The Multi -
offering a multitude of solutions

High-grade multi-color design, complex moldings with two or more components, decoration, printing, in-mold textile and film decoration, injection molding with assembling -  multi-component technology has undergone rapid development in recent years. Increasingly new variants of the processes, plastics and material combinations have been added for increasingly new applications in automotive, medical and communication technologies, electronics, packaging and sports industries. New applications have emerged that were unthinkable only a few years ago. We at Demag take credit for important contributions: The Multi has proved itself in hundreds of manufacturing facilities with innovative, user-specific solutions that combine a high standard of molding quality with a high level of productivity.

The range of applications

The term "multi-component technology" denotes a variety of methods employing specially designed mould and machine features. Essentially, they all use two or more injection units to inject two or more materials onto each other or in between each other. If injected onto each other, the components will either form an integral moulding (an automotive taillight) or a split moulding (a closure with a seal ring). If injection is with a shot in between the other shots, referred to as the sandwich technique, a laminated structure is obtained with a soft skin and a hard core (typically, regrind may be used for the core and virgin material to provide a high-quality surface).

The Multi at a glance:

• Integration of several features in one structural unit significantly reduces cycle times and production effort
• Setting-up of the machine is simpler and faster compared to two "mono" machines
• Operations are simplified
• Assembly effort is reduced
• Quality assurance and reproducibility are enhanced
• Less floor space is required
• Energy consumption is lower

Clamping unit

In order to profitably exploit the possibilities of multi-component injection moulding, the user needs flexible, high-capability modules.
The full hydraulic clamping unit of the Multi machine range (500 kN to 1,100 kN) features a short overall length, permits simultaneous ejector and secondary movements, and provides ample daylight to accommodate large moulds. The rugged construction of the machine with stiffened platens and the fact that the moving platen is supported on the machine base all contribute to a high degree of precision and uniform force transmission. Freely programmable inputs and outputs permit external equipment to be linked up to form a fully automated production cell.
The clamping unit of the five-point double-toggle type with computer-optimised decelerating and accelerating profiles provides powerful, and yet sensitive, movements with mould stresses reduced to a minimum. The rugged construction of the machine with finite element optimised platens and the fact that the moving platen is supported on the machine bed all contribute to a high degree of precision and uniform force transmission.

Machine-integrated and machine-adapted rotary table

Demag´s self-optimizing machine-integrated rotary plate can rotate to 120° and 180° positions. Thanks to the self-optimizing function, it is no longer necessary to manually optimize times and paths; the operator simply enters the desired maximum speed on the controller. Running a few cycles, the machine then optimizes the speed of rotation with accelerating and decelerating phases - allowing automatically for the mould weight. In addition, the fact that mould opening is in parallel with the rotary plate movement affords speed gains in transferring the part and reduces the cycle time.

Injection unit

The most important criteria for selecting a suitable injection unit configuration from one of the following four variations are listed below:
The mould configuration,the floor space requirements and the required size of the second injection unit.
The space-saving V- and R-configuration is recommended for small and medium-size injection units while large injection units require a stable base.

Vertical: the V-position

In the V-position, the second injection unit (IU) is arranged vertically above the mould. The vertical IU is fixed on guide-rails above the clamping unit and can be flexibly positioned by hand in the horizontal direction. Advantages of this option, which is preferred for small and medium-size machines, include: little space required (no more than for a mono-machine), no need for an extra machine bed (a cost factor), and separate temperature zones maintained between the nozzles.

Advantages:

• reduced footprint
• no additional machine base
• ready access to mould
• injection possible into parting line

From the side: the L-position

The greatest asset of the second injection unit (IU) placed on non-operator side of the machine is its enormous stability - optimal for large injection units with heavy shot weights.

Advantages:

• high mechanical stability
• lends itself well to large injection units
• ready access for linear robots

Slanting: the R-position

In R-position, the second IU is arranged at an acute angle above the main IU. Here again, both units are mechanically and hydraulically independent. Metering and injection can take place simultaneously or sequentially, which is optimal, for instance, for the core-back technique. Again, the R-option requires no more space than a mono-machine. The upper IU can be pushed back on a crossbeam, affording convenient access to the main plasticising unit, and it takes just one operation to change an injection unit. All handling devices are mounted on the stationary platen.

Advantages:

• small footprint
• no additional machine base
• easy access to mould
• easy access for linear robots

Parallel: the P-position

The P- or parallel position is mostly adopted where large machine clamping forces, heavy shot weights, and injection units of about the same size are provided. As space-saving as the R-position, the P-option can also be accommodated on the machine base of a standard machine. Both IUs are adjustable to permit convenient alignment of the machine nozzle to the sprue bushing. The parallel configuration makes for short flow distances and lends itself optimally to the use of the machine-integrated rotary plate. At the same time, it is possible to sandwich applications with a separating head. Both IUs are conveniently accessible and parts-handling devices for the transfer or removal of parts can be readily integrated.

Advantages:

• small footprint
• no additional machine base required
• ready access to mould
• short flow distance for the melt
• favourable for heavy shot weights

Multi-Plug

El-EXIS S Multi

Multi
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 Product Brochure
Multi 50-1300 GB (6.14 Mb)

Technical Description
Multi 50-420 GB/Technical Description (1.34 Mb)