Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
  • B05D5/10—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an adhesive surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/02—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to macromolecular substances, e.g. rubber
  • B05D7/04—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to macromolecular substances, e.g. rubber to surfaces of films or sheets

Definitions

• the invention relates to a method for at least partial direct coating of a stretchable carrier material with a pressure sensitive adhesive, the carrier material by means of a transporting device like this against a coating device is performed that the PSA on the carrier material through the coating device is applied.
• stretchy especially textile materials as supports, the elastic or have plastically formable properties are in technology and medicine known. They are used in a wide variety of areas, including also as Base materials in the manufacture of plasters and adhesive bandages
• plastically or elastically deformable should be understood to mean the stretchability of a material. A material is then stretchable if it has a length increase of at least 20% under a load of 10 N / cm.
• the stretchable carrier materials can be coated with various adhesive systems.
• the coating is generally possible over the entire surface or also partially, ie partially.
• partial coating shows that a correspondingly porous substrate results in a film that is highly permeable to air and water vapor and which, as a rule, is also easier to remove after the adhesive has been applied to the patient's skin.
• Screen printing is widespread as a method for producing such partially coated carrier materials, in particular screen, engraving or flexographic printing. It is also known that, for example when used as fixations, the self-adhesive finish can also be carried out on more than one side.
• Elastic or plastically formable substrates can generally be coated directly or indirectly.
• a preferably rigid or less elastic auxiliary carrier is first coated and then the adhesive is transferred to the elastic or plastically moldable carrier in a lamination process.
• the carrier material can be laminated undeformed and unpolluted, whereby the shape and technological properties such as basis weight, maximum tensile strength, maximum tensile strength stretch, hysteresis stretch are largely retained.
• the disadvantage of indirect coating lies in the relatively poor anchoring of the adhesive on the elastic or plastically deformable carrier.
• thermal lamination or lamination is not possible or has only little success.
• lamination can result in the adhesive layer being pressed completely into the backing, so that both the adhesive properties and the elasticity behavior deteriorate drastically.
• the carrier With direct coating, the anchoring of the Adjust adhesive, however, the carrier becomes mechanical and in use of hot melt pressure sensitive adhesives also thermally more stressed.
• adhesive is shown to be at least partially elastic or plastic malleable carrier material that this, although the carrier is unloaded and undeformed in the coating unit is given, is partially claimed so that its Change properties beyond repair. This is due to the fact that the adhesive system adheres to the coating unit with a system-dependent force.
• the object of the invention was to develop a direct coating process which it enables a stretchable carrier material to be at least partially coated with a pressure sensitive adhesive to coat without changing the carrier properties.
• the method according to the invention becomes at least partially direct Coating a stretchable carrier material with a pressure sensitive adhesive the carrier material by means of a transporting device of this type against a coating device performed that by the coating device, the PSA is applied to the carrier material, on the transporting device Detention or holding devices are available. These facilities bring the Supply to and for separating from the coating unit necessary forces in in such a way that the properties of the carrier are not in the coating to be changed.
• the coating of the Support material over the entire surface is provided.
• the holding devices consist of needles, which are from the transporting Protrude device and engage in the carrier material.
• the needles advantageously have a length greater than 10 ⁇ m, preferably between 30 ⁇ m and 5000 ⁇ m, particularly preferably between 35 ⁇ m and 1000 ⁇ m.
• the distance between the tips is preferably greater than 60 microns and the nature dependent on the wearer.
• the needles can at least partially on the surface of the transport Device be movable.
• a special embodiment of the needles is the Velcro connection, in which the Barbed needles.
• Another advantageous embodiment of the holding devices on the transporting device consists in the use of very rough surfaces, ie in a generally disordered arrangement of geometries suitable for engaging in the expandable carrier.
• the roughened surface can be formed from applied hard material particles and / or from a metal, ceramic or plastic surface roughened by the shaping process or by mechanical, physical or chemical treatment. Corundum or similar hard material coatings that have a surface similar to emery paper may be mentioned here by way of example. Metal surfaces roughened by etching or other methods are also suitable.
• the surface roughness is advantageously between 30 and 5000 microns.
• the transporting device consists of a prepared transport roller and the coating device consists of a rotating, heated, seamless, drum-shaped and perforated circular stencil, which is supplied with the hotmelt adhesive or the PSA dispersion via a nozzle, the PSA systems via a nozzle lip through the Round template to be applied to the carrier material passed by.
• the transport roller can preferably consist of metal, ceramic or plastic. In general, it can be plastic, elastic or rigid.
• the roller in its nature that the roughness or the needles or the alternative solutions evenly, randomly distributed or in a certain geometric There are patterns on the roller surface. Also adapted to the wearer geometric shape and extension of the adhesive elements.
• the angle of the needle orientation can be used for special uses between 10 ° and 170 ° to the tangent to the surface of the Roll in the coating direction and also between 10 ° and 170 ° perpendicular to Coating direction.
• the needles can also at least partially be designed to be movable so that their orientation and / or size, for example due to magnetic field effects or eccentric constructions during one revolution the transport roller can change.
• the coating device and / or the holding devices are preferably equipped with an adhesive, in particular by means of compounds containing silicon or fluorine or plasma-coated separation systems, the adhesive application on the coating device having a weight per unit area of 0.001 g / m 2 to 350 g / m 2 , preferably between 0. 01 g / m 2 and 10 g / m 2 , can be applied.
• the surface of the transport roller and / or the adhesive elements can further be pretreated both physically and chemically. Siliconizing and Teflonizing are mentioned here as examples. A static or an antistatic treatment can show application-related advantages. Methods for applying such separating coverings are sufficiently described in the technical literature, for example the dip, electrolysis, brush, spray and pressure coating are mentioned.
• the partitions can be cured both physically and chemically. For example, chemically curing systems for processing hotmelt adhesives have proven advantageous.
• the principle of thermal screen printing is the use of a rotating, seamless, drum-shaped perforated round stencil, which is fed with the hot melt adhesive via a nozzle.
• a specially shaped nozzle lip (round or square squeegee) presses the self-adhesive that is fed in through a channel through the perforation of the stencil wall onto the carrier web. This is guided against the outer jacket of the heated sieve drum at a speed which corresponds to the speed of rotation of the rotating sieve drum.
• This counter-pressure roller is equipped with a needled surface so that it can exert a force which, depending on the direction, is oriented so that it is slightly greater than the adhesive force of the cooling adhesive melt on the surface of the screen drum.
• the carrier web is removed from the counterpressure roller by vertical lifting.
• the nozzle doctor blade pressure conveys the hot melt adhesive through the perforated screen to the carrier material.
• the size of the spherical caps is determined by the diameter of the sieve hole.
• the sieve is lifted off the carrier in accordance with the transport speed of the carrier web (rotational speed of the sieve drum). Due to the high adhesion of the hotmelt adhesive and the internal cohesion of the hotmelt, the supply of hotmelt adhesive, which is limited in the holes, is subtracted from the base of the calottes already adhering to the contour or conveyed by the doctor blade pressure onto the carrier. At the end of this transport, depending on the rheology of the hotmelt adhesive, the more or less strongly curved surface of the spherical cap forms over the specified base area.
• the ratio of the height to the base of the spherical cap depends on the ratio of the hole diameter to the wall thickness of the screen drum and the physical properties (flow behavior, surface tension and wetting angle on the carrier material) of the self-adhes
• the described mechanism of formation of the domes preferably requires absorbent or at least carrier materials which can be wetted by hotmelt adhesive.
• Non-wetting support surfaces must be by chemical or physical processes be pretreated. This can be done by additional measures such as Corona discharge or coating with substances that improve wetting.
• the size and shape of the domes can be defined in a defined manner using the printing process shown.
• the adhesive strength values relevant for the application, which determine the quality of the products produced, are within very narrow tolerances when properly coated.
• the base diameter of the spherical caps can be selected from 10 ⁇ m to 5000 ⁇ m, the height of the spherical caps from 20 ⁇ m to approx. 2000 ⁇ m, preferably 50 ⁇ m to 1000 ⁇ m, the range of small diameters for smooth carriers being that of a larger diameter and larger spherical cap height is intended for rough or highly porous substrates.
• the positioning of the domes on the carrier is defined by the geometry of the application, which can be varied within wide limits, such as engraving, screen or nozzle geometry. With the help of the parameters shown, the desired property profile of the coating can be set very precisely, adjusted to the different carrier materials and applications.
• the carrier material is preferably at a speed of greater than 2 m / min, preferably 20 to 100 m / min, coated, the coating temperature being greater than the softening temperature is to be selected.
• the disclosed invention made it possible to save the auxiliary carrier for indirect coating and the environmentally friendly recovery of the solvent, which is cost-intensive and requires a lot of machinery.
• the bandage was coated in thermal screen printing with a mass application of 160 g / m 2 of adhesive based on a block copolymer.
• the block copolymer was a styrene-ethylene-butylene-styrene block copolymer to which paraffin hydrocarbons had been added. The ratio was one part polymer to one part paraffin hydrocarbon. 10% polystyrene resin (Amoco 18240) was added to this mixture.
• the adhesive contained one percent Irganox, an anti-aging agent ( ⁇ - (3,5 di-t.butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester)), and other hydrocarbon resins and fatty acid esters, which were only contained in small amounts in the total adhesive .
• the softening point of this adhesive was 100 ° C (DIN 52011) and the glass transition temperature, determined by the above method, -6 ° C.
• the high mass application could be achieved with a 14 mesh screen template.
• By the use of the large coating points could adhere well to the Carrier and clean cutting can be achieved.
• a needle roller which was filled with 25 needles / cm 2 , was used as the holding device.
• the length of the needles was 0.25 mm.
• the adhesive was skin-friendly and well adhering to the skin and back of the carrier.
• the bandage thus produced was also air-permeable (more than 15 cm 3 / (cm 2 * s) and water vapor-permeable (more than 1500 g / (m 2 * 24h) in a multi-layer bandage.
• the elastic adhesive bandage was used for compression, support and relief bandages used, the high immediate, permanent adhesive strength and shear strength were advantageous. The modelability and user experience were due to the partial order the adhesive has been improved.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Manufacturing Of Multi-Layer Textile Fabrics (AREA)
• Adhesive Tapes (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=7851788

Family Applications (1)

Country Status (3)

Cited By (3)

Families Citing this family (7)

Citations (7)

Family Cites Families (1)

• 1997
  • 1997-12-13 DE DE19755436A patent/DE19755436A1/de not_active Withdrawn
• 1998
  • 1998-11-25 EP EP98122137A patent/EP0922503A3/fr not_active Withdrawn
  • 1998-12-04 US US09/205,622 patent/US20010002289A1/en not_active Abandoned

Patent Citations (7)

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