FAQ

If you have any question about process, production or technology of extrusion of Polyethylene blow film, packaging or our products please fill this form and we will answer it quickly.

Process of co-extrusion (extrusion of multi layer film) with the selection of special materials enables for buyer remarkable financial savings the same time the product gets better mechanical characteristics and better optical look.

Advantages of three-layer Polyethylene film
With the proper selection of raw materials three-layer Polyethylene film gives better optical (transparency, shininess…) and mechanical (toughness) characteristics with the reduced thickness (20-30 % less thickness then mono layer film). The Polyethylene film is been sold by it weight and been used by its length and that means significant financial saving. Plus because of the reduced thickness in process of packaging buyers get more film in a roll which means fewer roll changes, less needs for storage space and less packaging waste (in Croatian packaging law for waste treatment 30 % less thickness means saving of 30 € per tone).

Disadvantages of three-layer Polyethylene film
Selection of proper materials in three-layer Polyethylene film raises film price per weight, but this film is still much cheaper then mono layer if you take in consideration that film is been used in its length. Three-layer Polyethylene film needs higher temperature in thermo tunnel in the packaging process for 5-10°C and in the older packaging machines more frequently blade check is required.

Why 6, 7, 8 print colors when you can get any color from the basic 3 colors?

In picture printing process the CMYK (cyan, magenta, yellow, black) color space is being used. Basic RGB (Red, Green, Blue) color space is being used just for monitors and that color space represent light color intensity (emitted energy). Light itself can not be printed so that why there is difference between the printed picture and the picture on monitor. CMYK don’t have such problem because it uses basic color pigments. Pigments represent energy that is not absorbed by a substance such as ink or paint. Basic pigments are cyan, magenta and yellow. Black (key) is being used for ink saving ant the fact that all 3 basic pigments can’t give good dark black color. CMYK have a limit. It can’t print very bright and metallic colors like silver or gold so other inks must be used.

For image print on the Polyethylene film a process called flexographic printing is being used. There are 4 basic operations in the flexographic printing operation.

1. Image Preparation
Image, picture or illustration is made or transferred to digital image. Image is additionally processed and printed on special paper. Because of the simulation of print, if the customer finds that the quality of the cool poof is satisfactorily the customer gives the approval for Flexographic Plate Making.
2. Flexographic Plate Making
Flexographic printing uses special made Flexographic Plate – plates with raised images (relief) made of flexible material, such as plastic and rubber. For each color one Flexographic Plate is made.
3. Flexographic Print
Flexographic Plate is attached to a special roller and trough 4 or more roller system ink (image) is transferred to the Polyethylene film.
4. Finishing
Printed Polyethylene film may run trough the additional processes like cutting, folding and binding and it’s ready for transport.

For getting colored Polyethylene film (white, black, blue…), in the extrusion process the ink in the shape of granulates (master batch) is added and that film doesn’t require additional printing.

Unprocessed Polyethylene have low surface energy and as such represents essentially "non- stick" plastics and isn’t good for merging (gluing) with other materials. Corona process is a process that raises the surface energy of Polyethylene film. It raises the surface energy level to approximate 38-42 dynes/cm and enables processes like printing and lamination of Polyethylene film.