3. production and control of bakelite 3.1 definition and standards
DESCRIPTION
3. Production and control of Bakelite 3.1 Definition and standards. Standard bakelite electrodes are composed by a bulk made of phenolic resin a surface made of melaminic/phenolic resin In the following: Melaminic = bulk phenolic and surface melaminic - PowerPoint PPT PresentationTRANSCRIPT
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.1 Definition and standards
3. Production and control of Bakelite3.1 Definition and standards
Standard bakelite electrodes are composed by • a bulk made of phenolic resin • a surface made of melaminic/phenolic resin
In the following:Melaminic = bulk phenolic and surface melaminicPhenolic = bulk and surface phenolic
Standard bakelite electrodes are composed by • a bulk made of phenolic resin • a surface made of melaminic/phenolic resin
In the following:Melaminic = bulk phenolic and surface melaminicPhenolic = bulk and surface phenolic
BULK
SURFACE
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.2 Quality control data flow
3. Production and control of Bakelite3.2 Quality control data flow
Bulk resistivity Determines the time constant of an elementary RPC cell, = 0 (r + 2 )
Average roughness Ra
It is related to the quality of the surface. A small Ra reduces spontaneous discharges which might affect the RPC rate capability
Dielectric constant r
It is related to and to the averagefast charge qe of a single avalanche
Bulk resistivity Determines the time constant of an elementary RPC cell, = 0 (r + 2 )
Average roughness Ra
It is related to the quality of the surface. A small Ra reduces spontaneous discharges which might affect the RPC rate capability
Dielectric constant r
It is related to and to the averagefast charge qe of a single avalanche
Protocol
Production
Measurement
Storage
Data acquisition
Out of range
Decide limits for accepting a given bakelite sheet on the basis of measurements
Decide limits for accepting a given bakelite sheet on the basis of measurements
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.3 Production requirements
3. Production and control of Bakelite3.3 Production requirements
Resistivity range :• 2/3 of production in the range = 2-5 1010 cm• 100% of production in the range = 1-6 1010 cm
Resistivity range :• 2/3 of production in the range = 2-5 1010 cm• 100% of production in the range = 1-6 1010 cm
Average Roughness range :
• Ra = < 0.2 m
Average Roughness range :
• Ra = < 0.2 m
Size (thickness = 2 mm): • 1.3 m x 2.8 m “small” slabs• 1.3 m x 3.2 m “large” slabs
Needs:• 3000 (+150) “small” slabs (11466 m2)• 500 (+ 25) “large” slabs (2184 m2)
Total 3675 Slabs (13650 m2)
Size (thickness = 2 mm): • 1.3 m x 2.8 m “small” slabs• 1.3 m x 3.2 m “large” slabs
Needs:• 3000 (+150) “small” slabs (11466 m2)• 500 (+ 25) “large” slabs (2184 m2)
Total 3675 Slabs (13650 m2)
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.4 Resistivity control
3. Production and control of Bakelite3.4 Resistivity control
Factory Main Parameters:
How muchthe resin spreads
out on the paper foil
Percentage of resin
in the paper
Relate the factory parametersto the bulk resistivity
• Type of Paper• Flow• Resin• Volatile• Heating Temperature• Pressing Temperature• Resin Reactivity
Percentage of additives Volatile
GOES
GOES
Up
Up
Up
Down
Resin
RPC Barrel EDR Chapter 3
A measured value has to bemultiplied for a multiplicativefactor (20/ to obtain ( i.e. at T=20 C )
A measured value has to bemultiplied for a multiplicativefactor (20/ to obtain ( i.e. at T=20 C )
T (0C)
3. Production and control of Bakelite3.5.1 Temperature dependence
3. Production and control of Bakelite3.5.1 Temperature dependence
The resistivity depends on the temperature T
20/= exp( (20-T) )
The resistivity depends on the temperature T
20/= exp( (20-T) )
To define a common production protocol we usually quote a resistivity value at T = 20 0C using as normalisation the following experimental curve.
To define a common production protocol we usually quote a resistivity value at T = 20 0C using as normalisation the following experimental curve.
20/
RPC Barrel EDR Chapter 3
Resistivity and Temperature
1,45
1,50
1,55
1,60
1,65
1,70
1,75
1 5 9 13 17 21 25 29 33 37 41 45 49 53
N. of measures (1 pt /15 minutes)
21,0
21,2
21,4
21,6
21,8
22,0
22,2
22,4
22,6Here temp starts to decrease
while
Then also startsto increase
3. Production and control of Bakelite3.5.2 Resistivity and Temperature
3. Production and control of Bakelite3.5.2 Resistivity and Temperature
Note also the ``inertia” of the bakelite in following the temperature change
(
x 10
11)
cm T (C)
is stillconstant
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.6 Resisitivity range
3. Production and control of Bakelite3.6 Resisitivity range
Bulk resistivity measurements - melaminic: production is able to reproduce the useful resistivity range
0,00
1,00
2,00
3,00
4,00
5,00
6,00
7,00
0 5 10 15 20
Slabs
(
x 10
10)
c
m
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.7.1 Roughness range
3. Production and control of Bakelite3.7.1 Roughness range
Roughness QualityRoughness Quality
Qualitative view of the surface improved bakelite. Pixel matrix greyscale of a micro-picture of the surface
Pix
e l G
reys
cal e
Val
ue
X (Pixels)Y (Pixels)
X 600magnification
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.7.2 Roughness range
3. Production and control of Bakelite3.7.2 Roughness range
Ra (
m)
Vertical deviation of the surface from its average profile
Ra
Measurements points on the surface
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.8.1 Resistivity measurement
3. Production and control of Bakelite3.8.1 Resistivity measurement
Needs good electrical contact between electrodes and bakeliteNeeds good electrical contact
between electrodes and bakelite
We tried several options for the contact - among others:
• sponge with water
• antistatic foam (with and without water)
• conductive gel
• conductive rubber
We tried several options for the contact - among others:
• sponge with water
• antistatic foam (with and without water)
• conductive gel
• conductive rubber
• Brass Electrodes• Upper 5 cm • Lower 10 cm for guard ring option
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.8.2 Resistivity measurement
3. Production and control of Bakelite3.8.2 Resistivity measurement
Constant pressure (3 atm) on the electrodes
How to measure ~ 1010 - 1011 cm
R = 10 ,100 k
= k V0/(V/R)
k = geometrical factor
V0 = 500 Volts
V0
VR
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite 3.8.3 Resistivity measurement
3. Production and control of Bakelite 3.8.3 Resistivity measurement
Upper electrode
Lower electrode
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.9.1 Systematic
3. Production and control of Bakelite3.9.1 Systematic
A piston with conductive rubber is continuously measuring the resistivity of a bakelite sample; after a predetermined set of measurements the piston moves up for a fixed time and back down on the sample for the next cycle of measures.
Number of cycles, number of
measurements within a cycle,
time between cycles and time
between measurements are
supplied by the user. Automatic
reading of Temperature and Humidity is provided.
A piston with conductive rubber is continuously measuring the resistivity of a bakelite sample; after a predetermined set of measurements the piston moves up for a fixed time and back down on the sample for the next cycle of measures.
Number of cycles, number of
measurements within a cycle,
time between cycles and time
between measurements are
supplied by the user. Automatic
reading of Temperature and Humidity is provided.
RPC Barrel EDR Chapter 3
0,9
1,0
1,1
1,2
1,3
1,4
1,5
1,6
1 23 45 67 89 111133 155177 199 221243 265287 309331 353 375397Time (A.U.)
20
(x 1
011)
cm
47
47,5
48
48,5
49
49,5
50
50,5
51
Hu
mid
ity
(%)
3. Production and control of Bakelite3.9.2 Systematic
3. Production and control of Bakelite3.9.2 Systematic
400 cycles of measurements, 10 meas./cycle, 10 sec after each measurements (~13 hours).
The resistivity (at T= 20 °C) of a melaminic sample as a function of time is plotted (left hand scale- purple). The recorded value of the Humidity is also shown (right hand scale - blue)
13 hours
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.9.3 Systematic
3. Production and control of Bakelite3.9.3 Systematic
0
0,05
0,1
0,15
0,2
0,25
0,3
0,35
0,4
0,7 0,9 1,1 1,3 1,5
Frequency distribution of 20/<20>
= 5,2 %
We can measure at a level of 5 %
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.1 Station for resistivity measurement
3. Production and control of Bakelite3.10.1 Station for resistivity measurement
Lifting belt- conveyors bed
Fixed frame Transverse beams supporting the upperelectrodes system
Pistons
BAKELITE
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite 3.10.2 Station for resistivity measurement
Upper position of the belt conveyors bedfor bakelite loading and unloading
Pistons integral to the upper beam of the fixed frame
Fixed frame
Mobile frame integral to the belt conveyors bed
Position of the lower electrodes integral to the lower beam of the fixed frame
Rectified cylinder
Pneumatic piston for belt conveyors lifting
Adjustable feet
Conveyors belts
Lateral guide
Lower position of the belt conveyors bedfor measurements
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.3 Station for resistivity measurement
3. Production and control of Bakelite3.10.3 Station for resistivity measurement
567.5 1135.0 1135.0 567.5
1384
.813
16.0
1042
.0
position A position
B
Side view lengths in mm
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.4 Station for resistivity measurement
3. Production and control of Bakelite3.10.4 Station for resistivity measurement
520.0 505.0 505.0 520.02050.0
position A
position B
Front view(lengths in mm) Bakelite
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.5 Station for resistivity measurement
3. Production and control of Bakelite3.10.5 Station for resistivity measurement
Top view(lengths in mm)
2050
.018
40.0
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.6 Station for resistivity measurement
3. Production and control of Bakelite3.10.6 Station for resistivity measurement
Setup for DAQ and measurements bench-tests
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.7 Station for resistivity measurement
3. Production and control of Bakelite3.10.7 Station for resistivity measurement
RS-232 Network Module
8 Ch, SPST Relays Module
8 Ch, 12 Bit Analog Input Modules
8 ch Universal Discrete Input Module
Electronics: modular distributed I/O architecture FIELDPOINT (Nat. Instr.) with analog and discrete I/O modules, terminal bases and network communication module (RS232)DAQ: Labview 5.0x
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.8 Station for resistivity measurement
3. Production and control of Bakelite3.10.8 Station for resistivity measurement
Pre-production Resistivity measurements at the factory
Man
ual M
easu
rem
ents
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.10.9 Station for resistivity measurement
3. Production and control of Bakelite3.10.9 Station for resistivity measurement
Pre-production Resistivity measurements at the factory
Man
ual P
roto
type
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.11.1 Quality control time schedule 3. Production and control of Bakelite3.11.1 Quality control time schedule
production
Slabs at rest for a week
measurementsloading unloading stacking
Manual Automatic Manual
15 sec 4 min 15 sec
•Slab in position •Pistons down•Measurements•Pistons up•Slab is moving out
6 hours / (4 min/slab) ~90 slabs/day ~ 1800 slabs/month
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.11.2 Quality control time schedule 3. Production and control of Bakelite3.11.2 Quality control time schedule
1/10 4/10
1999 2000
TASK Jul Aug Sept Oct Nov DecJan Feb Mar Apr May Jun
Tabledelivery
Setup
Ready tomeasure atfirm
BakeliteProduction
Measurement
5/10
RPC Barrel EDR Chapter 3
3. Production and control of Bakelite3.12.1 Ageing
3. Production and control of Bakelite3.12.1 Ageing
Gamma (137Cs) Irradiation Facility
Gamma (137Cs) Irradiation Facility
vs Temp. (0 C)
(B) vs Integrated Dose (Gy)
A
BSource ON
Source OFF
Melaminic sample
10 y LHC
RPC Barrel EDR Chapter 3
10 y LHC
Gamma (137Cs) Irradiation Facility
Gamma (137Cs) Irradiation Facility
vs Temp. (0 C)
(B) vs Integrated Dose (Gy)
A
BSource ON
Source OFF
Phenolic sample
3. Production and control of Bakelite3.12.2 Ageing
3. Production and control of Bakelite3.12.2 Ageing