Extrusion coating is a process used in food packaging industry
to coat complex materials used for aseptic packaging, such as containers for milk, wine, fruit juices , water, etc…
Materials properties are very important in food packaging industry.
Efficient barrier film against external agents is necessary in food package.
In order to guarantee the barrier effect, then , food quality preservation different material layers are coated in flexible package: paper, cardboard, aluminum, and plastic materials such as PE polyethylene, PP polypropylene, PET Polyethylene terephthalate.
Different substrates are coated in flexible packaging material !
Watch this NICE video !
Good adhesion of these different materials is crucial for a good package.
Extrusion coating is a critical process, for food packaging industry. So, becomes compulsry, to solve problems associated with adhesion. For this reason,
surface treatment results very useful on different substrates to be coated.
To obtain it, along the extrusion line, one surface treatment station, (or two in case of pre-post coating), improves drastically , the surface energy , then adhesion , of coated material. For same reason, also along converting line too there is a surface treatment station to refresh and /or optimize materials characteristics. In the converting line it’s compulsory a surface treatment to prepare the material to be further painted or laminated.
Both these lines: extrusion and converting lines, can be equipped with various alternative systems for pre-treatment, such as
plasma treatment, corona treatment or the most important and efficient system : flame treatment.
Surface Flame Treatment
is a “young” technology,
despite more than half century of his life.
it’s spread in
extrusion and converting line
all over the world !
The surface polarized flame treatment
Flame treatment it’s most widely used treatment, because it can replace all other treatments. In the United States is the most frequently used to improve materials adhesion. Emphasizing the important development of this technology introduced by “ESSECI” ,we can describe as follow, the most relevant and important improvements introduced that they are :
◊ the use of a combustion analyzer
flame temperature and composition can be adjusted within a wide range so as to have different possibilities of O2 free (it means, to have air/gas mixture by reducing or oxiding or stoichiometric ratio )on the different chemical compositions of paper and cardboard, or polypropylene, or aluminum or …
◊ the use of thermostatized and surface chromed treatment roll
The ability to heat or cool the film of material passing on the roll surface, so as to adjust web temperature and the right process conditions for the selected material; the certainty that the film passes always at the same distance from the flame (if there’s not variation on burner gap ) ; reduction of burner gap in a field 4 – 6 mm, allows an energy savingon gas consumption, (depending on line speed) at least twicw of other systems, where gap is larger. This type of plant is widely used in PP polypropylene and PE polyethylene extrusion lines and converting lines.
surface flame treatment extended
to the paper and cardboard
and it’s a real step forward in technology
and in the process of extrusion coating.
The benefits achieved arising by
the combustion analyzer
( different flame compositions or flame temperature setting)
the treatment roller
( heating or cooling web )
produce extreme flexibility on ” ESSECI ” system flame treaters
that allows to treat without any problem any type of material,
especially very thin papers,
with improvement of quality
(reduction on gas consumption)
increase on production
(the extrusion rate increases by 20%)
” ESSECI ” surface flame treatment on paper and cardboard
following results :
◊ elimination of hairs and small growths that may be present on the surface ;
◊ elimination of humidity or water evaporation , which could cause air bubbles between the two layers to be laminated ;
◊ decontamination of oils or fats that may be present due to previous contact with plastic surfaces ;
◊ creation of bonds on the surface to be coupled due to free oxygen in the flame. The material oxidizes the surface and is thus improved the adhesion with other material .
” ESSECI ” surface flame treatment on alluminum
◊ elimination (burning ) of waste oil mill ;
◊ elimination (burning ) of solvent;
ESSECI flame treaters is italian company
that customizes systems flame treatment
according to customer needs all over the world!