CASE STUDY: POKETONE Paper Coating Extrusion Trial

Overview

• POKETONE (Polyketone) is a tough semi-crystalline thermoplastic with high impact strength, high wear resistance, outstanding chemical resistance and the ability to withstand exposure to heat and humidity for an extended period of time.

Objective

• To replace up to 30% of EVOH with a grade of POKETONE in an extruded multi-layer paper coating structure to improve cost, performance and sustainability in an existing extrusion coated barrier paperboard structure used for food packaging such as orange juice and milk containers.

Coating Structures

• Current Coating Structure:
• PA6 / Tie Layer / LDPE / EVOH / LDPE / Tie Layer / PA6 / Paperboard / LDPE (printing)
  
• Proposed Coating Structure:
• PA6 / Tie Layer / LDPE / EVOH, Nucrel, POKETONE / LDPE / Tie Layer / PA6 / Paperboard / LDPE (printing)

Challenge

• Consistent extrusion process while achieving correct coating thickness with good adhesion

Results

• Extrusion process was consistent with a stable melt curtain
• Coating thickness was achieved, adhesion was good, and samples collected for testing
• The trial went very well with POKETONE after significant extruder temperature and pressure changes were made.

Benefits / Advantages

• Lower or maintain overall barrier board cost
• Increased temperature resistance leading to hot-fill
• Improved moisture and oxygen resistance/barrier
• Improved toughness & puncture resistance
• This new breakthrough technology could be used as a new unique market solution
• Decrease EVOH usage in a tight market

Next Steps / Moving Forward

• OTR and MVTR testing will be required to confirm the above performance advantages, along with mechanical testing. Then field testing can be considered
• Mitsui are now studying blending/compounding the POKETONE with nylon to eliminate EVOH all together
• Once we have successfully proven and established this packaging structure performs as promised and is cost effective and/or has a well-established value proposition, this new technology can be introduced to the market at large.