Method and a thermoplastic film for use in a printed packaging of absorbent hygienic articles

A method for establishing the suitability for printing of a thermoplastic film for use in a packaging of absorbent hygienic articles, said thermoplastic film comprising at least 30% recycled polymer material, the method comprising:

• scanning said sample to provide a pixelized image of said sample;
• computer analyzing said pixelised image using a thresholding method to transfer the image to a binary image in which each pixel is determined as either dark or light;
• defining each group of neighbouring pixels deemed to be dark as a Gel Spot;
• defining a Gel Spot Size for each Gel Spot being the circle equivalent diameter to the pixel area of the Gel Spot;
• determining an Amount of Gel Spots indicative of the number of Gel Spots in said sample, which have Gel Spot Size greater than or equal to 150 μm;
• and
• determining a Relative Gel Spot Coverage Area indicative of the relative area of said sample covered by Gel Spots having a Gel Spot Size greater than or equal to 150 μm, using said circle equivalent diameter;
• and
• if said Amount of Gel Spots is less than or equal to a first threshold and said Relative Gel Spot Coverage Area is less than or equal to a second threshold, determining that said thermoplastic film is suitable for printing;
• and
• if said Amount of Gel Spots is greater than said first threshold and/or said Relative Gel Spot Coverage Area is greater than said second threshold, determining that said thermoplastic film is not suitable for printing,
• wherein said film comprises coloured pigments in the film resin.