Secondary keywords:	wood;liquid PVA adhesive;dielectric properties;high frequency;heating;selectivity;
Type (COBISS):	Undergraduate thesis
Thesis comment:	Diplomsko delo, Univ. v Ljubljani, Biotehniška fakulteta, Odd. za lesarstvo
Pages:	XII, 55 f.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;agriculture and related sciences and techniques;forestry;farming;wildlife exploitation;kmetijstvo ter sorodne vede in tehnologije;forestry;gozdarstvo;forest products and their utilization;gozdni proizvodi in njihova uporaba;
ID:	21031