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SIKOPLAST SIKOREX: Inline Return Extruder for Edge Trim and Roll Goods
In nonwoven and film production, production waste arises continuously. Anyone processing these materials offline goes through two additional process steps: pre-shredding and regranulation. Both cost time, energy and machine effort.
The SIKOREX from SIKOPLAST is an inline return extruder that takes in production waste directly at the winder, melts it and feeds it as melt back into the production extruder without a granulation step. No cutting mill, no granulate as an intermediate product. A closed material cycle directly in ongoing production.
The product range includes standard systems with throughput capacities of 30 to approx. 250 kg/h per extruder.
From the Winder Directly into the Production Extruder: How the SIKOREX Works
- Material is fed directly from the winder (edge trim) and/or from the unwind stand (rolls) through one or two independently operated feed units
- In the intake area of the extruder, the material is taken in, compressed and melted, without pre-shredding
- A built-in pressure sensor continuously monitors the melt pressure
- The optional screen changer handles melt filtration
- At the melt pump, a controlled return rate can be set precisely
- A purge bore facilitates start-up of the system and enables fast material and colour changes
- The plastic melt reaches the production extruder through a melt line. An integrated non-return valve prevents melt backflow
Configuration of the SIKOREX System
The basic configuration includes the following components:
- Offline feed unit (1): for roll goods from the unwind stand
- Inline feed unit (2): for edge trim directly from the winder
- Extruder (3): with special conical screw for gentle melting without pre-shredding
- Pressure sensor (4): for continuous melt pressure monitoring
- Screen changer (5): optional, for melt filtration
- Melt pump (6): for precisely defined, controlled return rate
- Purge bore (7): for fast start-up and material changes
- Non-return valve (8): integrated, prevents melt backflow from the production extruder
- Production extruder (9): feed of the melt into the existing line
Applications and Material Spectrum
- Specially developed for the nonwoven and PE/PP film industry
- Nonwovens (SMS) with high MFI values and 100% meltblown content processable with highest process stability
- Direct return of production residues as melt into the production system or into a raw material reactor (e.g. for PA/PET fibres)
- Intake speeds up to 375 m/min; special designs up to 600 m/min and more on request
- Retrofitting of existing systems possible
Hydrophilic and Hydroentangled Nonwovens: Modified Solution from SIKOPLAST
Hydroentangled nonwovens place special demands on inline return: the material contains residual moisture that must be degassed during melting. Standard systems reach their limits here.
SIKOPLAST supplies for these materials a modified SIKOREX system with three constructive adaptations: a longer screw (6 x L/D) for sufficient degassing length, a vacuum extraction pump for controlled extraction of volatile components, and a metering pump for precise material guidance.
The result: hydrophilic nonwovens can be returned directly inline as melt, without an upstream drying stage.
SIKOREX vs. Offline Regranulation: a Direct Comparison
| Criterion | SIKOREX | Offline Regranulation |
|---|---|---|
Pre-shredding | Not required, no grinding dust, no mechanical pre-stress | Cutting mill required |
Intermediate granulation | Eliminated, melt is fed directly | Necessary, granulate as intermediate product with re-melting |
Energy consumption | Approx. 50% lower | Higher, two melting processes, cutting mill, blower |
Operating personnel | Fully automatic, no additional personnel required | Supervision of material feed necessary |
Material and colour changes | Fast, small L/D ratio and purge bore | More complex, larger quantity of material in the system |
Investment costs | Lower, eliminated units, short payback period | Higher, complete system with cutting mill and granulation system |
No pre-shredding step: no grinding dust, no thermal and mechanical pre-stress
No intermediate granulate: direct melt return in one step
Approx. 50% lower energy consumption compared to offline systems
Fully automatic: no additional operating personnel required
Fast material and colour changes through purge bore and small L/D ratio
Retrofittable: screen changer, diverter valve and melt pump optionally integratable
FAQ
What is an inline return extruder and how does it differ from an offline system?
An inline return extruder like the SIKOREX takes in production waste directly in ongoing production, melts it and feeds the melt immediately back into the production extruder, without pre-shredding and without intermediate granulate. An offline system, by contrast, processes the material in a separate step into regranulate. The SIKOREX therefore consumes around half as much energy as a comparable offline system.
Which productions is the SIKOREX suitable for?
The SIKOREX was specially developed for the nonwoven and PE/PP film industry. Wherever edge trim arises directly at the winder or roll goods at the unwind stand and are to be returned directly as melt, without production interruption and without additional personnel.
What throughput capacities are possible?
The product range includes standard systems with 30 kg/h to approx. 250 kg/h per extruder.
How fast can edge trim be fed in?
Up to 375 m/min. For high-speed applications, special designs up to 600 m/min and more are available on request.
Can the SIKOREX be retrofitted into an existing system?
Yes. Existing production lines can be retrofitted. On request with screen changer, diverter valve for fast colour changes and/or melt pump for precisely defined return rates.
What needs to be considered for hydrophilic or hydroentangled nonwovens?
These materials require a modified system with a longer screw (6 x L/D), vacuum extraction pump and metering pump. SIKOPLAST supplies correspondingly adapted solutions.