Brief history of film materials

A film is a flexible polymer material with a thickness below 300 µm. It was invented relatively recently, and its history began just in the middle of the 19th century. The first films were made from celluloid – a plastic material derived from cellulose nitrate, discovered in 1855 by the British metallurgist Alexander Parkes. Celluloid has several flaws, therefore the search for other materials for films continued. Science was quick to explore new opportunities, so with time more types of plastics suitable to be used in films emerged.

The History of Films


Films have multiple usages:

  • Packaging for industrial products and semi-finished products.
  • Technical films for industry and agriculture.
  • Packaging for various types of non-edible products sold in retail.
  • Packaging for food and edible raw materials.
  • Packaging for medical, hygienic, and pharmaceutical products.

The vast majority of films are used in packaging materials. Different goods require different types of packaging with specific properties. The properties of a film are determined by what it’s made of – the polymer material. Let’s take a closer look at polymers.

A few facts about polymers

Polymers are macromolecular compounds with large molecular masses (ranging from several thousand to several million) consisting of many repeating similar or different subunits – monomers, which are chemically bound into lengthy macromolecules.  


The number of monomers in a polymer macromolecule is called the degree of polymerization. The majority of polymers used in industry have a degree of polymerization in the range between 100 and 10000. The properties of a polymer are determined primarily by its molecular mass and degree of crystallinity.

Polymers are semi-crystalline compounds, part of their molecules is ordered and form a crystalline phase, whereas the other part is unordered and amorphous. The mass fraction of a compound’s crystalline phase is called the degree of crystallinity. In polymers, the degree of crystallinity never reaches 100% and depends on several factors which include the type of polymer (and its co-polymers, if there are any) and the catalysts which were used in its manufacturing process.

What are polyolefins and how they are used in films?

Polyolefins are polymers derived from olefins – unsaturated hydrocarbons with double bonds. The most common polyolefins used in the manufacturing of modern films are polyethylene and polypropylene. They are used in the production of the main types of films:

  • LDPE (low-density polyethylene).
  • LLDPE (linear low-density polyethylene).
  • HDPE (high-density polyethylene).
  • VLDPE, или POP (very low-density polyethylene).
  • ULDPE или POE (ultra low-density polyethylene).
  • PP (polypropylene).
  • r-PP (polypropylene random copolymer).
  • Block-PP (polypropylene block-copolymer).

Polyolefins’ popularity as a raw material for films can be explained by the following facts: these films are easily processed, they have low mass, high strength and tear resistance, they are flexible even in low-temperature conditions, they have high chemical resistance and cost relatively cheap when compared to other types of polymers. It’s also important to point out that ethylene and propylene are some of the most widespread and processible monomers in the world.

The main properties of polyolefin films
Type Name Structure Characteristics and copolymers Manufacturing process Properties
LDPE low-density polyethylene Branched (autoclave LDPE is more branched than tubular reactor LDPE) ρ = 0,915 – 0,935 g/cm#SUP#3#/SUP#  Wide MWD Radical polymerization:#UL# #LI# Autoclave#/LI##LI# Tubular reactor #/LI##/UL# #UL# #LI#Non-Newtonian melt rheology #/LI##LI#High melt strength #/LI##LI#Easily processed into tubular film  #/LI##LI#Lack of crystal orientation (thick films)#/LI##/UL#
LLDPE linear low-density polyethylene Linear (~20 short side branches per 1000 carbon atoms) ρ = 0,910 – 0,935 g/cm#SUP#3#/SUP#  Narrow MWD Butene, hexene, octene Catalytic polymerization:#UL# #LI#Ziegler–Natta#/LI##LI#Metallocene#/LI##/UL# #UL# #LI#Improved properties in comparison with LDPE (tear strength, puncture resistance, tensile stress at break, optical properties)#/LI##LI# Harder processing in comparison with LDPE#/LI##LI# Higher crystal orientation (thin films)#/LI##/UL#
HDPE high-density polyethylene Linear (0-6  short side branches per 1000 carbon ρ = 0,935 – 0,965 g/cm#SUP#3#/SUP#  Wide MWD Catalytic polymerization:#UL# #LI# Ziegler–Natta#/LI##LI# Chromium#/LI##/UL# #UL# #LI#High haziness #/LI##LI# High tensile strength #/LI##LI# Rigidity #/LI##LI# High water barrier #/LI##LI# Thermo-shrinkable#/LI##/UL#
VLDPE (POP) very low-density polyethylene A high amount of short side branches ρ = 0,890 – 0,910 g/cm#SUP#3#/SUP#  Narrow MWD Butene, hexene, octene Metallocene catalysed polymerization #UL# #LI#Highly elastic #/LI##LI#Moderate durability #/LI##LI#High transparency and gloss Welding
ULDPE(POE) ultra low-density polyethylene A very high amount of short side branches and co-monomer content ρ < 0,890 g/cm#SUP#3#/SUP#  Narrow MWD Butene, hexene, octene Metallocene catalysed polymerization #UL# #LI#Very high elasticity #/LI##LI#Low tensile strength #/LI##LI#Low elastic modulus #/LI##LI#Narrow and low melting range #/LI##LI#High welding characteristics
PP polypropylene Linear polymer. The location of methyl groups determines the type of the polymer: #UL# #LI#Isotactic #/LI##LI#Syndiotactic #/LI##LI#Atactic ρ = 0,905 g/cm#SUP#3#/SUP# Catalytic polymerization: Ziegler–Natta #UL# #LI#Low density #/LI##LI#High tensile strength (rigidity) #/LI##LI#Excellent optical properties #/LI##LI#Good water barrier High-temperature resistance
r-PP polypropylene random copolymer Linear with random locations of ethylene groups in the chain ρ = 0,905 g/cm#SUP#3#/SUP#      Ethylene, butene Catalytic polymerization: Ziegler–Natta Metallocenes #UL# #LI#Low melting point #/LI##LI#Welding #/LI##LI#Low rigidity, softness, elasticity #/LI##LI#Transparency
BlockPP polypropylene block-copolymer Linear with arranged locations of ethylene groups in the chain (blocks) ρ = 0,905 g/cm#SUP#3#/SUP#          Ethylene Catalytic polymerization: Ziegler–Natta #UL# #LI#Balance between impact viscosity and strength #/LI##LI#Welding #/LI##LI#High haziness #/LI##LI#Thermal stability

How characteristics of polymers impact the properties of films

Film properties depend on the characteristics of the polymers from which they are made of. Let’s examine the key characteristics of polymers.

Molecular weight

The average molecular weight of a polymer is determined by the melt flow index (MFI). MFI measures the ease of flow of the melt of a thermoplastic polymer. It is defined as the weight of the polymer in grams flowing in 10 min through a die of specific diameter and length by a pressure applied by a given weight at a given temperature. Low MFI means high viscosity and higher molecular weight. High MFI, on the contrary, is observed for polymers with low viscosity and lower molecular weight.

Density, branching, and melting point

The density of a polymer is related to its degree of crystallinity and determines its ability to crystallize. If a polymer is linear and doesn’t have branches (like HDPE), its density and degree of crystallinity are high. When the density of a polymer increases, so do the following characteristics:

  • rigidity
  • tensile strength
  • softening point
  • fold retention
  • curling
  • chemical resistance
  • heat resistance
  • barrier properties

If a polymer contains many short and/ or long branches (like LDPE), its density and degree of crystallinity are low. When the density of a polymer decreases, the following characteristics increase:

  • tear strength
  • puncture resistance
  • impact viscosity
  • friction coefficient
  • optical properties

Molecular weight distribution (MWD)

Synthetic polymers consist of molecules with different masses, which is explained by the statistical nature of polymerization. The ratio of molecules with different molecular masses in a polymer is defined as molecular weight distribution. Gel-penetrating chromatography or fractioning can be used to determine MWD, but it’s possible to estimate it by determining a polymer’s MFI under different loads: the more the ratio of MFI, the wider is MWD.

Wider MWD is associated with the following positive effects:

  • increased ability to process the polymer (the pressure of the melt is lower, which decreases the gear load, since the molecules with lower molecular weight act like lubricants)
  • the durability and stability of melt increase
  • fewer surface defects of the film (sharkskin)
  • orientation of the polymer is increased

Negative effects attributed to wider MWD:

  • less durable welding joints
  • worse optical properties
  • lower ripping resistance
  • low-weight molecules can form residues on the surface of the equipment

The impact of polymer characteristics on film properties

MFI — melt flow index

MWD — molecular weight distribution

Why are additives used in films?

Additives are intended to improve various properties of polymers. The following requirements must be adhered to regardless of additive function:

  • good compatibility with the polymer
  • no effects which could contribute to polymer destruction
  • resistance to water exposure
  • lack of smell
  • safety for health and environment
  • convenient dosing and usage

Additives used in polyolefin films can be divided into two broad categories:

  • additives which increase the stability and processability of the polymer
  • functional additives which improve certain properties of the polymer

The following types of additives are used to increase stability:

Antacids They neutralize the free acidity of catalyst residues used in polymers manufacturing, prevent equipment corrosion
Antioxidants They prevent oxidation and destruction of the polymer during processing, storage, and usage. They maintain the physical, mechanical, and optical properties of the film
UV stabilizers They protect the polymer from UV radiation exposure, maintain the physical, mechanical, and optical properties of the film, protect the packaged product
Processing additives They ease the processing, remove extrusion defects, and reduce carbonization and the content of gels

The common goal of these additives is to prevent molecular mass and structural changes in the polymer. The consistency of the polymer’s properties enables the use of it as intended for as long as possible. It expands the recycling window – the ability to reuse the polymer after the initial product has lost its consumer properties.

Functional additives used in polyolefin films include:

Slip agents Reduce the coefficient of friction, exclude sticking and blocking of films
Anti-blocking additives Reduce sticking (blocking) of layers of film in a roll
Antistatic agents Prevent the accumulation of electrostatic charges, and dust settling, and exclude film blocking
Nucleating agents Change the crystallinity of the polymer and the optical and mechanical properties of the film. Does not dissolve in polymer
Antifog additives Prevent film fogging due to water vapour condensation
Gas absorbents Absorb gases inside film packaging (ethylene, oxygen)
Clarifying agents Reduce haziness and increase the transparency of the film due to crystal size change. Dissolve in polymer
Antimicrobial additives Prevent the development of microorganisms, protect the packaged product
Pigments and dyes Gives colour to the film, in some cases protects against UV radiation (titanium dioxide)
Modifying agents Change any of the properties of the film, for example, increase rigidity, mattness, stickiness
Foaming agents Reduce the density of the film, form a porous structure
Fillers Affect the polymer’s mechanical properties, increase opacity, and change the polymer’s barrier properties. Reduce cost

Anti-blocking and slip agents are often used together. Anti-block agents prevent film surfaces from sticking together in a roll, creating a rough surface that forms an air gap between film layers. Slip agents migrate to the film surface and form thin layers that reduce the coefficient of friction between film layers.

Polyolefins for film manufacturing produced by SIBUR’s enterprises

SIBUR’s enterprises manufacture both polymers (raw materials for film manufacturing) as well as finished film materials. The assortment of polyolefins produced by SIBUR includes LDPE, LLDPE, mLLDPE, HDPE, EVA (ethylene-vinyl acetate) copolymers, HPP, RPP, and IPP. SIBUR BIAXPLEN manufactures biaxially oriented polypropylene (BOPP) films which are highly durable, flexible and have good optical properties.

The assortment of polyolefins for film manufacturing produced by SIBUR’s enterprises
Name Manufacturer MFI, g/10 min Density, g/cm3 Main characteristics Recommended uses
#B#LDPE for blown film#/B#
15803-020 Tomskneftehim 2,0 0,921 Base grades for film production Films for food and non-food packaging
15813-020 Kazanorgsintez 2,0 0,919
LD 20220 FE Tomskneftehim 2,0 0,926 Improved optical properties, better compatibility with LLDPE
10803-020 Kazanorgsintez 2,0 0,918 Base grades for film production Heat-shrinkable film, films for food and non-food packaging
15303-003 Tomskneftehim 0,3 0,922
15313-003 Kazanorgsintez 0,3 0,920
LD 03210 FE Tomskneftehim 0,3 0,926 Improved optical properties and ripping resistance
LD08220 FE Tomskneftehim 0,8 0,921 Improved optical properties, excellent compatibility with LLDPE Multilayer films for lamination, general-purpose films
#B#LLDPE for blown and stretch film#/B#
LL 09200 FE Zapsibneftekhim 2,0 0,920 High physical and mechanical properties, excellent welding, excellent optical properties Films for food and non-food packaging, films for lamination, industrial films
LL20211 FE 0,920
LL20211 FE 0,921 Improved physical, mechanical, and optical properties, excellent anti-blocking and slip properties of films Films for food and non-food packaging, films for lamination
LL 30200 FE High physical and mechanical properties, excellent optical properties Mono- and multilayer flat slit films, stretch films
LL30203FH (PE 5118 QM) Nizhnekamskneftekhim
LL30203FE (F2230) Kazanorgsintez
#B#mLLDPE, special LLDPE for blown film#/B#
mLL10183FE (F2010 M) Kazanorgsintez 1,0 0,920 Increased puncture resistance, good welding, good optical properties FFS film, stretch hood film, films for lamination
LL30183FE (F2030 M) Kazanorgsintez 3,0 0,920 High pre-stretch, good optical, physical and mechanical properties Mono- and multilayer stretch films, agricultural and high-strength films
LL 03320 FE Kazanorgsintez 0,3 0,931 High physical and mechanical properties in combination with good processability. High strength indicators Multilayer films, FFS films, films for lamination, heat-shrinkable films
#B#HDPE for blown film#/B# #B#Processing method#/B#
HD10500 FE Zapsibneftekhim 10,0 0,950 High physical and mechanical properties, wide MWD Mono- and multilayer films, bags, garbage bags, geosynthetic materials Film extrusion
HD12443 FE(293 285Д) Kazanorgsintez 12,0 0,946
HD12503 FE(273 285 Д) Kazanorgsintez 12,0 0,951 Extrusion blow moulding
HD80520 FE Zapsibneftekhim 8,0 0,952 Improved physical and mechanical properties, good processability, film roll stability Thin films, bags, industrial packaging. Use in blends with low-flow LDPE grades in heat-shrinkable film formulations Film extrusion
HD 03580 SB Zapsibneftekhim 0,3 (21,6 kg/ 2,16) 0,958 Improved physical and mechanical properties, good processability Use in blends with low-flow LDPE grades in heat-shrinkable film formulations, grain storage sleeves Extrusion blow moulding
#B#Special LDPE for cast film, foaming and lamination segment#/B#
LD 40251 FE Tomskneftehim 4,0 (190˚С, 2,16 kg) 0,925 Excellent optical properties and processability Mono- and multilayer cast films for food contact materials
LD 40200 FA 4,0 (190˚С, 2,16 kg) 0,921 Increased capacity, flow stability at high speeds Foam products, lamination
11503-070 Kazanorgsintez 7,0 (190˚С, 2,16 kg) 0,920 Applying coatings with low deposition rates Lamination of paper, cardboard, and aluminium foil; food and non-food packaging
LD 50210 EC (LA2150) 5,0 (190˚С, 2,16 kg) 0,921 High deposition rates, low extractives content, improved rheological properties
LD 75210 EC (LA2175) 7,5 (190˚С, 2,16 kg) 0,921
#B#EVA (ethylene-vinyl acetate)#/B# #B#Processing method#/B#
11104-030 Kazanorgsintez 3 (190˚С) Film, technical products Moulding, extrusion
11306-075 7,5 (190˚С)
11507-070 7 (190˚С) Insulating material, gaskets, adhesive compositions Moulding, extrusion, compounding
11708-210 21 (190˚С) Additive for petroleum products, composition for parchment and cardboard coating, for containers and food packaging coating Compounding, extrusion
11808-340 34 (190˚С)
12306-020 2 (190˚С) Heat-shrinkable film, composition for parchment and cardboard coating, for containers and food packaging coating Moulding, extrusion, compounding
12206-007 1 (190˚С) Moulding, extrusion, compounding
#B#HPP for CPP film#/B#
PP H080 CF/2 NPP Neftekhimia 8,0 Well-balanced physical and mechanical properties of finished films Multilayer non-metallized CPP films for food (grocery, confectionery and bakery products) and non-food (flowers, stationery) packaging
PP H080 CF/5 (PP1316M) Nizhnekamskneftekhim 8,0
PP H085 CF NPP Neftekhimia, Polyom 8,0 Improved slip and anti-blocking properties of finished films, high gloss and transparency
PP H081 CF/2 NPP Neftekhimia 8,0 Special stabilization formulation that does not contain metal stearates. Improved consumer properties and physical and mechanical characteristics of finished films Multilayer metallized CPP films for food and non-food packaging
#B#RPP, IPP for CPP film#/B# #B#Polymer type#/B#
PP R080 CF/5 (PP4216M) Nizhnekamskneftekhim 8,5 Well-balanced physical and mechanical properties of finished films. Sealing initiation temperature: from 135ºC Multi-layer non-metallized CPP films with low requirements for sealing properties (outer sealing layers) Random
PP R085 CF/5 (PP4215M) 8,5 Random
PP R065 CF/5 (PP4225L) 6,0 Improved physical and mechanical characteristics, anti-block and slip properties. Lower sealing initiation temperature: from 130ºC Multilayer non-metallized CPP films with increased requirements for sealing properties (outer welded layers) Random
PP I013 CF/5 (PP8310G) 1,6 Optimal balance of physical and mechanical properties. Excellent welding properties and strength indicators, increased resistance to thermo-oxidative degradation Processing by extrusion, for use in the inner heat seal layer of multilayer films (retort packaging) Block
#B#HPP, RPP for BOPP film#/B# #B#Polymer type#/B#
PP H031 BF Zapsibneftekhim, Polyom, NPP Neftekhimia 3,0 Special purpose grade with an enhanced formulation that does not contain metal stearates. Provides high performance and excellent optical properties Biaxially oriented mono- and multilayer films for food and non-food packaging, including metallized films Homopolymer
PP H036 BF Zapsibneftekhim 3,0 Special purpose grade with an enhanced formulation that does not contain metal stearates. Provides high performance and excellent optical properties. Does not contain phthalates Homopolymer
PP R060 BF/5 Nizhnekamskneftekhim 6,0 Lower melting point and thermal welding point (sealing initiation temperature: 130ºC) Multilayer biaxially oriented films, including metallized films (outer welded layers) Random


Flexible polyolefin packaging became popular in the middle of the last century, and it is still irreplaceable in many applications. In this article, we have just begun examining the properties of polyolefins and the ways of using them to manufacture films. Later on, we plan to look at technologies for processing polyolefins into films, the main types of films as well as various details of their manufacturing processes and uses. 

27 June 2023
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© PAO «Sibur Holding», 2023