MONO VS CO-EX (Multilayer Films)

Why Multilayer Films Are Superior To Monolayer Films In Packaging

•    Co-extrusion is a process to manufacture multilayer structure by the simultaneous extrusion of two or more polymers. It has been observed that a single polymer cannot meet the packaging requirements of properties such as high impact, high stiffness, good sealability, optical properties, barrier properties etc. However, a multilayer structure offers a good blend of properties.

•    Co-extrusion gives the processor the flexibility in choice of characteristics that are required to be built into the film as required, by use of different polymers.
      The feel of the bag, high strength, and increased gloss for better printability, improved optics, and enhanced sealability can all be tailored for a particular application.
    
•    The ability to combine the superior properties of different polymers, allows the use of higher loading of master batch without affecting sealability, and this results in lower production cost of the film composite.

•    The output rates of individual layers in a multilayer die are very much lower than for equivalent size of single layer die. This results in reduced shear rate and longer resistance times in the die spirals, leading to better homogeneity and additional relaxation of melt. Hence, the inherent benefit of Co-extrusion is the improvement of film quality.

•    Oxygen and Moisture are the two elements which cause lot of damage to the product packed in the film.   For example, influence of moisture causes:
•    Agglomeration of powders,   Stickiness in product    
•    Loss of nutritive value ,    Bitter taste    
•    Loss of crispness in baked/dried foods,
•    Hydraulic rancidity etc.               
•    influence of oxygen (even in small quantities ) causes:
•    Change in color, Formation of off-taste
•    Vitamin degradation, Change in Aroma    
•    Oxidation Rancidity    

All these can be eliminated by using a multilayer film structure which gives excellent moisture & oxygen barrier properties.

Studies indicate that a three layer film of same polymer can increase the tear, dart & drop strengths by as high as 25 - 30 % over those of an equivalent thick film made in single layer. This improvement allows the film to be down gauged (i.e. lower thickness) while still maintaining the product strength and abuse resistance. This results in raw material savings up to 35 - 40 %. The below table clearly illustrates the same.
•    The laminations film of 3 layers when laminated with BOPP and Polyesters enhances the barrier properties significantly for use in more complex & demanding applications.

Film properties : Multilayer( 3-layer) v/s Monolayer( 1-Layer)

Note:
•    All the above figures are merely indicative and for academic intent. They are not a commitment for any offered model of Film Plant and must be discussed in advance. Types of materials and material blends can reduce / enhance the characteristics mentioned above.
 
GENERAL APPLICATIONS OF MULTILAYER FILM PLANTS.

•    Milk packaging.
•    3 layer Co-extrusion film for flexible packaging applications for food items, crispy items, oil packaging for longer shelf life, salt packaging, horticulture sacks, Postal Envelopes, Tomato concentrate, Corn Flakes, & Other Foods packaging, breakfast cereal ,dehydrated vegetables.
•    Courier bags.
•    UV stabilized Nursery bags for plantations.
•    Heavy duty film bags for plastics raw materials.
•    Stretch cling films for household and pallet stretch wrap applications.
•    PE heat shrink films.
•    3 layer Lamination Films for laminating with reverse printed BOPP films for flexible packaging of snacks, shampoo, oils, etc for specific blend of properties.
•    Sachets of shampoos, detergents , edible oils and lube oils

COLOUR

Additives known as masterbatch add colour to clear polymer. Colours are endless from translucent to solids and just about any colour imaginable. Please contact us to discuss your colour requirements