What films can be produced by a three-layer co extrusion blown film machine

The three-layer co extrusion blown film machine is an efficient and multifunctional plastic film production equipment. It extrudes three different materials of molten resin at the same time, and after blowing and forming, it forms a composite film. This technology can combine the advantages of different materials to meet diverse application needs. The following is a detailed analysis of the main types of films that can be produced by a three-layer co extrusion blown film machine and their application areas:

1、 Film types classified by material combination

PE based composite film

LDPE/LLDPE/HDPE combination:

By combining low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), films with flexibility, strength, and puncture resistance can be produced. For example:

Packaging film: Supermarket vest bags, express packaging bags, utilizing the flexibility of LDPE and the rigidity of HDPE.

Agricultural mulching film: the middle layer is LLDPE to improve tensile strength, and anti-aging agent is added to the inner and outer layers.

PE/EVOH/PE high resistance diaphragm:

Ethylene vinyl alcohol copolymer (EVOH) is used as an intermediate barrier layer, with PE as the inner and outer layers, for:

Food packaging: Meat vacuum packaging, cheese products, barrier to oxygen and odor.

Pharmaceutical packaging: the substrate of moisture-proof aluminum-plastic composite film for drugs.

PP based composite film

PP/PE/PP heat sealing film:

Polypropylene (PP) provides high temperature resistance, and the PE layer improves heat sealing performance, suitable for:

Fast food packaging: instant noodle bowl cover film, can be microwave heated.

Stationery film: a wear-resistant layer on the surface of transparent folders.

PA (Nylon) Reinforced Film

PE/PA/PE puncture resistant film:

The nylon layer endows the film with excellent tear resistance and is used for:

Heavy packaging bags: ton bags for fertilizers and feed.

Industrial lining: Scratch resistant packaging for mechanical parts.

Biodegradable film

PLA/PBAT/PLA environmentally friendly film:

Polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT) co extruded, with both biodegradability and flexibility:

Environmentally friendly shopping bags: replacing traditional PE bags.

Food contact film: Disposable tableware film.

2、 Applications classified by functional characteristics

High barrier film

Structural example: outer PE/middle PA or EVOH/inner heat sealed PE.

Application Scenario:

Milk powder can inner membrane (moisture-proof, anti-oxidation).

Electronic component anti-static packaging (with added conductive layer).

High temperature resistant film

Material combination: PP/adhesive resin/PA, capable of withstanding cooking at temperatures above 120 ℃.

Usage: Sterilization packaging for medical devices, pre made high-temperature cooking bags for vegetables.

UV resistant film

Process key: Add UV absorbers (such as HDPE+carbon black) to the outer layer.

Typical applications:

Agricultural greenhouse film (lifespan extended to 3-5 years).

Outdoor advertising printing substrate.

Breathable film

Micro porous design: A breathable channel is formed by blending PE/PP with calcium carbonate.

Usage: Sanitary products (diaper bottom film), medical protective clothing.

3、 Special functional film

Anti fog film

Technical implementation: Adding anti fog agents (such as glycerol monoesters) to the inner layer for fresh fruit and vegetable packaging.

Shrink film

Material selection: Three layers of high shrinkage PE are used for beverage bottle packaging.

Conductive/anti-static film

Structural design: Adding carbon nanotubes to the middle layer for dust-proof packaging in the electronic industry.

4、 Industry application cases

food industry

Fresh meat tray sealing film (PE/EVOH/PE, oxygen resistant and easy to heat seal).

Snack packaging (matte outer layer PP+printing layer+heat sealing layer).

agricultural sector

Black and white dual color plastic film (with a white reflective outer layer and a black grass suppressing inner layer).

medical industry

Dialysis paper composite membrane (PE/paper fiber/PE, breathable sterilization).

The three-layer co extrusion technology can produce films with the following characteristics through flexible material combinations:

Performance customization: Simultaneously possessing high barrier, heat sealing, and printing adaptability.

Cost optimization: The barrier layer only needs to account for 10% -20% of the thickness to achieve the desired effect.

Environmental upgrade: recyclable design or fully biodegradable solution.

With the development of new materials such as graphene reinforcement layers and intelligent processes, the application boundaries of three-layer co extrusion blown film machines will be further expanded, covering emerging fields such as new energy battery separators and intelligent packaging (temperature change indication).