Innovative injection moulding technologies for special products
Whether multi-component injection moulding, water-injection, coated surfaces or the manufacturing of long, thin-walled plastic sections – ENGEL has the technology for every application –
ENGEL clearmelt - A flood of benefits
PURe quality. With a 3D effect. No scratches –
Scratch-proof, high quality surfaces combined with 3D effects that visibly impress. Thanks to ENGEL’s innovative clearmelt method, decor parts with these characteristics can now be produced in a time-saving, economic and highly productive manner. Sliding table technology floods a thermoplastic carrier with transparent polyurethane.
Compared to legacy methods, the required level of scratch resilience and 3D effect is achieved with thin coatings using the ENGEL clearmelt approach. Compared with coating systems, this means substantial material, time and emission savings. Time-consuming and expensive multiple coating techniques, which also produce a high level of rejects, are incapable of producing an attractive 3D effect below a coating thickness of 0.5 mm. In contrast to this, ENGEL clearmelt achieves visually impressive effects on decor parts using back-injected foils as a carrier. This makes panels in vehicle interiors real eye catchers. And: This technology might shed new light on the world of switches in the future. The reason for this is that ENGEL clearmelt also supports overlaid carriers with integrated circuits which are comprehensively protected by a layer of PUR sufficiently thin to support easy actuation.
ENGEL dolphin - softtouch solutions
The first injection unit for the conventionally injection moulded core is mounted – as is usual in such applications – behind the stationary platen. The second injection unit, for the overmoulded foam, is mounted on, and moves with, the rear side of the moving platen where the ejector is normally fitted. Thus the melt for the second component can be injected into the cavity via the shortest route and the bypass hot runner normally required in a double-daylight mould can be waived. The second component is mechanically foamed by means of the MuCell process. To this end, the plasticizing unit on the moving platen is equipped with the necessary gas injectors in the melt cylinder and a plasticizing screw with a downstream gas mixing section. Transfer of the core component from the first to the second injection station is performed with the aid of the central block, which is coupled with the moving mould half and rotates around its vertical axis. Depending on the actual application, this rotating central block can be arranged to index either through an angle of 90° or – as in the case of this Dolphin application – through an angle of 180°.
Compared with conventional processes for the production of multilayered foam-moulded parts, the Dolphin process offers a great many advantages. It is considerably faster and more economical, less complex and clearly advantageous from both a space-saving and a logistical aspect. A dashboard panel, for example, can be efficiently produced in one single operation. The conventional process involves the separate production of the core component and the foamed soft-touch outer skin and the subsequent lamination of the core component with the outer skin – all in different machines and with a not inconsiderable scrap rate.
ENGEL exjection - A new dimension
ENGEL EXJECTION® – injection moulding in a new dimension
The first-ever EXJECTION® system combines the advantages of both extrusion and injection moulding technologies! With this new technology, long profiles and bars can, for the first time, be manufactured on a small injection moulding machine.
What used to be impossible can now be done thanks to EXJECTION®:
manufacturing thin-walled profiles and bars with lengths up to 3 meters – on a small injection moulding machine with a clamping force of 500 to 1500 kN. The economic advantages are obvious: reduced equipment investment of up to 50 percent, and significantly lower manufacturing costs.
The process : Mould in Motion
In the EXJECTION® process, the cavity that is moulded in a slide is moved past the nozzle at the same time as the injection movement. The fluidity of the plastic melt needs only be sufficient to fill the profile cross-section. This permits the use of macromolecular, viscous types of plastic that are characterised by a very good profile of mechanical properties. The plastic part is injected into a mostly closed cavity. This mould concept opens new design possibilities, such as reinforcing ribs, screw bosses and end covers, as well as high-quality structured surfaces.
Broad range of applications:
There is a wide range of applications for the EXJECTION® procedure. It starts in the construction and furniture industry, goes through the areas of automobiles and air transport and lands in the packaging and white goods industry. In short, everywhere long plastic parts are currently used.
ENGEL x-melt - small shot weights
The real highlight of the ENGEL X-MELT technology is the outstanding repeatability of the process cycle. That results from the exact ‘to position’, electromechanical screw drive. Variations of the locking behaviour of the non return is eliminated by an adaptive software.
The residual pressure after melt pressure relaxation works like the post pressure as with the conventional moulding process
The x-melt concept –
ENGEL X-MELT is an unconventional process for the high-speed injection moulding of small and/or thinsection parts. Conventional high-speed injection moulding is based on a machine technology which utilizes a high drive output for the injection of the melt, involving high acceleration and deceleration of the screw as it performs its forward movement. X-MELT, on the other hand, utilizes the energy stored in the highly compressed melt in the space in front of the screw. Injection is effected simply by opening the needle valve nozzle, allowing the melt to expand and fill the mould cavity. No additional means of generating injection pressure are necessary.
Process stage 1: Plasticizing –
The plasticizing unit of the machine or, preferably, the hot runner system of the injection mould (see illustration above) is equipped with a needle shut-off mechanism. The nozzle is closed when in its starting position. The plasticizing screw rotates and plasticizes a defined amount of material.
Process stage 2: Compression of the melt –
Upon completion of the plasticizing process, and with the shut-off nozzle still in its closed position, the screw then serves as a plunger to compress the melt. Depending both on the application and on the material, the compression pressure ranges from 2,000 to 2,500 bar. At this pressure, the metered volume of melt is reduced by approximately 10 %. The state of compression is maintained for a short time in order to ensure a uniform temperature throughout the melt.
Process stage 3: Filling the mould –
The shut-off mechanism is now opened. The melt “explodes” abruptly and fills the mould cavities in only fractions of a second. The residual pressure acts as holding pressure to compensate shrinkage. During the mould filling operation, the screw is kept in exactly the same position, thus ensuring perfect reproducibility of the process.
ENGEL foilmelt - Surface design
ENGEL FOILMELT – Surface design for plastic components
Individually styled, high-quality products are a part of our environment. Surface design is an important aspect in this regard. With the aid of decorative films and foils, surface finishes and effects can be readily combined with the base material to meet individual needs. This process takes place in the injection moulding machine.
In-mould surface decoration with composite films or foils can be used for a great many different applications
- High-quality three-dimensional surfaces
- Special surface effects (metallic lacquer, aluminium finish, chameleon effect, holograms)
- Change of surface design possible from one part to the next
- No downstream finishing of moulded part necessary
The process –
- 3D – foil shaping by thermoforming or high pressure form pressing (necessary only with complex 3D contours – not required for flat parts or for low deep draw ratios. In that cases the foil shaping is effected by the injection process)
- Cutting of the foils by stamping, milling or cutting with high pressure water or laser beam
- Inserting of foils into injection mould. For securing the exact position in the mould a handling device is utilized. In the peripheral handling station, the foils are provided in stacks and after treatment with ionized air for dust removal centred for take over
- Plastic injection moulding process with special to purpose process control.
ENGEL foam melt - micro foam moulding
Lightweight technical moulded parts with excellent precision, low torsion and thus maximum dimensional and shape stability: this is what ENGEL foammelt/MuCell® stands for. This is achieved by dosing gas directly into the plasticising unit on the injection moulding machine, where the ambient pressure conditions allow it to completely dissolve in the melt. The blower gas (nitrogen or carbon dioxide) is not released by the melt until injected into the depressurized mould where it creates a foam structure with micro-cells in the mould cavity. It compensates for mould shrinkage effects, reducing the material density and thus the weight of the moulded part.
ENGEL foammelt is a low pressure injection moulding method. This means that machines with lower clamping force can be used compared to standard injection moulding
ENGEL optimelt - moulding optics
Innovative product potential –
ENGEL optimelt is an innovative Engel technology for the injection-compression moulding of optical components. Even thick-section lenses designed for the most exacting optical applications can be reliably and economically manufactured with Optimelt technology.
Inspired by nature –
High-quality optical components can nowadays be rendered non-reflective in several ways, not least through the use of microstructured surfaces. As is so often the case, it was nature which inspired this development: the non- reflecting, facetted structure of the cornea of a moth’s eye serves as an excellent camouflage.
Using ENGEL optimelt, such microscopic surface structures (< 1 µm) can also be moulded with excellent reproducibility.Scratch-resistant surfaces can be obtained through combinations with PC films. The process –
In most cases, complete volumetric filling of the cavity is chosen for the injection-compression moulding of small and thick-section optical components. In order to avoid jetting, which has a very negative effect on optical quality, a very low filling speed is necessary, but this in turn can result in excessive cooling of the melt while it is still being injected. This can be remedied by the so-called vario thermal mould cooling system, a temporally dynamic heating-cooling system which rapidly heats the mould cavity during injection of the melt and then cools it intensively. The result is a uniform melt temperature and minimized internal stresses. Cooling times can likewise be kept short.
ENGEL glazemelt - window moulding
For large parts, and especially for long ENGEL duo combimelt parts, Engel offers an ENGEL duo (largecapacity, two-platen) machine configuration with a rotating module mounted on a carriage within the clamping unit and two injection units working in conjunction with the two platens.
The horizontal plane of rotation and the cube-shaped central block of the injection mould permit better utilization of the available space between the tiebars than is possible with a rotary table system. A particular advantage lies in the diametrically opposed arrangement of the injection units on the two platens.
This permits a relatively simple design of the central block, as there is no need to equip it with a bypass hot runner.
The system is particularly suitable for the injection moulding of large-area parts with integrally moulded seals.
ENGEL gasmelt / watermelt
Shapes that lie comfortably in your hand, absolute dimensional precision, surface finishes that leave absolutely nothing o be desired – these are the qualities that decisively influence the success of a new product. Being able to combine design and function without having to pay heed to the limits imposed by the material has a twofold advantage: new materials can be utilized and, by the same token, new products can be developed – for the ultimate benefit of the user. Technologies for achieving optimum surface quality of the moulded part by applying, with either a fluid, a constant internal pressure during the critical holding and cooling phases considerably broaden the scope of possible applications for plastic parts. The technologies developed by ENGEL to this end are called gasmelt and watermelt.
The gasmelt and watermelt processes offered by ENGEL permit the moulding of parts with thicker walls and sections than normally permitted by the material used. With both processes, a separate medium is injected into the mould during the mould filling operation. This medium generates pressure inside the part so as to ensure that the shrinkage of the material which normally occurs during the cooling phase cannot pull the surfaces of the parts away from the walls of the mould cavity and cause sink marks and other surface blemishes.
The pressure medium used is either nitrogen or water. Nitrogen is used in cases where chemical inertness is a prime consideration; water is used in cases where cycle time, heat transfer and long melt flow-paths take priority. These pressure media do not just serve to compensate shrinkage but also, and equally importantly, to reduce wall thickness by producing hollow areas inside the parts. Reducing wall thickness also reduces the amount of material used, and this in turn means a reduction in cooling time.
ENGEL fibremelt - plastic with glass fibre moulding
In the context of the automotive industry, massproduced component parts and assemblies must not only feature a whole spectrum of material properties but also meet demanding production requirements. First and foremost, they must be resistant to corrosion, manufacturable by a single-stage process without any need for subsequent finishing, exceedingly strong and light in weight. Parts injection moulded from long glass fibre-reinforced thermoplastics have enormous potential for such innovative solutions. ENGEL fibermelt is the technology on which the production of such high strength parts is based.
ENGEL offers its fibermelt processing technology in conjunction with its ENGEL duo range of large capacity injection moulding machines. These machines are offered with a number of standard and special options. The nucleus of the fibermelt injection moulding system is the specially developed ENGEL fibermelt plasticizing unit.
In the context of the automotive industry, massproduced component parts and assemblies must not only feature a whole spectrum of material properties but also meet demanding production requirements. First and foremost, they must be resistant to corrosion, manufacturable by a single-stage process without any need for subsequent finishing, exceedingly strong and light in weight. Parts injection moulded from long glass fibre-reinforced thermoplastics have enormous potential for such innovative solutions. ENGEL fibermelt is the technology on which the production of such highstrength parts is based. ENGEL offers its fibermelt processing technology in conjunction with its ENGEL duo range of largecapacity injection moulding machines. These machines are offered with a number of standard and special options. The nucleus of the fibermelt injection moulding system is the specially developed ENGEL fibermelt plasticizing unit.
Particularly suitable for geometrically complex parts with many apertures and the ENGEL processing know-how minimizes damage tothe fibres
The ENGEL fibermelt equipment package:
- Basis: ENGEL DUO series of injection moulding machines with two-platen clamping system
- Technology module: ENGEL fibermelt injection unit
- fibermelt screw featuring optimized geometry (available in diameters from 90 mm upwards)
- Plasticizing cylinder with L/D ratio of 25:1 for gentle plasticizing action
- Electric screw drive for parallel metering (optional)
- Weigh feeding unit for glass fibre concentrates (optional)
- Screws and non-return valves from the ENGEL Marathon product range
ENGEL tecomelt - textile moulding
An intelligent low-pressure adaptation of the normal injection moulding process permits the direct combination of textile fabrics with moulded parts in one operation. This single-stage process not only saves time but can also be automated. And it also enhances the quality of functional plastic trim sections.
The ENGEL tecomelt moulding processes are lowpressure processes. There are two different processes, the choice of which depends on the size of part and/or the mould filling pressure: ENGEL tecomelt injection moulding and ENGEL tecomelt press moulding.
ENGEL tecomelt injection moulding –
The machines used for the ENGEL tecomelt injection moulding process are of the conventional, horizontal type, but feature certain modifications. The process differs from the conventional injection moulding process in that the cavities are filled under low pressure. This can be achieved either through cascade-controlled, multiple pin gating (sequential opening of the injection points) or by combining conventional injection moulding with a compression process. ENGEL tecomelt injection moulding is particularly suitable for long, narrow parts.
ENGEL tecomelt press moulding –
A vertical press is used for the ENGEL TECOMELT press moulding process. The melt is introduced into the bottom half of the mould by means of an extrusion coating system which follows the contours of the mould cavity. The decorative fabric is then placed over the layer of melt and the two components are pressed together. The woven or knitted structure of the fabric remains perfectly intact. The process is also suitable for a much wider variety of fabrics. Even the introduction of a fabric interlayer is a conceivable means of reinforcing the moulded art. The ENGEL tecomelt press moulding process is particularly suitable for the production of large-area parts.
ENGEL combimelt - multi component
Joint-ventures, mergers, fusions, blends, symbioses, alloys – all of them combinations of one form or another, and all of them testifying to the fact that it it is better to join forces than to go it alone. Combinations unite individual properties to form a stronger, more advantageous whole. Based on this principle, ENGEL combimelt technology embraces all the known methods of producing multi-component injection moulded parts from plastics featuring different properties and/or colours or from completely different types of material.
The combimelt process is divided in two main groups:
Multi-component injection moulding stands for the combination of different material qualities and properties in one component:
- Sequential moulding – sequential addition of different plastic components and affords the product designer completely new possibilities. The most important application is the production of multi-colour parts.
- Over moulding – Handles and finger grips, with soft, non-slip coverings. This is done by overmoulding the thermoplastic parts with an elastomer.
This process can be used for the production of multi-layer parts (usually three layers). In most cases, two different types of thermoplastic are injected into one another simultaneously, forming two outer skins and a core. The purpose of in-mould assembly is not to manufacture single multicomponent parts but to mould and assemble individual components into structural and / or working units. Utilizing the specific properties of the individual components, it is possible to produce units with articulated parts or components with integrated seals or gaskets.
In-mould fitting of seals and gaskets
The most important area of application for composite injection moulding is the in-mould fitting of seals and gaskets. Using the sequential moulding process, the ENGEL combimelt multi component injection moulding system can be used for the production of sealing elements from both thermosetting and thermoplastic elastomers.
Components with properties made to measure
Using selected combinations of thermoplastics, thermosets and elastomers, it is possible to manufacture components featuring a whole spectrum of made-to-measure properties, such as rigid/flexible composites with good damping characteristics, parts with integrated sliding bearings or components in-mould assembled from transparent and non-transparent parts.
By selecting materials which do not adhere to one another, it is possible to produce articulated parts – hinge or knuckle joints, for example – ready-assembled in the mould, thus waiving the need for downstream assembly.
ENGEL mould technology
Added productivity – Higher process stability – Higher quality
That‘s the result of perfect coordination between mould and machinery. Because they are planned and consistently implemented from the outset as a harmonious unit and part of an overall solution.
ENGEL creates this balance between machine, mould and automation for its customers. ENGEL’s mould technology specialists, who combine mould and system expertise, take care of the mould design. They attend to the individual requirements of the plastics manufacturer, whether it is a turn-key project comprising machine and automation, or only the mould.
A variety of factors speak in favour of purchasing one’s moulds from one manufacturer. ENGEL mould technology offers tailor-made system solutions for all needs. For example, if:
- plastics-specific know-how, key contacts and market knowledge are lacking in the start-up phase of injection moulding technology
- the complexity of the project requires a holistic approach
- internal company resources are insufficient for a major project with a large number of machines and moulds
- ENGEL as a general contractor has overall responsibility for the project and the turn-key solution comprises all areas from the injection moulding machine and mould to automation, including peripheral technology
Ready for production faster. Less time to break-even point
If the mould and machine purchase including automation are in the same hands, ENGEL will bear the entire system responsibility for its customers, including areas in which ENGEL cooperates with system partners. That reduces costs for meetings, travel and time for the internal project team, while at the same time avoiding coordination problems which could otherwise occur in negotiations with various different suppliers.
Advantages for the customer:
- Faster project planning
- Shorter start-up times
- Shorter time to series maturity (time-to-market)
- Higher productivity and efficiency due to optimised processes
Mould design à la carte from the appetizer to the espresso
In mould design the customer has the option of choosing either the entire menu or individual courses:
- Consulting on all aspects of mould purchase
- Selection of mould maker
- Feasibility studies
- Preparation of technical specifications
- Interface clarification
- Expediting and production monitoring
- Supervision of initial sampling
- Evaluation of moulded part quality
- Organisation of transport
ENGEL mould technology cooperates worldwide with renowned moulds manufacturing partners who are without exception specialists in their own fields. The ENGEL experts are familiar with the focal and strong points of their partners, enabling them to locate the ideal mould maker for each project.