)( D.1 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blow Moulding Process & Barrier Containers Part 2 Equipment
)( D.2 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Feeding system for the granules, regrind and masterbatches Melting and homogenizing of the plastic in a single screw extruder blowing of the bottle cooling of the bottle calibration and de-flashing leak proof testing Major process stages
)( D.3 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Extrusion blow moulding –continuous extrusion –intermittent extrusion Injection blow moulding Injection stretch blow moulding Blow moulding techniques
)( D.4 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Extrusion Blow Moulding – Wheel Machines
)( D.5 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Continuous extrusion blow moulding 1 Line with double station for Max. 24 cavities
)( D.6 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blow Moulding Machine
)( D.7 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Feeding system (volumetric, gravimetric, mixing), hopper -Extruder: screw, barrel, adaptor -(Filter screen-pack, filter changer) -Head, parison control, die: mandrel, bushing -Parison cutter -Blow unit -Mould(s) -De-flashing unit -On-line test unit (holes, top-load) -Labelling (glueing, IML), printing (flaming, Corona) Blow Moulding Line Equipment elements
)( D.8 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Die Hot knife cutter Blow pin Mould Parison Die centering adjustment bolts Equipment set-up
)( D.9 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Equipment set-up
)( D.10 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Dosing and mixing units
)( D.11 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Dosing and mixing units
)( D.12 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blow Moulding Line – Extruder
)( D.13 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blow Moulding Line – Extruder Functions of the extruder: - Convey the granules in the screw flight - Compress the solid granule and remove the air - Melt the granules - Mix the melt, to make it as homogeneous as possible - Produce the desired melt temperature - Produce the desired pressure to have the melt flowing
)( D.14 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blow Moulding Line – Extruder Typical extruder for blow moulding lines - Normally with grooved barrel - 3 zone screw or barrier screw with or without mixing elements
)( D.15 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Screw DScrew diameterLScrew length qFlight angle (17.65)PPitch FFeeding zone depthHMetering zone depth AFeeding zone length/DCCompression z. depth/D MMetering z. length/DNScrew speed, rpm Feeding zone zone Compression zone Metering zone P Connection to the motor D FH L
)( D.16 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Typical 3-zone screw: D= 90 mm L/D= 25 Compression ratio: 2.0 to 2.5 Length feed section: 10D Length compression section: 6D Length metering section: 9D Typical barrier screw with mixing head: L/D: 20 Screw
)( D.17 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Screw 3 Multi-Purpose Barrier Screw for Grooved Barrels
)( D.18 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Shear & mixing elements Mixing elements 2
)( D.19 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Screw 3 Multi-Purpose Barrier Screw for Grooved Barrels
)( D.20 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax DISTRIBUTIVE (ananas, Saxton, Dulmage) They divide and recombine flow streams DISPERSIVE (UCC; cavity transfer mix, static mixer) Cutting strains generate the reduction of particles of immiscible components
)( D.21 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Mixing elements
)( D.22 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Mixing elements 3
)( D.23 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Grooved zone Cooling Grooved barrel
)( D.24 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Filters – Screen pack – Filter Changer old filter new filter
)( D.25 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Spiders (PVC) -Mandrel -Spyral Types of dies
)( D.26 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Low cost - Reduced external dimensions - High precision with annular die gap - Difficult centering - Long time needed for color change - Output depending Mandrel die
)( D.27 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Standard die
)( D.28 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Multiple die
)( D.29 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Die design and polymer swell
)( D.30 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Die design and polymer swell
)( D.31 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Coextrusion dies for 3 layers
)( D.32 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Coextrusion die for 6 layers and wall structure
)( D.33 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax layers PE-LD/PE-HD 3 layers PET/PET/PET PET/PA/PET PE-HD/R PE-HD /PE-HD PE-HD/Adhesive/PA PE-HD/Adhesive/EVOH 4 layers PE-HD/R PE-HD/Adhesive/PA or EVOH State-of-the-art structure of multilayer bottles
)( D.34 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax layers PE-HD/adhesive/EVOH/adhesive/PE-HD PE-HD r PP EVOH or PA 6 layers PE-HD/R PE-HD/adhesive/EVOH/adhesive/PE-HD PE-HD or PP EVOH or PA State-of-the-art structure of multilayer bottles
)( D.35 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Radial flow head – Heart shaped melt flow channels
)( D.36 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Distance to exit on the back side of the mandrel is shorter than the one of the extruder side = lower pressure drop - Reduces parison bending - Melt parted in two (180°) for optimized distribution of thickness - Fusion lines on the opposite part of entry Radial flow head – Heart shaped melt flow channels
)( D.37 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Die mandrel can be centered by means of adjustment bolds. Poor centering leads to uneven wall thickness distribution, resulting in poor bottle stiffness. Die centering
)( D.38 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax No flexibility - Used for containers with special form (strong oval shape, square) Die deformation
)( D.39 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Die deformation/Partial thickness control (PWDS)
)( D.40 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Programming parison thickness through electronic system to optimize container wall thickness and performance Parison thickness control
)( D.41 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Vertical mandrel movements modify the die gap thus the parison thickness (and its swell) Parison thickness control
)( D.42 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blowing is done aside of the die - Blowing pin descends in to the neck opening (continuous extrusion lines, with or without neck calibration) Blowing systems
)( D.43 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blowing pin is part of the mandrel (Uniloy equipments) intermittent, with neck calibration - Blowing pin replaced by a needle (carousel lines for aseptic containers or toys) Blowing systems
)( D.44 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Two blowing pins moving aside, used for flat articles with high widening ratio. One of the pin is the blowing pin. Blowing systems
)( D.45 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blowing air needs high pressure - Too high air pressure causes protrusions closed to the partition lines of the mold - Too low pressure causes air trapping, rough surface and partition lines not homogeneous - Pre-cooled air or liquid nitrogen can help reducing cycle time and increasing production Blowing systems
)( D.46 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Pre-blowing with open parison - avoids parison collapse - Pre-blowing with closed parison - reduces parison elongation - optimize mold filling - improve formation of partition lines (by reducing accumulation at the end of the lines contributes to control parison/container thickness - reduce blowing time for large containers Blowing systems
)( D.47 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Cold knives for HDPE (hot for PP) - Tear through head movements (Uniloy lines and large containers) - Tear through mold movements Parison cut
)( D.48 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Manufactured using aluminum alloys with high heat transfer - Inserts for de-flashing made of steel with low abrasion coefficient Moulds
)( D.49 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Moulds 2 – Mould glossary
)( D.50 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Mould movements - normally the mould moves aside of the die to avoid the descending parison stitching on the mould Moulds 3
)( D.51 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Removal of the air from the mould cavity The air can be removed from the mould cavity along the partition lines - through venting - through sand blasting (rough surface) - Insufficient air venting causes opaque spots on the surface of glossy containers Moulds 4
)( D.52 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Movements of the extruder instead of the mould - To avoid the parison stitching on the mould, the extruder raises up (technique used for large containers) Moulds
)( D.53 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Bottle glossary
)( D.54 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Bottle glossary
)( D.55 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax The cooling time is the longest part of the production cycle - Well designed moulds have cooling channels and chambers - Recommended mould temperature is 15-30°C - Use of pre-cooled air is strongly suggested - Cooling units for medium and large containers are strongly suggested as well in general foe countries with hot climates - Polymer shrinkage must be take in consideration by mould design HDPE (< 2 mm): mm/mm Container cooling
)( D.56 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Blowing in the neck: the parison has the same dimensions of the neck (thread insert) - Flashing (neck, bottom and handle) are removed by a device constructed according to the container shape - The flash pockets facilitate the removal and optimize the partition lines De-flashing
)( D.57 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Facilitate flashing removal and correct partition lines formation - Flash pockets must force the material in the welding lines Factors influencing de-flashing: - pinch-off force - pinch-off angle - length of the pinch-off zone - mould closing speed De-flashing – Pinch-off zone and flash pockets
)( D.58 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax De-flashing For a good impact resistance f k = S K /S B ~ 1
)( D.59 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax De-flashing unit
)( D.60 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Closing force must be: - sufficient to keep the mould closed during blowing - sufficient to pre-cut the parison for an easy de-flashing Mould closing systems
)( D.61 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax plates unit Joint unit for small dimension lines Mould closing systems
)( D.62 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Accumulator system: - Used for large dimensions containers - Used for resins with low melt tension - No need for mould movements Blow moulding – Intermittent process
)( D.63 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Type ram + mandrel Type annular ram Blow moulding – Intermittent process – Type of accumulators
)( D.64 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Production Maintenance Processing conditions Labeling of containers
)( D.65 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax To run a trouble free production the operators must have a good knowledge of the equipment - knowledge of the line elements and their function - minimum and maximum performance, limitations - calibration (specially for coex lines) - databank per working conditions and formulations - die selection in function of container shape, weight and spec - die setting and thickness control through parison programming
)( D.66 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Temperature profiles
)( D.67 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax For maintenance and cleaning operations on head, die, screws and cylinder can only be used brass, bronze, copper or aluminum tools (mainly self-made) REMEMBER: all scratches caused by steel tools remain for life! Preventive and extraordinary maintenance should only be made by trained staff Preventive maintenance plan must be prepared for the full year, in function of resins and additives used Maintenance
)( D.68 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Preventive - program according to manufacturer instructions - calibration of the screw speed - calibration of the heating elements - calibration of the extruder pressure transducers (by comparison) and thermometers (extruders and molds) - check of the emergency switches - check of the working pressure Special - Dismantling and cleaning the screw and the cylinder - Dismantling and cleaning the head and the die Maintenance
)( D.69 Assocomaplast - Centro Direzionale Milanofiori - Palazzo F/ Assago - Milan - Italy - tel fax Self adhesives labels, paper or plastic, applied off line - Paper, plastic labels applied by gluing off line - IML (In-Mold-Labelling), labelling in the mould, with labels pre-inserted in the mould by robots, using labels made of polymers compatible with the one used for the container and shoving very low shrinkage - Printing in or off-line, using different technologies, after surface treatment, like flaming or Corona Container labelling