After market research, our current 700 model 7-layer co extrusion blown film machine can be applied to the field of high barrier packaging materials;
After market research, our current 700 model 7-layer co extrusion blown film machine can be applied to the field of high barrier packaging materials;

Basic structure of seven layer co extruded film
Seven layer co extruded film is a thin film made through multi-layer co extrusion technology, usually composed of different plastic resins to achieve high barrier properties, high strength, and other required packaging performance. The following is an example of the basic structure of a seven layer co extruded film:
Asymmetric structure: A common seven layer co extruded film structure is an asymmetric structure, such as PA/TIE/PE/PA/TIE/PE. This structure typically uses a combination of nylon (PA), polyethylene (PE), and adhesive resin (TIE). Nylon provides strength and barrier properties, polyethylene provides good sealing and flexibility, while adhesive resin helps improve interlayer bonding strength
Symmetric structure: Another type of structure is symmetric structure, such as PE/PE/TIE/PA/TIE/PE/PE. This structure also uses nylon and adhesive resin in the middle, but with more polyethylene layer on the outside to provide better sealing and protection for the contents
High barrier structure: For applications that require higher barrier performance, structures containing ethylene vinyl alcohol copolymers (EVOH) can be used, such as PE/TIE/PA/EVOH/PA/TIE/PE. EVOH is a high-performance barrier material that effectively prevents the permeation of oxygen, water vapor, and other gases.
Fresh meat preservation film structure: For the special needs of fresh meat refrigeration preservation, the seven layer co extruded film can adopt the following structure: PE/TIE/PA/EVOH/PA/TIE/EVA. This structure can be immersed in water at 80 ℃ for 1-3 seconds before being attached to the body, and has excellent barrier properties, suitable for product packaging stored at low temperatures below -25 ℃
It should be noted that the material and structure of the seven layer co extruded film can be adjusted according to specific application requirements to meet different quality requirements and packaging performance.
Inflatable preservation type
|
Number of layers
|
1st floor
|
2nd floor
|
3 levels
|
4th floor
|
5th floor
|
6th floor
|
7th floor
|
|
structure
|
PE
|
TIE
|
PA
|
TIE
|
PA
|
TIE
|
PE
|
Fresh meat preservation type
|
Number of layers
|
1st floor
|
2nd floor
|
3 levels
|
4th floor
|
5th floor
|
6th floor
|
7th floor
|
|
structure
|
PE
|
TIE
|
PA
|
EVOH
|
PA
|
TIE
|
EVA
|
High temperature stretching type
|
Number of layers
|
1st floor
|
2nd floor
|
3 levels
|
4th floor
|
5th floor
|
6th floor
|
7th floor
|
|
structure
|
PA
|
TIE
|
PP
|
TIE
|
PA
|
TIE
|
PP
|
Low temperature stretching type
|
Number of layers
|
1st floor
|
2nd floor
|
3 levels
|
4th floor
|
5th floor
|
6th floor
|
7th floor
|
|
structure
|
PA
|
TIE
|
PE
|
TIE
|
PA
|
TIE
|
PE
|
High barrier and anti-seepage type
|
Number of layers
|
1st floor
|
2nd floor
|
3 levels
|
4th floor
|
5th floor
|
6th floor
|
7th floor
|
|
structure
|
PA
|
TIE
|
PE
|
EVOH
|
PA
|
TIE
|
PE
|