INDIAN PLASTICS INSTITUTE CHENNAI CHAPTER One Day Seminar on FLEXIBLE PLASTICS FILM LAMINATES 20th September 2004 - Hotel Savera DEVELOPMENTS IN MACHINERY FOR FILM MANUFACTURING Presented by : Shri I Chakravarthy Senior manager (R&D) Kabra Extrusion Technik, Daman.
BIO-DATA Mr. I Chakravarthy, B.Tech. (Mechanicl Engg.) Nagarjuna University. Has been associated with Extrusion Machinery design for 12 years. Presently as Managr (Engg.) at kabra Extrusions Technik Ltd. Daman.
KOLSITE GROUP OF COMPANIES DEVELOPMENTS IN MACHINERY FOR FILM MANUFACTURING I.Chakravarthy
Requirements of film for Laminates 1) Wrinkle-free film 2) Equal tension along entire web width 3) Web flatness (No bands/zones of sagging) 4) Uniform gauge (Minimum GSM variation across width) 5) Easy bubble openability on 2-station winder 6) Good winding with no built-in stresses in wound roll 7) Large wound rolls for longer run (to reduce changeover wastage)
Machinery to manufacture film for Laminates 1) Blown Film Plant a) Economical and simple b) Co-extrusion is easy and popular c) Bi-axial orientation (Better physical properties in MD & TD) 2) Cast Film Plant a) Costlier and technology-intensive b) Better roll flatness c) Excellent optical properties d) Poor in TD properties e) Downgauging Blown Film Plant is the most widely used.
Requirements of Blown Film Line for Laminates `FLEXIBILITY is the key 1) Flexibility in width of film 2) Flexibility to process multi-slit (2-up/3-up) 3) Flexibility to process different applications a) Film for Gutka (20-40 mic.) b) Film for biscuits/wafers b) Film for edible oil packaging (70-100 mic.) c) Film for Wheat flour (Atta) 4) Flexibility of wide BUR range 5) Flexibility to match properties of each application with optimum polymer combination / die gap selection 6) Provision to run machine to its optimum capacity always
Recent Developments in 3- Layer Blown Film Plants Conventional 3-Layer film plants Output levels of 125-270 kg/hr available with LFW upto 1700mm High output 3-layer film plants with Internal Bubble Cooling Output levels of 250-400 kg/hr available with LFW upto 1700mm `Kabrastack Stackable die head Computer-Integrated Control (CIC) systems
Recent Developments in 3- Layer Blown Film Plants DEVELOPMENTS IN STD. 3-LAYER PLANTS EXTRUDERS - BARRIER SCREWS INSTEAD OF CONVENTIONAL PROFILE CANDLE FILTERS KABRAFLEX DIE HEAD & DIE SET with changeable die lip AIR RING OSCILLATING PLATFORM FLATTENING / COLLAPSING BOARDS
Recent Developments in 3-Layer film plants EXTRUDERS Feature : Barrier Screw Design Benefits : Complete melting of polymers, thereby minimise Gels Good control over melt temperature Excellent melt Homogenity & Mixing Minimise shear heat generation & zone overshooting To improve Colour master batch dispersion To process different varieties of polymers Best result with new polymers like Metallocenes Reduce screw / barrel wear
Recent Developments in 3-Layer film plants FILTER MECHANISM Feature : Candle Filter instead of Torpedo Screen Changer Benefit : Longer production run as filtering area larger by 6 times Leak-proof working Minimise conventional spots of over heating & gel formation Compact design Lesser overall heat consumption OSCILLATIG PLATFORM Feature : New spacious and sturdy design Benefit : No need for pit beneath the platform Safe and easy cabling and piping PLC based control for oscillation with double override protection
Die Gaps for different polymers Physical properties are affected by Draw Down Ratio Draw Down Ratio (DDR) = Die gap/final film thickness Die gap affects --- Mechanical properties Balancing of MD / TD properties If die gap increases MD tear strength drops --Dart impact resistance drops Optimum die gaps : LD/LD/LD -------- 1.5 mm LL/LL/LL ------ 2.2 mm (2.5mm if melt fracture persists) LD/HD/LD -------- 1.5 mm LD shrink film ---- 1.2 mm / 1.5 mm Metallocene rich blends --- 2.5 mm / 2.8 mm
Recent Developments in 3-Layer film plants `KABRAFLEX Die head V-1 Features : Superior spiral flow path Geometry Hardened, highly polished die surfaces Hard chrome plated melt flow paths Easily changeable die gap, by replacement of top punch lip Benefits : Superior gauge uniformity Designed to process wide range of polymers Easy to assemble and dismantle Eliminates traditional spots of over heating and gel formation Lesser overall heat consumption
Recent Developments in 3 Layer film plants AIR COOLING RING (KOLSITE VERSION 1.0 ): Excellent Gauge control, even at high output levels Highest yield ( Meterage/ kg polymers ) in the Industry Dual lip Air ring with streamlined air flow Geometry Made of high strength hardened aluminium alloy to minimises warpage and enhance life of ring Precision machined and highly polished air paths Suitable for BUR from 1.8 to 3.6 Excellent bubble stability even in thin films Best suited for low melt strength materials like Metallocenes Provided with Temperature & pressure gauges to measure & repeat settings at a later date.
PBT ROLLER FLATTENING BOARD ADVANTAGES LOW COLLAPSER FRICTION ----- REQUIRED ESPECIALLY IF THE REEL FLATNESS IS CRITICAL. PREVENTS EXCESSIVE BAGGINESS DUE TO DRAG. ROLLERS ARE EXTREMELY USEFUL WHEN DEALING WITH THIN & WIDE WIDTH WEBS AND WHEN BOARD LENGTH IS LIMITED BETTER FOR STIFF WEBS LIKE HDPE/HMHDPE
Guidelines for improving film flatness 1. Maintain bubble roundness 2. Use low angle collapsing boards 3. Provide side/lateral guides 4. Allow differential collapsing surface speeds by segmented rollers 5. Maintain maximum bubble stability 6. Collapse rigid materials (like HDPE) when it is still hot 7. Select optimum layer material combination
3-layer film plant with IBC ADVANTAGES OF INTERNAL BUBBLE COOLING ( IBC) : Increased output of over 50% compared to conventional machines, maintaining mechanical properties ( Usually maximum film outputs in kg/hr is 0.9 to 1.1 times die exit dia.in mm i.e 315-385 kg/hr for 350 mm die ) Reduced blocking Improved clarity (for clear film) Tighter layflat width control Faster start-up (once operators are trained) Better operational productivity
3-Layer film plant with IBC A typical 3-Layer plant with IBC consists of : Max. Layflat Width 1700 mm, Max. output -375 kg/hr 60mm x 30:1, Grooved feed extruders 3 nos. Screen changers 3 sets Kabraflex-V2 die head with IBC, die size 375 mm Air ring version 2.0 5-orifice IBC lip set OBC & IBC systems with separate heat exchangers 12-seg. Scissors type bubble guide basket Contact type sensors for IBC control Oscillating Haul-off with 1800 mm nip roller width Web aligner KVP-1800, Fully automatic 2-stn. Surface winder Electrical control panels
OBC & IBC air circuit H.E.(OBC) H.E.(IBC) COOLED AIR TO AIR RING COOLED AIR TO IBC DIAMETER SENSOR PRECISION BUTTERFLY VALVE AIR RING BLOWER (OBC) TWIN SHAFT A.C. MOTOR AIR IN EXHAUST BLOWER INLET BLOWER EXHAUST AIR TO ATMOSPHERE AIR OUT VARIABLE SPEED TWIN IBC BLOWER
3-Layer IBC film plant
3-layer film plant with IBC Types of Bubble Diameter Sensors : CONTACT TYPE SENSORS (Pneumatic transducer) - simple in working, maintenance-free, economical - may leave impression on film surface - works satisfactorily for all general applications - not suitable for very thin and tacky films NON-CONTACT TYPE SENSORS (eg. Ultrasonic sensor) - better in width control - expensive - works for all types of films
Oscillating haul-off
Oscillating haul-off HORIZONTAL OSCILLATING NIP ARRANGEMENT
3-layer film plant with IBC HORIZONTAL OSCILLATING HAUL-OFF Sturdy design with large slewing ring bearings Degree of Oscillation : 360 deg. Air Turn bars of larger dia.150 mm to reduce wrinkles Turn bars to act as normal guide rollers when oscillation is in `HOME position - reduces wear on turn bars Easy accessibility provided to nip rolls and turn bars for ease of film threading and maintenance purpose All gears of larger module for longer life Osci. direction reversal with double limit switch protection Special package for tacky films
3-Layer film plant with IBC KVP-FULLY AUTOMATIC 2-stn. SURFACE WINDER FULLY AUTOMATIC OPERATION FROM NEW SHAFT FEEDING TO WOUND ROLL UNLOADING HYDRAULIC UNLOADING OF WOUND ROLL IS STANDARD FEATURE LOAD CELL BASED TENSION CONTROL DIFFERENT ROLL WIDTHS POSSIBLE ON EITHER STATION THR U CENTER SLITTER ROLLS PRODUCED ARE DIRECTLY MARKETABLE --- NO NEED OF SLITTING/REWINDING ELECTRONIC LENGTH COUNTER IS STANDARD FEATURE ROBUST DESIGN WOUND ROLL CAPACITY UPTO DIA. 1000 MM / 700 KG EDGE TRIM WINDER AS OPTIONAL INSTEAD OF TRIM SUCTION BLOWER 24
KABRASTACK V1 DIE HEAD Stackable die head For die range 200-375mm 1. Up-gradable to 5 layer 2. Low residence time 3. Better gauge uniformity 4. Minimum gels 5. Quick colour changeover
KABRASTACK V1 DIE HEAD Stack Spiral with Dual Binary Flow pattern Horizontal spiral Distribution of melt
KABRASTACK V1 die head with IBC Advantages of Stackable die over conventional spiral die Upgradability into 5 or more-layered die to produce Barrier films Minimum wet path best suited to run heat-sensitive polymers Almost equal wet path for all layers (In conventional dies, outer layer has 4 to 5 times more wet path than inner layer) Possible to set different temperature profiles for each layer without affecting adjacent layer Minimum scope for `gels formation Superior physical quality of film Better scavenging (less changeover time from coloured film to natural film) Low back pressure and low residence time Less wastage while start-up since die volume is lesser Better gauge uniformity Ability to process polymers with wide range of operating temperatures
Computer-Integrated Control Systems Advantages of CIC Systems Works on WINDOWS-XP platform with Industrial PC & tailor-made software Data storage of machine parameters, recipe and output details Retrieval of Process data anytime Analysis of process data for any future reference and trouble shooting Historic trends/graphs for key parameters like Melt pressure, Amperes, Temperatures, Speed, etc. for analysis Fault display of all drives directly though communication with drive Up-gradability to future automations like Thickness control, Width control, Gravimetric Feeding with Line/Yield control Fault/Defect recording for future analysis Lesser machine wiring and easy to maintain Graphical representation of the machine operation