Fibre Tension Systems

Servo Controlled | Electronic Closed Loop |  Self Compensating |  Bookshelf Creels

Servo Controlled Tensioners

Features:

• Electronically controlled fibre tension system with closed loop Servo controlled feedback
• Integration with CNC system to allow programmable tension settings and real time tension data acquisition via data acquisition system.
• Fibre guidance/delivery rollers are manufactured from glass filled PTFE
• Fibre take up option programmable within winding program
• Multi spindle external unwind tension control systems
• Fibre packages up to 200 mm diameter x 300 mm long and 10 kg weight capacity.
• Tensions ranging from 4 to 45N – other ranges available
• Free-standing, can be used with additional units if greater number of rovings/tows required.
• Optional moving fibre creel carriage

Description

Method of Control

• Fibres pass from the spindle mounted spools around re-direct pulleys which include a precision load cell.
• The system also incorporates a dancer arm to add compliance to the system allowing very dynamic tension variations.  Rotation of the dancer arm is controlled pneumatically.
• Fibre tension control is obtained from the feed back of the system mounted load cell.  The programmed tension additionally sets the pressure to the air cylinder connected to the dancer arm through an electro-pneumatic valve from the CNC control.
• Fibre tension is set via the data acquisition touch screen.  The screen also displays real time fibre tension for each spool.
• Back winding can be set to be active via the winding program or switched on/off from the touch screen or tension control cabinet.
• Fibre break sensing can also be set via the winding program or switched on/off from the touch screen or tension control cabinet.

Fibre tension control:

• Tension range:   4.4 – 44.0 N.
• Static tension accuracy: 4.4 – 24 N  +/- 1.6N and 24 – 44 N  +/- 1.8N
• Dynamic tension accuracy:  +/- 4N

Construction

• Two cabinets, upper and lower are mounted on upright supports.  These supports are fitted with wheels to allow the units to be moved.  The supports are also fitted with screw down foot pads to hold the creel stand in position when the required position is achieved.
• The lower cabinet is fitted with the spool spindles and servos arranged each side.
• The upper cabinet is fitted with the load cell/dancer units, arranged each side corresponding to the lower spool spindles.
• Each unit is enclosed by panels with access to equipment contained inside.
• Spool spindles are mounted in rigid bearing housings for each spindle
• Optional pneumatic package holders are available.

Controls

• Anodised aluminium control panel on which are mounted:
• Tensioner On/Off switch
• Power indicator
• Rewind function On/Off
• Fibre break On/Off function

Services

• Electrical – Single Phase AC 115-240V 50-60 HZ
• Pneumatics – Clean compressed air at 6 bar (80 psi)

Options

• Optional fibre break sensor
• Sensors detect a broken fibre and signal “alarm” or can be set to stop machine.
• Optional interface
• Dynamic tension display at touch screen display when data acquisition is purchased
• Digital fibre length counter – indicating fibre lengths used, with reset switch to return counter to zero

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Electronic Closed Loop Tensioners

Features

• Electronically controlled fibre tension system with closed loop feedback
• Integration with CNC system to allow programmable tension settings and data aquisition
• Pre-preg fibre delivery option available
• Fibre take up on dancer arms
• Multi spindle external unwind tension control systems
• Fibre packages up to 260mm diameter and 20kg
• Tensions ranging from 4 to 40N – other ranges available
• Free-standing, can be used with additional units if greater number of rovings/tows required
• Optional moving fibre creel carriage

Description

Method of control

• Fibres pass from the spindle mounted spools around re-direct pulleys to the tension dancer arm
• The dancer arm has two freely rotating grooved pulleys to guide the fibres
• Rotation of the dancer arm is controlled pneumatically
• Fibre tension setting is obtained by varying the pressure to the air cylinder connected to the dancer arm, which is adjusted by rotating the tension control knob on the control panel or through an electro-pneumatic valve when CNC controlled
• Back tension between the dancer arm and spool is controlled by the dancer arm rotation being sensed by a feedback device connected to a servo unit which controls the brake in the fibre spool
• Fibre tension control remains constant with speed

Construction

• Two cabinets, upper and lower are mounted on upright supports
• The lower cabinet is fitted with the spool spindles arranged each side
• The upper cabinet is fitted with the dancer units, arranged each side corresponding to the lower spool spindles
• Each unit is enclosed by panels with access equipment contained inside
• Spool spindles are mounted in freely running bearings, each spindle has a magnetic particle brake to control fibre back tension between spool and dancer arm

Controls

Anodised aluminium control panel on which are mounted:

• Manualtension setting system
• On/Off switch
• Power indicator
• Analogue tension indicator
• Tension adjustment button

Services

• Electrical – Single phase AC115-240V 50-60 HZ
• Pneumatic – Clean compressed air at 6 bar (80m psi)

Options

Optional fibre break sensor

• Sensor arms detect a broken fibre and signal “alarm” or can be set to stop machine

Optional interface for Integrated Manufacturing System (IMS)

• Manual/automatic switch
• Manual mode – tension set manually
• Automatic mode – tension controlled from the Winding machine CNC winding program
• Indicator light shows Manual/Automatic status
• Digital tension indicator

Digital fibre length counter – indicating fibre lengths used, with reset switch to return counter to zero

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Self Compensating Tensioners

(Illustrated in lower right hand image)

Features

• Fast load/unload spindle for standard fibre packages
• Optional automatic fibre break sensing
• Optional fibre take up at spool
• Variable tension setting
• Optional tension setting from computer control
• Automatic tension compensation for spool size variation

Description

Each spindle unit is self-contained

Comprising a

• Base
• Spindle
• Tension brake
• Compensating arm
• Tension cylinder

The units can be mounted on a steel framework to give the required multi-spindle layout.

The standard spindle is suitable for 75 mm (3 inch) cardboard core fibre package.

• Optional adapters can accommodate larger size fibre package.
• Weight can be up to 25 kg and diameter 290 mm.

A roller mounted on a pivoting arm runs on the outside of the fibre spool.  The arm movement automatically compensates the tension device ensuring uniform fibre tension during the large diameter change. (Typically a factor of 3.4 for a change of 260 mm to 76 mm)

The tension range is from 250 gms to 1500 gms.  Tension is set by regulating air pressure to the units.  The standard manual system has a pressure regulator and gauge which will supply multiple units, ensuring repeatability and uniformity of tension.

When a PULTREX Integrated Manufacturing System (I.M.S) interface is fitted an electro-pneumatic regulator is used which sets tension either manually or automatically from the filament winding machine control.

Where fibre demand damping or take-up is required a standard PULTREX multi-fibre damper unit can be located after the fibre tension creel with resin impregnation if required.

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Bookshelf Creels

Modular in design and bespoke for individual applications.