Unveiling the Secrets of Thin-Film Production Materials: A Comprehensive Guide to Raw Material Lists for Different Film Types

Preface 

In the membrane technology industry, the thin-film family includes various types such as packaging films, optical films, and water treatment membranes—each with distinct functions rooted in their unique material properties. “ Raw materials ” Understanding the raw materials of different films not only helps professionals make precise product selections but also enables them to grasp the logic behind film performance—for example, the reasons for high-temperature resistance and corrosion protection. This article begins by categorizing these raw materials, proceeding with “ General-purpose Film ““ Functional Film ““ Specialty Separation Membrane ”  Dissect the core materials and organize a practical knowledge system. 

I. Raw Materials for Thin Films 3 Major Core Category 

(1) Base Resin: For the Film “ Skeleton ”

• Core Role : Forms the main structural framework and determines fundamental properties (such as flexibility and high-temperature resistance). 
• Common types : Polyethylene PE ）、Polypropylene（ PP )、Polyethylene terephthalate PET ）、Polyvinyl Chloride（ PVC )、Polyamide PA ）。 
• Choice Logic : Choose based on flexibility PE , requiring high-intensity selection PET , needs oil-resistant selection PA 。

(II) Functional Additives: For Thin Films “ Performance Enhancer ”

Core Role : Addressing resin defects or imparting new functionalities—common types and their roles: 

• Slip agent / Anti-adhesion agent : Reducing friction and adhesion (e.g. PE Membrane plus erucylamide); 
• Antioxidant : Slowing down aging (e.g., PP Membrane plus hindered phenols); 
• Ultraviolet Absorber : UV-resistant (such as PVC Shed film plus benzotriazole-based compounds; 
• Antibacterial agent : Inhibit microorganisms (such as PET Food film with silver ions); 
• Plasticizer : Enhancing flexibility (e.g., PVC Soft film plus eco-friendly citrate esters; 
• Coloring agent : Assigning colors (such as colorful) PE Membrane plus organic /  Inorganic pigments). 

(III) Auxiliary Materials: Produced “ Supporting Infrastructure ”

Core Role : Ensuring production or enhancing processing performance—common types and their functions: 

• Compatibilizer : Improving resin miscibility (e.g., PP/PE Blended membrane with maleic anhydride grafting PP ); 
• Nucleating agent : Accelerate crystallization, enhance strength (e.g., PP Membrane plus sorbitol derivatives; 
• Mold release agent : Anti-stick equipment (such as PET Membrane with zinc stearate); 
• Solvent : Used in solution casting methods (e.g., dissolving resin for certain optical films). 

II. General Films: A List of Commonly Used Raw Materials 

(1) Polyethylene PE ）Thin film 

1. Core foundational resin ：

• LDPE : Highly flexible and transparent, used for food wrap and shopping bags; 
• HDPE : High strength, impact-resistant, used for heavy-duty packaging films and trash can liners; 
• LLDPE : Puncture-resistant and cold-resistant, used for ground films and stretch wrapping films. 

2. Key Additive : Lubricant (erucylamide), antioxidant 1010 + 168 ), opening agent (silica). 

3. Typical Applications : Food保鲜膜（ LDPE ）、agricultural plastic film LLDPE ）。 

(2) Polypropylene PP ）Thin film 

1. Core foundational resin ：

• PPH : High rigidity, transparent, used for BOPP Thin film; 
• PPR/PPB : Flexible, impact-resistant, used for CPP Thin films, heat-seal films. 

2. Key Additive Nucleating agent (sorbitol-based), antioxidant 1076 + 168 )、Anti-adhesive agent (calcium carbonate). 

3. Typical Applications ： BOPP Cigarette packaging film PPH ）、Food Heat-Sealing Film（ PPR ）。 

(III) Polyethylene terephthalate PET ）Thin film 

• Core foundational resin : Homopolymer PET (Film-grade, with uniform molecular weight), high-temperature resistant 120℃ ), high strength. 
• Key Additive : Antioxidants (phosphate esters), matting agents (silica, for matte films), slip agents (magnesium stearate). 
• Typical Applications : Beverage bottle label films, electronic component protective films. 

(4) Polyvinyl Chloride PVC ）Thin film 

• Core foundational resin : General-purpose PVC Resin SG-3 Used for the dura mater, SG-5~7 Used for soft films. 
• Key Additive Plasticizer (eco-friendly citrate esters), stabilizer (calcium-zinc complex), lubricant (stearic acid). 
• Typical Applications ： PVC Raincoat film (soft film), PVC Floor film (hard film). 

III. Functional Films: Raw Materials for Special Applications 

(1) Electronic Insulating Film 

1. PET Insulating film ：

• Base resin: High-purity film-grade PET ；
• Additives: Voltage-stabilizing agent (nano-titanium dioxide), antioxidant (high-efficiency hindered phenol); 
• Application: Motor coil insulation. 

2. PI Insulating film ：

• Base resin: Polyimide resin (dianhydride) + Diamine polymerization, purity 99.9% The above); 
• Features: High-temperature resistance ( 260℃+ )、High-pressure resistance; 
• Applications: New energy vehicle motors, aerospace electronic equipment. 

(II) Optical Films 

1. Light-guiding film ：

• Base resin: Optical grade PMMA/PC (Transmittance ≥92% , Haze ≤1% ); 
• Additives: Light-guiding particles (nano-silica), UV stabilizer (benzotriazole-based); 
• Application: Mobile Phone / Computer backlight module. 

2. Brightness-enhancing film ：

• Base resin: Optical grade PET (Transmittance ≥90% , Flatness Error ≤5μm ); 
• Process materials: UV-curable resin (for microstructures), fluorine-based release agent; 
• Application: Liquid crystal television screens. 

(III) Barrier Membrane 

1. Oil-resistant barrier film ：

• Base resin: PA6/66 (Oil-resistant), compatible with PE/PET Compound; 
• Additives: Toughening agent (maleic anhydride grafted) POE )、Oil-resistant stabilizers (sterically hindered amines); 
• Application: Packaging for fried foods. 

2. Highly Airtight Barrier Film ：

• Base resin: EVOH (Ethylene content 32% Right, excellent barrier properties), and PE/PET Composite moisture-proof; 
• Application: Pharmaceutical aluminum-plastic blister packaging. 

IV. Specialized Separation Membranes: Highly Selective Raw Materials 

(1) Water Treatment Membranes 

1. Permeation membrane RO ） ：

• Basic material: Organic membrane (aromatic) PA , Desalination rate ≥99% ), support layer (polyester non-woven fabric +  Polysulfone porous layer); 
• Requirements: PA Monomer purity ≥99.5% , Polysulfone PDI ≤ 2.5 ；
• Applications: Desalination of seawater, preparation of ultrapure water. 

2. Ultrafiltration membrane UF ） ：

• Basic material: Organic membrane PES/PAN , resistant to contamination), inorganic membranes (ceramic, high-temperature resistant) 500℃+ ); 
• Requirements: PES/PAN High purity, high-purity alumina powder for ceramic membranes (particle size < ≤1μm ); 
• Application: Household Water Purifiers PES )、Industrial wastewater reuse (ceramics). 

(II) Gas Separation Membranes 

• Basic Materials : Organic membrane ( PI/CA , high selectivity), inorganic membranes ( Pd-Ag Alloy, nearly hydrogen-selective 100% ); 
• Requirements ： PI Balancing permeability and selectivity, Pd-Ag Purity ≥99.99% ；
• Application : Oil refinery hydrogen recovery ( PI ）、High-purity hydrogen production（ Pd-Ag ）。 

V. Selection of Raw Materials 3 A Core Principle 

(1) Matching Functional Requirements 

Clearly define the core function—choose resin; opt for high-temperature resistance. PET/PI , Oil-resistant option PA/EVOH , High-Transparency Optical Grade PMMA/PC。

(II) Controlling Purity and Stability 

Basic resin purity ≥99% , Additives ≥98% , Performance fluctuations within the same batch ≤5% , avoid impurities from affecting performance. 

(III) Balancing Performance and Cost 

High-performance materials PI 、 Pd Alloys are costly—choose according to your needs: for standard insulation purposes. PET ,高端用 PI ; For domestic water treatment PES , ceramics for industrial high-temperature applications. 

Conclusion 

Raw materials are the core of film performance and applications, ranging from general-purpose PE Membrane to the high-end PI Membranes—material combinations determine their value. Today, eco-friendly plasticizers and high-performance PI New materials such as resins are constantly being upgraded, and paying attention to material innovation allows you to stay ahead of membrane technology trends. We hope the raw material list and selection logic presented in this article will serve as a valuable reference for your product selection and R&D efforts, helping you make informed decisions in the field of membrane materials.