Home » Technical rubber industry » Extrusion, straining and preforms
Extrusion, straining and preforms
- Combex continuous preformer
- Planetruder single drive system
- Shark cold feed strainer
- iCOM - integrated continuous mixing
Combex continuous preformer
The basic aim for the development of the VMI-AZ Combex system was to design a machine for continuous production of rubber preforms to be used in vulcanization presses. For the production of rubber preforms the rubber needs to be homogeneously plasticized, extruded with constant output and cut into the required length i.e. weight. All these three process steps can be continuously performed by a VMI-AZ Combex - Preformer. This is achieved by combining a single screw rubber extruder with a volumetric operating gear pump and a knife.
The VMI-AZ Combex system comes in three sizes as follows:
- Combex 45 for low output preform production.
- Combex 60 for medium preform production requirements.
- Combex 90 for high preform production requirements.
The picture shows a Combex 60 preformer with extruder, gear pump and cutter.
Planetruder single drive system
The Planetruder® with single drive is used as side feed extruder in continuous mixing applications such as for production of thermoplastic elastomers (TPE / TPV) or continuous rubber mixing. For such applications the Planetruder is connected to the compounding extruder and feeds continuously with an extremely high precision rubber to the compounding extruder. In most applications the used compounding extruder is a co-rotating twin screw as it is well known from plastic industry.
Planetruder® as a side feeder for compounding extruders offer following advantages:
- Precise feeding
- Rubber pre-heating
- Easy integration
- 100% leakage free
The picture shows an example of a Planetruder® S.
There are three single drive Planetruder® versions:
- Planetruder® S
- Planetruder® M
- Planetruder® L
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The picture shows a Planetruder® L single drive as used for feeding a co-rotating twin screw extruder.
Shark cold feed strainer: Extruder gear pump systems (Shark®)
Shark® Systems, mainly for applications of cold feed straining and vacuum extrusion in the technical rubber industry, consist of a single screw extruder in conjunction with a two rotor gear pump. Depending on the application, the single screw extruder can be a pin type, transfermix or transfermix vacuum extruder. Contrary to Combex systems the Shark® features increased drive power to handle all kinds of cold feed applications.
The picture shows a Shark® 120 cold feed strainer with hydraulically locked double strainer head.
iCOM - integrated continuous mixing
VMI-AZ Extrusion has developed a superior final mixing process using transfermix single screw extruder mixing technology (MCTD) in conjunction with a gear pump. Mixing is done in our Shark® transfermix extruder. Thanks to the variable screw speed of the transfermix extruder, mixing efficiency can be easy optimised for each compound. Chemical dosing is provided by gravimetric operating feeders. Customers have confirmed that our iCOM® process significantly reducing production costs as compared with a batch mixing process and improves the compound quality (vulcanisation characteristics).
The VMI-AZ iCOM® process is available for all Shark® sizes!
The picture shows the iCOM® - VMI continuous mixing line.
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The picture shows the iCOM feeding
The picture shows the iCOM with a Shark 150
For more information please see our brochures or contact us sales@vmi-group.com