News & interesting facts

If polyethylene or plastic is used sensibly and if it is recycled correctly, it is a valuable material that is wrongly categorically dismissed as harmful to the environment.

News

A little material science

LDPE

Low Density PolyEthylen

Soft polyethylene
produced at high pressure
Low density
Flexible and stretchable

HDPE

High Densitiy PolyEthylen

Hard polyethylene
produced at low pressure
high density
strong structure

LLDPE

Linear Low Density PolyEthylen

Mix of LDPE and HDPE
tough
form-fitting
puncture resistant

MDPE

Medium Density Polyethylen

Mix of LDPE and HDPE

Our film experts will inform you about all possibilities and advice you on which material makes the most sense for your specific need. We pay attention to potential savings, cost efficiency and environmental protection. Our two films Ecothene and Linothene are the result of many years of research and are developed to find the optimum balance between reduced thickness and relevant film properties.

Glossary of terms

Used film

Film that is processed into regenerated granulate from which new film can be produced.

Additive

Additives are used to extend or improve the basic properties of a material such as changes in smoothness, UV resistance, coloration and much more.

German Waste Act (AbfG)

regulates the handling and disposal of waste with the Kreislaufwirtschaftsgesetzt (KrW).

Antistatic film

Film that does not become electrically (statically) charged, or only to a very small extent. It is important for the logistics of many industries with sensitive electrical components.

Biaxial

Films can be stretched monoaxially (lengthwise in one direction) and biaxially (lengthwise and crosswise in two directions). In the production of polypropylene films (PP films), biaxially oriented films account for the largest proportion of all PP films at almost 90%. They are usually referred to internationally as BOPP: Biaxially Oriented PP.

Blown film

A type of film that is blown upwards under pressure from the opening of the blow head using an extruder. The film is then hardened by cold air, creating tubular film. It is fed over a system of rollers and cut with knives into flat film or semi-tubular film, for example. Finally, the film is wound into rolls or further processed into various products such as bags, sacks or cut-to-size pieces. It is characterized by high elasticity and stability.

Coextrusion film (Coex)

In this process, several different plastic materials are melted in individual extruders and extruded into a common die head. The layers are joined in the nozzle, resulting in different film properties.

Puncture resistance

refers to the ability of a film product to provide resistance to punctual penetration by sharp or pointed objects without tearing or breaking.

Extruder / Extrusion

The extruder, also known as a screw (extrusion) press, is one of the most important devices for processing thermoplastics. During extrusion, the plastic granulate is continuously melted and transported to the extruder outlet by one or more screws. The melt is then discharged via a special tool and blown out of a ring-shaped nozzle using air. The result is a 10 to 20 meter high film tube, which is then further processed.

Flexo printing

is a printing process by means of roller rotation in which flexible printing plates, so-called clichés, and low-viscosity printing inks are used. Flexo printing is mainly used for printing on packaging materials such as plastic, paper, cardboard and paperboard as well as flexible packaging and labels.

Film

flexible, flat packaging material made of plastic or metal. The thickness is heavily dependent on the base material and varies accordingly.

Film tube

starting material for all further processed film products in blown film extrusion.

Film sealing machine

is used to create products (sacks, bags, shrink hoods, etc.) from the tubular film or to shrink-wrap products in film.

Blocked

Usually bags out of film are blocked. They are welded together at the top edge and perforated underneath the block so that they can be easily torn off.

GKV

means Gesamtverband Kunststoffverarbeitende Industrie e.V. The GKV is the mother organization of the German plastics processing industry. It bundles and represents the common interests of its member associations and acts as a mouthpiece for politics and the public.

Granules

Plastic grains that are produced by cutting an extruded plastic strand. They should be divided into the same size and shape as far as possible. Granules are almost always the starting material in film production.

Inliner

Film sections or film bags that are inserted into other packaged goods (paper bags, big bags, drums, etc.). They provide additional protection for the packaged goods. When used upside down, inliners become practical hoods.

ISO 9001 / ISO 14001 / ISO 22000

ISO 9001 is a globally recognized standard for the certification of quality management systems. ISO 14001 is the globally accepted and applied standard for environmental management systems. ISO 22000 is the only globally recognized and certifiable standard for food safety management systems.

Cliche / printing plate

Printing plate used in flexo printing with the motif to be printed. Today, a photopolymer material is used as a flexo printing plate, onto which the image information is applied by exposing the plate. The unexposed parts of the plate are washed out and the parts of the motif required for printing remain as an elevation on the printing plate.

Compostable film

A film that is manufactured by using renewable raw materials. The film decomposes in the compost back into its starting materials carbon and hydrogen and can be completely reintroduced into the natural cycle.

Further processing

The tubular film produced during extrusion is made up into sacks, bags, etc. in the next process on a converting line.

Masterbatch

Concentrates of additives, such as pigments or additives, which are added to thermoplastics in order to achieve properties such as color and finish (e.g. antistatic finish). Masterbatches are available as granules or powder and are added to the (colorless) thermoplastic granules.

Multilayer film

In contrast to coex film, multilayer films are bonded together and different materials such as aluminum and polyethylene can be joined together. This is done in order to utilize the different barrier properties of the materials.

Monoaxial

Films can be stretched monoaxially (lengthwise in one direction) and biaxially (lengthwise and crosswise in two directions). However, monoaxially stretched films tend to be the exception. The majority of films are biaxially stretched.

Mono films

Films that consist of only one material or base material. Mono-material packaging is very easy to reuse and can be recycled (mechanically and chemically). Uniform base material increases the quality of the regenerated material obtained from it.

my /µ

The film thickness is measured in µ or micrometers. A micrometer corresponds to 1/1,000 millimetres and is marked with the symbol “µm”. Often only the designation µ or my is used.

opaque

is derived from “opacity”, which means “clouding”. Together with transparency (see-through), it defines the light transmission of a packaging.

Post-Consumer-Recycling (PCR)

refers to the process by which products that have been thrown away by consumers are collected, cleaned and transformed into new products. It is an important part of the circular economy as it helps to reduce the amount of waste and increase resource efficiency.

Post-Industrial-Recycling (PIR)

refers to the process in which industrial production waste from the manufacture of plastic products is reused in another production cycle. PIR is also synonymous with “pre-consumer recycling”.

Polyethylen (PE)

is obtained by heating naphtha (crude petrol) to a high temperature, ethylene is released and processed from a gaseous state into a liquid mass. In the next step, granules are produced from it. This is then processed into film after melting. Chemically, PE consists of carbon and hydrogen.

Regenerated material

Raw material obtained by catching up a material. During processing of the regained material, additives are added to improve its properties. Regained material has uniform grain sizes and no dust content. It consists of defined values that determine the relevant properties.

Tear resistance

The ability of a film to withstand tensile forces without tearing. A film with high tear resistance is resistant to mechanical stresses such as pulling, tearing or puncturing. This is particularly important for packaging films that are subjected to stress during transportation and handling and are intended to protect the contents.

Shrink cover hood

A shrink hood is a film hood or cover with shrinking properties. It is usually pulled over a packed pallet. The film is shrunk under the influence of heat, the film contracts and fits tightly around your packed goods on the pallet.

Shrinkage behavior

The shrinkage behavior of a film or hood is predetermined by the inflation ratio during the production of the film. The inflation ratio is the ratio between the diameter of the uninflated tubular ring and the diameter of the film bubble after inflation.

Welding seam

A joint or seam formed by welding film. The film is heated and becomes malleable. The film is welded together by pressure as it cools. The weld strength defines the load-bearing capacity of the seam before it tears.

Side gusset

Additional fold on the sides of a film product that creates a three-dimensional shape. This creates a larger volume that can hold more contents. A gusset is often used on bags or packaging to create additional space for larger or irregularly shaped goods.

Thickness

of a film is measured in micrometers (µm / my) and is an important quality feature. It has a significant impact on material costs, which is why films with reduced thickness are also used.

translucent

or semi-transparent, is a term for the light transmission of films that are neither transparent (translucent) nor opaque.

Release layer film

When shrinking polyethylene goods with a shrink film, these goods can start to melt into the shrink film due to the heat generated. The protection (the film) can be damaged when the transport protection is removed. This is why a release layer has a material on the inside that has a higher melting point. It is therefore a CoEx film.

UV resistance

An additive delays damage to the film caused by light. The UV resistance can be controlled by the amount of admixture.

What is the difference between PIR and PCR?

The following graphic illustrates the origin of the various recycled plastics very well. Image courtesy of Newsroom Plastic Packaging

Food packaging

Have you ever thought about how strict the rules are for consumer-friendly packaging of food or meat products? Probably not, but one thing is certain: it’s a science in itself.

These films are subject to extremely strict regulations. They may not (yet) be manufactured from recycled material, i.e., regenerated material. The processing of 1a granulate from pure, new plastic is guaranteed.

With the help of our modern extrusion equipment, this results in the finest, transparent film bags that meet the criteria specified by law. And everyone involved in the process must work under special hygienic conditions. This is also a particular challenge for the packaging ladies, who secure all TERDEX products in cartons before delivery.

By the way: Highly qualified and well-trained employees monitor production in all areas in a process-oriented manner. All our products are carefully examined. Only products of impeccable quality leave our premises.

Of course, we comply with all legal requirements and hygiene standards during production process. Our customer advisors and our quality management team will be happy to provide you with detailed information on this – or take a look at our certificates.

Are you interested in our vision? We hope it will be possible to produce regenerates that meet the highest standards for food packaging in the future. Then we will also be able to create products for food packaging in an environmentally conscious way. Promising research is bringing this dream of the future soon

Things to know about plastic packaging

In this newsroom you will regularly find new information about food protection, hygiene, sensible packaging and the correct handling of waste. There are also background stories on packaging and health or the important topics of environmental, climate and water protection.

Together, we find the perfect product for your situation.

About us

TERDEX is a manufacturer and international supplier of films – with a strong focus on the environment. Polyethylene products are our speciality. Our primary focus is on processing recycled raw materials, known as regenerates.