The present invention relates to a packaging structure that prevents the generation of waste, is composed of reinforced polyethylene that acts as a barrier, and does not consist polyester, and to production method thereof.

BACKGROUND ART

Today, plastics have replaced many materials such as glass, metal, ceramic, stone, wood, etc.. Plastics have entered our lives in recent years and are used on a wide scale in especially packaging and construction. The extensive use of plastics becomes dangerous day by day due to improper and indiscriminate disposal methods, thereby creating environmental problems.

While only 30% of plastic waste is commonly recyclable, the remaining waste either takes many years to decompose in the natural environment or never decomposes. There are applications that enable recycling the said remaining waste into useful products. A large amount of the remaining waste is industrial scrap. Since it is relatively contamination-free, it is more convenient to obtain better properties by recycling industrial scrap.

Today, applications for recycled mixed plastic waste are limited due to their poor properties. Special applications including separation and reprocessing of plastic components have been developed as a solution to this problem. In regards to this limitation in the applications for recycled mixed plastic waste, there are also new applications known to be enhanced for the use of recycled material. Nowadays, plastic packaging films are in the form of film laminates consisting different layers (depending on the application and function). Polyolefins such as polyethylene (PE) or polypropylene (PP) are often used in combination with polyethylene terephthalate (PET) working as an outer, printed layer. In this case, the packaging structure is obtained by combining different plastic layers. It can be supported by applications such as laminates of plastic layers with other materials such as aluminum or paper. Packaging is always produced with an externally visible print. There are various types of plastic packaging and the most important ones are those that include PET (polyethylene terephthalate), PVC (polyvinylchloride), PS (polystyrene), and PE (Polyethylene) film layers.

Being a thermoplastic material from the polyester family, PET (polyethylene terephthalate) constitutes 70% of all synthetic fibers used especially for industrial applications. Moreover, PET films are utilized in 30% of different laminates employed in packaging products. Structures composed of non-identical laminates cannot be recycled 100 per cent. PE (Polyethylene) is the most common type of plastic used in homes. It is employed in a wide variety of areas such as bleach, detergent and shampoo bottles, motor oil bottles, and garbage bags. It is a recyclable form of plastic.

LPDE (Low-Density Polyethylene) is translucent or colored. It is a semi-rigid and durable plastic. It is flexible, soft, easily cut, and wrinkle-free. LDPE plastics are mostly utilized as film raw materials because they are smooth, flexible, and relatively transparent. LDPE plastics are transparent in color if no pigment is added. They also have a wide range of areas of use including sacks, shrink and stretch films, film bags, garbage bags, bread and sandwich bags, various food bags, meal boxes, freezer bags, cheap kitchen utensils, grocery bags, margarine containers, flexible lids for various pots and jars. Flexible packages are made of films such as OPP, CPP, PET (polyethylene terephthalate, polyester), polyethylene, pearlized, aluminized, metallized, all of which are formed at certain micron values. The structure of packaging depends on the physical and chemical features of the product to be contained therein. The majority of the materials can be used upon being laminated. Co-extrusion and coating techniques are applied.

Foil rolls take shape in accordance with the features of the packaging machines. The technology employed in these operations has developed the fill-seal principle very well. It uses heat or cold seal.

Currently, products obtained by laminating polyethylene terephthalate, polyester, and polyethylene films are generally preferred and utilized while manufacturing flexible packages for commercial items such as wet wipes. Flowever, structures composed of non-identical laminates do not present the chance to be recycled 100 per cent. This project, therefore, aims to benefit from 100% recyclability of polyethylene by way of using the same laminates.

Fligh-performance packaging materials are typically designed with the combination of above-mentioned materials in order to achieve their intended purpose, i.e. a high-performing material. However, the same combinations generally either make it challenging or impossible to subject the relevant packaging material to a standard reprocessing or recycling flow. DESCRIPTION OF THE INVENTION

The present invention is a packaging structure and production method thereof that are developed to eliminate the above-mentioned disadvantages and bring new advantages to the related technical field, and it relates to a production method that presents a 100 per cent recyclable packaging by employing polyethylene (PE) and polyethylene (PE) lamination technique with extrusion blow molding and lamination. The main aim of the invention is to eliminate the non-recyclable polyester and its derivative polymers, and to provide a production method that allows and ensures a completely recyclable packaging whose layers are only made of polyethylene.

Another aim of the invention is to use a reinforced polyethylene structure acting as a barrier.

DETAILED EXPLANATION OF THE INVENTION

Consisting of extrusion blow molding method and lamination processes, the 100 per cent recyclable packaging production method includes the below-mentioned stages:

- Extrusion blow molding method is used for the production of both the upper film and lower film structures.

For the upper film structure:

- As a raw material, polyethylene granules are taken and melted at 150-200 °C before extrusion.

- It is then added into the formulation from the dosing section.

- Formulation of 5-screw extruder is as follows:

20% A 90-98% HDPE PE + 2%-10% Masterbatch additive

20% B MDPE-LLDPE

20% C MDPE-LLDPE

20% D MDPE-LLDPE

20% E 90-98% HDPE PE + 2%-10% Masterbatch additive.

- Screw temperature for A-E is 200-230°C while it is 180-215°C for B-C-D.

- Screw speed for A-E is 50-55 rpm while it is 80-90 rpm for B-C-D.

- Screw pressures are between 440-540 bars.

- The capacities of the fans employed in extrusion machine for production are as below: o External cooling fan at 65%, o Blowing air fan at 48%, and o Suction air fan at 50%.

- The process is proceeded with the mixture.

- The product, which is passed through a cooling chamber while the raw materials go up in the form of a balloon, is sealed slowly after being directed by guide rollers or plaques and once it cools, it is packaged in the form of a double-walled film wrapped in the coil.

For the lower film structure:

- As a raw material, polyethylene granules are taken and melted at 150-250 °C before extrusion.

- While the film is being drawn, ethylene vinyl alcohol (EVOH), a raw material that will act as an oxygen barrier, is added into the mixture. This substance is again a polyethylene derivative. It is added into the formulation from the dosing section.

- Formulation of 5-screw extruder is as follows:

25% A 90%-98% LDPE PE + 2%-10% Masterbatch additive

23% B 60%-80% LDPE PE + 20%-40% Binder

4% C 100% EVOH

23% D 60%-80% LDPE PE + 20%-40% Binder

25% E 50% -70% LDPE PE + 30%-40% LDPE PE + 10%+20% Masterbatch additive.

- Screw temperature for A-E is 180-210°C while it is 200-240°C for B-C-D.

- Screw speed for A-E is 85-100 rpm, 160-170 rpm for B-D, and 25-30 rpm for C.

- Screw pressures are between 170-480 bars.

- The capacities of the fans employed in extrusion machine for production are as below: o External cooling fan at 60%, o Blowing air fan at 58%, and o Suction air fan at 63%.

- The process is proceeded with the mixture, and EVOH is added therein at the same time as other raw materials while the film is being drawn. - The product, which is passed through a cooling chamber while the raw materials go up in the form of a balloon, is sealed slowly after being directed by guide rollers or plaques and once it cools, it is packaged in the form of a double-walled film wrapped in the coil.

Lamination of lower and upper film is performed as described hereinbelow:

- Upper and lower film coils are inserted into laminator.

- Following their insertion, values of lamination machine are set to: o Unwinding tension between 5% and 10% o Intermediate tension 5% o Winding tension 10%-15% o Drawing Press 5 bar o Transfer Press 3-5 bar o Winding Press 2-4 bar o Tram roller size 54

- The upper film is laminated by use of medium or high strength 3 to 5 grams lamination glue.

- It is then subjected to lamination process for 250m/min at a temperature between 90 and 120°C.