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注塑机能耗的测量
Measuring energy consumption in
injection moulding machines
Tat Ming Technology Co. Ltd.
Kevin Tong
Nov 2013
1
Test standards
• European std (2013.1)
– Euromap 60.1
– Euromap 60.2
• Chinese std(2009)
– Industrial std
• Hong Kong std(2013)
– HKPMA std
2
3
Why energy eff. test std?
• Many factors affect energy consumption
• Factors
– Machine size
– Product
• Material
• Shot weight
• Wall thickness
– Cycle time
• Perf. test according to std. to hold factors constant
• So comparison of brands and design makes sense
• Result is unit energy consumption or efficiency class
Use std molds?
• There are pros and cons
• Standard molds
– Reduce # of param. spec.(pros & cons)
– Limited # of molds to cover a big range of m/c(cons)
– Used by industrial std
– Used by HKPMA std
• No molds specified
– Euromap 60.1
• Any mold could be used
– Euromap 60.2
4
5
Industrial std
• Proposed by a group of manufacturers headed by Haitian in Oct 2009
• Machines are class. by shot vol.
– Class upper limit = 3*lower limit
– Geometric series
– Each class uses its own std mold
– Cold runner molds
– Circular disks with sprues
6
5 molds
7
Mold spec
8
Other spec
• PS material
– Undried, not pre-heated
– Specific gravity 1.05 g/cm3,
– MFR(200,5) = 4.5 ~ 5.5 cm3/10 min
– Barrel temperature 250±10℃
• Room temperature 15℃~35℃
• Shot vol >3888 cm3 or when std molds could not be used
– Use mold spec. by manufacturer or user
– Undried and not pre-heated PP
– Shot weight 1/4~3/4 of machine shot weight
– Include sprue weight if there is sprue
9
Indicator and eff. class
• Indicator is kWh per kg of PS used
• Make 50 shots
• 6 efficiency classes
• Classes 1 &2 are energ.
efficient classes
• Arithmetic series
– Class size 0.15 kWh/kg
10
Std characteristics
• #3 mold covers 145 - 432 cc shot volume range
• Corr. to m/c w/ clamping force 75 – 180 tons
• Servodrive machines could reach class 1
• Variable displacement pump m/c could reach class 2
• Small machines have higher kWh/kg
– Many shots to make 1 kg, low plasticizing capacity
• Big machines have lower kWh/kg
• Includes peripheral equipment energy consumption
11
kWh/kg
12
Machine size
• Shot volume range 16 - 3888 cc
• Clamping force range about 20 – 700 tons
• Only 5 classes of machine size
• Each with its own mold
• Class upper limit is 3 times lower limit
• Class range is big – About 75 – 180 tons for #3 mold
• So not too many molds are needed to cover range
• Big machine has a high kWh/h, but a low kWh/kg
HKPMA std
• 5 molds
• Shot vol. range 85 - 2719 cc
• 5 classes of machines, delimited by shot vol
– High limit is double low limit
– Geometric series
• PP material used
• 220° C barrel temperature
• More parameters spec vs industrial std
13
14
EUROMAP 60.1 & 60.2
• EUROMAP is an assoc. of European plastic
equipment manufacturers
• Most well-known for its CE safety std
• EUROMAP 60.1 and 60.2 eff. test std
announced in Jan 2013
• Euromap 60.1 does not spec molds
• Euromap 60.2 uses any molds
Euromap 60.1
• PP material used
– Not dried, not pre-heated
– MFR(230℃ ,2.16 kg) = 20 ~ 25 g/10 min
– Barrel temp. 220℃ ±3℃,within 30 min.
• Room temp. < 30℃
• Peripheral equip. excluded
• All shots are made consecutively
• Not shorter than 10 min. & not fewer than 5 shots. For screw diameter >= 80 mm, 3 shots are OK
• Defined idle state and idle power
• Is an IMM eff. test, classify IMM into 10 classes
15
2 cycles
• Cycle I , standard IMM
• Cycle II, high injection speed IMM
• For each cycle, clamping and injection
parameters are specified
– Same clamping parameters for both
– Diff. inj., plast., back prs. and cooling parameters
• Adjust. nozzle to generate injection pressure
• Clamping block to generate clamping force 16
10 efficiency classes
等级 比能耗kWh/kg 的几何数列
1 >1.50
2 ≤1.50 1.50
3 ≤1.20 1.199
4 ≤0.96 0.958
5 ≤0.77 0.766
6 ≤0.61 0.612
7 ≤0.49 0.489
8 ≤0.39 0.391
9 ≤0.31 0.313
10 ≤0.25 0.25 17
8 6
Class boundaries
18
Indication of results
• + means low idle power
– Idle power ≤ 1 kW for m/c below 400 tons
– Idle power ≤ 3 kW for m/c equal or above 400 tons
• On a std machine test, the specific energy
consumption is 0.8 kWh/kg, idle power is 0.9
kW, Euromap 60.1 indication is (CycleⅠ) eff.
class 4+
19
Euromap 60.2
• Uses any mold
• Not a test of IMM, no efficiency classes
• Measures a particular mold on a particular
IMM with certain peripheral equipments
• 5 blocks of equipment, meas. their powers sep.
– IMM motion, mold motion, barrel heaters
– Peripheral equipment
• Cyclic(e.g. robot)。 Non-cyclic(e.g. hopper dryer)
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Detailed report
• IMM information
• Product information
• Temperature
• Energy consumption
- Specific energy consumption kWh/kg
- Avg. power(3 – 5 blocks measured separately)
- Idle power
21
kWh is a big unit
22
Insufficient resolution
23
• Home power meter has 0.1 kWh resolution
• At 0.4 kWh/kg, needs 25 kg resin to use up 10
kWh, then resolution is 1%
• For a small machine, 50 shots does not use up
25 kg of resin
– Resolution in doubt
– Can tell two IMM’s apart?
• Digital power meter has a 0.001 kWh resolution
Digital power meter
24
IMM PLC + Dig. p. meter
• Automate the measure.
– Fast, accurate, error-free
– Integral # of cycles
– Separate meas. of motion, heat,
peripheral equipment
– Can use any std
– Can be a tool for optimization
– An option in Tat Ming machines
• Stand-alone unit
– Moveable, can measure all IMM in the factory 25
Current transformers
26
Machine ener. consump.
27
Heater energ. consump.
28
Para. affect ener. cons. 1
• Slow plasticizing
– Finish plast. w/ cooling
– Suitable for var. disp.
pump
• Fast plasticizing
– Fastest plast., then stop
– Suitable for servodrive
• Back pressure
– High bp = high energ. con.
– Find min. bp possible
• High temperature
– Higher heat loss
– Longer cycle time
– Lower screw torque
• Short cycle time
– Acc. & dec. waste energ.
– Vibr. reduces m/c
reliability
– Reduces heat loss
29
Para. affect ener. cons. 2
• Clamping force
– As low as possible
– Without flashing
• Opening stroke
– As short as possible
• Injection pressure
– As low as possible
– While completely filled
• Ejection force
– As low as possible
– Don’t hit bottom
– Push & pull, no springs
– Springs not too stiff
• Ejection count
– As few as possible
30
Barrel energ. consump.
• Reduce heat loss
– Convection, highest
– Radiation, smaller
– Conduction at rear zone
• Loss by convection,
radiation
– Prop. to surf. temp.
• Insulation to increase
temperature drop
– Prop. to surf. area
• Induction heating
– Induction cooker princ.
– Heat gen. in barrel mat.
– Fast resp. to set temp.
– Off when set temp.
reached
• Infrared heating
– Avoided contact
resistance
– Big surf. area 31
Barrel temperature
• Barrel cover
– Stainless steel shell
– Insulation mat. in shell
– Epoxy cover on top
• Rising temp. profile
– Set low temp. at rear
zone
– Raise water collar temp.
– Reduces conduction loss
– Reduces temp. override
downstream
32
Perip. equip. energ. cons.
33
Hong Kong pavil. 3E231
• Green manufacturing
theme
• Energy saving
• Environmental friendly
resins
– Degradable
– Renewable
34
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