Printing, lamination & material structure

The brief process of printing, lamination and materials used in the lamination.

1. Printing, Lamination & Material Structure Muhammad Zubair Qadir Intern Engineer (Flexible Packaging) (01/06/2018 - 13/07/2018) UET LHR (KSK Campus)

2. Printing Section

3. Printing  is a process for reproducing text and   images  using a master form or template . Packages Limited is using two types of printing techniques at the moment. Gravure printing OR Rotography Flexography Printing

4. Flexography A rotary relief printing method using rubber or plastic plates and fluid inks or dyes for printing on fabrics and impervious materials such as plastics , as well as on paper . Types of Printing

5. Cont… A  photopolymer  or light-activated resin is a polymer that changes its properties when exposed to light , often in the ultraviolet or visible region of the electromagnetic spectrum .

6. Gravure printing R otogravure  (roto or  gravure for short) is a type of intaglio  printing  process, which involves   engraving  the image onto an  image carrier. Cont…

7. Flexographic Machine Layout

8. Gravure Machine Cont…

9. Flexographic Processing The first step in the flexographic printing process is to develop the image and text that is going to be printed. Once the design has been created, plates need to be molded or engraved to reflect the designs that are to be printed. For each color that needs to be printed, a unique plate is created. Once the plates have been made, the printing process is ready to begin. Processing

10. For the most part all flexos work using the same broad method using a series of three rollers. The first roller applies the ink, the second has the plate attached, and the third is an impression roller. The first roller is programmed to disperse a predetermined measurement of ink to the plate. Then , the material being printed on is passed between the print plate and the impression roller, which applies pressure to the keep the material firmly against the plate to create the highest quality of final product. Cont…

11. Rotogravure Processing The ink is applied directly to the cylinder and from the cylinder it is transferred to the substrate . While the press is in operation, the engraved cylinder is partially immersed in the ink fountain, filling the recessed cells. As the cylinder rotates, it draws ink out of the fountain with it. Acting as a squeegee, the doctor blade scrapes the cylinder before it makes contact with the substrate, removing excess ink from the non-printing (non-recessed) areas. Cont…

12. Next, the substrate gets sandwiched between the impression roller and the gravure cylinder, this is where the ink gets transferred from the recessed cells to the substrate. The purpose of the impression roller is to apply force, pressing the substrate onto the gravure cylinder, ensuring even and maximum coverage of the ink. The capillary action of the substrate and the pressure from impression rollers force the ink out of the cell cavity and transfer it to the substrate. Cont…

13. Comparison

14. Lamination Section

15. A   Laminating  is the process through which two or more  flexible packaging  webs are joined together using a bonding agent. The substrates may consist of films, papers or aluminum foils.  Usually there are two types of lamination processes used in industry. Wet Bond lamination Dry Bond lamination Lamination

16. Wet Bond lamination A laminating process used to laminate two substrates, one of which is porous, such as paper. For example, a foil and paper substrate lamination may be accomplished through a wet bonding process. Once the wet bonding process is applied to each substrate, the two substrates will then be combined prior to passing through an oven, which is used for the drying process. This drying process is where the adhesive materials will dry, essentially adhering the two substrates together, therefore, the two substrates need to be combined before the adhesive is dried in the oven. Laminating Processes

17. Dry Bond lamination A laminating process used to laminate two substrates, both of which are non-porous, or impervious to filtration. For example, film on film, and film on foil laminations would go through the process of dry bonding. The adhesive used to combine the two substrates together will be applied to either one of the substrates, and then dried in an oven prior to being combined with the second substrate. The two substrates are combined after the adhesive is dried for maximum efficiency of the dry bond lamination process. Cont…

18. Wax lamination W here the bonding agent is a wax or hot melt and is applied in a molten state onto one of the two substrates. This process allows the production of paper-paper or paper-aluminum foil laminates that are widely used for the packaging of biscuits and bakery products. Solventless lamination W here the adhesives used do not contain solvents. Solventless adhesive generally indicates a specific type of adhesive composed by two components reacting with each other and consequently not requiring drying. Cont…

19. Wet Bond lamination Layout

20. Dry Bond lamination Cont…

21. Adhesive Comparison

22. Problems

23. Lamination Materials

24. A critical part of the flexible packaging process is selecting the proper type of packaging material for your product . General Laminated Film is made of multiple raw material layers with barrier properties that are chosen depending on the customer’s needs.  With its increased efficiency, General Laminated Film is widely used in high speed production for flexible packaging because of its advantages for quickly packaging as it increases efficiency. Introduction

25. Material Types

26. Cont…

27. Properties Poly Ethylene Terephthalate (PET) PET film is mostly found in nonfood, non-packaging applications , such as photographic film, x-ray film and magnetic audio and video recording film. Its primary packaging uses, however , are in metallized packages, such as those for potato chips and pretzels, as well as in microwave packaging , brick packs and medical packaging It also can be found in tobacco wrap, cigarette wrap and labels. PET is used in these and other applications because it has good mechanical properties such as toughness and stiffness and good thermal properties.

28. Polypropylene (PP) PP has good chemical resistance, is strong, and has a high melting point making it good for hot-fill liquids. This resin is found in flexible and rigid packaging, fibers, and large molded parts for automotive and consumer products . Excellent optical clarity in biaxial oriented films and stretch blow molded containers Low moisture vapor transmission Inertness toward acids, alkalis and most solvents Containers for yogurt, margarine, takeout meals, and deli foods. Medicine bottles. Bottle caps and closures. Bottles for catsup and syrup. Cont…

29. Polystyrene (PS) PS is a versatile plastic that can be rigid or foamed. General purpose polystyrene is clear, hard and brittle. It has a relatively low melting point. Typical applications include protective packaging, foodservice packaging, bottles, and food containers. PS is often combined with rubber to make high impact polystyrene (HIPS) which is used for packaging and durable applications requiring toughness, but not clarity . Excellent moisture barrier for short shelf life products Significant stiffness in both foamed and rigid forms Low density and high stiffness in foamed applications Low thermal conductivity and excellent insulation properties Cont…

30. Polyvinyl Chloride (PVC, Vinyl) In addition to its stable physical properties, PVC has good chemical resistance, weather-ability , flow characteristics and stable electrical properties. High impact strength, brilliant clarity, excellent processing performance Resistance to grease, oil and chemicals Rigid packaging applications include blister packs and clamshells. Flexible packaging uses include bags for bedding and medical, shrink wrap, deli and meet wrap and tamper resistance. Cont…

31. High Density Polyethylene (HDPE ) HDPE is the  most widely used type of plastic.  It’s used to make many types of bottles and containers .. Because HDPE has good chemical resistance, it is used for packaging many household and industrial chemicals such as detergents and bleach. Excellent resistance to most solvents Higher tensile strength compared to other forms of polyethylene Relatively stiff material with useful temperature capabilities Bottles for milk, water, juice, cosmetics, shampoo, dish and laundry detergents, and household cleaners. Bags for groceries and retail purchases. Cereal box liners. Cont…

32. Low Density Polyethylene (LDPE)/(LLDPE) LDPE is used predominately in film applications due to its toughness, flexibility and relative transparency, making it popular for use in applications where heat sealing is necessary. LDPE also is used to manufacture some flexible lids and bottles as well as in wire and cable applications. Excellent resistance to acids, bases and vegetable oils Toughness, flexibility and relative transparency (good combination of properties for packaging applications requiring heat-sealing) Bags for dry cleaning, newspapers, bread, frozen foods, fresh produce, and household garbage. Shrink wrap and stretch film. Coatings for paper milk cartons and hot and cold beverage cups. Container lids. Squeezable bottles (e.g., honey and mustard). Cont…

33. Bi-Oriented Poly-Propylene (BOPP) OPP & BOPP are the same type of films Film is stretched in both the machine and transverse direction after it is extruded This increases the films stiffness clarity & tensile strength It is used for the wrapping of hard candies and chocolates Resistant to heat and moisture Shiny, high gloss appearance When laminated with metal foil (MET), it increases the film’s oxygen & water barrier. It also block out UV rays Cont…

34. Nylon Films Since they have high melting point, they are used for cooking applications such as microwave and baking Very good clarity and moisture barrier Considered as very strong film Cont…

35. Laminated Aluminum Foil Bags Laminated foil roll is resistant to water and a number of chemical components. Opaque, the adhesive foil lamination process is ideal for foils employed to protect sensitive materials from light Laminated aluminum foil film and bags have great seal abilities, and good chemical and water resistance Its advantages are excellent as they are opaque, with good oxygen barrier, well formed, and maintain fresh the content with long-term preservation. Laminated aluminum bag and rolls can be used on pizza wraps, beverage packaging, tablet packaging, coffee bags and snack food packaging, as well as cosmetic, facial mask, bio medical packaging, anti-static semiconductor packaging etc. Cont…

36. Comparison

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