plasticising unit Higher performance, increased useful life and efficiency of injection moulding machines

Transcription

1 plasticising unit Higher performance, increased useful life and efficiency of injection moulding machines

2 It all depends on the plasticising unit. The quality and performance of modern injection moulding machines rely on it. The plasticising unit determines the realisable melt quality, the repeatability of the injection moulding process, and above all, the useful life and efficiency of the machine. Best melt quality High degree of material and thermal homogeneity under varying process conditions. Repeatability Highest precision. From shot to shot. Through highly developed components Useful life and efficiency Application specific material designs. For highest efficiency. High plasticising performance and throughput Screw geometries adjusted to the plastic ensure maximum throughput and plasticising performance. Best service and support Countless types of plastic, looks, and combinations, as well as increasing demands on products and efficiency, require competent consulting and support. 2_plasticising unit plasticising unit_3

3 Solutions according to material classes The optimal edition for your plastic The flexible Advanced Package Thanks to a hardening process and hard-facing, the plasticising components of the Advanced Package achieve high corrosion-resistance, high abrasion-resistance and a long useful life.for example, large screws, starting at a diameter of 80 mm, are produced with high-quality hard-casing: A plating alloy is PTA-(Plasma-Transfer-Arc-) -welded to the screw-flight surface in a thickness between 1 and 2 mm. Chrome coating ensures wear-resistance in the drain. The chrome also acts as corrosion protection; in addition, the base material used is corrosion resistant. The performance attribute for smaller screws, with a diameter of up to 70 mm, is through-hardening. When producing the screw, a chrome steel with a high carbon content is hardened, resulting in an abrasion-resistant martensitic microstructure. abrasion- and corrosion-resistant screw material bi-metallic barrel laser alloyed non-return valve For thermoplastics with reinforcement levels (glass fibre or fillers) of up to 30%, for example PA. The tough High-Performance Package The best Basic Package ENGEL raises the bar in terms of value and quality. This starts at the base. Even the Basic Package has extraordinarily high-grade equipment: The bi-metallic barrel as well as the laser alloyed non-return valve are standard in this package. This allows for the extremely efficient and economical production of multiple applications, such as utility objects made of polypropylene or polystyrene. nitrided screw high surface hardness through nitriding bi-metallic barrel standard equipment laser alloyed non-return valve standard equipment for non-reinforced thermoplastics, e.g. PE, PP, PS. Plastic components, such as those used in automobile engine compartments, are subject to an extremely high requirements profile. They are designed for increased mechanical stability, as well as a long useful life under high operating temperatures, and for permanent contact with fuel, oil, and braking fluid. Also: They have to be low-weight and meet high demands on safety. These challenges are usually addressed with highly filled or reinforced plastics. The High-Performance Package is the right answer for these and many other similar challenges. The highest wear- and corrosion-resistance, robustness, and maximum useful life of the plasticising components guarantee significant economic advantages for your injection moulding production. Through-hardened PM (powder metallurgical) steel screw Tungsten carbide (TC) reinforced bi-metallic barrel laser-alloyed non-return valve For thermoplastics with reinforcement levels of over 30 %, e.g. PA with 50 % glass fibres. 4_plasticising unit plasticising unit_5

4 Plasticising technology solutions For your special requirements Determined by geometry. While 3-zone screws have versatile uses, barrier screws offer the highest productivity. ENGEL offers a wide range of application-specific geometries. These assure you of the highest plasticising performance, inspiring colouring quality, and impressive dosing consistency. Versatile: Solution to increase throughput SPS (special purpose screw) double-flighted G2.3-screw The evolution in mould and temperature control technology has resulted in a continuous reduction of cooling times as well as significantly higher throughput, by shortening cycle times with parallel movements on fully electrical and hybrid machines. The double-flighted screw ensures the required performance increase in a very economical fashion. With its optimised feed section, the double-flighted screw allows for the application of a very high degree of shear energy, which results in a large proportion of molten material even prior to compression. Starting at the feed section, a second flight is directly facing the first, and the resulting uniform distribution of force during dosing provides a symmetrical pressure profile. This allows for significantly higher throughput as compared to a single-flighted screw, especially in technically demanding applications. These include, for example: technical components made of PP thin-walled technical components made of PA components made of light-bodied POM Homogenous: Solutions for direct colouring SMS (standard mixing screw) mixing screw with G13-geometry When injection mould components have to be produced in various colours, it makes sense to add colouring to the plastic directly in the injection moulding machine. So-called master batches, consisting of carrier material plus concentrated colour pigments, are mixed in quite frequently. Excellent mixing results depend on suitable screw geometry as well as the use of suitable carrier material in the master batches. The mixing screw with G13 geometry ensures even distribution of colour pigments throughout the melt. plasticising unit_7

5 Robust: Solution for high throughput, high output and colouring MBS (mixing barrier screw) barrier screw with mixing head and G16S-geometry Polyolefins present a special challenge to production, especially when high throughput is required and the plastic is to be coloured with master batches. The solution is to use barrier screws with dynamic mixing heads. The procedural principle of separating solid and molten material through the barrier flight guarantees the highest level of melting capacity, while an additional dynamic mixing head ensures a very even distribution of colour pigments. Flexible: The automotive solution UAS (universal automotive screw) double-flighted screw with G18 mixing head Requirements in the automotive industry demand a screw concept that delivers high performance across a broad range of applications. With the double-flighted screw concept, the large screw surface transfers energy into the plastic in a targeted fashion. The subsequent mixing and shearing sections very gently homogenize the molten material. This results in very high throughput across a wide range of applications, especially in the automotive sector. technical components made of PC-ABS blends components made of PC-PET bumper made of PP-EPDM or PP-talc MBS (mixing barrier screw) Snappy: The solution for high throughput and output UBS (universal barrier screw) high performance barrier screw with G16-geometry UBS (universal barrier screw) High performance machines such as the fully electric ENGEL e-motion T deliver the shortest cycle times and the highest level of productivity. One example of application is end cap production in the packaging industry. Another would be in medical technology, e.g. the production of polystyrene Petri dishes, or blood vials. The plasticising components must be geared towards achieving the required plasticising and throughput levels while simultaneously maintaining optimal melt quality. And continuously at that with the highest degree of process consistency. With its high performance barrier screw, ENGEL provides the ideal solution for these requirements. UAS (universal automotive screw) As compared to other high performance barrier screws, the design of this screw stands out with its high universality, while at the same time achieving a high melting capacity. This allows for processing a wide range of plastics (partially crystalline, amorphous, and plastic mixes) with a high throughput. One step ahead: excellent self-cleaning behaviour Dwell time and energy input have been optimised based on the increased gradient of the barrier flight as compared to the main flight in the barrier zone. Gentle flight-depth and flight-pitch changes in the transition areas between the individual zones result in improved self-cleaning behaviour, even at maximum performance. 8_plasticising unit plasticising unit_9

6 Forward thinking on non-return valves hard shell tough core Requirement Fit for high loads Hardly any other part of the injection moulding machine has to fulfil as many different demands as the non-return valve: Injection and holding-pressure phase From the point of view of function, it prevents the backflow of molten material during the injection and holding-pressure phase. A precisely repeatable closing process at the start of the injection process is one of the most important factors in controlling the quality of the injection-moulded components. Dynamic load is extremely high during this phase pressures of 2,400 bar or more can occur. Plasticising phase The non-return valve is open during this phase. The deciding factors here are: very low flow pressure demand for high output performance of the screw, and excellent self-cleaning behaviour. During both process phases, i.e. injection and plasticising, the forces between individual components are extremely high. Therefore, the tips have to be extremely hard and tough in order to achieve a long, useful life. The solutions The high materials competence of ENGEL also makes for innovative solutions when it comes to non-return valves. For example, the laser alloy coating on the non-return valve tip a patented ENGEL-development ensures rupture safety and long lifetimes. A majority of the ENGEL tips have been equipped with this especially beneficial laser alloy. plasticising unit_11

7 Ring non-return valve universal-shut UNR9 Ring non-return valve universal-shut UNR9 Ring non-return valve universal-shut UNR9 Carbidic hard material phases are designed for extreme use, and are therefore best equipped to meet the very highest demands. This material design incorporates a laser alloyed tip to reduce wear between the tip and the shut-off ring. The alloy is applied with laser technology. This ensures melt-metallurgical bonding to the base material. Using this technology, the base material of the tip can be made extremely tough. The advantage: The tip can take high dynamic loads. In the UNR9 model, the shut-off ring consists of a powder-metallurgical Cr-steel that is very abrasion- and corrosion-resistant. Ring non-return valve opt-shut OPR9 ENGEL developed the OPR9 non-return valve especially for transparent applications. As compared to the UNR-9 non-return valve, the components of the OPR9 are all additionally PVD-coated. This further improves the already excellent self-cleaning behaviour of the UNR9 non-return valve. Ring non-return valve quick-shut QUR9 Another model of the ring non-return valve, the QUR9 was developed specifically for high-speed applications. This valve is characterised by a shortened hub and an extensive dwell time. 12_plasticising unit plasticising unit_13

8 Ball non-return valve tough-shut TOR10 The larger the diameter of the non-return valve, the more challenging it is to achieve excellent closing response. Especially when producing thin-walled components, the form must be filled with great precision. In the case of larger screw diameters, these requirements are best met by ball non-return valves especially when pressure relief cannot be set after dosing to ensure component quality. Multiple ball non-return valve clear-shut CLR12 When processing transparent plastics with high shot weights, the requirement is excellent clamping behaviour combined with very good self-cleaning behaviour. To ensure high quality of optical components, the injection speed at the beginning of the injection process must be very low, which places high demands on the closing response of the non-return valve. These demands are best met with a multiple ball non-return valve. The standard version of this design is already equipped with a chromium nitride coating. The advantage: The coating reduces layer build-up in the area of the non-return valve, and significantly improves the self-cleaning behaviour. Non-return valve smart-shut SMR13 Even though modern, electrical injection units have been proven to execute movements with the highest degree of repeatability, locks are the decisive factor in achieving consistent processes. The forced shut-off action of the ENGEL smart shut reduces weight fluctuation to a minimum. The new, smart solution ENGEL smart-shut works as follows: After the dosing procedure, the screw is briefly turned in the opposite direction, and the shut-off ring is moved in the shut-off direction by a special control gate. As a result, the non-return valve is already closed before injection commences. The advantage: The ENGEL smart-shut will fulfil your highest demands in regard to closing point and shot-weight consistency. 14_plasticising unit

9 Perfectly matched focus on customer-specific solutions Thanks to our comprehensive plasticising expertise, upon request ENGEL can provide optimised plasticising systems that are perfectly matched to a variety of production engineering requirements. Stable processes with the PVC-U Package Dry blend or granulate PVC, also known as hard PVC, belongs to those plastics classes that place special demands on the entire injection moulding machine. Low shear, high speeds, and chemical resistance characterise this machine's equipment. The modifications of the PVC-package perfectly cover the requirements of the machine's equipment. Corrosion-resistant barrel with a specifically developed screw (SPS G3) From Ø 80mm: drilled screw to integrate screw cooling From Ø 80mm: chrome-plated screws Screw seal in screw shaft Increased torque Anti-reverse lock "Pre-injection" program optimised for dry blend (SPS-G3-DB) An ENGEL injection moulding machine with the PVC package is suitable for processing PVC in both powder (so-called dry blend) and pellet form. Robust Processing of Fluoro-Plastics For processing fluoro-plastics such as PVDF and PFA, highly corrosion-resistant materials are used for all plasticising unit components. High alloy nickel base materials guarantee maximum corrosion resistance: All components consist of nickel base material bi-metallic barrel with nickel-plated in-feed aperture Screw with armoured web and non-return valve Flange and nozzle plasticising unit_17

10 Focused Technology Optics Package Optical parts with large wall thicknesses pose a particular challenge for the plasticising unit. After all, large wall thicknesses mean long cooling times and thus long dwell times of the plastic in the plasticising unit, both in the hotrunner and in the mould. A particularly gentle melting process and the best possible homogenisation are therefore prerequisites for the production of lenses. The use of optimised geometries and material designs can help to extend the process window for the user. If needed, material can be fed into the machine in a controlled fashion. In this option, the plasticising unit is "underfed" with material. This reduces the dwell time and further improves the quality of the moulded parts. bi-metallic barrel with nickel-plated in-feed aperture Screw with PVD coating in custom geometry SPS-G15 for PMMA Screw with optional coating in 3-zone screw geometry for PC OPR9 non-return valve (PVD-coated) Corrosion-resistant flange and nozzle Corrosion-protected design of the melt hopper sliding unit Optional underfeeder (metering unit) Clear solution: Glazing Package Producing optical components with heavy shot weights, such as plastic glazing, places special demands on the plasticising unit. High melt quality is a precondition for producing streak-free, low-tension components. Furthermore, heavy shot weights have to be achieved with comparatively small screw diameters. The clear solution: Thanks to the specially developed Glazing package and an optimised plasticising screw with excellent screw venting, large glazing parts can now be produced with smaller screws, taking advantage of metering strokes of up to 3 times the screw diameter. The Glazing package comprises of a longer plasticising unit with a L/D ratio of 25. The chrome-plated, armoured screw includes an optimised shearing part and ensures very good self-cleaning behaviour. The package also includes a multiple ball non-return valve (R12) and a corrosion-resistant special front end consisting of a flow-optimised flange and the corresponding nozzle design. The benefits of the Glazing package for the processor: Very good melt quality Clear components 18_plasticising unit plasticising unit_19

11 Speed matters: The End Cap Package Maximum speed, dynamics and performance: ENGEL speed plasticising is geared entirely towards permanent high performance. Fast turning screws, short strokes, and rapid, precise injection; all system components can withstand even the most extreme demands and are specifically geared towards the intense requirements of the packaging industry. High strength materials in combination with sophisticated barrier screw geometries, with a L/D ratio of up to 28, result in maximum performance. The optional mixing head provides excellent homogeneity and colouring. The ball non-return valve ensures a rapid and precise injection process. high throughput with homogenous melt preparation high dosing rate optimised screw geometry and coating for HD-PE with MFR < 1-15 non-return valve for very high throughput Easily foamed: foammelt (MuCell ) ENGEL foammelt produces precise lightweight construction components made of microfoam structures according to the MuCell -principle. Propellant gas (nitrogen or carbon dioxide) is injected into the melt in a controlled fashion, and then thoroughly mixed to form a homogenous polymer-gas-solution. The foaming process does not start until after injection into the mould cavity. This results in an integral foam structure with a compact surface layer and a foamed core. The screw is equipped with an efficient mixing component that homogenizes the plasticgas mixture, thus optimising gas distribution and the result of foaming. The plasticising units are characterised by one or two gas injectors, and have a procedural length with a L/D ratio of up to 28. Located in the foremost third, the second valve prevents the backflow of gas, thus ensuring a very stable process. Basic Package for non-reinforced plastics Advanced Package for plastics with 35% glass fibre optionally with two injectors Mucell-specific non-return valves MuCell is a registered trademark of Trexel, Inc. 20_plasticising unit

12 Overview of plasticising units according to colouring portion and plastic type Basic applications High-performance applications Specialapplications Type General Purpose Screws GPS Standard Mixing Screw SMS Universal Automotive Screw UAS Universal Barrier Screw UBS Mixing Barrier Screws MBS Geometrie Special Purpose Screw SPS Geometry G1 G13 G18 G16/G11 G10/16S Geometry G1 G1+ LGF G3 G5 G6 G7 G9 G12 G15 G2.3 Length L/D up to 24 up to 28 Screws ø < 90 S1 S8 S10 S8 S8 Screws ø > 80 S6 S4V S23 S4V SV4 S13 Barrel M3 M3 M9 M3 M3 M3 M3 PE PP PP-EPDM PPT PS SAN TPE PA POM PBT PPS ABS ABS-Blend PPE-Blend ASA PC COC PET PC-Blends PVC-soft LCP High temperature-ks L/D up to 25 Screws ø < 80 Screws ø 80 Material packages (Page 4) S9 S8 S8 S10 S1 S8 S10 S10 S10 S1CrN S4V S4V S6 S4V S4V S4V Barrel M3 M3 M3 M3 M9 M3 M3 M9 M3 M9 M3 M3 M3 Fluoride-KS PP PP + LGF PA PA + LGF PVC-hard PVC-C Duromer + BMC + Elastomer LSR, LIM + + PIM + PC v + PMMA POM PBT Basic package S1: Nitriding steel, quenched, tempered and plasmanitrided S6: Nitriding steel, quenched, tempered and plasmanitrided, welded flights M3: bi-metallic barrel S8 High-performance package S10: Screw made of HIP-ed PM steel S23: WC-coated screw M9: bi-metallic barrel w. WC Advanced package S4V: Chromium steel, welded flights, chromium-plated screw surface S8: Through hardened chromium steel S13: Screw with welded flights, quenched and tempered steel, chromium-plated screw surface M3: bi-metallic barrel CrN: chromium nitride plated no colouring glass fibre percentage > 30% + customer specific adjustments required glass fibre percentage 30% colouring without glass fibre This is an excerpt out of the ENGEL product line for plasticising systems. Other versions are available upon request. 22_plasticising unit plasticising unit_23

13 ENGEL Solution Competency The history of plastics is a story of rapid change. The requirements on the plasticising unit are constantly becoming tougher. Plastics with special properties continually require the use of new additives or other admixtures to fulfil these requirements. Low component weight, lower material costs, higher strengths, and constantly changing overall conditions motivate continuous development. With a view to increasing productivity, these new plastics need to be processed faster and with premium quality on state-of-the-art injection moulding machines. These factors lead to increased stress on all plasticising unit components. The screw competency team at ENGEL in ST. Valentin is the organisational unit responsible for both the function and the production method of plasticising units. In the context of the Concurrent Development process, all relevant requirements are equally considered. A team of experts from the areas of metallurgy, welding technology, rheology, plastics, technology, as well as construction and manufacturing technology, is working on new screw concepts. Constant improvements in manufacturing and process assurance are as important for this team as research into complex physical and chemical processes. The consistent and complete electronic integration (CAx) of data into the design and production process forms the basis for the consistently high quality of components. The Support Team provides our customers with premium support and facilitates the successful implementation of projects. CUSTOMER production R&D materials DEVELOPMENT R&D plasticising quality management CAx modelling support MARKETS 24_plasticising unit plasticising unit_25

14 State-of-the art materials laboratory ENGEL has an exceptionally equipped materials laboratory for the precise testing of processes, materials and plastics. Apart from the standard equipment of a good materials laboratory, which ranges from various hardness testing methods, preparation technique and etching technology, to various light microscopy testing procedures, we have a scanning electron microscope, a white light interferometer, and a tribometer at our disposal. This allows our metallurgists to examine the chemical structure and and the microstructure of our metallic materials, to measure in three dimensions the highly qualitative surfaces of plasticising components, and to characterise their slip properties. A team of plastics technicians calculates rheological parameters that form the basis of simulation, dimensioning and optimisation of plasticising components. In-house screw test bed In the R&D area, a separate injection moulding machine is reserved for material and geometrical development of plasticising screws, mixing heads and non-return valves. A multitude of sensors in the barrel area allow engineers to peek into the plasticising unit and precisely analyse the plasticising and injection process. Flexible competence solution-oriented support The ENGEL Plasticising Support Team provides customers with on-site or remote support in all plasticising matters. Whether changing products, changing plastics, or optimising performance our team of experts is available to optimise your processes and solve problems. These very experienced plastics technicians have the methods and measuring equipment to swiftly conduct problem analyses and initiate corrective measures. Economic considerations are as important in this as technical solutions. In cooperation with development and manufacturing, customer-specific adjustments can be quickly implemented. Flexibility and competence creative and fast implementation this is what you can expect from the Plasticising Support Team. Please direct inquiries to your local contact, or submit them on our home page, via "support". 26_plasticising unit

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