RAPREX® High Melt Strength Polyethylene Resins
Introduced in 2003, the RAPREX family of modified resins represents today's new generation of value-added, improved-performance irradiated polyethylene (PE) resins.
Derived from conventional high-density and linear low-density polyethylenes through a patented process, RAPREX resins deliver improved processability, along with a variety of enhanced physical properties to meet the specific performance needs of our customers.
Prior to the introduction of RAPREX, the preferred means of improving end-use properties in PE products was to utilize chemicals or to modify the formed parts with post-processing irradiation, both of which imparted a high degree of crosslinking. However, recyclability was lost in the process.
With RAPREX resins, chemical crosslinking agents are not required. The enhanced properties are achieved prior to forming the finished products with radiation processing being only one of the essential steps. The result is formed polymer products with better mechanical properties than their unmodified versions, along with full recyclability.
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Processability Improvements
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Physical Property Enhancements
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Radiation processing makes the difference
State of the art in every way, RAPREX resins use radiation processing as an important component in their production and a driver for their enhanced performance. This processing is part of a patented Sterigenics process designed to ensure proper selection of the base resin, type of radiation, radiation conditions and stabilization package, as well as guidance on converter equipment setup. Sterigenics' broad capabilities and proprietary knowledge of these components ensure customer needs are thoroughly and efficiently met.
Long chain branching
Unlike chemically cross-linked PE, through the controlled RAPREX process linear HDPE and LLDPE are long chain branched so that they remain fully recyclable and can be processed in conventional extrusion equipment.
Controlled rheology
RAPREX long chain branched PE resins exhibit high melt viscosity at low shear rates and strain hardening at high extension rates, offering improved processability in many applications: profiles, films, foams, thermoforming and blow molding.
The right product for every need
RAPREX high melt strength PE resins are available in a range of grades:
RAPREX® R-100 for extrusion applications, thermoforming and blow molding applications
- Improved stiffness and other mechanical properties
- Higher burst strengths in tubes and piping
- Higher melt strength (sag resistance and improved material distribution)
RAPREX® R-200 for films, low density foams and injection molding
- Improved balance of physical properties
- Improved blown film processability (higher blow-up ratios and gauge uniformity)
- Extrusion foamable to very low densities
RAPREX® R-300 for film and foam application
- Improved melt strength (higher blow-up ratios and gauge uniformity)
- Superior tear strength and puncture strength
- Enhanced mechanical properties
- 100% LLDPE-based RAPREX can be used with conventional film and foam processing equipment
Expert custom solutions
Sterigenics Advanced Applications would welcome an opportunity to tailor a RAPREX solution for your specific needs. Contact us today to learn how a RAPREX application could you help improve product performance and reduce cost.