All DESMA machines are equipped with injection units that work according to the First-In-First-Out principle. That means: the material plasticized first is the first to be injected into the mould. From this results an even residence time of the compound in the injection unit with constant stock pressure.
During the entire plasticizing process it is possible to set the stock temperature to a higher value so that cure times are distinctly reduced. Thus, DESMA also supports resource-conserving production methods.
The new FIFO-Advanced injection unit offers a range of new options. In addition to a raised injection accuracy, the new extremely stable overall construction allows the integration of a significantly larger silicone stuffing system. This in turn allows substantial reductions in refill cycle times.
It almost goes without saying that the FIFO-Advanced injection unit is also available with the patented FlowControl+-injection technology for cure time reduction.
The ActiveFeed option is the first system to offer a fully integrated active-drive feeding roller. This allows strips of much larger dimensions to be fed-in. It can also reliably draw in strips with fluctuating dimensions and also those made with difficult compounds. This can save considerable costs in strip production and help avoid production stand-stills due to strip tear.
The PlastControl system (patent applied for) incorporates a hydraulically operated non-return valve offering for the first time the option of actively shutting the non-return valve. This raises dosing precision by a factor of approx. 50 %. When using low-viscosity materials it guarantees definite closure of the non-return valve. In connection with the standard swivel unit for the screw cylinder unit, it makes changing materials all the more easier.
The patented FIFO A system is one of the most successful injection units of DESMA. This injection unit is equipped for medium to very large injection volumes and provides an ideal ease of operation with high machine stability. The standard execution comprises the hydraulically retractable nozzle.
The injection unit FIFO B is frequently used for DESMA horizontal machines. This injection unit can be basically used for all machines with lateral injection into the mould split line. The hydraulically retractable nozzle ensures efficient production processes.
The injection unit FIFO C can be applied for smallest to medium injection volumes. The fixed-lying nozzle permits a short nozzle length. DESMA supplies the FIFO C as standard injection unit for C-frame machines and small horizontal machines.
With the patented FIFO D system DESMA was able to develop an injection unit which is especially suited for small to medium injection volumes. The minimum nozzle length guarantees an extraordinary ease of operation.
DESMA offers injection units of different sizes for the use of TPE. These injection units can be used on all injection machines from the DESMA product range. For example on the D 957.050 HydroBalance with its innovative two-platen clamping system as well.
For all DESMA injection units of the series FIFO system A and FIFO system B the actively controllable FlowControl+ nozzle technology is optionally available. With this nozzle technology the heat input can be precisely controlled during the injection process. As a result, cure time reductions as high as 50 % are possible. The nozzle design corresponds to the patented FlowControl cold runner nozzle which has been patented for several years. As against the FlowControl cold runner nozzle, the nozzle position can be set variably. It is also possible to modify the nozzle position in 5 stages during the injection process to allow thus for a variable heat input. The hydraulic position control guarantees an impeccable repeated accuracy. The adjustment of the nozzle position is made via the machine control. The main advantage of this patented nozzle technology is that the heat input into the compound takes place directly at the nozzle outlet only. Therefore there is no risk of preliminary vulcanization within the nozzle. Compared to other systems with pre-chambers, a much higher flexibility in preselecting the heat input is given. The FlowControl+ nozzle system is insensitive even in case of longer production interruptions.
Combined with the available high-pressure injection units, full use can be made of the potential of this technology.