introduction

Transcription

introduction

Gintaras Kunigonis, Gintaras Keturakis, Antanas Baltrušaitis
IMPACT OF TECHNOLOGICAL FACTORS
ON THE ROUGHNESS
OF MILLED WOOD SURFACE
8th meeting of the Northern European Network for Wood Science and Engineering (WSE)
September 13 - 14, 2012, in Kaunas, Lithuania
INTRODUCTION
• One of the main criteria to evaluate the quality of
the processed surface is its roughness.
• It determines the further processing and finish of
the surface, esthetical view and usage possibilities.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
8th meeting of the Northern European Network for Wood Science and Engineering (WSE) September 13 - 14, 2012, in Kaunas, Lithuania
INTRODUCTION
• While analyzing the works of different authors, it
was determined that the following main factors
affect the surface roughness the most:
species of wood,
mode of surface milling,
wear of milling tool,
cutting and feed speeds.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
INTRODUCTION
• The main objective of this research is to
determine the influence of wear of milling tool,
cutting and feed speeds on the surface roughness
when the birch and pine wood is milled along the
fiber.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
MATERIAL AND METHODS
• The surface roughness of planed products was
researched.
• The tests were done with wood of biological
species of birch and pine.
Table 1. Physical characteristics of wood
Wood species
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Moisture
content ω, %
Number of
annual rings
per 1 cm
Average width of
annual ring, mm
Density,
kg/m3
Birch (Betula)
7...9
5.10
1.96
632
Pine (Pinus sylvestris)
6...9
4.40
2.27
535
• The samples were planed by four-side moulding
machine (Weinig Powermat 400 LE and
Weinig Unimat 2000 Speed).
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Foto: G.Kunigonis
Fig. 1. The four-side moulding machine (Weinig Powermat 400 LE)
• The samples were planed according to the
scheme of longitudinal milling, when the directions
of vectors of cutting v and feed u speeds are
opposite to each other.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Foto: G.Kunigonis
Fig. 2. The scheme of longitudinal milling
•Two wood milling knives were fastened in the
knives’ head (PowerLock).
INTRODUCTION
EXPERIMENTS
Foto: Michael Weinig AG
RESULTS
CONCLUSIONS
Fig. 3. The cutter head (Weinig PowerLock Type 538)
• The knives (80×40×5 mm) were made from highspeed steel (HS 18) and covered with resistant to
wear cover (Leitz Marathon MC).
• When the blades of milling knives were fixated in
the head, they were jointed for multi-cut surface
finishing by each knife in the head.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Foto: G.Keturakis
Fig. 4. The wood milling knive (Leitz Marathon MC)
Table 2. Milling test conditions
Cutting speed v, m/s
54.4; 62.8
Feed speed u, m/min
16; 21
Feeding per cutter uz, mm
Depth of milling h, mm
1...2
Width of milling b, mm
40...70
Cutting circle diameter D, mm
INTRODUCTION
0.75...1.30
Number of cutting edge z, unit.
100; 130
2
EXPERIMENTS
RESULTS
Cutting angle δ, degree
CONCLUSIONS
60
• The parameter Rz of the processed surface
roughness was measured by contact stylus tip
profilometer (Mahr MarSurf PS1).
• The radius of diamond tip of which was 2 µm,
measurement angle 90º, and measurement length
was 17.5 mm.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Foto: G.Keturakis
Fig. 5. The contact stylus tip
profilometer (Mahr MarSurf PS1)
• The surface unevenness was measured in the intervals
of cutting path L: 10; 500; 1000; 1500 and 2000 m.
• Five sectors were selected in one sample
(17.5×17.5 mm), and their roughness was measured
along and across the fiber.
• In total 1250 measurements were done during the
testing series.
• All the measurement results were processed by
Gaussian digital filter (according to DIN EN ISO 11562).
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
• The measurement error of unevenness did not exceed
±10 %.
19
18
17
16
15
14
13
12
u = 16 m/min
u = 21 m/min
Rz , m
Rz , m
RESULTS
0
500
1000
L, m
1500
18
17
16
15
14
13
12
11
10
2000
u = 16 m/min
u = 21 m/min
0
500
a
Rz , m
Rz , m
32
30
u = 16 m/min
u = 21 m/min
26
0
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
500
1000
L, m
1500
2000
a
34
28
1000
L, m
1500
2000
b
41
39
37
35
33
31
29
27
u = 16 m/min
u = 21 m/min
0
500
1000
L, m
1500
b
Fig. 6. Surface roughness Rz of pine wood
(when v = 54.4 m/s):
Fig. 7. Surface roughness Rz of birch wood
(when v = 54.4 m/s):
a – along the fiber; b – across the fiber
2000
17
16
15
14
13
12
11
10
15
u = 16 m/min
u = 21 m/min
v = 54.4 m/s
v = 62.8 m/s
14
Rz , m
Rz , m
RESULTS
13
12
11
0
500
1000
L, m
1500
2000
0
500
39
37
35
33
31
29
27
25
u = 16 m/min
u = 21 m/min
0
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
500
1000
L, m
1500
2000
a
1500
2000
b
Rz , m
Rz , m
a
1000
L, m
41
39
37
35
33
31
29
27
25
v = 54.4 m/s
v = 62.8 m/s
0
500
1000
L, m
1500
2000
b
Fig. 8. Surface roughness Rz of birch wood
(when v = 62.8 m/s):
Fig. 9. Impact of cutting speed v on the surface
roughness Rz of birch wood:
CONCLUSIONS
1. In the same conditions of milling regime, the
quality of pine wood surface is worse than that of
birch. The surface roughness of birch wood
along the fiber is smaller by 4 % on average,
and across the fiber – by 8 %.
2. In the same conditions of milling regime, the
quality of pine wood surface is worse than that of
birch. The surface roughness of birch wood
along the fiber is smaller by 4 % on average,
and across the fiber – by 8 %.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
CONCLUSIONS
3. As the cutting speed gets faster and the feed
speed stays the same, the surface roughness of
birch wood across and along the fiber differs very
little.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
4. In general researches done with Marathon coated
knives confirm traditional theoretical statements
about higher density wood better workability and
surface quality at the same milling conditions. Still
reasonable discrepancies mainly characterized by
irregular and saltatory surface roughness changing
comparing with the uncoated HSS knives
performance have been received.
ACKNOWLEDGEMENT
The report’s authors are grateful to UAB “Kirvilė”
and UAB “Medinis profilis” (representatives of “Weinig
group” in Lithuania) for the provided technical support
while conducting the researches on wood milling
processes and surface roughness.
UAB „Kirvilė“
Medelyno g. 4, LT– 69446 Jūrės km.
Kazlų Rūdos sav.
INTRODUCTION
EXPERIMENTS
RESULTS
CONCLUSIONS
Tel. +370 687 37106
Faks. +370 343 96046
www.kirvile.lt
UAB "MEDINIS PROFILIS"
Tel.
MICHAEL WEINIG AG
atstovybė Lietuvoje
Faks.
Savanorių pr. 73
El. paštas:
LT-44208 Kaunas
00370 37 200461
00370 37 750207
00370 37 750208
[email protected]
Thank You for attention !
INTRODUCTION
EXPERIMENTS
RESULTS
Foto: Truehow.info
CONCLUSIONS

introduction

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