Styrene-Butadiene Copolymers in Low Shrink Force Shrink Film

							Styrene-Butadiene Copolymers in Low
Shrink Force Shrink Film Applications
Presented by:
Cliff C. Pettey
Market & Applications Development
Chevron Phillips Chemical Company LP
                    Presentation Overview


What is Styrene Butadiene Copolymer?

Shrink Film Requirements

Performance of SB Copolymers in Films

Questions
                          SBC Chemistry




                      1,3-butadiene
  styrene


SBC is made by anionic polymerization
Batch solution reactors make living chain
block polymers
                                        SBC Morphology

Typical SBC morphology is spherical or lamellar
No distinct melting point
Glass transition
   styrene ~ 100°C

   butadiene ~ -80°C
                                K-Resin® SBC   Impact PS
Melt flow rate of 6 to 12 g/10 min
   Measured at 200°C - 5.0 kg load

Density is typically 1.02 g/cm3
             Shrink Film Requirements

Sufficient Shrinkage
  Machine Direction
  Transverse Direction
Optics
  Clarity
  Gloss
Strength & Stiffness (Modulus)
Puncture Resistance
Ability to be Sealed
                        Film Overview

Gauge: 2.5 mils
Frost Line Height: 30 inches
Equipment: Battenfeld Glouster Eng.
Die Gap: 0.060 in
Layer Structures
  A/B/A
  A/B/C
  15%/70%/15%
                              Shrinkage Overview

Machine Direction Shrinkage Target
  50% to 70%


Transverse Direction Shrinkage Target
  5% to 15%


Adjustment Options
  Output rate: 250 lbs/hr
  Melt temperature: 400° F
  Haul-off rate:
  Blow-up ratio (BUR): 2.5:1
  Frost Line Height (FLH): 30 inches
                                                      Materials Overview
                                                                                (Shrink Film)

Skin Layer - A (15%)             Core Layer - B (70%)             Skin Layer - C (15%)
  Styrenic blend                    LLDPE 7109                     EVA 880
      SBC (XK44): 75%                  Hexene                          7.5% vinyl acetate
      Crystal PS MC3100: 25%           Specific Gravity: 0.918         Specific Gravity: 0.930
                                       Melt Index: 0.9 g/10 min        Melt Index: 1.2 g/10 min
  mMDPE D350:                                                          Melting Point: 82° C
      Metallocene                   LDPE 5628
      Specific Gravity: 0.933          Specific Gravity: 0.922     SBC KR52
      Melt Index: 0.9 g/10 min         Melt Index: 0.4 g/10 min        Melt Flow Rate: 9.0
                                                                       Specific Gravity: 1.01
  LDPE 5755:                        SBC DK11                           Vicat: 60° C
      Specific Gravity: 0.925          Melt Flow Rate: 7.5
      Melt Index: 0.8g/10 min          Vicat: 81° C                Styrenic Blend
                                                                       SBC (XK44): 75%
  SBC KR52:                         SBC DK13                           Crystal PS (MC3100): 25%
      Melt Flow Rate: 9.0              Melt Flow Rate: 10.0
      Specific Gravity: 1.01           Vicat: 61° C
      Vicat: 60° C
Shrinkage Comparison
               (150°C)
Shrink Force
     ( at 150°C)
Shrink Tension
        (at 150°C)
                   Why are Optics Important?

Competitive retail marketplace
  Limited shelf space
  Brief opportunity impulse purchases
Clarity
  Easy product identification
  Package acts as advertisement
Gloss
  Attracts attention to product
                                   Surface Haze Overview

     A smooth surface layer in a co-extrusion can
  eliminate surface haze and allow a clear film to be
produced. The ideal material requires little or no anti-
     block and has adequate clarity and stiffness.


                                                Smooth skin layer

           Core layer with high haze due to surface roughness

       Smooth skin layer
Haze Comparison
     (2.5 mil thickness)
60º Gloss Comparison
1% Secant Modulus
          (2.5 mil film)
                             Summary

SBCs can be co-extruded
with a variety of LDPE and
LLDPE grades to produce
shrink films with
customizable:
      MD & TD Shrinkage
      Shrink Force/Tension
      Stiffness/Modulus
      Gloss
      Haze
     Thank you
PRESENTED BY

Cliff C. Pettey
Director of Global Market &
Applications Development

pettecc@cpchem.com



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