MXPA05000263A - Adhesive film for providing resistance to different materials, and equipment for applying the same. - Google Patents

Abstract

The present invention describes a film for reinforcing materials of different compositions, which is made of a polyolefin film having or not an embossed element of different geometry and dimensions, the inventive film allowing fluids retained between the protected surface and the adhesive to be released. The reinforcing adhesive film has a film resistant to tensile stress and elongations, and an adhesive that facilitates the attachment thereof to the substrate regardless of high speeds. The invention also includes an application equipment comprising three main steps: unwinding, cutting and distributing the film. The film, acting as a backing for the adhesive film, is resistant to cuts performed over materials where the film is placed. The equipment for applying the adhesive film includes systems for the exchange and engagement between rolls in order to provide the process with continuity, as well as rollers, springs or electronic systems for controlling the stress provoked by speeds o f up to 300 m/min.

Description

FILM ADHESIVE TO GRANT RESISTANCE TO DIFFERENT MATERIALS, AND EQUIPMENT FOR APPLYING THE SAME. TECHNICAL FIELD OF THE INVENTION The present invention relates to the construction of an adhesive film having a caliber or thickness sufficient to withstand deforming or cutting forces when placed on surfaces of different nature, as well as an adhesive of acrylic nature, silicone, ethyl vinyl alcohol, polyolefins , natural or synthetic rubber or combinations of all the above, with the ability to firmly attach to the surfaces of the materials that are intended to reinforce. The present invention also involves equipment for the application of the new adhesive film in variable positions, in distributed distances within a particular area of the substrate material, under high speed conditions, under high mechanical stress and under variable temperatures.

BACKGROUND OF THE INVENTION There are descriptions of adhesive films that are used as reinforcement of different materials which are subject to cutting or tearing during the manufacturing operation or the final application. Materials that are reinforced with adhesive films include paper, corrugated cardboard, wood, glass, aluminum, and polypropylene or polyethylene films. One of the most commonly found reinforcement applications is that of paper or corrugated cardboard used in the construction of packaging and packaging. Depending on the requirements of the end user, the adhesive films are constructed using a polyolefin film as a backing, in addition to an adhesive related to paper or corrugated cardboard. The film adhered to the substrate can be handled in the process of forming the final packaging or packaging, ending as a final component of the latter. The initial objective of the reinforcing adhesive film is to provide greater resistance to the substrate against cutting efforts, stress due to bends or changes in temperature with condensation of moisture from the surrounding medium.

Commercially available versions of reinforcing adhesive film, known under the term reinforcement ribbons, which show a polyolefin film as a backing and combinations of adhesives that include mainly acrylic compounds, adhesives of natural rubber or rubber compounds synthetic, ethylvinyl alcohol adhesives (EVA for the acronym in English of the compound ethylvinyl alcohol) and combinations of the above. The conditions of application of these reinforcement tapes vary according to the processes and needs of the end user. It is common to find reinforcement applications for paper and corrugated cardboard with ribbons that have composite constructions such as a polyolefin film with polyamide filaments, polyester filaments, polyethylene filaments, polypropylene filaments, fiberglass or cellulose fiber. The integration of the above components into the polyolefin film can be in various ways and can sometimes include adhesive of variable composition including formulations of heat activated compounds. In the application of reinforcement of paper or corrugated cardboard, companies such as Adalis and Tesa have products that are placed directly on the surfaces of the cellulose substrate, receiving a heat or pressure treatment before being placed in the desired position. There are other versions of reinforcement belts such as Mutual Industries and Minnesota Mining and Manufacturing Co. that are placed directly on the surface of corrugated paper or cardboard, without the need for any special treatment other than light pressure.

Other companies such as Adhesive Films Inc. that offer specialty ribbons that can reinforce other materials such as nonwovens or synthetic and natural fiber textiles. These tapes have a special application and come to require a preliminary process before their final application on the desired substrate.

In the state of the art, adhesives of different composition are described for the union and reinforcement of different materials. In the international application WO20036448S the formulation of acrylic and / or vanillic resin components is described for obtaining an adhesive that offers resistance to tearing and tension, when two substrates are joined. Mainly, it is recommended for the formation of corrugated paper or cardboard items. The description of this invention is directed primarily to the use of the adhesive described directly on the substrate, without the more detailed description of the reinforcement before cutting or tearing through a backing polyolefin film.

Other formulations are recommended for the manufacture of panels which tend to function as structures for walls and walls, facilitating the erection of constructions resistant to environmental conditions. An example is the international application WO200345687 which mentions the advantage of having an adhesive on the edges of the paper or wood panels to form structures of variable resistance. Said application also makes mention of the convenience of the combination of polymeric compounds in the preparation of an adhesive that allows the reinforcement of the structure formed by the panels.

Additionally, there is in the current state of the art the description of adhesives of composition of copolymer of styrene and maleic anhydride for the application of labels and resistance of the same to the process of forming bottles. This type of adhesives is mentioned in the international application O2001185866 which additionally provides an application method that provides better results. The above reference is an example of the invention represented by the creation of a new adhesive as well as the most suitable method for its use.

The description of the alternatives in the market and the current state of the art includes innovations in the composition of the adhesive that allows a correct subjection of the substrates that are joined. Many of these adhesives have a chemical structure strong enough to cope with cutting or tearing efforts in applications. There are also formulations of adhesives in the state of the art that incorporate other polymeric compounds in order to improve the resistance to tensile forces or elongation of the reinforcing materials. The products also mention the use of polyolefin films as backing, in order to form an adhesive film or tape to give greater resistance to materials of different nature. It is remarkable in the case of reinforcement products to find a particular detail of the construction of adhesive films or reinforcement ribbons, but nevertheless it lacks details on methods of application of these products in processes in which there is movement of the substrate, there are different application locations and immediate instantaneous adhesion is required under changing temperature and relative humidity conditions. Of particular interest within the state of the art the existence of adhesives to create adhesive films or tapes to reinforce paper, corrugated cardboard, textiles or non-woven cloths is diverse, identifying products such as those commercialized by Adalis (HB Fuller Company), Tesa and Minnesota Mining and Manufacturing Company. The above products have different trade names that are known in the market and that have at the same time additional applications with materials such as wood or wood sawdust tablets. In many cases the design of a machine and the recommendation of the process for movement conditions and applications in variable temperature and humidity environments are not included. The development of a method for applying the adhesive film or reinforcement tape becomes very useful in cases where the conventional application becomes difficult or is connected with a limiting process. In particularIn the paper and corrugated cardboard industry, there are operations that are connected in sequence to deliver a product with the established price. The most well-known example of this type of industry is the generator of cardboard boxes or drink baskets, which are based on cardboard sheets of different weights or paper yields (in grams per square meter), depending on the resistance to cutting or tearing. what is desired In order to achieve such resistance, the manufacturers of corrugated paper and cardboard use virgin or recycled paper in high weights, which implies greater use of raw material during manufacturing and more analysis on the composition of the cellulose to obtain a material strong. At the same time, in order to achieve the target cost, the companies in the sector referred to place operation of forming, printing if necessary and die-cutting, in a sequence of steps what "comes to show production speeds of up to one hundred square meters per minute Any alternative to the current state of the art must face the need to maintain a good performance in the final application with high resistance, as well as to maintain the sequences of steps and speeds of production of paper and corrugated cardboard. similarities are observed in the current state of the art for the production of textiles, non-ejidos, aluminum sheets, sheets of compressed wood sawdust, etc.

The present invention considers an adhesive film that is placed on the substrate and provides greater resistance to the cutting or tearing effort, in addition to transmitting greater resistance to the substrate material, against tension and elongation efforts. This helps reduce the weight of the substrate material and the use of raw materials for its manufacture. The present invention also includes equipment for placing the adhesive film on the substrate material so that the productivity is maintained under current manufacturing systems or that cause minor changes in them. The design of an adhesive film that gives resistance to different materials, which also has a team designed for its placement in the manufacturing processes is an advantage to achieve the necessary characteristics for the finished product, as well as to achieve the desired manufacturing costs . Additionally, if the designed equipment is able to place the tape in different positions on the materials to be reinforced, then an advantage is offered over the current state of the art.

In order to achieve the target cost of the product and at the same time In all the referred cases of the state of the art, mention is made of adhesives of different composition, preferably of the pressure sensitive type (PSA or pressure sensitive adhesive). These adhesives manage to keep on the reinforced material, the polyolefin film or another composition, without peeling off. In the same way, the uniform and flat application of the adhesive ensures a permanent contact with the protected surface. The presence of a flat profile in the adhesive causes a permanent contact of the latter with the surface so that a single structure is created that resists tension, elongation or tearing forces. The present invention not only considers this flat profile, but also introduces the formation of a profile in the adhesive with different geometries using pre-etched surfaces as found in the products of the ScotchCal line of Minnesota Mining and Manufacturing Company. The above favors the reduction of air trapped in the space formed by the adhesive and the surface of substrate material. Moreover, the present invention also considers that the adhesive of different composition can be placed in a thin flat layer or film or in versions such as lines, spirals, triangles or any other geometry that offers better contact with the substrate material and better removal thereof. In the case of the products referred to in the patents of the state of the art and products marketed, the absence of application equipment of flexible design as of the present invention, causes that the location of the adhesive film or tape in different points (two, three or even fifteen positions), it is also complicated that they imply the need to introduce an additional step in the manufacture of the reinforced product. The design of the equipment of the invention makes it feasible to place the reinforcing adhesive film in different positions of the substrate material, at the same time as it adapts to the already established manufacturing stages at high speeds (up to 100 square meters per minute). knowledge of previous works with synthetic rubber compounds such as those described by Sandtrom et. al in the European patent EP 970091, where synthetic rubber formulations with stearyl acrylate are discussed for the reinforcement of tires, present the alternative to introduce the use of compounds of a similar nature to reinforce materials such as paper, corrugated cardboard, aluminum, wood and wood sawdust tablet.

The use of adhesives with synthetic rubber components has been common in the market of the manufacture of pressure sensitive adhesives (PSA for the acronym in English "Pressure Sensitive Adhesives"), and in the case of applications of reinforcement combinations between styrene polymers or copolymers, butadiene, isoprene and neoprene, the use has not considered the advantages of the ability to hold well to the substrate material while supporting cutting or tearing, tension and elongation efforts. Products such as the commercial tapes 370 and 371 from Minnesota Mining and Manufacturng Company, and those from the "Sesame Tape" line from Adalis (HB Fuller Company) include ethylene vinyl alcohol compositions and synthetic rubbers which have a very strong adhesion on cellulose surfaces or fibers of it. The addition of synthetic rubber compounds promotes adhesion on the cellulose surfaces, in addition to eliminating the need to add heat as in commercial reinforcement ribbons which have a heat activated adhesive before being placed on the substrate. This makes the innovative film presented particularly useful since it can be placed immediately on the cellulose substrate at room temperature and at high speeds. In the packaging industry, where boxes or baskets are made for beverage bottles, the strength of the paper is solved by using a material weight of up to 70 grams per square meter, which is also necessary due to the condensation of ambient humidity when the bottles are in refrigeration up to 2 ° C and are then exposed to the external surrounding medium. The addition of more weight in the boxes and drink baskets, however, becomes insufficient when the relative humidity of the surrounding medium is above 60%. The most common failure mode found in paper and cardboard boxes and baskets is that represented by tearing caused by weakening of the fiber due to moisture condensed or added as an external agent, as well as the accidental cut that occurred during handling and transportation. The end user buys the beverage whose bottles are inside a cardboard box or basket. When removed from the refrigerator or compartment of low temperature, the failure occurs due to the paper tearing due to the modification of the properties by the low temperature, while the same fails as well as cutting by folds occurs minutes after removing the box or basket due to the condensation of moisture on the cardboard. The failure results in the deformation of the box or basket with the fall and damage of the bottles by impact. The technology of papermaking allows to manufacture fibers resistant to the conditions described above. However, a reinforcing adhesive film gives greater stability to the cardboard and conflabilidad to the final user who acquires the bottles, that the packaging will remain stable at all times of the useful life of this.

It has been detected that the failure of the box or basket for the bottles, occurs more frequently in the areas where, its eta when it is loaded to transport it or remove it from the container at low temperature. The equipment of the present invention allows to place the reinforcing film in the mentioned zones, when the cardboard sheets are being printed or are being softened during the manufacture of the boxes or baskets.

OBJECTIVES OF THE INVENTION Considering the revision of the consulted state of the art, the objective of the present invention is the manufacture of an adhesive film that gives resistance to different materials, using different compositions for the film and adhesive, as well as the equipment that allows to place the film on the materials, in different positions.

It is the object of this invention to provide alternatives to the current systems of reinforcement of materials by incorporating an adhesive film that does not require preliminary treatment before adhering to the substrate, while it can be dosed by a team that includes operations of unwinding, cutting and distribution in several points of the substrate. The present invention offers various alternatives of construction designs of a reinforcing adhesive film, provided that failures caused by cutting, tension, elongation and tearing efforts are reduced.

It is another object of the invention to present a device that allows various ways of positioning the reinforcement film on the material to be reinforced, allowing the current systems for manufacturing said materials to be used. An additional objective is to present an alternative for the reinforcement of paper or cardboard that will be used in boxes or baskets for beverage bottles, in order to reduce the incidence of failure due to tearing of the cardboard caused by moisture condensation, handling and transportation.

BRIEF DESCRIPTION OF THE INVENTION The presented invention is formed by: a. A movie or backup. b. An adhesive c. A primary or Corona treatment. d. A non-stick compound and. An equipment for unrolling, cutting and distributing the reinforcement film.

In all cases, the chemical composition can be varied depending on the final application where the product is intended to be used. In the case of the film or backing, the composition may include polyolefin compounds or natural fibers, which may or may not have an etching of different geometry. An additional option is to place a polyolefin film or sheet of paper with etching and coated with an anti-adhesive compound, so that the adhesive acquires the geometry of the engraving when the film or sheet is removed. This ensures that the amount of air trapped between the adhesive and the substrate material is minimal and the adhesion contact is more efficient.

Several products have been presented to reinforce materials against tearing or cutting. Of these, several are already marketed in international markets, which makes it accessible to get one's own for the desired application. Among the materials sold are polyethylene, polyester, polyamide, or polyurethane films to which fibers of the same or combined composition can be included in addition to natural fibers, within a structure that adds adhesive compositions that include acrylic polymers , synthetic rubber or natural rubber compounds, adhesives based on ethylene vinyl alcohol or polyvinyl alcohol. The above products have the disadvantage of not including equipment to place it in the current systems in which the materials or products to be reinforced are produced, which implies the search for an additional system that is coupled to the adhesive film.

The present invention involves placing a layer of adhesive on the surface of a backing film. This layer of adhesive must be sufficient to achieve an instantaneous adhesion of the film on the surface of the substrate material, even under conditions of high speed of movement of the latter.

Different formulations of adhesives are susceptible to be chosen, which will also define the way in which the adhesion will be built on the surface of the reinforced material. Considering composition and dimensions of the surface to be reinforced, as well as the shape and place where the adhesive film is going to be placed, the force with which it is maintained on the substrate material will vary making it more difficult to detach it. In both cases, it is necessary to ensure that the adhesive film is well adhered on the substrate material so that it forms part of its structure.

To keep the adhesive on the film or backing, it is sometimes necessary to place a Corona or primary treatment, in order to improve the interaction between the film or the backing itself and the adhesive. The theory of the functioning of the corona treatment and the primary has been widely studied and is known by those who are experts in the art. Many equipment and formulations are used in the manufacture of products such as labels, adhesive tapes, protective sheets, medical tapes, etc. The product of the present invention also includes on the other side of the film or backing, an anti-adhesion compound that prevents bonding or loss of adhesiveness of the adhesive. This non-stick compound has a diverse composition and is preferably for this invention, of the type of silicone or silicone and urea compounds.

The placement of the adhesive on the film or backing is capable of being carried out by the known processes for making tapes or adhesive sheets. Among the known processes are those that use systems of melting of an adhesive without organic solvent, and those that have application systems of adhesives dissolved in organic solvents (toluene, heptane, ethyl acetate, etc.) or water. In all cases, the operating conditions for adhesive placement will require consideration of the nature of the film or backing, and of the adhesive. It is important to note that for those known in the art the use of any current system or to be created that involves the elementary principle of placing a thin layer on an engraving, constitutes a derivation of the present invention.

The manufacture of the product of the present invention includes, but does not limit its description or sequence: 1. Application of Corona or primary treatment on one side of the film or backing. 2. Application of a non-stick compound on the other side of the selected film or backing. 3. Heat drying of the primary and non-stick, in ovens or other drying equipment.

. Place a thin layer of adhesive on the surface of the film or backing, following the outline of the engraving. 5. Removal of the solvent present in the adhesive or cooling of the melted adhesive. 6. Rolling the film in a master roll.

In the market there are currently versions of protective tapes or sheets that have an adhesive that adheres to the substrate material after treatment with heat. This generates the requirement of a system that provides the energy with which the adhesive will be activated. An inefficient heating of the area with adhesive causes the adhesive to not adhere properly to the substrate material. The inefficient bonding of the reinforcing adhesive film with the material to be reinforced renders the final operation of the latter unsatisfactory by showing faults by rupture or tearing when subjected to normal conditions of use. The product of the present invention includes a backing film with an adhesive that does not require pre-heating, and the application pressure is easily applicable as in other products using pressure sensitive adhesives.

A derivation of the construction of the invention is the formation of capsules or small spherical or semi-spherical particles, which contain the adhesive. Within this type of components are those marketed under the brand name Scotch Grip of the Minnesota Mining and Manufacturing Company, and include the products of the technology presented by the products Scotch Grip 2353, Scotch Grip 25X0, Precote 85, Precote 80 and Precote 30 .

Additionally, the existence of an engraving on the adhesive through the surface reproduction of the type of Scotch Cal® products of Minnesota Mining and Manufacturing Company allows to offer an alternative that reduces the defects due to lack of contact between the adhesive and the material. substrate due to the presence of air. This improvement can be achieved if the backing film carrying the adhesive has an etching on its surface.

The present invention includes a team that combines the unwinding, cutting and application of the tape in the positions that are required on the materials to be reinforced. During the application, the equipment of the present invention includes the distribution to more than one position on the material to be reinforced, in variable dimensions and speeds. This allows it to adapt to the manufacturing processes of the materials to be reinforced, without major changes. There are machines in the market that apply packaging tapes, such as those designed by Tapeler Tape Machines Inc., Gettig Technologies Inc. and Minnesota Mining and Manufacturing Co. which have in their mechanism a system for unwinding the packaging adhesive film or tape. packaging, and with a cutting system to dose the amount required on the surface of the substrate material. The previous machines can include additional equipment to address the packing tape in different positions, but only with a tape and without cutting a master roll to obtain different strips that are distributed over the substrate material. The present invention considers that in many occasions the obtaining of an attractive manufacturing cost is given by a continuity in the processes that allow to obtain a greater quantity of finished product per unit of time. Additionally, the adaptation with minimum changes allows to reduce the investment in the current manufacturing systems, which offers an alternative to the high initial investment systems.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the different geometries and distributions of the engraving in the film or backing of the present invention. These examples in the forms la, Ib, le, Id, le, lf and ig are not limiting and may include other geometries that construct a final product similar to that of the invention. Figure 2 shows the main thicknesses in the film or backing used: the total thickness of the film or backing (H) and the thickness of the base thereof (h).

Figure 3 shows the angle (i) that the engraving may have on the film or backing. Figure 4 shows a diagram of the finished protective adhesive film, consisting of an adhesive top layer (ii), a lower layer of adhesive (iii) and an engraved film or backing (iv). Figure 5 shows an example of the geometry in a film or backing with engraving, and the distance (v) that exists between them to obtain channels. Figure 6 shows a system diagram of the belt applicator equipment, which shows the unwinding of the rolls of reinforcing adhesive film and the basic mechanism for changing the work roll. Figure 7 shows a diagram of the portion of the application equipment of the reinforcing adhesive film, extended to three rolls of work and including the direction of the tape when it is unrolled from the main rolls. It also shows the points where the changes in the work rolls are made, through a pneumatic mechanism. Figure 8 shows a diagram of the portion of the application equipment of the reinforcing adhesive film, where the cutting and distribution of the strips formed from a master roll is carried out. The drawing is not limiting and only tries to be demonstrative of the basic form from which the reinforcement film can be placed in different positions, in different sizes and at the same time.

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of a film or backing of diverse composition that includes, but is not limited to polyethylene, polypropylene, polyester, polyvinyl chloride, polyamide, polyimide, polyvinyl fluoride, polyurethane, among others. This film or backing may or may not have an engraving of variable size and shape that maintains on its surface, a thin layer of adhesive. The film or backing may have various geometric shapes in its engraving, as shown in figures la, Ib, le, Id, le, lf and lg. In the same way, the dimensions of this engraving may vary, being preferably but not unique those shown in the table 1: Table 1. Dimensions of the engraving on the film or backing.

Figure Depth Length (or Width (mm) geometric of the (mm) diameter) (mm) etching Polygon 0.127 - 2.0 1.5 - 7. 0 1.5 - 7.0 Circle 0.127 - 2.0 1.0 - 5. 0 - In the case of compressible materials, the depth of the engraving must be increased in accordance with the compression distance suffered by the material of the film or backing. The latter can maintain total thicknesses between 0.135 to 2.5 mm, being not restricted to other dimensions combined in the geometric figures and that serve the same purpose of allowing the free passage of vapors, gases or liquids. The engraving maintains dimensions that allow the adhesive to be placed on its surface, in different thicknesses that include a size similar to that of the engraving itself. Preferably, the dry adhesive maintains the following dimensions, which are intended to show the recommended but not unique examples applicable to the invention, of Table 2: Table 2. Thickness of the dry adhesive on the engraving or flat surface of the backing film.

It should be noted as illustrated in Figure 2, that the dimensions H and h identified as the total thickness of the film or backing and the thickness of the base thereof, may vary, depending on the needs of the final application of the product of this. invention. In any case, the existence of a more or less thick film or backing will be determined by the properties of the material of which it is composed, as well as the facility to be used in the desired final application. Depending on the nature of the adhesive, preferably of the pressure sensitive type (PSA), the thickness of the latter is determined on the film or backing. Anyone familiar with adhesives of any composition may understand that the amount of solids, adhesion strength, removal force and other properties of an adhesive film is influenced by the chemical composition of the selected adhesive. In this way, depending on the type of adhesive selected to produce the product of the present invention, a different thickness will be employed. The composition of the adhesives employed in the present invention include but are not limited to acrylic derivatives of iso-octyl acrylate or 2-ethylhexyl acrylate acrylate with acrylamide or acrylic acid, methacrylates, styrene-isoprene compounds, styrene-isoprene- styrene, isoprene, butadiene, natural rubber derivatives, acrylic latex, ethylene vinyl alcohols, neoprene, among others.

An important feature in the engraving of the film is the angle at which the geometric shape can be built on the surface. This angle can vary between 0o to 70 ° with respect to the perpendicular of the base of the film or backing itself. This is observed in Figure 3, which shows in a way understandable to those familiar with the technique that the angle (i) can be modified in combinations with the depth of the engraving shown in the different figures la, ib, le, Id, le, lf and lg. The presence of the angle also causes the adhesive to slide towards the bottom of the engraving, depending on the inclination. A steeper slope causes a greater amount of adhesive that slips to the bottom of the engraving. However, the flowability of the adhesive is controllable according to the composition and formulation of the adhesive used. It is desirable in the construction of the present invention that the majority of the adhesive be maintained on the upper surfaces of the engraving (ii), leaving the smallest proportion in the walls and bottom of the geometric figure (iii) in the film or backing ( iv), as shown in the figure. r The adhesion properties of the final product are influenced by the type of adhesive, the contact surface and the geometric figure selected on the backing or film. A larger contact surface with a high adhesive in its instant bond strength can keep the product on glass surfaces, ceramic or steel. The contact surface of the film or backing that comes into contact. with the adhesive and at the same time, the surface that is positioned on the protected surface also establishes the force with which the product of the invention will remain firmly adhered. Additionally, the compositions of the adhesives employed will help to strengthen the affinity and adhesion of the product on the reinforced surface. It is also important to note that the type of adhesive will be selected depending on the manufacturing process in which the reinforcing adhesive film will be introduced. In the cases in which the material to be reinforced moves at high speeds, an adhesive of high instantaneous adhesion will allow the fast union on the moving surface. Any combination of adhesive type and application process are valid according to the particular needs of the user. Different combinations can be used between the nature of the film or backing and the adhesive. Any person skilled in the art will be able to deduce that variations in the strength of adhesion on a given surface can be selected from a variety of combinations derived from the present invention. Some examples that describe the adhesion forces derived from the combinations of adhesive and film or backing, are shown in Table 3, which do not attempt to limit the derived possibilities but constitute illustrative examples: Table 3- Adhesion Strength (ASTM-D-3303) obtained with different adhesives and engravings -in the film or backing.

Adhesive Geometry Adhesion strength. { ounces / 24 in2) Diamond Acrylic sensitive to 20-35 square pressure Rubber synthetic 35-50 styrene-isoprene-styrene with tackifying resin Hexagon Synthetic adhesive 5-10 styrene-isoprene-styrene 10-15 Flat surface Adhesive of ethylene vinyl alcohol When the film or the adhesive has an engraving, the distance between the geometric figures must allow that even after the placement of the adhesive, the gases, vapors or liquids go out through the channels or -ducts. As shown in Figure 5, the existence of a sufficient space (v) through which adhesive is placed without flooding the space, will maintain the exit route of impurities that are additionally mixed with gases, vapors or liquids. Considering the nature of the adhesive placed on the backing or film, in terms of composition, solids content and viscosity, the distance between the geometric figures of the film or backing will vary in order to reduce the defects in the defined protection application.

For cases in which the adhesive or the backing film have an etching, it is important to preserve the spaces formed by the combination of the adhesive and the protected surface. A thickness of adhesive that matches the engraving depth in the film or backing will eliminate the channels or ducts where gases, vapors or liquids will escape. In the same way, a geometry that on the edges of the film reduces the space of the channels or conduits will considerably reduce the effectiveness of eliminating gases, vapors or liquids from the section formed by the adhesive and the substrate material. In all cases, the speed with which gases, vapors or liquids are eliminated should indicate the size of the channels or ducts that will remain in the finished product. Preferably, a ratio of half the depth of the engraving and / or the distance between the geometric figures in the engraving is used, as thickness of the adhesive placed to make the product. Other relationships are valid to originate the present invention on the basis of the desired results.

The adhesives used to construct the present invention are selective of the type of environmental conditions in which it is intended to be used. In all cases, it is necessary to consider these environmental conditions in order to ensure that the adhesive remains stable during its use.

The placement of the adhesive on the film or backing is possible through processes known in the state of the art, provided that it is capable of placing an adhesive in the desired thickness. It is required for the placement of the adhesive, to know the amount of solids that the formulation possesses, as well as the temperatures with which it will be placed. The stresses of the film or backing during the placement of the adhesive will depend on the type of system in which it is applied. In this way, the preferred systems of adhesive placement that do not limit the use of others known in the state of the art, are included in table 4.

Table 4. Adhesive placement systems on the film or backing.

The engraved films or backings used in the present invention can be manufactured with different mechanisms. It is also feasible to find them commercially, such as those offered by Bloomer Plastics Co. or Minnesota Mining, including Manufacturing Company, Mitsubishi Polymers, Dupont Company, among others. The various compositions and physical properties allow to build protective films of great diversity. It is an important factor in the present invention, the thickness of the film and the nature thereof, which is used to give reinforcement to the materials where it will be applied. In the same way, the chemical nature of the film will be defined by the environmental conditions under which it will be used during the reinforcement. A regular polyolefin film can be made more resistant to stress or cutting or tearing stress when placing polyolefin or fiberglass fibers, in its structure. The introduction of the fibers can be carried out by means of the same systems for generating the polyolefin film, such as extrusion or blowing, or by applying it with adhesive which is similar to the film and the fibers. The thickness of a backing film for the present invention can comprise from 0.001 to 0.01 inches (0.0254 to 0.254 mm) in order to achieve the reinforcement sought for a particular material. Films made with materials such as polyimide and ultra high molecular weight polyethylene, can be coated with pressure sensitive adhesives to obtain a reinforcing film. Its usefulness will depend on the conditions of use and the client's requirements on cost and effectiveness.

It is noted by a person skilled in the art that the increase in the thickness of the backing film is dependent on the degree of reinforcement and type of application to be achieved. At the same time, the characteristics of the applicator equipment of the reinforcement film tape included in the invention will vary in terms of cutting and distribution to different moving points, according to the same factors. The design of the equipment for the application of the adhesive film can be adapted to be used with different compositions, since it considers systems of unwinding and cutting of different changes to adapt to the properties of the film.

The present invention considers that the structure of the backing film can include cellulose and derived compounds to suit the needs of the end users. This favors the manufacturing processes that incorporate 'stages of recycling of the substrate material. Of particular importance is the use of films of this nature, in the reinforcement of paper and corrugated cardboard where the substrate material is recycled in different proportions to be reused in boxes, panels or containers. The thicknesses can vary in the range of 0.0009 to 0.01 inches (0.023 to 0.254 mm), on which the selected adhesive is added.

To improve the retention of the adhesive on the film or backing in the construction of the present invention, it is possible to employ known methods that promote a better interaction that avoids the separation of the adhesive from the final product. Among these examples is the Corona treatment and the application of a primer on the side where the adhesive will be placed. Both methods are well known in the current state of the art. Its inclusion in the present description is to exemplify those preferred in the construction of the present invention, but does not limit the use of any other method that allows the permanence of the adhesive on the film or backing of the product. Corona treatment selection can vary up to 60 kW over 1.2 meters wide, while the primary can be selected from a group of compounds that include acrylics and natural or synthetic rubber derivatives (available from various companies such as Dupont, Minnesota Mining and Manufacturing Co . , among others) .

The present invention includes the design of a device that places the reinforcing adhesive film, in the desired size and positions on the substrate. This equipment, shown in figure 6, has three main stations: unrolling (figure 6a), section (figure 6b) and distribution (figure 6c.) In the first, the ribbon output of the main roll is made where it is located. the film, while also introducing a system of splicing between the rolls of adhesive film, in order to ensure the continuity of the application (figure 7) in the second is carried out the cutting of the tape in the width and length which is required to cover the substrate and offer the reinforcing effect; finally, in the third station the film is given direction in the position of the substrate where the reinforcing effect is greater.

The application equipment of the reinforcement film has a basic dimension in its first station, consisting of a pedestal made of steel or other resistant material. The elementary figure is a vertical pole mounted on a base with wheels which are able to be immobilized to avoid unwanted movements (figure 8a.) This post is added with horizontal arms from top to bottom in varied distances (marked as E, F and G in Figure 8a), to allow the location of the rolls of adhesive film (shown as A, B and C in Figure 8a.) The distance between the arms and with respect to the base (illustrated as D in Figure 8a) ) depends on the diameter of the rolls of adhesive film, being as exemplification and not restrictive of the invention, between 20 and 100 cm (figure 8b, letter X.) The length of the posts is variable (letter Y, figure 8), depending on the tension that is sought to exert on the adhesive film at the time of unwinding. On the arms it is possible to place rollers of free or controlled movement (mechanical or electronic systems), to • control the same tension. Also on the vertical post rolls rollers can be placed, where the rolls of the adhesive film will be located (shown with the letter Z in figure 8b.) These rollers may have a rotation control system (related to the speed of unwinding ) mechanical or electronic. Arab systems seek to regulate the dosage of the belt towards the cutting station.

The cutting station receives the adhesive film and by means of knives, performs the construction of the strips of different sizes to be placed on the substrate to be reinforced. The station has a series of knives that cut the adhesive film to the desired dimensions. "The arrangement of the knives is essential to achieve a balance between the tension generated in the unwinding station and that received at the distribution station. For the present invention, it is possible to use a set of straight knives known as "razor blades", such as those shown in figure 9a, which are located at different angles F to offer greater or lesser resistance to the movement of the adhesive film. The angle can vary in the range of 30 to 175 °, according to the characteristics of the film in terms of mechanical properties, speed of work and wear of the cutting area of the knife. nut can allow the location of the knives (as sold by the Stanley company), at different distances from the horizontal formed by the adhesive film a in movement The previous action allows to use in its majority, the zone of cut of the straight knives. An alternative to this type of knives, is the assembly on a pneumatic supply support circular knives, known as "score rolls" and shown in Figure 9b. These knives turn to the movement of the adhesive film that moves towards the distribution station. The arrangement of straight or circular knives between them allows, in an important way, to obtain the width of the strips that will be distributed on the substrate.

The distance between the knives (shown as f in Figure 9b) must be close to the width that is sought with the adhesive film, while regulating the tension created on the mass by stopping it at the moment of cutting. Thus, a width of adhesive film of 4 mm. it will require a distance between 4 mm blades. +/- 0.5 mm. A width of 10 mm will require a blade distance of 10 nun +/- 0.5 mm. The accuracy of the cut will depend to a large extent on the calibration of the distance between knives. The circular knives have a useful diameter between 3 and 7 cm. These dimensions are not limiting and it should be clear to a person skilled in the art that the selection thereof will be based on the combination of factors already described herein.

The module where the knives are, whether straight or circular, can be added with motors of different power (1/4 HP or 1 HP, for example) in order to facilitate the movement of the adhesive film and its cut. These motors can, at the same time, coordinate in their speed with the speed of the substrate to be reinforced, so that the synchronization avoids unwanted waste of the adhesive film and substrate. Examples of electronic synchronization systems are common in the market and the most convenient for the particular application can be selected.

The distribution station is composed of a mechanism of separation and location of the strips consisting of rollers or reels with channels that direct and control the movement of the strips. These reels can have different dimensions, in accordance with the width of the strips formed in the cutting station (figure 10.) It is an important part in the invention the dimensions of the rollers and the reels, as well as the material from which they are made, since it depends on this that the tension exerted on the strips and back on the original roll of the film, remains uniform and controllable. Additionally, the location of the rollers or reels is relevant to ensure the placement of the strips in the desired position and at variable speeds (20 and up to 300 m / min, for example.) The geometry presented in figure 6 demonstrates an angle of distribution that covers the range shown with the letter 0, from 10 to 90 °. This range can vary according to the width of the substrate and the position where you want to place the adhesive film.

The distance between the rollers or reels with respect to the cutting blades, shown in figure 6, letter a and b, is variable, being for example between 30 and 100 cm. The distance between the rollers or reels in the first distribution station where the strips coming from the cutting station are separated can vary between 2 and 10 cm. The geometry can be, as shown in figure 6, letter c, preferably in triangle, when the widths of the substrate to be reinforced extend above 90 cm (figure 6, letter d.) This geometry, however, can be maintained in widths less of the substrate depending on the particular requirements of the application.

The rollers or reels can be arranged in horizontal arrays in progressive sequence from the station of cutting knives, as shown in Figure 6, letter c, this arrangement allows to maintain the direction of the tape towards the point where it will be located.

It is also relevant to observe by a person known in the art that the distribution of the reels in the equipment proposed in this invention is different from the application systems of a single strip, which provides an improvement and advantage for allowing the placement of the reinforcing adhesive film, in different positions at the same time, with precision and at changing speeds of movement of the substrate to be reinforced. The equipment of the present invention considers, at the same time, an advantage over current systems in adapting to the already established production processes of the substrates to be reinforced, eliminating the need for an additional step where the reinforcing adhesive film is placed. This is the case, for example, of the manufacture of printed corrugated paper or cardboard, which introduces the equipment of the present invention at the time of printing thereby eliminating the additional step of placing the tape, after it is completed the process of flexography or rotogravure printing.

The rollers or reels in: the distribution station can be placed on metal springs, plastics or other material, with the purpose of regulating the tension of the adhesive film during its movement toward the surface of the substrate. Pneumatic and electronic systems, such as those marketed by the Festo company, can also be used for automatic voltage control.

Particular examples where the construction of a reinforcing adhesive film and its application equipment are shown, are shown below.

Example 1. Reinforcement tape for metal parts such as aluminum or zinc. An adhesive composed of iso-octyl acrylate and acrylamide compounds in 90% / 10% proportion, is placed in a polypropylene film, which has an engraving with circular geometry with dimensions of 1 millimeter of depth and distance between one and another circle of 0.5 millimeters. The amount of acrylic adhesive that is placed is sufficient to maintain an adhesive thickness of -about 0.25-0.3 millimeters. The placement of: this adhesive is carried out through systems known in the art, which include but do not restrict application systems of hot melt with die or of the font die type. It can also be done through roller coating systems. The construction is completed with the placement of a non-stick compound such as silicone or compounds of silicone and urea, on the other side of the backing or film. The reinforcing adhesive film is placed in an application equipment consisting of an unwinding and lattice system using motorized and free-moving rollers, in a two-roll arrangement where one is the working one and the second is the spare one. The distance between the axes of each roll is 63 cm. and the full height of the pedestal of the equipment is 1.20 m. The change between the work roll and the replacement roll is executed through a device that measures the diameter of the rolls and when a value entered in the memory is obtained, a pneumatic piston is activated which realizes a connection between the two adhesive films stretched between the motorized and free-moving rollers. The equipment also includes a cutting system with straight blades ("razor blades") or circular ("score rolls") that generates strips from the original width of the master roll working of the adhesive reinforcement film. The result is strips with different widths that are located in the desired positions of the material that is being reinforced. Additionally, the equipment contains a system of reel-type rollers that distribute the strips at variable angles according to the required application point. These angles can vary between 0 and 90 ° so that they are located in the position of the substrate.

Example 2. Reinforcement tape for glass or acrylic plates. An adhesive composed of iso-octyl acrylate and acrylamide compounds in 90% / 10% proportion, is placed in a polyester film, which has an engraving with hexagonal geometry with dimensions of 1 millimeter of depth and distance between one and the other 1 mm circle. The amount of acrylic adhesive that is placed is sufficient to maintain an adhesive thickness of approximately 0.3 millimeters. The placement of this adhesive is done through systems known in the art, which include but are not limited to systems of application of hot melt with die or of the type of source flow with die (font die); It can also be done through roller coating systems. The construction is completed with the placement of a non-stick compound such as silicone or compounds of silicone and urea, on the other side of the backing or film. The reinforcing adhesive film is placed in an application equipment consisting of an unwinding and lattice system using motorized and free-moving rollers, in a two-roll arrangement where one is the working one and the second is the spare one. The distance between the axes of each roll is 50 cm. and the full height of the equipment pedestal is 1.0 m. The change between the work roll and the replacement roll is executed through a device that measures the diameter of the rolls and when a value entered into the memory is obtained, a pneumatic piston is activated that makes a connection between the two adhesive films lying between the motorized and free-moving rollers. The equipment also includes a cutting system with straight blades ("razor blades") or circular ("score rolls") that generates strips from the original width of the master roll working of the adhesive reinforcement film. The result is strips with different widths that are located in the desired positions of the material that is intended to reinforce. The widths of these strips can vary from 2 to 8 mm. Additionally, the equipment contains a system of reel-type rollers that distribute the strips at variable angles according to the required application point. These angles. they can vary between 0 and 90 ° so that they are located in the position of the substrate.

Example 3. Adhesive adhesive film for corrugated paper and cardboard. An adhesive composed of synthetic rubber compounds styrene-isoprene, neoprene and tackifying resin to make a pressure sensitive adhesive is placed on a flat surface polyester film. The thickness of the polyester film can vary, without being a limiting factor but demonstrative of the example in question, between 0.001 and 0.005 inches. The amount of adhesive that is placed is enough to maintain a thickness of approximately 0.25-0.3 millimeters. The placement of this adhesive is carried out through systems known in the art, which include but do not restrict application systems of melted adhesive (hot melt) with die or die-source type. The construction is completed with the placement of a non-stick compound such as silicone or compounds of silicone and urea, on the other side of the backing or film.

Example 4. Reinforcement tape for boxes, baskets or packing containers. An adhesive composed of 2-ethylhexyl acrylate and acrylate compounds. acrylic acid in proportion 90% / 10%, is placed in a polyethylene film, which has an engraving with diamond geometry with dimensions of 0.8 millimeters of depth and distance between one and another circle of 0.4 millimeters. The amount of acrylic adhesive that is placed is sufficient to maintain an adhesive thickness of approximately 0.3 millimeters. The adhesive is placed in systems that include but do not restrict! of application of melted adhesive (hot melt) with die, or of the source flow type with die (font die). It can also be done through roller coating systems.

The construction is completed with the placement of a non-stick urea compound on the other side of the backing or film. The invention is completed, on the other hand, with the design of an application equipment consisting of a system of unwinding and lattice using motorized and free-moving rollers, in a three-roll arrangement where each is interposed from top to bottom and vice versa, to be the work or spare roll. The distance between the axes of each roll is 62 cm. and the full height of the equipment pedestal is 2.1 m. The change between the work roll and the replacement roll is executed through a device that measures the diameter of the rolls and when a value entered into the memory is obtained, a pneumatic piston is activated that makes a connection between the two adhesive films lying between the motorized and free-moving rollers. The pneumatic piston and the splice are located in a metallic arm that originates in the Priscilla column of the applicator equipment support. This arm can be varied in length, depending on the tension created during the unwinding of the belt. The above dimensions are feasible to be in the range of 30 to 70 cm. The equipment also includes a cutting system with straight blades ("razor blades") or circular ("score rolls") that generates strips from the original width of the master roll working of the adhesive reinforcement film. The result is strips with different widths that are located in the desired positions of the material that is being reinforced. The widths of these strips can vary from 2 to 8 mm. Additionally, the equipment contains a system of reel-type rollers that distribute the strips at variable angles according to the required application point. These angles can vary between 0 and 90 ° so that they are in the position of the substrate. The rollers or reels can be placed on metal springs, plastics or other materials that help to control the tension caused by the displacement of the adhesive film, towards the substrate to be reinforced.

Example 5. Adhesive tape of polyolefin films (polyester, polyethylene, polyamide, etc.). An adhesive composed of iso-octyl acrylate and acrylic acid compounds in a proportion of 90% / 10%, is placed in a film of polyamide with a flat surface and thickness between 0.002 and 0.006 inches. The amount of acrylic adhesive that is placed is sufficient to maintain a thickness of adhesive of approximately 0.25 The invention is completed with the design of an application equipment consisting of a system of unwinding and lattice using motorized rollers and free movement, in an arrangement of three rolls where each one is inserted from top to bottom and vice versa, to be the work or spare roll. The distance between the axes of each roll is 62 cm. and the full height of the equipment pedestal is 2.1 m. The change between the work roll and the replacement roll is executed through a device that measures the diameter of the rolls and when a value entered into the memory is obtained, a pneumatic piston is activated that performs a splice between the two adhesive films stretched between the motorized and free-moving rollers. The pneumatic piston and the splice are located on a metal arm that originates in the main support column of the applicator equipment.

This arm can be varied in length, depending on the tension created during the unwinding of the belt. The above dimensions are feasible to be in the range of 30 to 70 cm. The equipment also includes a cutting system with straight blades ("razor blades") or circular ("score rolls") that generates strips from the original width of the master roll working of the adhesive reinforcement film. The result is strips with different widths that are located in the desired positions of the material that is being reinforced. The widths of these strips can vary from 2 to 8 mm.- In addition, the equipment contains a system of reel-type rollers that distribute the strips in variable angles according to the required application point. These angles can vary between 0 and 90 ° so that they are in the position of the substrate.

Various modifications and alterations of this invention will become apparent to those familiar with the technique, even if they do not arise from the objective and principles of the same. It should also be understood that this invention is not limited to the examples illustrated herein.

Claims (28)

CLAIMS Once the invention is described, it is considered as a novelty and property is claimed as contained in the following clauses:

1. A reinforcing adhesive film to give resistance to different materials, characterized in that it comprises a film or backing resistant to the tearing, tension and rupture efforts, in addition to an adhesive that allows its attachment to the material that is intended to be reinforced.

2. A protective adhesive film according to claim 1, characterized in that it comprises a backing or film of different composition with or without engraving, which has a geometric engraving and an adhesive of diverse composition in a thin layer that covers the engraving.

3. An adhesive film for providing strength according to claims 1 and 2, characterized in that it is used as a reinforcing tape or foil of surfaces of diverse composition.

4. An adhesive film for providing resistance according to claims 1 to 3, characterized in that the depth of the engraving in the. The film varies with respect to the thickness of the base of the film or backing, such as, for example, in the ratio of 2 to 1, 3 to 1 or 4 to 1.

5. An adhesive film for imparting strength characterized in that it comprises an adhesive of diverse composition and that maintains an engraving promoted by a roller, by a film or by the combination of the two so that the resulting engraving in the adhesive is a negative of the engraving present in the roller or the film.

6. A movie . adhesive for providing resistance according to claims 1 to 5, characterized in that the distance between the geometric figures varies depending on the speed at which it is desired to remove trapped gases from the phase formed by the surface of the substrate and the surface of the adhesive.

7. An adhesive film for providing strength according to claims 1 to 5, characterized in that the thickness of the adhesive layer, placed on the engraving of the film or backing, varies depending on the final application, being for example between 0.1 and 1.5 millimeters .

8. An adhesive film for providing strength according to claims 1 to 6, characterized in that the film or backing is of variable composition, such as for example polyethylene, polypropylene, polyester, polyamide, polyurethane, among others.

9. An adhesive film for providing strength according to claims 1 to 8, characterized in that the engraving comprises a diverse geometry that includes for example: circles, hexagons, squares, diamonds, trapezoids, among others.

10. An adhesive film for providing strength according to claims 1 to 9, characterized in that the adhesive is of the type of pressure sensitive adhesive.

11. An adhesive film for providing strength according to claims 1 to 10, characterized in that the adhesive resists temperatures between -20 and 300 ° C.

12. An adhesive film for providing strength according to claims i to 11, characterized in that the film or backing maintains its integrity at temperatures of -20 to 300 ° C.

13. An adhesive film for providing strength according to claims 1 to 12, characterized in that one of the sides has an anti-adhesion compound such as silicone or silicone and urea.

14. An adhesive film for providing strength according to claims 1 to 12, characterized in that the adhesive is of acrylic nature to be placed on metal or painted surfaces.

15. An adhesive film to bestow. strength according to claims 1 to 13, characterized in that the adhesive is rubber-resin nature, to be placed on glass or cotton and / or polyester fabrics.

16. An adhesive film for providing strength according to claims 1 to 14, characterized in that the adhesive is of acrylic nature, to be placed on pieces of plastic, glass, aluminum, steel or iron.

17. An adhesive film for providing resistance according to claims 1 to 15, characterized in that the surface that is intended to provide strength comprises a piece of cardboard such as that used in the construction of baskets or boxes for packaging of different products, such as for example example, drinks.

18. An adhesive film for providing strength according to claims 1 to 16, characterized in that the angle of the engraving with respect to the base of the film or backing is variable, for example, between 0 and 90 ° with respect to the perpendicular of the base. of the movie- or backup.

19. An adhesive film for providing strength according to claims 1 to 17, characterized in that the adhesive and the backing film can be added with other compounds that make it more resistant to various environmental conditions, such as ultraviolet light, infrared light, among others.

20. An adhesive film for providing resistance according to claims 1 to 18, characterized in that the film or backing comprises compounds to make it more resistant to various environmental conditions, such as ultraviolet light, infrared light, among others.

21. An adhesive film for providing strength according to claims 1 to 19, characterized in that it presents or comprises a further compression property given by a film or backing which is compressed in a distance such that it does not equal the thickness of the adhesive placed thereon.

22. A process for producing the film according to claims 1 to 20, comprising the application of a thin layer of adhesive.

23. A device for applying the adhesive film according to claims 1 to 22, comprising three stations: - unwinding, cutting and distribution, capable of supporting tape applications in the range of 1 to 300 meters per minute.

24. An equipment according to claim 23, which includes a pedestal roll holder consisting of a vertical pedestal of iron or steel and a base of the same material or any other capable of resisting the stress and strain created by the film as it is dosed to the substrate to be reinforced, counting additionally with lateral bevels just in the section in which it is attached to the base, in an arrangement of 4 on each face of the vertical pedestal.

25. A team of conformity to claim 24, which includes two arms of iron or other resistant material, joined horizontally to the main vertical pedestal, in which are placed rollers, pistons and automatic joints of the adhesive film that is placed in two rolls, each arranged parallel to the horizontal axis of the arms, at a distance of approximately 1.0 m., in addition to the width of the vertical pedestal with respect to the arms can be 2 to 1, 1 to 1 | or 3 to 1 .

26. Equipment according to claim 25, which includes a set of straight knives arranged at an angle of 2 to 175 °, made of stainless steel and with a length of up to 5 cm. to cut the strip into strips.

27. An equipment according to claim 26, which includes a assembly of circular knives with a diameter of up to 7 cm. , made of stainless steel or a resistant material to cut the strip into strips.

28. An equipment according to claim 27, which includes a system of rollers or reels of different sizes, arranged at distances between 5 and 70 cm. to locate the strips generated by the cutting blades, on the surface of the substrates to be reinforced.