barwell gear pump cover:barwell gear pump cover
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CONTINUOUS GEAR PUMP PREFORMERS
www.barwell.com
The Future of Continuous Preforming
The Barwell Gear Pump Preformer
Combining the plasticizing properties of a coldfeed screw extruder with the volumetric flowcontrol properties of a gear pump together withthe proven Barwell cutter system
This combination increases the process capabilitiesof difficult materials including tight dimensionaltolerances and overcomes temperature to outputrestrictions.
A significant advantage in using a Gear pump isthat the output is linear relative to the Gear Pumprpm. Therefore outputs are much more predictable.The use of Herringbone gears greatly complimentsthis effect by ensuring even flow through thepump and maintaining precise extrusion. Effects ofscrew extrusion pulsing is therefore eliminated andquality controlled production is assured.
INCREASED PRODUCTIVITY
DIMENSIONAL STABILITY
PROCESS FLEXIBILITY
LOWER TEMPERATURE PROCESSING
FULLY AUTOMATED SYSTEMS
COMPLETE SYSTEMS OR RETROFIT PACKAGES
SIMULTANEOUS SCREENING
TOUCH SCREEN CONTROLS WITH DATABASE
Gear Pump Systems
Operational Princip
PRINCIPLE OF OPERATION
Material is delivered to the Gear Pump by a screw extruder which masticatesthe material prior to entry into the Gear Pump.
TYPICAL FEED SCREW ARRANGEMENT (PLASTISCREW)
The masticated material is pulled into the Pump by the intermeshing gearteeth at a constant rate, irrespective of screw rotation speed, ensuring theGear Pump cavity remains full at all times. Minimal shear is generated inthe Gear Pump so increases in material temperature are kept to a minimum,especially important when processing temperature sensitive materials.
The material is then compressed at the outlet point at a constant rateenabling precise control over extrudate dimensional stability. The constantrpm of the Gear Pump and constant monitoring and regulation of inletpressure help overcome extruder pulsing. This is important when consideringthe effects of strip feed change-over. The Gear Pump is independentlydriven but controls the screw rpm by means of inlet pressure monitoring.
Without a Gear Pump the pressure build up and extrusion uniformity is directlyinfluenced by the screw rotation and compound variations. When a Gear Pumpis incorporated into the system line these variations are monitored at the Pumpinlet and adjustments made automatically to maintain constant output flow.
Whilst the pressure at the inlet varies (due to material changes, variations infeed etc.), the pressure at the outlet of the Gear Pump remains constant. Thisensures improved extrusion quality and tight control of extrudate dimensions.
By keeping the Gear Pump rpm constant, it is possible to influence theplasticizing effect on materials by changing the screw rpm. Increasing thescrew rpm increases the inlet pressure and also the compound temperature asgreater mastication is achieved during the dwell time in the extruder barrel.
This can have significant advantages when processing difficult materials thatneed additional mastication to achieve output requirements. Care should betaken to ensure that material temperatures remain within normal process limits.
We use only the latest “Heas developed by
Three Basic GSPUR HELI
ADVANTAGESNone
DISADVANTAGESLimited Applications
Pulsing EffectHigh Stress on Bearings
No Flow Stability
ADVANNon
DISADVACreates Cu
Pulsing High Stress o
Difficult TNo Flow
PROFILES
ples & PerformanceMaterial flow through the gear pump is generally linear and thereforeentirely dependent on the gear pump rotation speed. Increasing the gearpump rpm will automatically adjust the screw feed accordingly, maintainingthe inlet pressure and cavity fill.
This linear effect is not influenced by varying material characteristics.As long as the screw is capable of achieving adequate plasticizing thethroughput will remain linear.
Very little energy is put into the material by the gear pump which meansthe system can be used at lower temperatures or alternatively, higheroutputs can be achieved at normal process temperatures.
A metal detector is fitted as standard to all Barwell complete systems. Thisgreatly reduces the possibility of foreign objects or material contaminationto cause serious damage to either the screw or the Gear Pump. Detectorsensitivity can be adjusted to avoid unnecessary stoppages during production.
Barwell can offer complete Gear Pump Preforming systems, ProfileExtrusion only systems or alternatively Gear Pump retrofit packages to suitcustomers existing extruders. Although the Gear Pump has an outletpressure up to 350 Bar, Barwell offers two head options, a Standard 210Bar GP (or SH) head for normal compounds or alternatively a 350 Bar HighPressure GP Head for tougher compounds or for mater
erringbone” Design GearsHATEC, Germany.
Gear DesignsCAL HERRINGBONE
TAGESne
ANTAGESrved FlowEffect
on BearingsTo CleanStability
ADVANTAGESPrecise Flow Control, No Pulsing
Even Distribution, Straight ExtrusionsDimensional Stability
Easy CleaningLabyrinth (Self Lubricating) Bearings
DISADVANTAGESNone
PREFORMS
Easy Access CleaningQUICK CLEAN METHOD
Stage 1.
Undo the ‘C’ clamp holding the screw inposition. Press the machine open pushbutton.
The head will move forward allowingaccess to the screw extruder and breakerplate in front of the screw.
Remove breaker plate and any rubber byhand.
Start the screw and run all remainingcompound out of the screw.
Check the inlet to the gear pump is clearof compound.
Refit the breaker plate.
Stage 2.
Close the machine by pressing both themachine close buttons together
Close and tighten the ‘C’ clamp. For safetythe gear pump will not run unless thescrew is in position.
With the head open and the cutter cageclosed, run the gear pump to remove anycompound still in the gears.
Open the cage and pull out from thefront of the gear pump any remainingcompound.
To remove accessories from head.
Slacken accessory retaining and die con-centricity adjusting screws.
Lift out the die extractor making sure it isin the middle of the die holder
Select die extractor up to push theaccessories out
Retract the die extractor after the acces-sories have been removed
Put the die extractor back in its homelocation.
Easy Access, Power AssistedMinimal Downtime
Gear Pump Cleaning process: Stage: No. 1
Gear Pump Cleaning process: Stage: No. 2
Remove Compound
From Screw
FromGearPump
Hydraulicallypowered forward
Remove Compound
Remove Accessories
READY FOR NEW / COMPOUND PRODUCT
DIMENSION “A”DIMENSION “B”DIMENSION “C”TOTAL WEIGHT (approx)
mmmmmmkg
2330125016002500
3250190016002950
4350190017505200
5100300017506000
5900360017507400
BPP70 BPP180 BPP320 BPP550 BPP1200
Max OutputMax Pump RPMScrew SizeScrew L/D RatioHeating/cooling zonesMax operating pressureMax Die size (350 Bar Head)Max Die size (210 Bar Head)Cutter Speeds (Variable)Touch screen controlsDatabaseWeigh scale loop feedbackAccuracy (by volume)Extrusion only versionShoe Sole Head available
kg/hrrpmmm
barmmmm
%
705550
10:14
3506464
50-500Y
2000Y
+/-1YN
1805075
10:14
3506464
50-500Y
2000Y
+/-1YN
3204090
12:15
350140190
50-500Y
2000Y
+/-1YY
5503612012:1
6350190190
50-500Y
2000Y
+/-1YY
12003015012:1
6350190190
50-500Y
2000Y
+/-1YY
BPP70 BPP180 BPP320 BPP550 BPP1200
Basic Data & Dimensions
Barwell International Ltd
Head OfficeAtria Court • 60 Papworth Business Park • Stirling Way
Papworth Everard • Cambs • CB23 3GY • EnglandTel: +44 (0) 1480 832060 • Fax: +44 (0) 1480 832070
E-mail: [email protected] • Web Site: www.barwell.comCB24 4QX . England
ChinaBarwell China
Room 502 • No. 1 Lane 600, Tianshan Rd Shanghai • China • 200051
Tel: +86 21 611 39 270E-mail: [email protected] • Web Site: www.barwell.com
USA Canada & MexicoBarwell Machinery USA
2868 Westway Drive • BrunswickOhio 44212 • USA
Tel: +1 330 225 9500 • Fax: +1 330 225 9555E-mail: [email protected] • Web Site: www.barwell.com
BrasilBarwell Do Brasil
Equipamentos Para Borracha Ltda • Edificio Columbia Office CenterAv. Jabaquara • 2819 • Bairro: Mirandopolis • 0405-004 SAOTel: +55 11 5589 7168 / 5071 2983 • Fax: +55 11 3848 0903
E-mail: [email protected] • Web Site: www.barwell.comCB24 4QX . England
Tel: +44 (0) 1954 230383 Fax: +44 (0) 1954 230821E-mail: [email protected] Web Site: www.barwell.com