WO2022066115A1

WO2022066115A1 - 100% recyclable metalized barrier polyolefin film production method

Info

Publication number: WO2022066115A1
Application number: PCT/TR2020/051465
Authority: WO
Inventors: Uğur Yildirim
Original assignee: Beşel Basim Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇
Priority date: 2020-09-25
Filing date: 2020-12-31
Publication date: 2022-03-31
Also published as: TR202015259A2

Abstract

The present invention relates to the 100% recyclable metalized barrier polyolefin film that will be used, preferably, in the packaging of individual wet wipes and also in the packaging of products such as cleaning cloth for glass and glossy surfaces, wet cleaning cloth for washroom hygiene, wet floor cloth, baby wet wipes, antibacterial wet wipes, wet toilet paper, deodorant wet wipes, and nail polish remover wet wipes, and that offers high chemical protection, high mechanical strength, perfect impermeability, high barrier protection, and a metalized appearance that will be aesthetically pleasing for consumers, and whose thickness may be adjusted as desired, and the production method thereof.

Description

100% RECYCLABLE METALIZED BARRIER POLYOLEFIN FILM PRODUCTION METHOD

TECHNICAL FIELD

BACKGROUND ART

Wet wipes are being utilized in our daily lives at our homes and workplaces and have become increasingly popular. Despite the fact that it was initially developed as a personal care product, its success led to the development of various products for home care and industrial applications such as cleaning, disinfection, and polishing.

Packages that protect the product placed therein from external factors throughout the distribution chain, which starts with the production and continues until the product reaches consumers, and facilitate the whole process of transportation, storage, distribution, and promotion of the product by keeping it intact have been a part of our daily lives since ancient times. There are some definitions for packages in respect of their functions. Packages are containers and casings in which goods are placed so that they can be properly protected, stored, and carried. Packaging is a tool that ensures a good is delivered to end-users without being destroyed or spoiled and with minimum cost. Package is a means of advertisement in a marketplace. It attracts consumer’s attention and provides the consumer with both objective information and emotional content. Whenever the consumer utilizes a good at home, packaging functions as a vehicle that invigorates and enriches the consumer’s image and attitude relating to the relevant product. Packaging is a sales talk by way of visuals. Package is a vehicle that carries the meaning of the product placed therein. In short, it is “a silent communication tool.”

Due to its close link with production and distribution, packaging has become a broad topic that interests business administration, marketing, and branches of the industry engaged in the manufacture of packaging materials, as much as various production sub-sectors. As such, benefits and functions, as well as characteristics of the package in connection therewith, differentiate in the fields of agricultural production, food industry, production industry, business administration, domestic and foreign marketing, transportation, storage, and packaging material production.

A diverse set of materials are employed in the packaging of products. Today, plastic packaging films are composed of film laminates that consist of different layers (in accordance with application and function). Polyolefins such as polyethylene (PE) or polypropylene (PP) are generally combined with polyethylene terephthalate (PET) as an outer, printed layer. In this case, a packaging structure is obtained as a result of the combination of different plastic layers. Plastic can be fortified by applications such as laminations of layers with other materials such as aluminum or paper. Package is manufactured always with an externally visible printing. There are different types of plastic packaging and packages containing film layers of PET (polyethylene terephthalate), PVC (Polyvinyl chloride), Polyolefins, PS (Polystyrene), and PE (Polyethylene) are the main ones.

Polyolefins are produced from oil or natural gas after a process of polymerization. In this process, short chains of chemicals (monomers) connect to each other to create long chains (polymers) by use of a catalyst. Polymers are solid thermoplastics that can be processed in two ways including film extrusion or molding. In film extrusion, polymers, in the form of melt, are heated and then extruded to obtain thick plates, thin films, or fibers. Film thickness may be adjusted to produce various products from lightweight food packages to heavier films suitable for use in agriculture. The molding process includes heating of polymer in an extruder and then forcing it into a mold to harden in the desired shape.

The versatility of polyolefins made them one of the most common plastics in use at present. Their areas of use include the following:

LDPE: stretch film, carrier bags, agricultural films, milk carton coatings, electrical cable covers, industrial heavy-duty bags.

LDPE: stretch film, industrial packaging film, thin-walled containers, and medium and small heavy-duty bags.

HDPE: crates and boxes, bottles (for food products, detergents, cosmetics), food containers, toys, oil tanks, industrial packaging and films, pipes, and household items. PP: yogurt pots, margarine tubs, dessert and snack packages, microwave-safe containers, carpet fibers, garden furniture, medical packages and tools, luggage, kitchenware, and pipes.

Both end-users and the industry are increasingly interested in metalized packaging produced by way of deposition of metal onto plastic and composite materials. Metalized films are offered as an alternative to aluminum foils and/or plastic-coated aluminum laminates. Aluminum foil is manufactured by using a less shiny metal (Figure 1 ). Moreover, other important advantages of these films include being lighter and having good barrier properties. Since these packaging films have high barrier properties, they can be used in the food packaging industry, decorative coatings, electromagnetic shielding, and protective coatings against abrasion. In addition, they are also used in thermal insulation applications since they have good reflective properties.

Vapor deposition onto materials, especially metals, are used in various technological situations. Not only scientists but also industry members carry out comprehensive studies about metalized films. Metalized polymer films are suitable to be used in packaging applications because they are decorative, have high barrier properties, and can be utilized in capacitor production. Metalized films are replacing aluminum foils that require high energy in the production process. Most commercially used metalized films are manufactured based on the process of deposition of nanometer-thin aluminum onto the film. Polymeric films can consist of polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, cellulose, different polymer mixtures, or recycled polymers. This very thin aluminum layer that is used to coat the surface affects the optical and electrical properties, gas permeability, and therefore the shelf life of the product, as well as its aesthetic and bright appearance. Although the gas barrier properties of the biaxially-oriented polyester films are sufficient, their barrier performance can be further improved by way of metallization.

PE (Polyethylene) is the most frequently used type of plastic at homes. It is used for various purposes such as bottles of bleach, detergent and shampoo, motor oil bottles, and garbage bags. It is recyclable.

There are different types of polyethylene as seen below:

- HDPE (High-density polyethylene)

- LDPE (Low-density polyethylene)

- LLDPE (Linear low-density polyethylene)

- mLLDPE (Metallocene linear low-density polyethylene)

In the current state of the art, flexible packaging structures such as wet wipes are commonly manufactured by the use of products obtained as a result of laminating polyethylene terephthalate, polyester, and polyethylene films. Structures containing laminates produced as such are not 100% recyclable.

The document numbered TR2015/04320 summarizes the related invention as follows: “The present invention relates to a wet wipes package (1 ) that ensures hygiene and ease-of-use, includes, in its most basic form, minimum one label (2) that is located at the opening (4) on top of the wet wipes package (1 ) and serves as a lid, allows extracting wet wipe without the touch of a hand, and contains on the interior surface of the label (2) a material (3) that will create a sticking/adhering surface for wet wipes in the package (1 ).” This document does not provide any information relating to the formulation of the content of the said wet wipes package, the focus is rather on formal production.

In conclusion, the need to eliminate the above-mentioned shortcomings and disadvantages in the prior art, as well as those relating to the currently used structures and applications, has necessitated a development in the relevant technical field.

DESCRIPTION OF THE INVENTION

The present invention relates to the 100% recyclable metalized barrier polyolefin film and the method related thereto in order to remove the above-mentioned disadvantages and provide new advantages to the relevant technical field.

The aim of the invention is to obtain a packaging film with improved barrier properties that will be employed in especially packaging of wet wipes.

Another aim of the invention is to create a barrier film that is resistant to gas, moisture, light, and odors from outside sources thanks to its metalized layer.

A further aim of the invention is to achieve a packaging film that has a lighter structure compared to equivalent products in the market.

Another aim of the invention is to guarantee a high-strength film.

Another aim of the invention is to produce a more efficient packaging material by using less energy.

A further aim of the invention is to obtain a packaging material that will be preferred in situations especially where heat, friction, nail impact is possible and resistance in other conditions is needed. The present invention is a barrier against gas, moisture, and light while it is resistant to solvents and oils. A further aim of the invention is to conveniently ensure thermal insulation of the product contained therein.

A further aim of the invention is to prevent environmental waste by guaranteeing 100% recyclable package production.

Another aim of the invention is to manufacture a wet wipes package with increased brightness.

DETAILED EXPLANATION OF THE INVENTION

This detailed description of the structuring subject to the invention is given only to ensure a better understanding of the subject and in a way that will not create any limiting impact.

The production method of the invention is characterized in that it consists of the following process steps:

- White PE-EVOH-PE film is drawn in the blown film machine,

- Metalized coating is applied through the sputtering method to the surface where the number 1 extruder is located of the PE-EVOH-PE film that is preferably White 70 microns but can be adjusted according to the thickness of the desired product,

- The obtained metalized coated white barrier PE-EVOH-PE film is placed in the front unwinder,

- The polyolefin film that is preferably 30 microns but can be adjusted according to the thickness of the desired product is placed in the rear unwinder,

- LDPE copolymer is extruded onto the metalized surface via coating machine,

- Metalized surface with extruded copolymer is laminated with polyolefin film that is preferably 30 microns but can be adjusted according to the thickness of the desired product. The formulation of the preferred White 70 microns PE-EVOH-PE film:

The numbers 1 , 2, 3, 4, and 5 refer to extruders. Each extruder has six different dosing. In the preferred application of the invention, dosing of three materials is applied since a maximum of three different raw materials are supplied to each extruder, and the other doses, i.e. , K4, K5, and K6, are not used because the variety of types of raw materials are limited to four.

The values given hereinabove are preferred options. However, there may be a 5% change, up and down, in these percentages over the course of the production.

44-54% LDPE, 0-6% antistatic, and 45-55% EAA are used to prepare the first layer in the extruder.

55-65% MDPE, 15-25% LLDPE, and 15-25% Masterbatch are used to prepare the second layer in the extruder.

100% EVOH is used to prepare the third layer in the extruder.

55-65% MDPE, 15-25% LLDPE (maleic anhydride), and 15-25% Masterbatch are used to prepare the fourth layer in the extruder.

90-100% m LLDPE and 0-10% antiblock are used to prepare the fifth layer in the extruder.

These layers are then combined in the blown film machine to form a single film. Materials are given through 5 screws in the blown film machine and as a result, a single-layer film is generated.

Layers are adjusted in line with the physical properties of raw materials and screw diameters.

Blown film machine operating principle

Rotator speed: 25-35%

External cooling fan: 55-65%

Blowing air fan: 45-55%

Suction air fan: 45-55%

Basket height: 1100 mm-1300 mm

Air system height: 160 mm-180 mm Productivity: 700-750 kg/h Drawing speed: 30-35 m/min

Corona treatment is applied at the first extruder. Corona treatment is exercised in order to prepare film and various surfaces for printing or adhesion. Corona unit applies electrical power to the surface to be worked on, thereby roughening the surface and allowing it to better hold onto the ink or glue. Metalized coating is applied to the 1^st extruder corona-treated surface of the film. Metalized coating is performed by the use of the sputtering method.

Sputtering method: The metallization process is based on the deposition of metal material onto a surface in a vacuum chamber. This procedure requires a metallic feeding source, an accumulation area, a winding area, and a vacuum chamber. Aluminum will be used as the metallization source. The aluminum is fed to the system by reels, and a pool of melt metal is created under high temperature in the heating area. The melted metallic source evaporates and covers the surface. The risk of explosion is eliminated since the process is performed with a vacuum chamber. Moreover, a cooling cylinder is utilized in order to prevent the evaporated metal from damaging the surface while it condenses on the surface to be coated. The thickness of the coating can be adjusted at the nanometer or submicron level. The metallization process is semi-continuous. In other words, production is based on the method known as roll-to-roll in a closed system. In addition to thermal metal vapor deposition, many different materials can be evaporated as a result of the electron beam physical vapor deposition process. This method involves the use of the energy of the electron beam to heat the filament used as a source, and the electrons resulting from this source can be accelerated, bent, or focused on the product to be coated. The coating process is completed with the condensation of the heated filament on the product to be coated.

The copolymer is extruded onto the metalized surface via coating machine, and 12 microns copolymer is extruded between the metalized surface and 30 microns polyolefin film, thereby performing the coating process. LDPE is utilized in the coating machine. Thus, the layers of the film are finished off upon the extrusion of LDPE between the 30 microns polyolefin film and the white PE-EVOH-PE film that is coated in metal by way of metalized sputtering and whose formulation is given hereinabove.

In the coating process, the metalized coated white barrier PE-EVOH-PE film is placed in the front unwinder while the polyolefin film is placed in the rear unwinder. Polyethylene is extruded in between. Values for coating machine:

99% LDPE and 1 % LDPE are used in layer A. 99% LDPE and 1 % LDPE are used in layer B.

The operating principle of the coating machine:

Claims

CLAIMS The invention relates to the 100% recyclable metalized barrier polyolefin film that will be used, preferably, in the packaging of individual wet wipes and also in the packaging of products such as cleaning cloth for glass and glossy surfaces, wet cleaning cloth for washroom hygiene, wet floor cloth, baby wet wipes, antibacterial wet wipes, wet toilet paper, deodorant wet wipes, and nail polish remover wet wipes, and the production method thereof, and its feature is that it is characterized by being a white PE-EVOH-PE film whose layers are formed as below:

- 44-54% LDPE, 0-6% antistatic, and 45-55% EAA are used to prepare the first layer in the extruder.

- 55-65% MDPE, 15-25% LLDPE, and 15-25% Masterbatch are used to prepare the second layer in the extruder.

- 100% EVOH is used to prepare the third layer in the extruder.

- 55-65% MDPE, 15-25% LLDPE (maleic anhydride), and 15-25% Masterbatch are used to prepare the fourth layer in the extruder.

- 90-100% mLLDPE and 0-10% antiblock are used to prepare the fifth layer in the extruder. In accordance with Claim 1 , the invention relates to the 100% recyclable metalized barrier polyolefin film that will be used, preferably, in the packaging of individual wet wipes and also in the packaging of products such as cleaning cloth for glass and glossy surfaces, wet cleaning cloth for washroom hygiene, wet floor cloth, baby wet wipes, antibacterial wet wipes, wet toilet paper, deodorant wet wipes, and nail polish remover wet wipes, and the production method thereof, and its feature is that it is characterized in that it consists the following process steps:

- White PE-EVOH-PE film whose formulation is also given herein is drawn in the blown film machine,

- Metalized coating is applied through the sputtering method to the surface where the number 1 extruder is located of the white PE-EVOH-PE film,

- The obtained metalized coated white barrier PE-EVOH-PE film is placed in the front unwinder in the coating machine, - The polyolefin film that is preferably 30 microns but can be adjusted according to the thickness of the desired product is placed in the rear unwinder,

- LDPE copolymer is extruded onto the metalized surface in the coating machine,

- The metalized surface with extruded copolymer is laminated with polyolefin film that is preferably 30 microns but can be adjusted according to the thickness of the desired product. In accordance with Claim 1 , the invention relates to the 100% recyclable metalized barrier polyolefin film that will be used, preferably, in the packaging of individual wet wipes and also in the packaging of products such as cleaning cloth for glass and glossy surfaces, wet cleaning cloth for washroom hygiene, wet floor cloth, baby wet wipes, antibacterial wet wipes, wet toilet paper, deodorant wet wipes, and nail polish remover wet wipes, and the production method thereof, and its feature is that it is characterized in that the formulation of the copolymer content used in the process performed with the coating machine consists

- 100% LDPE in extruder screw A and

- 100% LDPE in extruder screw B preferably with a thickness of 12 microns. In accordance with Claim 1 , the invention relates to the 100% recyclable metalized barrier polyolefin film that will be used, preferably, in the packaging of individual wet wipes and also in the packaging of products such as cleaning cloth for glass and glossy surfaces, wet cleaning cloth for washroom hygiene, wet floor cloth, baby wet wipes, antibacterial wet wipes, wet toilet paper, deodorant wet wipes, and nail polish remover wet wipes, and the production method thereof, and its feature is that aluminum metal is preferably employed in the metalized coating process.