Field of the Invention

The present invention relates to an antifog stretch film which is used for the storage, preservation or packaging of foods/products, protects the product against condensation, sweating and droplet formation, and ensures that the foods last for a long time without spoiling.

Prior Art

Package is a product made of any material used for the transportation, protection, storage and sale of the products at the stage of delivery to the consumer (user). There are different types of materials produced from different raw materials for packaging. Paper, cardboard, plastic and metal raw materials can be given as examples. Today, plastics are used as a substance used in the packaging of any kind of food, beverage or any material. There are many reasons why polymers have many application fields. Some of these are their durability and stability at high temperatures, high impact resistance, improved electrical properties, repeated process cycles, low equipment cost and low production cost. Today, there are many types of packaging materials with plastic raw materials used currently, but the most practical and widely used of these are stretch films.

Stretch film is a name given to a stretch plastic packaging film that provides bulk and tight packaging of various materials. The elastic structure of the stretch film ensure to collect the packaged products in a tight manner as can be understood from its name. Shrink films which are another type, are used after being loosely wrapped around the products and stretched with heat. Stretch films are used so as to standardize loads in pallets and to group smaller products together. The main types of stretch film can be categorized as hand stretch film, expanded core stretch film, machine stretch film and dissipative stretch film. While the production of stretch film is in a very fine detail, the stretch film material is made of linear low density polyethylene. In addition to this, different types of polyethylene materials and PVC materials are widely used in the production of stretch film. Most of the stretch films that vary depending on their production, have a stretch margin of around 100% - 300%. The most important properties of stretch films are tearing tension, adhesion and attachment level, tear resistance, clearness, puncture resistance, burst resistance and static discharge.

The most common wrapping material of the stretch films is obtained by copolymerization of ethylene and low-density polyethylene material. It contains mostly butene, hexene and octene and their derivatives. These materials are specifically important in terms of elongation and puncture resistance. Other types of polyethylene and PVC can also be used in production. Stretch film production is carried out in two ways; blowing method, after the resin is melted at high temperature, it is required to be blown out with air cooling. Indeed, the process is much slower in this method, but it provides much higher quality and durability in all areas. Production and design costs are more costly than other methods. Film cooling cylinders are passed over the prepared material in the casting method. This makes the cooling process faster and quicker. Thus, lower quality but lower cost products can be achieved. Stretch film is produced in various sizes and forms for purposes such as packaging, wrapping and collecting and it is generally put on the market by preparing the same in roll form. Stretch films are used in pallet shipments so as to prevent the materials from rolling over and being affected by external weather conditions.

Many plastic type packages are used in the current systems for flexibility. One of the most important of these is polyethylene. Polyethylene is a thermoplastic film formed from the polymerization of gaseous ethylene monomer under high pressure and temperature. These transparent films are used more in package printing and during the production of aseptic packaging boxes in layers compared to other films. In particular, it is preferred in fruit-vegetables, bakery products and pharmaceutical packaging, laminations and coextrusions due to its durability, barrier properties, heat sealability and low cost properties. However, said polyethylene packages do not have the transparency of the polypropylene film. For this reason, LDPE, that is, low density polyethylene material, is used in plastic packaging films in some systems. LDPE raw material is very durable and has high transparency. Furthermore, the LDPE material ensures easy adhesion of the film and has an adhesive property. Therefore, it is also used as a binder so as to provide thermal bonding in lamination applications. It has a high tear strength and impact resistance.

In current situations, either only polyethylene or LDPE is used as the raw material of the stretch film. However, in case only LDPE is used, it causes the products to which the stretch film is applied to absorb moisture and air and create steam against the external environment. Furthermore, ethylene vinyl alcohol (EVOH) can be used so as to prevent evaporation in other stretch films which are used currently. EVOH is a moisture sensitive polymer and the presence of water weakens the ability of the material to block oxygen. For this reason, EVOH is used as an inner layer in packaging structures. However, the presence of EVOH can increase the flexibility of the stretch film and reduce its durability. Therefore, a stretch film structure which is both durable and adhesive and protects from external environments without steam formation is required in stretch films packages.

The inventive stretch film with antifog structure prevents the formation of droplets by modifying the surface tension. The inventive stretch film is produced from polyethylene, which is not harmful to health. The field of use of antifog stretch film is primarily foods that will be stored in the refrigerator or freezer. It can also be used in other food products. In case droplet formation is prevented, the stretch has a more transparent appearance and ensures the preservation of food for a longer time. The production of the inventive stretch film is carried out with a cast film extruder machine. The raw materials and additives received are dosed to the A, B, C, D and E extruders at appropriate rates in the dosing units. In the invention subject to the application, raw material is produced with mixing ratios as follows; 87.9% LLDPE (low density polyethylene), 1.95% POE (polyolefin), 1.95% PIB (polyisobutylene), 8% ANTIFOG (masterbatch) and 0.2% PPA (fluoroelastomer). The temperature value of the cast film machine in the invention which is the subject of the application is 250-260 °C. The stretch film coming out of the cast film machine is wrapped according to the desired dimensions.

In the state of the art, there is no explanation regarding the technical features and the technical effects provided by the invention of the present application. Stretch film structure that is both durable and adhesive and protects from external environments without steam formation is not available in the current applications.

Aims of the Invention

The aim of the present invention is to produce a stretch film that prevents antifog, fogging, sweating, and droplet formation of the product, and keeps the food fresh for a long time.

Another aim of the invention is to obtain a stretch film which does not contain harmful components since the low density polyethylene used in the production is not harmful to health.

Another aim of the present invention is to obtain a stretch film which is transparent, light and economic with its antifog properties. Another aim of the present invention is to obtain a stretch film which has a dirt resistant structure with the help of its brightness and slipperiness.

Another aim of the present invention is to obtain a stretch film which is both durable and moisture-repellent.

Another aim of the present invention is to obtain a stretch film which maintains its durability during the transportation of the product to be wrapped or packaged from one location to another.

Another aim of the present invention is to obtain a stretch film into which moisture or water entry is prevented in any way.

Another aim of the present invention is to obtain a stretch film which has high durability and is not harmful to health, although it has a transparent structure.

Brief Description of the Invention

The antifog stretch film which is used in the production of an antifog stretch film as defined in the first claim and other claims depending on this claim, realized to achieve the aim of the present invention, prevents droplet formation by modifying the surface tension. The inventive stretch film is produced from polyethylene, which is not harmful to health. The field of use of antifog stretch film is primarily foods that will be stored in the refrigerator or freezer. It can also be used in other food products. In case droplet formation is prevented, the stretch has a more transparent appearance and ensures the preservation of food for a longer time. The production of the inventive stretch film is carried out with a cast film extruder machine. The raw materials and additives received are dosed to the A, B, C, D and E extruders at appropriate rates in the dosing units. In the invention subject to the application, raw material is produced with mixing ratios as follows; 87.9% LDPE, 1.95% POE, 1.95% PIB, 8% ANTIFOG and 0.2% PPA. The temperature value of the cast film machine in the invention which is the subject of the application is 250-260 °C. The stretch film coming out of the cast film machine is wrapped according to the desired dimensions.

Detailed Description of the Invention

The stretch film realized to achieve the aim of the present invention is shown in the attached figures, in which;

Figure 1. is a perspective view of the stretch film structure.

The parts in the figure are enumerated one by one and the parts correspond to these numbers are given in the following.

1. Stretch film

2. Inner layer

3. Middle layer

4. Outer layer

The present invention is an antifog stretch film (1) which is used for the storage, preservation or packaging of foods/products, protects the product against condensation, sweating and droplet formation, and ensures that the foods last for a long time without spoiling, characterized in that; it comprises the following;

87.9% LLDPE (linear low density polyethylene) raw material,

1.95% POE (polyolefin) additive,

1.95% PIB (poly isobutylene) additive,

8% ANTIFOG (masterbatch) additive and

It contains 0.2% PPA (fluoroelastomer) additive. The inventive stretch film (1) is used for the storage, preservation or packaging of foods/products. The stretch film (1) has an antifog structure which that protects the product against condensation, sweating and droplet formation, and ensures that the food will last for a long time without spoiling. The stretch film (1) prevents antifog, fogging, sweating, and droplet formation of the product, and keeps the food fresh for a long time. The stretch film (1) does not contain harmful components since the low density polyethylene used in the production is not harmful to health. The stretch film (1) is transparent, light and economic with its antifog properties. The stretch film (1) has a dirt resistant structure with the help of its brightness and slipperiness. The stretch film (1) is both durable and moisture-repellent. The stretch film (1) maintains its durability during the transportation of the product to be wrapped or packaged from one location to another. Moisture or water entry is prevented from entering in the stretch film (l)in any way. The stretch film (1) has high durability and is not harmful to health, although it has a transparent structure. The stretch film (1) is recyclable.

The inventive antifog stretch film used in the production of the antifog stretch film (1) prevents the formation of droplets by modifying the surface tension. The inventive stretch film is produced from polyethylene, which is not harmful to health. The field of use of antifog stretch film is primarily foods that will be stored in the refrigerator or freezer. It can also be used in other food products. In case droplet formation is prevented, the stretch has a more transparent appearance and ensures the preservation of food for a longer time. The production of the inventive stretch film (1) is carried out with a cast film extruder machine. The raw materials and additives received are dosed to the A, B, C, D and E extruders at appropriate rates in the dosing units. In the invention subject to the application, raw material is produced with mixing ratios as follows; 87.9% LLDPE (low density polyethylene), 1.95% POE (polyolefin), 1.95% PIB (polyisobutylene), 8% ANTIFOG (masterbatch) and 0.2% PPA (fluoroelastomer). The temperature value of the cast film machine in the invention which is the subject of the application is 250-260 °C. The stretch film (1) coming out of the cast film machine is wrapped according to the desired dimensions.

A EXT. B EXT. C EXT. D EXT. E EXT.

The inventive antifog stretch film (1) contains the following; 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in the A extruder, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in the B extruder, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in C extruder, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in D extruder and 61.80% LLDPE, 8% ANTIFOG, 15% POE, 15% PIB and 0.2% PPA process additives in E extruder.

In this embodiment of the invention, the LLPDE material used in the content of the stretch film (1) is used as raw material and it is the name of the large molecule formed by connecting many monomers with covalent bonds. LLPDE material is produced by ethylene polymerization. LLPDE material is a polyethylene thermoplastic. Mechanical properties of LLPDE material, polyethylene vary according to branching type and crystal structure. LLDPE differs from LDPE with the absence of long chain branching. Linear low-density polyethylene (LLDPE) is more durable and heat-sealable than LDPE, but is more unclear, namely it is not transparent. On the other hand, PVC has a low oxygen permeability, but is more permeable to water vapour than LDPE. Its use for food packaging gradually decreases in terms of compliance with health rules due to the chlorine output in PVC molecules. LLDPE is preferred because it is compatible with food. In this embodiment of the invention, the ANTIFOG material used in the content of the stretch film (1) is used as raw material. ANTIFOG material is an antifog masterbach. ANTIFOG material prevents the formation of fog and droplets on the stretch film by modifying the surface tension of the food stretch film. ANTIFOG material thus ensures longer preservation of food.

In this embodiment of the invention, the POE material used in the content of the stretch film (1) is used as an additive. POE material is an elastomeric and thermoplastic material formed by combining polyolefin elastomer carbon chains. POE material has very good mixing property with LLDPE. POE material is very elastic, so it is resistant to punctures. POE material prevents slipping and increases the coefficient of friction. POE material is generally preferred because it is easy to shape and has low density.

In this embodiment of the invention, the PPA material used in the content of the stretch film (1) is used as a process additive. PPA material is fluoroelastomer- based additive which improves the processes of thermoplastic polymers. The PPA material reduces the friction of the polymers during the process and the melt breaking effect. PPA material provides homogeneous melting, low friction and smooth surface in the product. PPA material cleans the burns in the dead zones of extruders and prevents the appearance of lines on the film. PPA material is used to increase the processability of plastics, increase productivity and quality, and reduce production costs.

In this embodiment of the invention, the PIB material used in the content of the stretch film (1) is used as an additive. PIB material is a masterbatch based on a special polyisobutylene blended with LLDPE. PIB material is an adhesion promoter and adhesion agent with correct dosing and homogeneous distribution. In this embodiment of the invention, while the stretch film (1) is being formed, the additive consisting of 61.80% LLDPE, 8% ANTIFOG, 15% POE, 15% PIB and 0.2% PPA in the E extruder forms the inner layer (2). While the stretch film (1) is being formed, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in A extruder, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in B extruder, 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in C extruder and 91.80% LLDPE, 8% ANTIFOG and 0.2% PPA process additives in the D extruder form the middle layer (3) and the outer layer (4).