In this type are
grouped all the plants that have as goal the production of plastic
granules. They are suitable for processing of films, fibers, foam,
mixed plastics, rigid plastics and for compounding.
The various systems
differ depending on the extruder model used in the line and
depending on the type of material to be treated.
[Film FMPL] [Rigid
plastics and Compounding RGPL]
[Expanded
plastics EXPL]
[Fibers FBPL]
[Mixed
plastics MXPL]
[Film FMPL]
Type of material that can be processed:
Filmed LLDPE LDPE PE PP plastic material, printed, coupled, metalised etc.
Reels, production waste, post consumer recovered material or agricultural washed material etc.
[Rigid
plastics and Compounding RGPL]
Type of material that can be processed:
Rigid materials even in blocks with large dimensions.
Materials to be mixed with additives.
[Expanded
plastics EXPL]
Type of material that can be processed:
Thermoplastic foam material such as EPS, XPS, PE, XPL….. coming from production wastes or with drawn directly from cuttings or waste.
[Fibers FBPL]
Type of material that can be processed:
Nylon, polyester, polypropylene fibres deriving from processing waste adequately milled with 12 mm grids.
[Mixed
plastics MXPL]
Type of material that can be processed:
This type of system processes with single campaigns, all types of regenerable plastic materials. Its configuration allows it to be completely versatile and both materials simply milled or stored in big bags and re-granulated materials departing from production waste, start up fusions, materials coming from washing systems, densification systems, melted materials, in reels, empty bodies etc can be obtained.
Description of machine functions
SHREDDING - GRINDING
In the case of very bulky and heavy materials, a shredder (TM series) and a
grinder (G series) are used in sequence to reduce the volume of the material to be processed.
The shredder is usually fed by a conveyor belt and its purpose is that of obtaining material dimensions adequate to be milled with the mill.
The grinder can be fed manually by the operator or using a conveyor belt that may be equipped with a metal detector,
or with a reel feeding system.
Once ground, the material is moved by means of a pneumatic conveying system
(TP series).
STORAGE
Depending on the type, the destination market and the company logistics, the material can be stored directly in big-bags or inside suitable silos destined for the successive phases.
Inserting a stocking silo (PS, FS, HSF series)
or a mixing silo (VM series), with adequate dimensions, makes the use of the system easier and continues separately with the
grinding phase and the pelletizing phase.
Furthermore, it is possible to apply an automatic system for withdrawing the
ground material from the big bags (SVBB series).
FEEDING
Depending on the type of material to be processed and its characteristics, it is possible to apply to the feeding section of the extruder a simple hopper (TN series),
a hopper with a star-valve (TR series) whose dosage speed can be set by the operator with the appropriate parameters depending on the extruder's speed,
or force feeding systems (FFVE, DS, series).
The main purpose is that of easily introducing into the extruder materials characterised by very low weights using a special
forcing screw.
Furthermore, it is possible to apply a gravimetric (DPP series) and/or volumetric (DPM series) dosage system in order to create the appropriate mixtures.
EXTRUSION
The extruder (EX series) is the main machine for the entire system: it fully completes the plasticization of the material introduced, by combined thermal and mechanical energy. It is mainly made up of a cylinder within which the appropriate size screw turns.
The length-diameter ratio (L/D); the height of the threads and the morphology of the screws are designed based on the types of material intended to be processed in order to obtain an excellent product on exit.
The extruder is equipped with a degassing system, single or double, used for eliminating gas residuals found within the plasticized material.
The EXDS extruder models are normally used for regenerating plastic films with a high print percentage. They are made up of a "special" "by pass" degassing system that allows elimination of greater gas quantitative.
FILTERING
The filtering system is required for completely eliminating the impurities contained inside the material. By means of a push from the extruder, the melt is forced through
a screen with different dimensions based on the filtration grade to be achieved.
In function with the type of material to be processed and depending on the filtration grade to be achieved, it is possible to set two "alarm" pressures:
the first alarm warns the operator that the filtration network is clogged; the second completely blocks the extruder to prevent risks of breaking.
The pressure is continuously monitored through a digital detection system applied directly to the filter changers.
There are two types of screen changers: manual ones with a change lever (CL series) and quick change automatic ones, controlled by the hydraulic central control unit (FLASH series).
PELLETIZING AND DRYING
Obtaining granules completely dry and
ready to be stored can be entrusted to two different systems,
depending on the material processed.
The first is the classic "spaghetti" means the material exits
through a perforated head, is solidified through a pool of water,
dried with forced ventilation and cut with cutter.
The second is entrusted to a single compact machine called "die face
cutter" water (WF series, Series DFC, EP series), water (AF series,
series DFCA).
Granulation is realised directly on the surfaces of the extrusion, made up of a draw plate with many holes upon which a blade cutting device acts.
This device is particular because both its speed and pressure contact between the blades and the draw plate can be varied at the same time.
The immediate contact with
the fluid (water or air) solidifies the material, which passes
immediately to the drying stage through a vertical centrifuge or a
fan.
Special machines and opening quick
release systems are provided for applications of compound, to
facilitate and reduce cleaning times in passing from one material to
another.
STORAGE
The pelletized material can be conveyed by a pneumatic system (TPG series) with various storage types such as a stocking silo (PS series) or unloaded directly into big bags.
