Have the thin and lightweight packaging films, flexible materials on building exterior walls, and thin functional layers inside electronic products ever caught your attention? They all belong to the category of "membrane materials" - a type of material with a wide coverage and diverse functions. Have you ever wondered why this seemingly unremarkable material can span across multiple industries such as packaging, construction, healthcare, electronics, and energy? What is its structural composition? In what aspects is the technological content reflected? This article will systematically analyze the performance characteristics, process systems, application scenarios, and industry trends of membrane materials from different perspectives.

1、 What is the membrane material?

Membrane materials generally refer to sheet-like or rolled materials with a thin layer structure and a thickness typically ranging from a few micrometers to millimeters. They have the characteristics of flexibility, continuity, and strong functionality, playing a key role in modern manufacturing systems. Its main raw materials include polymers (such as PET, PE, PVC, PVDF, etc.), metals (such as aluminum foil, copper foil), ceramic powders, composite multilayer materials, etc.

1.1 Basic composition of membrane materials

Most membrane materials consist of three parts:

Substrate layer: provides basic support and morphology (such as PET film, PI film);

Functional layer: endows with barrier, anti-static, conductive, reflective and other properties;

Protective layer/coating: enhances scratch resistance, adhesion, or achieves other surface effects.

2、 Classification and performance differences of membrane materials

According to different functions and application requirements, membrane materials can be classified as follows:

2.1 Division by Function

Barrier film: used for food packaging to prevent the penetration of water vapor, oxygen, odors, etc;

Conductive film: applied to touch screens and flexible circuits;

Anti static film: used for packaging electronic components;

Optical film: applied to displays, lenses, etc;

Thermal insulation film/sunscreen film: used for glass film and building sunshade;

Biofilm: Used for medical dressings, artificial blood vessels, and tissue engineering.

2.2 Classification by Material

Plastic film materials: PE, PET, PVC, PP, EVA, etc., lightweight and low-cost;

Metal film materials: aluminum foil, copper foil, mainly used for shielding, thermal conductivity, and barrier;

Composite film material: Combining various material characteristics, such as aluminum-plastic composite film, paper plastic composite film;

Inorganic/Ceramic Membrane Materials: Highly heat-resistant and corrosion-resistant, suitable for precision separation and purification applications.

2.3 Division by thickness

Ultra thin film (<25 μ m): such as privacy film for mobile phones;

Conventional film (25 μ m~100 μ m): suitable for most industrial packaging;

Thick film (>100 μ m): such as impermeable film, wear-resistant protective film, etc.

3、 Core performance characteristics of membrane materials

3.1 Flexible, lightweight and thin

The thickness is extremely small but does not lose strength, making it easy to roll, fold, and stack multiple layers, achieving functional integration without occupying space.

3.2 Customizable functions

Through formula design and coating technology control, diversified functions such as flame retardancy, UV resistance, antibacterial, self-cleaning, and conductivity can be achieved.

3.3 Mature film-forming process

Modern film materials widely adopt processes such as casting, blow molding, coating, co extrusion, sputtering, etc., supporting large-area, high consistency, and mass production.

3.4 Good processing adaptability

Membrane materials can be cut, punched, laminated, heat sealed, glued, etc., to meet the needs of different equipment and terminals.

3.5 Safety and Environmental Protection

With the tightening of environmental regulations, many film materials have shifted towards non-toxic, recyclable, and even biodegradable formulations, providing a material foundation for sustainable development.

4、 Detailed explanation of typical application areas

4.1 Packaging Industry

One of the most widely used fields of membrane materials. include:

Food packaging film (cling film, cooking film, freezer bag);

Medical packaging film (blister packaging, sealing film);

Industrial packaging film (electronic device packaging, anti-static packaging).

Its barrier properties, sealing properties, and safety are key indicators, especially playing an important role in preservation and anti pollution.

4.2 Architecture and Decoration Field

Membrane materials are used for exterior wall membrane structures, roof sunshade films, window films, fireproof films, etc.:

Thin film roof systems are widely used in airports and sports venues;

Sunscreen film and energy-saving film are widely attached to building glass;

PVC waterproofing membrane is an important part of building waterproofing system.

4.3 Electronics and Optoelectronics Industry

High end film materials are widely used in fields such as display screens, circuit boards, and semiconductor protection

Polarizing film, diffusion film, and brightening film in LCD displays;

PI film and PET film for flexible circuit boards;

Anti blue light, anti fingerprint, frosted protective film applied to electronic consumer goods.

4.4 Medical and Bioengineering

Medical membrane materials are used for wound dressings, medical catheters, anti infection membranes, biofilters, etc;

Medical polyurethane film has the characteristics of moisture permeability, breathability, transparency, etc;

Artificial kidney dialysis membrane is one of the representatives of high-end membrane materials.

4.5 New Energy and Environmental Protection Fields

Membrane materials are used for solar cell backboards, wind turbine blade wrapping, and water treatment filtration membranes

Membrane separation technology is widely used in sewage treatment and seawater desalination;

The proton exchange membrane of a fuel cell determines its conversion efficiency.

5、 Analysis of Manufacturing Process for Membrane Materials

Membrane products for different purposes use different process routes:

5.1 Blow molding process

Suitable for PE flexible packaging film, with low cost and high production capacity.

5.2 Casting process

Used for high transparency and high flatness film materials, such as CPP and BOPP, suitable for surface treatment and printing.

5.3 Co extrusion composite process

It can achieve multi-layer composite of different materials, integrated molding, and improve barrier and mechanical properties.

5.4 Precision Coating Process

Accurately apply functional liquids such as adhesives, anti fog agents, anti-static agents, etc. on the base film through scraper, groove coating, and other methods.

5.5 Vacuum Sputtering and Evaporation Coating

Used for metal films, optical films, etc., to enhance reflective, conductive, wear-resistant and other properties.