INDIAN PLASTICS INSTITUTE CHENNAI CHAPTER One Day Seminar on FLEXIBLE PLASTICS FILM LAMINATES 20th September 2004 - Hotel Savera POLYOLEFINS FOR FLEXIBLE PLASTICS FILM LAMINATES Presented by : Shri K Hariharan Deputy Manager (Tech.) Reliance Industries Ltd. Chennai
BIO-DATA Mr. K Hariharan, M.Sc. (App.Chemistry), Anna University and M.Tech. (Poly. Science & Tech.) IIT, Delhi. Has been associated with Polymer Industry since 1998 and worked extensively with all major laminators in Western and Southern parts of India. Presently as Deputy Manager (Tech.) - Reliance Industries Limited, Chennai
Polymers for Flexible Plastic Film Laminates IPI Seminar, Chennai 20 th September 04 K. Hariharan Reliance Industries Limited
What is a Flexible Laminate..? A flexible film laminate is a combination of two or more layers of different films bonded together to form a multi-ply structure.
What is a Flexible Laminate?..contd. REV. PRINTED PET 3 LAYER POLY FILM Lamination REV. PRINTED PET 3 LAYER POLY FILM 2 Ply Laminate REV. PRINTED PET MET. PET 3 LAYER POLY FILM Lamination REV. PRINTED PET MET. PET 3 LAYER POLY FILM 3 Ply Laminate
Why Flexible Laminates..? It combines the properties of individual layers and gives options to develop a packaging structure that suits the exact requirements of the product to be packed.
Typical Laminate Structures PET (10-12µ) PE co-extruded film PET (10-12µ) m-pet (10-12µ) PE co-extruded film 2-ply 3-ply PET Paper Al Foil PE Co-extruded film 4-ply Laminate
Biscuits packaging Structure Thickness (microns) BOPP/BOPP 15/20 BOPP/CPP 15/25 BOPP/M-BOPP 15/20 BOPP/M-BOPP 12/20 PET/M-PET/POLY 10/10/25 BOPP/POLY 15/25 Excellent Aesthetics (Printing & Gloss) Good moisture barrier property Heat Sealable
Lube Oil Packaging Structure Thickness (microns) PET/POLY 12/ 90-110 Excellent Aesthetics (Printing & Gloss) Sealing Layer with Good barrier properties and resistance to Oil & Grease Seal thru contamination and good sealability at higher line speeds.
Detergents Packaging Structure Thickness (microns) PET/POLY 10/ 25-75 Excellent Aesthetics (Printing & Gloss) Sealing Layer with Good Seal thru contamination. Good mechanical properties (for higher volume pkg.) Heat Sealable at high FFS line speeds
Atta Packaging Structure Thickness (microns) PET/POLY 12/50-110 Excellent Aesthetics (Printing & Gloss) Sealing Layer with Good Seal thru contamination. Good mechanical properties (5 kg and 10kg pkg.) Heat Sealable at high FFS line speeds
Snacks Structure Thickness (microns) PET/M-PET/POLY 12/12/25-50 Excellent Aesthetics (Printing & Gloss) Excellent gas barrier Sealing Layer with Good Seal thru contamination.
Lamination Process
Types of Lamination Process 1. Adhesive Lamination - Adhesive is applied between the two layers of substrates which are to be bonded. 2. Extrusion Lamination - Extrusion coating where polymer film is extruded on a single web (2-ply laminate) or between 2 webs (multi-ply laminate). 3. Heat & Pressure Lamination - Usually adopted for Aluminium foil. Readymade film is pre-heated and combined with foil to form a composite.
Components of a laminate 1. Printing Layer 2. Barrier Layer 3. Sealing Layer
Printing Layer (TOP LAYER) Role : Printing & Barrier function
Printing Layer (TOP Layer) 1. PET (Reverse printing) 2. BOPP (Reverse printing) 3. BOPA (Reverse printing) 4. PE (Reverse or Surface printing)
Polyester (PET) Excellent optical properties Higher tensile strength, better stiffness Good oxygen barrier property Excellent printability & machinability Better chemical resistance Density : 1.4 g/cc
Biaxially Oriented Polypropylene (BOPP) Excellent optical properties Good moisture barrier property Low density ~ 0.9 g/cc, therefore higher yield Good mechanical properties Better chemical resistance Plain/Heat Sealable films easily available
Biaxially Oriented Polyamide (BOPA) Good oxygen barrier properties Good opticals Good mechanicals Good barrier to oil & grease Low Stiffness
PE - Surface Printed films Edge-to-Edge coating is applied and cured with this EB system Thinner bags for source reduction and cost savings
Polyethylene - EB cured film pouches Silver Award Winner in Printing Achievement (2004 Flexible Packaging Achievement Award) Scott's Miracle-Gro Potting Mix Bag developed by Exopack, LLC using electron beam cured coatings in conjunction with the 8-color flexo printing process in order to eliminate a lamination layer Package weatherability, fade resistance and scuff resistance maintained Major savings in cost
Barrier Layers
Why Barrier? Three primary ways of good degradation Physical Damage or bruising Chemical Changes Oxidative reaction enzymatic actions Microbiological Changes Temperature, Water content and composition of atmospheric gases surrounding a product should be controlled.
Aluminium Foil Barrier Against Oxygen, Vapour, Light, Aroma, Foreign Odour. Chemically / Thermally Resistant Neutral with Regard to taste and smell Heat conductivity about 600 times better than PE, so the heat applied arrives early at the interface and is also dissipated faster. Hence the seal seam solidifies faster.
Metallised PET/BOPP Good aesthetic looks To achieve barrier properties that aluminum can provide. Excellent Moisture and Oxygen Barrier. Metal Oxide Coating Transparent Barrier Aluminium Oxide / Silicon Oxide.
Combination of Metallization and Metal oxide Stunning golden metallic look and triangular clear windows Demetallizing agent reacts chemically with the metallic layer to create a transparent window.
Aluminum Oxide coated PET pouch Aluminum-oxide coated polyester film, extrusion coated with a polyolefin sealant layer Used to package nutritional supplements that are highly moisture sensitive
Silicon Oxide coated PET pouch Silicon-oxide coated polyester film Extend the shelf life of the product while maintaining the clarity of the film
EVOH Random Copolymer of Ethylene and Vinyl Alcohol Outstanding gas barrier properties Excellent resistance to odour and flavour permanence Excellent resistance to oils and organic solvents Excellent gloss and clarity Higher rigidity
EVOH - Effect of Orientation
PVDC Coating Transparent Barrier Excellent resistance to gases and moisture Excellent retention of flavour and aroma Stress crack resistance to a wide variety of chemicals
Extrusion Coating of PVDC Conventional coating system based on PVDC water dispersion imposes a limit on barrier thickness. Extrusion Coating is a new alternative for coating different substrates with PVDC. Desired coating weight is obtained in one pass Delivers a PVDC layer that is pinhole free and impervious to flex cracking
Polyamide - Nylon Good oxygen barrier properties Good mechanicals Good barrier to oil & grease Better availability
Comparison of barrier materials
Sealing Layer
Sealing Layer Generally a multilayer film. 3 layer films widely used in India 5 layer films sparingly used. Tailor-made with different properties in each layer to suit the end-use requirements Key constituent of a flexible packaging system
Typical Sealing Layer Structure LD/LLD LD/LLD/HD LD/LLD LD/LLD TIE LAYER BARRIER LAYER TIE LAYER LD/LLD 3 LAYER FILM 5 LAYER FILM
What are Functional Requirements for Lamination Films?
Functional Requirements What are the key functional requirements of a Lamination Film? Sealing Heat Seal Strength Hot Tack Strength Seal thru Contamination COF Static and Kinetic
Functional Requirements Barrier ppty. of film (ex. Lube Oil Packaging) Easy Tear (Shampoo pouches) Stiffness (Standy Pouches) Strength (5 & 10 Kg Atta Packaging) Optical Properties (See thru pouches) etc. etc.. Seal layer design decides the Laminates Performance
PE based - 3 layer film
Low Density Polyethylene (LDPE) Good optical properties Synergistic effect on sealing characteristics when blended with LLDPE Linear Low Density Polyethylene (LLDPE) Good mechanical (Tensile, Tear and excellent puncture resistance) Good balance of properties in MD/TD directions Superior sealing characteristics
High Density Polyethylene (HDPE) Higher stiffness Better barrier properties
Which film composition will give the best properties?
Macro Structure - 3 layer film 75% LLDPE + 5 % HDPE + 20% LDPE Usually tailor made to suit the end-use requirements like the nature of contents, pack size, line speed, shelf life etc. Lower end / General purpose - Conventional C4 LLDPE Critical applications - O- LLDPE, M-LLDPE used.
Seal Layer Design - Parameters Product being packed Package type and its size Packing machine & packing speed Storage requirements viz. time & conditions Handling requirements Aesthetics Cost
Over-designing a practice of past? We need to understand what exactly the consumer needs and supply it. Over-designing means we are spending too much for the film than required If there s one common denominator in the business today it s: Take the Cost out! It has become all about price
Industry needs Applications Past Present % Shampoo 70 microns 40 microns 43% Edible Oil 110 microns 90 microns 18% Lamitubes 255 microns 195 microns 24% Cost Reduction - Downgauging (without compromising stiffness and barrier properties) Higher Line speeds Reduction in leakage levels
PE based - 5 layer film
Macro Structure - 5 layer film LD/LLD TIE LAYER BARRIER LAYER TIE LAYER LD/LLD Barrier Layer used - Nylon/EVOH Tie layer include XUS 61515/Bynel/Admer etc.. 5 layer film used for mainly vacuum Packaging & Edible oil packaging
Cast - PP films
Cast Polypropylene Higher thermal resistance, ideal for hot fill applications and Retort Pouches Product Type of pack Laminate Structure Shelf Life Kesar Bhath, Idli, Dosa etc Retort Pouches PET/ Al Foil/ Nylon/ CPP 12 18 Months
RIL/IPCL Grades for Lamination
Repol/Koylene BOPP grades S. No. Grade MFI 1 Repol H029SG 2.9 2 Repol H029SP 2.9 3 Repol H035SG 3.5 4 Koylene SS30NS 3.0 RIL/IPCL offers a range of BOPP grades to suit various needs of the processing industry.
LDPE & LLDPE Slip Grades Without Slip Grades Polymer Density MFI Density MFI Grade Grade gm/cc g/10 m gm/cc g/10 m F19010 0.918 0.9 F18010 0.918 0.9 20FS010 0.920 1.0 20FA010 0.920 1.0 B-LLDPE 20FY010 0.920 1.0 F18020 0.918 2.0 F22020 0.918 1.7 20FA020 0.920 2.0 20FS020 0.920 2.0 O-LLDPE O19010 0.918 0.9 O21010 0.918 0.9 1005FY20 0.920 0.5 22FA002 0.920 0.2 LDPE 23FY005 0.921 0.5 1003FA20 0.920 0.3 1020FA20 0.920 2.0 RIL/IPCL product range includes LDPE, B- LLDPE & O-LLDPE
HDPE & HMHDPE Polymer HDPE Grades Density MFI gm/cc g/10 m Remarks F46003 0.946 0.3 F56003 0.956 0.3 Better barrier ppty Polymer HMHDPE Grades Density MFI(I5) gm/cc g/10 m 50GF003 0.950 0.30 52GF004 0.952 0.45 Remarks
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