Antistatic film

Abstract

The present invention relates to an antistatic film for manufacturing a packaging material for packaging items that are processed in a cleanroom, the antistatic film comprising: a non-woven substrate comprising polypropylene; and a coating applied to a first side and an opposite second side of the substrate, wherein the coating comprises an antistatic agent and polypropylene. The invention also relates to a packaging material for packaging items that are processed in a cleanroom, manufactured by welding and / or stitching an antistatic film. The invention further relates to a container for packaging items that are processed in a cleanroom, wherein the container comprises a pouch system, wherein an antistatic film forms separate pouches that are suspended in a framework. Finally, the invention relates to a method for manufacturing a packaging material for packaging items that are processed in a cleanroom.

Description

[0001] ANTISTATIC FILM

[0002] TECHNICAL FIELD

[0003] The invention relates to an antistatic film for manufacturing packaging material. The invention also relates to a packaging material manufactured from this film, a method for manufacturing said packaging material, and a container.

[0004] The invention is particularly suitable for packaging electronic and highly sensitive items, where reusability, cleanability, and recyclability of the packaging material are important.

[0005] BACKGROUND

[0006] When working with electronic equipment, static electricity can cause irreparable damage due to electrostatic discharge (ESD). This can range from total to minor damage, which often only leads to noticeable complaints and malfunctions in the longer term. Microelectronics, produced on a microscopic scale, include integrated circuits such as microprocessors and computer memories. Due to the ever-decreasing dimensions of these components, they are particularly susceptible to ESD.

[0007] Antistatic films are essential for packaging microelectronics. Current films, however, are often not strong enough for packaging heavier items, such as machine components that are installed in cleanrooms. These components must be packaged antistatically to prevent them from becoming statically charged and to avoid interaction with dust particles, as this can be harmful to the electronics. Cleanrooms are controlled environments in which the air is filtered to remove harmful particles. Both the production of microelectronics and the installation of the required machinery take place in such environments. The machine components must be individually packaged in antistatic films to protect the machine components during transport and to avoid static electricity.

[0008] Current antistatic films are not sturdy enough for heavy and sharp machine components, causing them to tear or fail under the weight. Traditional packaging materials such as Tyvek do provide strength, but have limited tear propagation resistance. Consequently, it is necessary to locally reinforce these packaging materials, for example with self-adhesive strips made from another material. This is labor-intensive. In addition, these packaging materials are difficult to recycle, because these reinforcement strips must first be removed, which causes environmental issues. There is therefore a need for a cost-effective, fully recyclable packaging material that meets the stringent requirements of cleanrooms and provides antistatic properties.

[0009] The present invention aims to provide a solution to these problems by developing improved antistatic films and packaging materials suitable for heavier items that are handled in cleanrooms.

[0010] SUMMARY OF THE INVENTION

[0011] In a first aspect, the present invention relates to an antistatic film according to claim 1. Preferred embodiments of the antistatic film are set forth in the dependent claims.

[0012] The invention relates to an antistatic film for manufacturing packaging material used for packaging items that are handled in a cleanroom. The antistatic film comprises a non-woven substrate made of polypropylene, and a coating applied to both a first side and an opposite second side of the substrate. The coating comprises an antistatic agent and polypropylene. This film provides a strong and durable base that withstands mechanical stress and reduces static electricity, which is crucial for protecting sensitive electronic components. The invention provides improved stability, recyclability, and versatility. The film is 100% recyclable since both the substrate and the coating are made of polypropylene.

[0013] An objective of the present invention is to develop an antistatic film suitable for manufacturing packaging materials, especially for use in cleanrooms where strict hygiene and safety standards apply.

[0014] An objective is to reduce or eliminate static electricity by using antistatic agents in the coating, which is essential for protecting sensitive electronic components against damage from static charges.

[0015] An objective is to design a film that is recyclable, wherein both the substrate and the coating are made of polypropylene, which contributes to sustainability and environmental friendliness. An objective is to facilitate the production and handling of the film by enabling the film to be welded or stitched, thereby eliminating the use of adhesives and further improving recyclability.

[0016] An objective is to develop a versatile antistatic film suitable for packaging a wide range of items, from sensitive electronic components to other products requiring protection against static charges.

[0017] In a second aspect, the present invention relates to a packaging material according to claim 11.

[0018] In a third aspect, the present invention relates to a container according to claim 12.

[0019] In a fourth aspect, the present invention relates to a method according to claim 13.

[0020] DESCRIPTION OF THE FIGURES

[0021] Figure 1 shows a construction of an antistatic film according to an embodiment of the present invention.

[0022] Figures 2, 3, and 4 show a container provided with a framework having multiple pouch systems according to an embodiment of the present invention.

[0023] DETAILED DESCRIPTION

[0024] Unless defined otherwise, all terms used in the description of the invention, including technical and scientific terms, have the meaning commonly understood by the skilled person in the technical field of the invention. For a better understanding of the description of the invention, the following terms are explicitly explained.

[0025] As used in this document, the articles "a", "an" and "the" refer to both the singular and the plural unless the context clearly dictates otherwise. For example, "a segment" means one or more segments.

[0026] When "about" or "around" is used in this document with respect to a measurable quantity, a parameter, a time or moment, and the like, variations are meant of + / - 20% or less, preferably + / -10% or less, more preferably + / -5% or less, even more preferably + / -1% or less, and even more preferably + / -0.1% or less than and of the quoted value, insofar as such variations are applicable in the described invention. However, it must be understood that the value of a quantity used where the term "about" or "around" is used, is itself specifically disclosed.

[0027] The terms "comprise", "comprising", "provided with", "include", "including", "contain", "containing", are synonyms and are inclusive or open terms that indicate the presence of what follows, and which do not exclude or prevent the presence of other components, characteristics, elements, members, steps, as known from or disclosed in the prior art.

[0028] Quoting numerical intervals by the endpoints comprises all integers, fractions and / or real numbers between the endpoints, these endpoints included.

[0029] In a first aspect, the invention relates to an antistatic film suitable for manufacturing packaging materials, in particular for items that are handled in cleanrooms. The antistatic film comprises a non-woven substrate and a coating. The substrate comprises polypropylene. The coating comprises an antistatic agent and polypropylene, and is applied to both a first side and an opposite second side of the substrate.

[0030] Many polymers or polymer blends are relatively poor conductors, which can lead to the buildup of static charge during processing and use of the polymer. As a result, for example, small dust particles may be attracted. Moreover, electrostatic charge can pose a serious obstacle in the production process of such polymers. Antistatic agents are materials added to polymers to prevent them from becoming electrostatically charged or, when a charge is already present, to promote the dissipation of such a charge. The use of a non-woven substrate comprising polypropylene provides a strong and durable base material that withstands mechanical stress. This is essential for packaging material that is frequently handled and moved, thereby preserving the integrity of the packaging and effectively protecting the packaged items. In addition, the coating, which is applied to both sides of the substrate and comprises both polypropylene and an antistatic agent, provides a double layer of protection against static electricity. The antistatic properties of the coating help reduce or eliminate static charges, which is crucial in cleanrooms where sensitive electronic components and other equipment are handled. Static electricity can cause significant damage to sensitive items, so this protection is invaluable. Moreover, the coating contributes to the overall durability of the film, which extends the service life of the packaging material and increases its reliability. The doublesided coating also ensures consistency in antistatic performance, meaning that protection against static charges does not diminish regardless of which side of the film is used.

[0031] The choice of polypropylene as the main component of both the substrate and the coating is particularly advantageous because of the properties of this material. Polypropylene is lightweight, strong, and resistant to a wide range of chemicals, which contributes to the versatility and usability of the film. In addition, this film is fully recyclable, which contributes to sustainability and environmental friendliness. Because both the substrate and the coating are made of polypropylene, the film can be fully recycled without the need for material separation. This makes the film not only ecologically responsible but also economically advantageous in the long term. Another important advantage is that this film can be welded or stitched, making the use of glue or other adhesives unnecessary. This not only increases the recyclability of the material but also simplifies the production process and reduces potential contaminants.

[0032] This combination of durability, recyclability, and antistatic protection therefore makes this film particularly suitable for use in cleanrooms and other environments with strict hygiene and safety requirements.

[0033] In a further or alternative embodiment, the substrate has a surface weight of at least 62 g / m2and at most 320 g / m2. Preferably at least 80 g / m2, preferably at most 290 g / m2, more preferably at most 260 g / m2, even more preferably at most 220 g / m2, even more preferably at most 190 g / m2, even more preferably at most 165 g / m2, even more preferably at most 150 g / m2, even more preferably at most 136 g / m2, even more preferably at most 125 g / m2, even more preferably at most 110 g / m2. In particular, the substrate has a surface weight of about 90 g / m2. This weight provides an optimal balance between strength and flexibility, enabling the substrate to withstand mechanical stress and damage during transport and handling. It provides sufficient thickness of polypropylene, which contributes to the durability and long service life of the film, while remaining light enough for easy handling and processing. In a further or alternative embodiment, the substrate has a thickness of at least 0.28 mm and at most 0.74 mm according to EN ISO 9863-1:2016, preferably at least 0.30 mm and at most 0.40 mm, more preferably at least 0.30 mm and at most 0.35 mm. This is at a load of 200 kN / m2. This thickness provides sufficient mechanical strength and puncture resistance, which is essential for protecting delicate items.

[0034] In a further or alternative embodiment, the substrate has a fiber diameter of at least 40 pm and at most 60 pm. This fiber diameter contributes to the strength and durability of the material, while simultaneously maintaining the flexibility required for effective packaging.

[0035] In a further or alternative embodiment, the substrate has an energy absorption between 1.0 and 6.0 kJ / m2, preferably between 2.0 and 3.0 kJ / m2, more preferably between 1.5 and 2.0 kJ / m2. This means that the substrate can effectively absorb shocks and impacts, thereby reducing the impact on sensitive items. As a result, the integrity of the packaging is maintained even under mechanical stress, which provides increased durability and reliability. The flexibility in energy absorption values makes the material suitable for a wide range of packaging needs.

[0036] In a further or alternative embodiment, the tensile strength of the substrate lies between 3.0 and 15 kN / m, preferably between 4.0 and 10 kN / m, and more preferably between 5.0 and 8.0 kN / m. This ensures that the substrate can withstand high forces without tearing, which enhances the durability and reliability of the packaging. This tensile strength makes the material suitable for various packaging needs, from light to heavy applications, and optimizes it for specific use situations.

[0037] In a further or alternative embodiment, the elongation of the substrate is between 10% and 60%, preferably between 20% and 50%, more preferably between 30% and 45%, and even more preferably between 35% and 40%. This provides sufficient flexibility to stretch the packaging without tearing, which contributes to the robustness and adaptability of the material. These elongation values make the substrate suitable for safely packaging items of varying shapes and sizes, while maintaining the integrity of the packaging.

[0038] The energy absorption, tensile strength, and elongation are determined according to EN ISO 10319:2015. In a further or alternative embodiment, the substrate has a puncture resistance, according to EN ISO 12236:2006, between 500 N and 2900 N, preferably between 700 N and 1600 N, more preferably between 700 N and 1000 N, in particular about 750 N. The substrate is resistant to penetration by sharp objects, which better protects the contents from damage and increases the durability and reliability of the packaging. This makes the substrate suitable for safely packaging both light and heavy, as well as sharp items.

[0039] In a further or alternative embodiment, the substrate has a tear resistance, according to ASTM D4533M-15, between 160 N and 320 N, preferably between 200 N and 260 N, in particular about 215 N. This means that the substrate is sufficiently strong to resist tearing, which increases the durability and integrity of the packaging and better protects the contents against damage.

[0040] According to a further or alternative embodiment, the substrate has a grab strength, according to ASTM D4632M-15a, between 300 N and 900 N, preferably between 420 N and 650 N, in particular of about 450 N. The substrate is robust enough to withstand mechanical stresses without tearing, which increases the durability and reliability of the packaging and better protects the contents.

[0041] According to a further or alternative embodiment, the coating has a weight of at least 25 g / m2and at most 85 g / m2per side. Preferably at least 30 g / m2, more preferably at least 35 g / m2, more preferably at least 40 g / m2, more preferably at least 45 g / m2, and even more preferably at least 42.5 g / m2per side. Preferably at most 80 g / m2, more preferably at most 75 g / m2, more preferably at most 70 g / m2, more preferably at most 65 g / m2, more preferably at most 60 g / m2, more preferably at most 55 g / m2, and even more preferably at most 52.5 g / m2per side. In particular, the coating has a weight of about 50 g / m2per side. This weight is advantageous because it provides balanced protection and functionality of the film. This optimal weight provides sufficient thickness to ensure effective antistatic properties, which is essential for protecting sensitive electronic components against static charges. In addition, this thickness contributes to the mechanical strength of the film, making it more resistant to tearing and wear during use and transport. The uniform distribution of the coating also ensures consistent performance over the entire surface of the film, thereby improving the reliability and durability of the packaging material. Moreover, the film remains light and flexible enough to be easy to handle and process, enabling efficient packaging operations. According to a further or alternative embodiment, the coating comprises the antistatic agent in an amount of at least 1 wt% and at most 10 wt% relative to the total weight of the coating measured before the coating is applied to the substrate. Preferably at least 2 wt%, more preferably at least 3 wt%, more preferably at least 4 wt%. Preferably at most 9 wt%, more preferably at most 8 wt%, more preferably at most 7 wt%, more preferably at most 6 wt%. In particular, the coating comprises the antistatic agent in an amount of about 5 wt% relative to the total weight of the coating. This is advantageous because it provides an optimal concentration for effective antistatic performance without adversely affecting the mechanical properties of the film. With in particular 5 wt%, there is sufficient antistatic agent present to efficiently neutralize static charges, which is crucial for protecting sensitive electronic components in cleanroom environments. In addition, this optimal concentration ensures that the coating remains homogeneous and stable, resulting in antistatic properties that are consistent over the entire film. This prevents hotspots or areas without adequate protection, thereby increasing the reliability of the packaging material. Moreover, at the aforesaid wt% of antistatic agent the coating remains compatible with the other components of the film, such as the polypropylene, thereby preserving the durability and integrity of the film.

[0042] According to a further or alternative embodiment, the coating has a thickness of at least 100 pm and at most 300 pm. Preferably the thickness is at least 110 pm, more preferably at least 120 pm, more preferably at least 130 pm, more preferably at least 140 pm, more preferably at least 145 pm. Preferably the thickness is at most 250 pm, more preferably at most 225 pm, more preferably at most 200 pm, more preferably at most 175 pm, more preferably at most 155 pm. This thickness range provides various advantages for the antistatic film. The minimum thickness ensures that the coating has sufficient material to provide effective antistatic performance. This thickness is sufficient to guarantee uniform coverage, whereby the antistatic properties are distributed consistently over the entire surface of the film. This is crucial for preventing static charges that can be harmful to sensitive electronic components and other equipment processed in cleanrooms. On the other hand, the maximum thickness ensures that the coating is robust enough to provide durable protection without compromising the flexibility and handleability of the film. Thicker coatings provide additional mechanical strength, making the film more resistant to tearing, wear, and other physical damage during use and transport. This increases the service life and reliability of the packaging material. This thickness range provides flexibility in production and makes it possible to adjust the coating thickness to specific requirements of different applications. For example, for applications requiring additional protection, a thicker coating can be applied, whereas for lighter applications a thinner coating suffices. As a result, the film can be optimized for a broad range of cleanroom applications, while always maintaining the appropriate balance between protection and workability.

[0043] According to a further or alternative embodiment, the antistatic agent is selected from a list consisting of: a quaternary ammonium salt, a trifluoromethanesulfonate salt, an alkylsulfonium salt, an amine oxide, an ethoxylated amine, a phosphate ester, a polyglycol, a polyethylene glycol, an alkyl(phosphoryl) salt, an imidazolium salt, a pyridinium salt, a derivative of an aminosilane, or a combination thereof. Each of these antistatic agents offers unique advantages that contribute to the effectiveness of the coating and the protection of the packaged items.

[0044] Quaternary ammonium salts are highly effective at reducing static charges due to their high ionic character, enabling them to dissipate static electricity quickly and efficiently. Trifluoromethanesulfonate salts, for example potassium trifluoromethanesulfonate, provide excellent thermal stability and efficiency at low concentrations, ensuring long-lasting antistatic protection without affecting the mechanical properties of the film. When trifluoromethanesulfonate salts are present on the surface of polymeric materials, they facilitate the transfer of electrons and thereby eliminate the buildup of a static charge. Trifluoromethanesulfonate salts are thermally stable so that they can be processed into thermoplastics and can migrate to the surface during processing of the polypropylene layer to perform their function there.

[0045] Alkylsulfonium salts are suitable as antistatic coatings for packaging due to their unique chemical properties. These salts contain a positively charged sulfonium group capable of effectively neutralizing static electricity. When applied to packaging materials, alkylsulfonium salts help reduce the buildup of static charge by increasing the electrical conductivity of the surface. This prevents electrostatic discharge (ESD), which can be harmful to sensitive electronic components. Moreover, alkylsulfonium salts are chemically stable and can provide a durable antistatic effect, making them ideal for use in cleanroom environments where control of static electricity is crucial. Amine oxides act as surfactants that lower surface resistance, allowing static charges to be dispersed over a larger surface area and reducing the likelihood of harmful charges. Ethoxylated amines offer excellent compatibility with polymers and increase the flexibility of the coating, making the film durable and easy to process. Phosphate esters act as effective plasticizers, increasing the flexibility of the coating and improving adhesion to the substrate, while simultaneously providing antistatic properties.

[0046] Polyglycols are known for their excellent moisture-regulating properties, which help maintain low static buildup under various environmental conditions. Polyethylene glycols offer a good balance between flexibility and antistatic performance, making them suitable for a wide range of applications and packaging conditions. Alkyl(phosphoryl) salts have high ionic strength and therefore provide rapid and effective dissipation of static charges, which is crucial in highly sensitive applications.

[0047] Imidazolium salts provide thermal stability and durability, ensuring that the antistatic effect is maintained over a long period, even under heavy use conditions. Pyridinium salts are highly efficient at reducing surface tension and dissipating static charges, making the film safe for use with sensitive electronic equipment. Aminosilane derivatives provide excellent adhesion properties and ensure a strong, durable coating that resists wear and aging.

[0048] By combining or selecting these different antistatic agents, the coating of the film can be optimized for specific applications and conditions. This ensures reliable and effective protection against static charges, which is essential for safely packaging and protecting sensitive items in cleanroom environments.

[0049] According to a further or alternative embodiment, the coating further comprises a UV stabilizer. A UV stabilizer is added to the antistatic film to improve the service life and performance of the material when exposed to ultraviolet (UV) light. The term "UV stabilizer" in the present invention refers to an additive that reduces or prevents damage caused by ultraviolet radiation. UV radiation, originating from sunlight or artificial light sources, can degrade polymers such as polypropylene, leading to breakdown of the material structure. This results in loss of mechanical properties, discoloration, and a reduction in the effectiveness of the antistatic coating. By adding a UV stabilizer, the harmful energy of UV radiation is absorbed or neutralized, keeping the polymers protected and allowing the film to last longer without significant degradation. This is particularly important for packaging material that is exposed to light for extended periods, such as during storage or transport, and helps ensure that the protective properties of the film are maintained. For the antistatic film intended for packaging items in cleanrooms, various UV stabilizers can be used to improve the service life and effectiveness of the film. Hindered Amine Light Stabilizers (HALS) are highly effective because they neutralize free radicals formed by UV radiation, which is especially useful for polypropylene. In addition, UV absorbers such as benzotriazoles, benzophenones, and triazines can be employed; these absorb UV light and convert the energy into heat, thereby preventing polymer degradation. When selecting a UV stabilizer, it is important to ensure compatibility with polypropylene, stability at processing temperatures, long-term protection, and no adverse effect on the antistatic properties of the film. By adding these UV stabilizers, the antistatic film becomes not only more durable but also better suited to the demanding conditions in cleanrooms.

[0050] According to a further or alternative embodiment, the coating has a static coefficient of friction of at least 0.35 and at most 0.60, preferably at least 0.36 and at most 0.58, more preferably at least 0.37 and at most 0.56, still more preferably at least 0.38 and at most 0.54, and even more preferably at least 0.39 and at most 0.52. The lower limit means that the film offers less resistance to sliding. This means that the film moves more easily relative to other surfaces and can be advantageous in applications where smooth movement is desired, such as during unwinding of the film. The upper limit provides sufficient grip during handling of the packaging film. An optimal coefficient of friction provides low resistance upon contact, which facilitates handling and processing of the film. This is particularly important in automated packaging processes where smooth throughput of the material is essential. In addition, a low coefficient of friction reduces the likelihood of damage to both the film and the packaged items during transport and storage. This contributes to the protection of sensitive parts, such as electronic components, which are often processed in cleanrooms. Furthermore, it helps prevent static buildup due to friction, which is essential for maintaining the antistatic properties of the coating. Preferably, the coating has a kinetic coefficient of friction that is at most 20% lower than the static coefficient of friction, preferably at most 15% lower, still more preferably at most 10% lower, and still more preferably at most 5% lower. The term "coefficient of friction" in the present invention refers to the degree of friction between the coating and another surface, measured according to ASTM D1894-14.

[0051] According to a further or alternative embodiment, the coating has a surface roughness (Ra) of at most 5.0 pm, preferably at most 4.5 pm, more preferably at most 4.0 pm, more preferably at most 3.5 pm, more preferably at most 3.0 pm, more preferably at most 2.5 pm, more preferably at most 2.0 pm, more preferably at most 1.5 pm, more preferably at most 1.0 pm, and more preferably at most 0.5 pm. This ensures that the film has a smooth and uniform surface. This is important because a smoother surface is less prone to retaining dust particles and other contaminants, which is essential in cleanroom environments where the highest levels of hygiene and cleanliness are required. In addition, low surface roughness helps to minimize friction between the film and other surfaces with which it comes into contact. This contributes to the protection of sensitive parts during packaging, transport, and storage, as there is less chance of scratches and other forms of mechanical damage. Furthermore, this also contributes to the consistency and effectiveness of the antistatic properties of the coating. A uniform surface finish ensures an even distribution of the antistatic agent across the film, which improves overall performance and increases reliability.

[0052] The term "surface roughness (Ra)" in the present invention refers to the average roughness of the surface of the coating, measured according to ISO 21920-2:2021.

[0053] According to a further or alternative embodiment, the antistatic film comprises at least 90 wt% polypropylene, preferably at least 91 wt%, more preferably at least 92 wt%, more preferably at least 93 wt%, more preferably at least 94 wt%, more preferably at least 95 wt%, more preferably at least 96 wt%, more preferably at least 97 wt%, more preferably at least 98 wt%, and more preferably at least 99 wt%. A high polypropylene content, such as at least 90 wt%, ensures that the film fully benefits from the advantageous properties of polypropylene. Polypropylene is a thermoplastic polymer known for its excellent mechanical strength, chemical resistance, and low density. These properties make the film strong, durable, and resistant to various chemical substances, which is essential for applications in demanding environments such as cleanrooms. At a concentration of at least 99 wt% polypropylene, these benefits are further enhanced. An almost pure polypropylene film offers maximum uniformity and consistency in material properties, resulting in reliable and consistent performance. This is particularly important in cleanrooms, where even minor variations in material performance can lead to undesirable outcomes. In addition, a high concentration of polypropylene contributes to the recyclability of the film. Polypropylene is a readily recyclable material, and by minimizing the content of other components, the recycling process becomes simpler and more efficient. This makes the film more environmentally friendly and contributes to sustainability. Furthermore, an almost pure polypropylene content ensures that the coating adheres well and remains effective, without interference from other materials. This contributes to the long-term effectiveness of the antistatic properties of the film.

[0054] According to a further or alternative embodiment, the film is suitable for manufacturing various types of packaging materials, such as containers, pouches, and sleeves, which are suitable for, for example, the automotive industry and other sectors where antistatic properties are required. A specific example of an application is the packaging of electronic components that are highly sensitive to static electricity. The film provides an effective solution for protecting these components during transport and storage. Preferably, the pouches or sleeves manufactured from this film can be stitched or welded together. This provides flexibility in production methods and enables the packaging materials to be tailored to the specific needs of the customer. Stitching or welding the materials ensures strong and durable joints without the need for adhesives or other fasteners, which contributes to the recyclability of the material.

[0055] According to a further or alternative embodiment, the surface resistance of the antistatic film, determined in accordance with IEC 61340-5-1:2017, lies between 108and 1011Ohm, preferably between 109and 1010Ohm. In a preferred embodiment, both the front side and the back side of the film meet the criterion of achieving a 90% discharge within two seconds. Such surface resistance is necessary to prevent static charging of materials packaged in the film.

[0056] According to a further or alternative embodiment, the antistatic film has a thickness between 300 and 500 pm, preferably between 325 and 480 pm, more preferably between 350 pm and 470 pm, such as 460 pm, measured according to ISO 20534: 1993. According to a further or alternative embodiment, the antistatic film has an average tear strength between 80 N and 270 N in the width direction and 105 N and 270 N in the length direction, preferably between 85 N and 265 N in the width direction and 110 N and 265 N in the length direction, more preferably between 90 N and 260 N in the width direction and 115 N and 260 N in the length direction, even more preferably between 95 N and 255 N in the width direction and 120 N and 255 N in the length direction, measured with a tear test with incision in accordance with ISO 9073- 4: 1997. A tear test with incision is performed to measure a material's resistance to tearing when a cut is already present. During this test, a specimen of the material is prepared with a small incision and then placed in a testing machine. The machine pulls the material at a constant speed until it tears, and the force required to propagate the tear is measured.

[0057] The term "width direction" is to be understood as the direction perpendicular to the length of the roll. The term "length direction" is to be understood as the direction parallel to the length of the roll. The term "roll" is to be understood as the wound form in which the film is produced and stored. The film is preferably produced as a long strip of film that is then wound into a cylindrical form for convenient storage, transport, and use. When the film is wound, the width direction is thus the direction perpendicular to the length of the roll, i.e., from one side edge to the other side edge of the roll. The length direction is parallel to the length of the wound film, i.e., from one end of the strip to the other end, along the length of the roll.

[0058] According to a further or alternative embodiment, the antistatic film has a breaking force between 100 N and 300 N in the width direction and between 200 N and 550 N in the length direction, preferably between 150 N and 280 N in the width direction and between 250 N and 500 N in the length direction, more preferably between 200 N and 250 N in the width direction and between 300 N and 450 N in the length direction, more preferably between 210 N and 240 N in the width direction and between 350 N and 400 N in the length direction, even more preferably between 220 N and 230 N in the width direction and between 380 N and 390 N in the length direction, measured according to ASTM D5035-11R2019. The breaking force is the maximum force the film can withstand before it breaks. This is a measure of the strength of the material under a given load. As with breaking strength, breaking force is typically measured by placing a material in a testing machine and increasing the force gradually until the material fails. The measured force at the moment of break is the breaking force. According to a further or alternative embodiment, the antistatic film has a delamination force of at least 5 N in the width direction and at least 5 N in the length direction, preferably at least 6 N in the width direction and at least 6 N in the length direction, more preferably at least 7 N in the width direction and at least 7 N in the length direction, measured with a Tinius Olsen apparatus. This indicates strong cohesion between the layers of the material, which is essential for structural integrity.

[0059] According to a further or alternative embodiment, the antistatic film has a burst strength between 500 N and 1500 N, preferably between 600 N and 1400 N, more preferably between 700 N and 1300 N, more preferably between 800 N and 1200 N, even more preferably between 900 N and 1100 N, and even more preferably between 950 N and 1000 N, measured with a CRE ball burst test according to ASTM D6797- 15. This means that the film withstands the stated force before bursting when tested with a standard method that uses a ball-shaped probe to apply pressure to the material until it fails. This specification emphasizes the robustness of the film under point loads, which is important for applications requiring high resistance to puncture or bursting.

[0060] In a second aspect, the invention relates to a packaging material for packaging items processed in a cleanroom, manufactured by welding and / or stitching an antistatic film. The antistatic film is a film as described in the first aspect of this invention.

[0061] Welding and / or stitching offers several advantages. These methods provide strong and durable joints, ensuring that the packaging material remains sturdy and reliable, even with heavy and sharp items. Moreover, welding and stitching ensure a good seal, which is essential to prevent dust and contaminants from reaching the packaged items. This is especially important in cleanroom environments, where control over air and surface purity is of critical importance. Additionally, the use of welding and stitching avoids the need for adhesives, which contributes to the fully recyclable and reusable nature of the film and the manufactured packaging. By not using adhesives or the like, the recycling process becomes significantly simpler and more environmentally friendly, as no adhesive residues or other contaminants need to be removed. Consequently, the packaging material is not only efficient and effective, but also sustainable and environmentally friendly. In a third aspect, the invention relates to a container for packaging items processed in a cleanroom, wherein the container comprises a pouch system, wherein an antistatic film forms separate pouches that are suspended in a framework.

[0062] Preferably, the container comprises packaging material and antistatic film as described in the other aspects of this invention. The packaging material in this case forms a pouch system, wherein the antistatic film forms separate pouches that are suspended in a framework. In one embodiment, the pouch system is suspended from the framework by means of a profile provided with a hook element. The purpose of this is that the materials can be packaged and removed from the installation quickly and easily. Since the antistatic film according to the present invention is flexible, these pouches are foldable in order to save space, and consequently transport costs, when unloaded. The pouches of the pouch system can have any dimensions. In a preferred embodiment, the pouch is sufficiently large to package parts (such as plates) of machines for manufacturing electronics (for example, microelectronics). In one embodiment, the depth of the pouch lies between 500 mm and 4000 mm, preferably between 600 mm and 3000 mm, more preferably between 800 mm and 2500 mm. In one embodiment, the width of the pouch lies between 500 mm and 5000 mm, preferably between 800 mm and 3500 mm, more preferably between 1000 mm and 3000 mm. In one embodiment, the height of the pouch lies between 500 mm and 4000 mm, preferably between 600 mm and 3000 mm, more preferably between 800 mm and 2500 mm.

[0063] In one embodiment, the framework is provided with multiple pouch systems. Each pouch system in this case consists of the antistatic film according to the present invention suspended by a loop system from a profile. The loop system is manufactured from the antistatic film itself.

[0064] Thus, an envelope-shaped pouch system is created in which materials can be stored. In one embodiment, one side of the material forms a loop system for one profile, and the other, opposite side of the material forms a second loop system that goes around a second profile. Thus, a pouch system is formed that will behave independently of the other pouch systems present in the framework.

[0065] Each of these profiles is provided at both ends with a hook element, which then serves to suspend the profile and the pouch system from two opposite support bars of a framework. The framework is further provided with vertical bars that define the size of the framework. The framework may also be provided with wheels to allow easy transport of the packaged materials (for example, to and from the aircraft).

[0066] The framework may also be provided with closure means such as an elastic band attached to two opposing support bars of the framework. When the framework is transported, it may also be provided with one or more dust-resistant, removable covers that partially or completely enclose the framework. These covers are removed one by one each time the framework is brought into a new sub-area of the cleanroom. Preferably, when entering a sub-area of the cleanroom, at least one of the covers is removed.

[0067] The antistatic film and / or the packaging material according to the present invention can be used for frameworks and profiles of different lengths and sizes, and is therefore multifunctional.

[0068] In a fourth aspect, the invention relates to a method for manufacturing a packaging material for packaging items processed in a cleanroom.

[0069] Preferably, the method comprises manufacturing an antistatic film, wherein a nonwoven substrate comprising polypropylene is provided; and a coating comprising an antistatic agent and polypropylene is applied to both a first side and an opposite second side of the substrate.

[0070] Preferably, the method comprises manufacturing the packaging material by stitching and / or welding the aforementioned antistatic film to itself.

[0071] According to a further or alternative embodiment, the coating is calendered, preferably by means of smooth rolls which have a surface roughness of at most 0.5 pm, preferably at most 0.4 pm, more preferably at most 0.3 pm, even more preferably at most 0.2 pm, and even more preferably at most 0.1 pm. The smoothness of the coating will be improved by a calendering process, which leads to a lower coefficient of friction. This makes the material easier to clean and handle, which is especially important in cleanroom environments. The packaging materials can also be cleaned before they are shipped to ensure that they are free of contaminants. According to a further or alternative embodiment, the film or packaging can be cleaned before it is shipped, which further improves cleanliness and performance in cleanroom applications. The film can also be tested for puncture resistance, with preference given to films that provide high puncture resistance for additional protection of the packaged items.

[0072] When installing machines in a cleanroom, the various parts of the machine are often packaged separately before they are brought into the cleanroom where the machine will be installed. Packaging the various parts of the machine preferably also takes place in a cleanroom. In a preferred embodiment, the parts are packaged in a pouch system manufactured from the aforementioned film. In a preferred embodiment, in order to avoid dust or other unwanted particles entering the cleanroom with the pouch system, the pouch system is cleaned before it is brought into the cleanroom. In a further preferred embodiment, after cleaning, the pouch system is packaged in another enclosing film and the pouch system is only taken out of this enclosing film in the cleanroom. In a further embodiment, the pouch system is vacuum packaged. Once the pouch system has been removed from the enclosing film, the parts of the machine can be packaged in this pouch system. The filled pouch system can then be brought into the cleanroom where the machine will be installed. In a preferred embodiment, the pouch system is reused.

[0073] It will be apparent to a person skilled in the art that the antistatic film according to the first aspect is suitable for manufacturing a packaging material according to the second aspect and / or a container according to the third aspect. Moreover, the method is suitable for manufacturing an antistatic film and / or packaging and / or container according to corresponding aspects of the present invention. Any embodiment or feature disclosed in this document is therefore applicable to each aspect of this invention.

[0074] In what follows, the invention is described by way of non-limiting examples illustrating the invention, and which are not intended to and should not be interpreted as limiting the scope of the invention.

[0075] DESCRIPTION OF THE FIGURES

[0076] Figure 1 shows a schematic representation of an antistatic film (1). This film (1) consists of a central substrate (3) and two coatings (2) on both sides. The substrate, located in the middle, is made of a non-woven polypropylene material and forms the core of the film (1), which contributes to the strength and flexibility of the packaging material. The upper and lower layers are the coatings, which contain an antistatic agent and polypropylene, and provide the antistatic properties of the film (1). This structure offers a combination of mechanical strength and antistatic protection, ideal for packaging items that are processed in a cleanroom.

[0077] A machine that manufactures microelectronics is installed in a cleanroom. The various parts of this machine are packaged separately before they are brought into the cleanroom where the machine will be installed. Packaging the various parts of the machine likewise takes place in a cleanroom. The parts are packaged in a bag made from an antistatic film (1) constructed as follows: a coating (2) as the outer layers and a non-woven substrate made of polypropylene. Due to the combination of the substrate and the coating, the film (1) is, on the one hand, strong enough to carry the weight of heavier materials and, on the other hand, the final weight of the film (1) is also limited. Consequently, the material is also fully recyclable. The coating is apolar, whereby it repels water and provides protection against moisture from the outside.

[0078] Figures 2, 3, and 4 show a container consisting of a framework (4) provided with multiple pouch systems (5) according to the present invention. The antistatic film (1) according to the present invention forms separate pouches (5) that are suspended in a framework (4). In one embodiment, the pouch system (5) is suspended from the framework (4) by means of a profile (6a, 6b) provided with a hook element (7). Each pouch system (5) consists of the antistatic film (1) according to the present invention, which is suspended by means of a loop system (8) from a profile (6). The loop system (8) is made from the antistatic film (1) itself.

[0079] In this way, an envelope-shaped pouch system (5) is created, in which piece goods can be stored. In one embodiment, one side of the film (1) forms a loop system (8a) for one profile (6a), and the other, opposite side of the film (1) forms a second loop system (8b) that goes around a second profile (6b). Thus, a pouch system (5) is formed that will behave independently of the other pouch systems (5) present in the framework.

[0080] In the embodiments shown in Figures 3 to 5, the pouch system consists of multiple pouches, wherein one profile (6a) is provided with a single loop system (8a) formed from the film according to the present invention (1), which divides into two or more pouches, each of different size (depth and width). Each of the divided portions is then connected, via a separate loop system (8b), to a second profile (6b), which is located either immediately adjacent to the first profile (6a) or at a distance therefrom, with one or more intermediate profiles positioned between the first and second profiles, which likewise form part of the pouch system and are connected by a loop system. In this way, a multiple pouch system is formed, with pouches of different size and capacity.

[0081] In another embodiment, not shown, the formed pouch systems will comprise two profiles (6a, 6b) arranged consecutively. Thus, a single pouch system is created.

[0082] Each of these profiles (6) is provided at both ends with a hook element (7a, 7b), which then serves to suspend the profile (6) and pouch system (5) from two opposite support bars (9a, 9b) of a framework (4).

[0083] The framework (4) is further provided with vertical bars (10) that define the size of the framework. The framework (4) may also be provided with wheels (11), to allow easy transport of the packaged piece goods (for example to and from an aircraft).

[0084] In another embodiment, not shown, the formed pouch systems are welded closed or stitched along the sides, thereby forming a type of bag for packaging items.

[0085] The reference numerals in the figures are: 1= Antistatic film

[0086] 2= Coating

[0087] 3= Substrate

[0088] 4= Framework

[0089] 5= Pouch system

[0090] 6= Profile

[0091] 7= Hook element

[0092] 8= Loop system

[0093] 9= Support bar

[0094] 10= Vertical bar

[0095] 11= Wheels

Claims

CLAIMS1. An antistatic film for manufacturing a packaging material for packaging items that are processed in a cleanroom, the antistatic film comprising:- a non-woven substrate comprising polypropylene; and- a coating applied to a first side and an opposite second side of the substrate, wherein the coating comprises an antistatic agent and polypropylene.

2. The antistatic film according to claim 1, wherein the substrate has a surface weight of at least 62 g / m2and at most 320 g / m2.

3. The antistatic film according to claim 1 or 2, wherein the coating has a weight of at least 25 g / m2and at most 85 g / m2per side.

4. The antistatic film according to any one of the preceding claims 1 to 3, wherein the coating comprises the antistatic agent in an amount of at least 1 wt% and at most 10 wt% relative to the total weight of the coating, measured before the coating is applied to the substrate.

5. The antistatic film according to any one of the preceding claims 1 to 4, wherein the coating has a thickness of at least 100 pm and at most 300 pm.

6. The antistatic film according to any one of the preceding claims 1 to 5, wherein the antistatic agent is selected from a list comprising: a quaternary ammonium salt, a trifluoromethanesulfonate salt, an alkylsulfonium salt, an amine oxide, an ethoxylated amine, a phosphate ester, a polyglycol, a polyethylene glycol, an alkyl(phosphoryl) salt, an imidazolium salt, a pyridinium salt, a derivative of an aminosilane, or any combination thereof.

7. The antistatic film according to any one of the preceding claims 1 to 6, wherein the antistatic film comprises at least 90 wt% polypropylene.

8. The antistatic film according to any one of the preceding claims 1 to 7, wherein the coating further comprises a UV stabilizer.

9. The antistatic film according to any one of the preceding claims 1 to 8, wherein the coating has a static coefficient of friction of at least 0.35 and at most 0.60, measured according to ASTM D1894-14.

10. The antistatic film according to any one of the preceding claims 1 to 9, wherein the coating has a surface roughness (Ra) of at most 5.0 pm, measured according to ISO 21920-2:2021.

11. A packaging material for packaging items that are processed in a cleanroom, manufactured by welding and / or stitching an antistatic film, wherein the antistatic film is according to any one of claims 1 to 10.

12. A container for packaging items that are processed in a cleanroom, wherein the container comprises a pouch system, wherein an antistatic film forms separate pouches that are suspended in a framework, wherein the antistatic film is according to any one of claims 1 to 10 and / or the pouches are a packaging material according to claim 11.

13. A method for manufacturing a packaging material for packaging items that are processed in a cleanroom, comprising the steps of: manufacturing an antistatic film, wherein i. a non-woven substrate comprising polypropylene is provided; and ii. a coating comprising an antistatic agent and polypropylene is applied to both a first side and an opposite second side of the substrate; producing the packaging material by stitching and / or welding said antistatic film to itself.

14. The method according to claim 13, wherein the coating is calendered, preferably by smooth rolls which have a surface roughness of at most 0.5 pm, measured according to ISO 21920-2:2021.

Images