Presentation on theme: "SPE FlexPack Conference Houston, TX March 1, 2011 Frank A. Ruiz President, Plastimin LLC Research Consultant, Heritage Plastics, Inc. P.O. Box 271769 Flower."— Presentation transcript:
SPE FlexPack Conference Houston, TX March 1, 2011 Frank A. Ruiz President, Plastimin LLC Research Consultant, Heritage Plastics, Inc. P.O. Box 271769 Flower Mound, TX 75027 FrankRuiz@att.net
Development of Film Extrusion Compounds for Packaging Applications Identify cost requirements Define critical end-product parameters Mechanical, Optical, Barrier Evaluate processing requirements vis-à-vis current equipment
Compostable Product Development Impetus Volume of Solid Waste Generated in U.S. Increasing 70 MM Tons in 1960 229 MM Tons in 2001 Number of Landfills in U.S. is decreasing 7924 in 1988 1858 in 2001 (-77% in 13 years, mostly smaller operations) Virtually impossible to site new landfills (NIMBY) Incineration resisted in many areas Recycling rates have been difficult to increase
A process using thermophilic (heat-loving) bacteria that are naturally-occurring in organic waste Bacteria grow and consume raw materials under the proper conditions: High heat (136 – 158 deg F) Moisture Oxygen Organic raw materials High heat “sterilizes” waste by killing pathogenic bacteria (i.e., the ones that make us sick)
Compost microorganisms “eat” just about anything organic: Yard Waste Wood trimmings Food Waste Carrion/Road Kill Paper & Waxed (not PE-coated) Linerboard Compost end product is a valuable soil nutrient and augmentation New composting facilities opening in US Encouraged by EPA as a method of landfill diversion Requires less physical “footprint” than landfill New operation in Brooklyn, NY!
Product Development Impetus First Major Compostable Film Opportunity: Develop compostable bags and can liners for: Organic Waste diversion from grocery stores & restaurants Yard Waste collection by municipal & private waste haulers destined for composting
Product Development Requirements Product MUST meet ASTM D 6400: Specification for Compostable Plastics ASTM D 6400 requires: 90% mineralization to H 2 O & CO 2 in 180 days Fragmentation: 90% to < 2.0 mm Ecologically non-toxic when measured using ASTM D 6002 or OECD Guideline 208
Development of Compounds for Trash Bag & Can Liners Commodity Market; Cost Critical; competition is cheap labor Need high puncture, tear, & tensile strength combined with high ductility Clarity not critical (translucent) Not require drying Process on current equipment Same extruder screw, die, air ring Able to print, heat seal, slit…
Commercially-Available Compostable Resins in N.A. Aromatic/Aliphatic Co-polyester Easy to extrude, no need to dry Film extremely elastic Plasticized Starch Blend Easy to extrude, moisture level critical, very rapid biodegradation Poly-Lactic Acid VERY moisture sensitive Not suitable by itself for film extrusion & conversion PHA Film extrusion difficult without modification
Aliphatic-Aromatic Co-Polyester (A-A copolyester) Readily available in US from BASF as Ecoflex™ Suppliers of similar grades in Asia not exporting to N.A. Does not require drying prior to extrusion BASF dedicated to the growth of the Market Technical and Marketing Support
Plasticized Starch Blends Available in US from Novamont Partially based on renewable resources Require a specific moisture level for extrusion Novamont helped pioneer and is dedicated to the growth of the Market
PolyLactic Acid (PLA) Readily available in US from NatureWorks LLC Based on renewable resources Moisture Sensitive NatureWorks very dedicated to the growth of the market Technical and Marketing Support
PolyHydroxy Alkanoates (PHA, PHB) Available commercially from Telles & Tianen Biologic Based on renewable resources Telles has started a 50KT/yr. plant in Clinton, IA Dedicated to the growth of the Market Technical and Marketing Support * Telles is a J.V. between Metabolix and A.D.M.
Processing Characteristics of Compostable Polymers Drying of PLA required before extrusion to prevent breakdown to lactic acid Most co-polyesters also must be dried (except BASF Ecoflex™) PHA does not require drying except for HT extrusion Starch blends require proper moisture level for extrusion
Physical Properties of Compostable Polymers Physical properties Co-polyesters very elastic PLA very rigid PHA rigid to flexible; crystalline surface Modified starch a range of properties Blends offer a range of properties Temperature Resistance PLA heat resistance – new grades available Co-polyesters poor heat resistance PHA higher heat resistance (MP = 180° C).
COMPOSTABLE PACKAGING APPLICATION DEVELOPMENT PROCESS Market is growing rapidly (50%/yr) as more institutions initiate organic waste diversion (airports, malls, stadiums, office buildings, golf courses) Base product on compostable polymers Blend polymers and mineral(s) to achieve desired end-use properties Utilize low levels of additives if necessary to improve processing without sacrificing D 6400 Certification
Product Development Strategy Formulate polymer blends to achieve intermediate properties, processability Utilize Heritage Plastics polymer mineral reinforcement technology to modify co-polyester film properties Increase Stiffness Improve Productivity, Convertability Improve Bag Aesthetics Reduce Cost Any additives must not interfere with composting process All ingredients must have no potential for bioaccumulation or plant uptake
Product Development Synergy Test compounded blends at Heritage Bag Company Utilize film extrusion & conversion expertise Support desire to enter market Adapt rate of degradation Rapid for organic waste diversion Slower for fresh-cut grass and yard trimmings Result: Compounded blends of Biodegradable polymers & either talc or calcium carbonate
Compostable Product Development Bench-Scale Compost Testing – Atlanta, GA
Compostable Product Development Bench-Scale Compost Testing
Development of Compounds for Compostable Film Extrusion Work to date has yielded two commercial compostable film extrusion grades: Compound A: A-A-copolyester, poly-lactic acid, talc (Biotuf™ 970) Compound B: A-A-copolyester, poly- hydroxyalkanoate, & calcium carbonate (Biotuf™ 978)
Development of Compounds for Compostable Film Extrusion Compound A: A-A-copolyester base poly-lactic acid added to increase stiffness talc added to increase stiffness, bubble stability, film antiblocking, reduce cost 2500ppm slip
Development of Compounds for Compostable Film Extrusion Compound B: A-A-copolyester base poly-hydroxyalkanoate for stiffness, mineralization rate increase, bio-based content calcium carbonate to increase bubble stability, film antiblocking, reduce cost Developed in partnership with Telles/Metabolix
Extrusion of Compostable Film Compounds Melt temperatures 160 – 180 ° C (320 – 360° F) Cooler than LLDPE or HMW-HDPE, similar to LDPE PHA begins to thermally decompose > 180° C Minimize shear and residence time (PHA) Resins & Compounds are Polar: Effective “purge” agents Higher tendency to stick to metal (i.e. screw root) Conventional PE slip agents less effective Purge & start up line with 2 – 4 MI LDPE to minimize scrap
Processing of Compostable Resins Extruder Type *65mm GF Extruder RPM70 Die Size, mm225 Die Gap, mm1.5 Melt Temp °C (°F) 216 (420)160 (320)170 (340) Output Rate, kg/ hr. (lb.hr) 218 (480)180 (396)170 (374)
Blown Film Extrusion of Compostable Compounds Extruder = 65 mm grooved-feed, 24/1 L/D GP dual purpose screw (LLD & HMW-HDPE) Die = 225 mm Die gap = 1.5 mm Compound A extensional rheology (bubble) similar to LDPE Compound B extensional rheology (bubble) similar to LLDPE (run “In the Pocket”)
Extrusion of Compostable Resins CompoundAB Extruder Profile: Barrel Profile, °F280/290/300/300340/320/300/300 Adapter/Die, °F320/320340/340 Process Conditions: Extruder RPM70 Head Pressure, psi34003200 Melt Temp °C (°F)160 (320)170 (340) Output Rate, kg/ hr. (lb.hr)180 (396)170 (374)
Properties of Compostable Films Compound TypeCompound ACompound BC-6 LLDPE Film Thickness, mils 1.2 Dart Impact, g350240280 Elmendorf Tear, gMD320250280 TD180700480
Properties of Compostable Films Compound TypeCompound ACompound BC-6 LLDPE Film Thickness, mils 1.2 Tensile Strength @ yield, psi MD2000No defined yield 1500 TD210017001600 Tensile Strength @ break, psi, MD450040005500 TD380032804500
Compostable Product Certification Films biodegrade >90% in <180 days Films satisfy the requirements of ASTM D6400– 04: Standard Specification for Compostable Plastics: Compound A at 3 mils and below Compound B at 14 mils and below Certified by BPI
Compound B @ 0.25 mm Hot Composting Test at OWS Jan. 08, 2010XS
Compound B @ 0.35 mm Hot Composting Test at OWS Jan. 08, 2010XS
Advantages of Compostable Bags and Liners Certification by Biodegradable Products Institute required for Composter evaluation (not acceptance!) Allows Pre- and post-consumer food waste diversion with minimal health hazard and odor Provide tear and puncture resistance similar to PE products in use Lifting strength and load capacity necessary for wet refuse
Environmental Higher renewable materials content Faster Composting (More rapid mineralization) Reduce resistance to film at compost facilities (Not for fresh cut grass) Greater D6400 maximum thickness Rating 0.35mm Potential Bio-Energy Production - Anaerobic Digestion with sufficient PHA content Logistical Domestically-sourced material (Telles) Non-petroleum Feedstock ($ stability) Characteristics of PHA containing compostable compound
Film Properties Commercial Film Processing Rates Excellent Dart and Tear strength MD strain hardening yields high load capacity Bag Shelf Life approximately 12 mos.
Summary Compounded blends of available compostable polymers yields compostable film formulations Mineral addition improves product performance and lowers cost Proper ratios of resins and minerals key to obtaining desired processing characteristics and end product properties Different compounds may require equipment modifications to equipment configuration and/or process conditions Look to supplier for guidance More commercial composting = more opportunity for compostable packaging Will require labeling & consumer education
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