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(11) | EP 2 964 425 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
PROCESS FOR PRODUCING ABRASIVE TAPE REELS PROZESS ZUR HERSTELLUNG VON SCHLEIFBANDSPULEN PROCÉDÉ PERMETTANT DE PRODUIRE DES ROULEAUX DE BANDE ABRASIVE |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present patent concerns the field of abrasive tapes and in particular it concerns a new process for producing abrasive tape reels.
[0002] In many abrasion, roughing, surface finishing, lapping and similar operations abrasive tapes or abrasive discs are used, which are referred to simply as abrasive tapes here below.
[0003] Abrasive tapes are usually constituted by a flexible support on which a layer of abrasive granules in a given size is firmly attached.
[0005] The abrasive granules are usually constituted by aluminium oxide, carborundum (silicon carbide), zirconia (zirconium oxide), ceramic aluminium oxide.
[0006] The abrasive tapes are obtained by cutting very long and very wide rolls or reels in strips: the abrasive granules are attached to the flexible support, whose maximum width is 2 linear meters and whose length is variable, and the flexible support is successively cut in strips having the necessary width and length or according to circular or triangular or other patterns.
[0007] During lapping operations the problem arises that the abraded material is not eliminated and forms a layer between the piece to be processed and the abrasive tape, thus making the action of the abrasive tape ineffective.
[0008] WO 94/27833 relates to an abrasive material and method for making it, wherein said abrasive material comprises a substrate with an adhesive and abrasive particles held by the adhesive. Said abrasive particles can be applied in rectangular areas, thus constituting strips without said particles, wherein said strips are perpendicular or parallel to the edge of the substrate. In order to overcome the drawbacks described above a new process for producing abrasive tape reels has been designed and implemented.
[0009] The new process comprises the steps, as defined in claim 1. The flexible support can be constituted by paper with weights A-G, cotton fabric, polycotton fabric with weights FF and J, cloth with weight X and cloth with weight Y and any other type of weight.
[0010] The flexible support is unwound from its reel and conveyed towards a first spraying unit or another equivalent device suited to spread a layer of adhesive resin on the surface of the support.
[0011] The flexible support coated with adhesive resin then passes through a device suited to distribute or scatter the abrasive granules on its surface.
[0012] Said device for distributing or scattering abrasive granules is preferably constituted by an electrostatic deposition device suited to deposit the abrasive granules on the resin layer in a uniform and balanced way.
[0013] Said distribution and scattering device comprises devices suited to selectively deposit the abrasive granules on specific areas of the surface of the tape and the resin, meaning on rhomboidal, triangular, rectangular, hexagonal, polygonal and elliptic areas, in such a way as to obtain portions or strips without abrasive granules.
[0014] During the use of the abrasive tape, said portions or strips without abrasive granules constitute discharge ways for the abraded material.
[0015] According to the invention, the portions or strips without abrasive granules are inclined with respect to the width of the reel tape, so as to facilitate the elimination of the abraded material from the area included between the abrasive tape and the surface being processed.
[0016] Successively, the flexible support, coated with resin and scattered with granules, is subjected to a drying process, in such a way as to harden the resin layer and definitely fix each granule onto the supporting tape.
[0017] Finally, the flexible support with the abrasive granules attached thereto is subjected to a second resin spraying step and to a subsequent drying step.
[0018] Said second resin layer makes it possible to join each abrasive granule to the adjacent abrasive granules, considerably improving the adhesion of the granules to the supporting tape and obtaining a longer duration of the finished abrasive tape.
[0019] According to the invention, a filler layer can be sprayed or spread on the reel tape with abrasive granules obtained as described above.
[0020] The enclosed drawing illustrates the new process for producing abrasive tape reels by way of non-limiting example.
[0022] A layer of adhesive resin is initially sprayed or in any case spread on the flexible support (F), unwound from the reel on which it is stored, by means of special devices (S1).
[0023] Successively, the flexible support (F) with the adhesive resin thereon passes through a distribution or scattering device (D) suited to distribute or scatter abrasive granules.
[0024] Said device (D) for distributing or scattering abrasive granules is constituted by an electrostatic deposition device suited to deposit the abrasive granules on the resin layer in a uniform and balanced manner.
[0025] Said distribution or scattering device (D) comprises templates (M) suited to deposit the abrasive granules on selected areas, for example rhomboidal areas as shown in Figure 2a, in such a way as to obtain portions or strips without abrasive granules.
[0026] The flexible support (F) coated with resin and with the granules deposited thereon is subject to a drying cycle by means of thermal resistor heaters or infrared ray heaters (E1), in such a way as to harden the resin layer and definitively fix each granule onto the flexible support (F).
[0027] After said first drying step, the flexible support (F) with the abrasive granules attached thereon is subjected to a second resin spraying step, during which suitable spraying devices (R2) spread a second resin layer suited to deposit mainly among the various abrasive granules.
[0028] Said second resin spraying step is followed by a second drying step performed by means of thermal resistor heaters or infrared ray heaters (E2). The abrasive tape obtained in this way is wound on a winding reel.
[0029] Figures 2a, 2b, 2c, 2d, 2e, 2f show some examples of deposition of abrasive granules on specific areas of the tape, respectively: rhomboidal areas, polygonal areas, alternating triangular areas with alternating orientation, triangular areas generically in series forming a square pattern, staggered triangular areas, irregular areas.
1. Process for producing abrasive tape reels, comprising the step of spreading (S1) a
layer of a base adhesive resin on a flexible support or tape (F), the step of distributing
or scattering (D) abrasive granules thereon, the step of drying (E1) the resin with
the consequent adhesion of the abrasive granules, the step of spreading (S2) a second
bonding resin layer, the step of drying (E2) the second resin layer, characterized in that it comprises one or more templates (M) suited to obtain the selective deposition
of the abrasive granules on areas delimited by linear strips, from edge to edge, without
abrasive granules, said strips constituting, during the use of the abrasive tape,
discharge ways for the abrasive material, and wherein said abrasive granules are deposited
on poligonal areas, such as rhomboidal areas, triangular areas, rectangular areas,
hexagonal areas, or elliptic areas, so that said strips without abrasive granules
are inclined with respect to the width of the reel tape so as to facilitate the elimination
of the abraded material from the area included between the abrasive tape and the surface
to being processed, and wherein the distribution of said abrasive granules takes place
through electrodeposition.
2. Process for producing abrasive tape reels according to claim 1, characterized in that said strips without abrasive granules include wider portions.
3. Process for producing abrasive tape reels according to claim 1, characterized in that said abrasive granules are deposited on triangular areas.
4. Process for producing abrasive tape reels according to claim 1, characterized in that said abrasive granules are deposited on rectangular areas.
5. Process for producing abrasive tape reels according to claim 1, characterized in that said abrasive granules are deposited on hexagonal areas.
6. Process for producing abrasive tape reels according to claim 1, characterized in that said abrasive granules are deposited on polygonal areas.
7. Process for producing abrasive tape reels according to claim 1, characterized in that said abrasive granules are deposited on elliptic areas.
8. Process for producing abrasive tape reels according to the preceding claims, characterized in that it comprises a third step of spraying resin with the subsequent drying step.
1. Verfahren zur Herstellung von Schleifbandrollen, Folgendes umfassend: den Schritt
des Aufbringens (S1) einer Schicht einer Klebeharzgrundlage auf einen flexiblen Träger
bzw. auf ein Band (F), den Schritt der Verteilung oder des Streuens von Schleifmittelkörnern
auf diese, den Schritt der Trocknung (E1) des Harzes mit daraus folgendem Anhaften
der Schleifmittelkörner, den Schritt des Aufbringens (S2) einer zweiten Bindeharzschicht,
den Schritt des Trocknens (E2) der zweiten Harzschicht; dadurch gekennzeichnet, dass es ein oder mehrere Schablonen (M) umfasst, dazu geeignet, die selektive Ablagerung
der Schleifmittelkörner auf Bereiche zu erzielen, die von Kante zu Kante durch lineare
Streifen ohne Schleifmittelkörner begrenzt sind, wobei die besagten Streifen während
der Verwendung des Schleifbands Ableitwege für das Schleifmaterial bilden, und wobei
die besagten Schleifmittelkörner auf vieleckige Bereiche wie rautenförmige, dreieckige,
rechteckige, sechseckige Bereiche oder auf elliptische Bereiche abgelagert werden,
so dass die besagten Streifen ohne Schleifmittelkörner bezüglich der Breite des Rollenbands
geneigt sind und damit die Entfernung des abgetragenen Materials aus dem Bereich zwischen
dem Schleifband und der zu bearbeitenden Oberfläche erleichtern, und wobei die Verteilung
der besagten Schleifmittelkörner durch Galvanisierung erfolgt.
2. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Streifen ohne Schleifmittelkörner breitere Abschnitte umfassen.
3. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Schleifmittelkörner auf dreieckige Bereiche abgelagert werden.
4. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Schleifmittelkörner auf rechteckige Bereiche abgelagert werden.
5. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Schleifmittelkörner auf sechseckige Bereiche abgelagert werden.
6. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Schleifmittelkörner auf vieleckige Bereiche abgelagert werden.
7. Verfahren zur Herstellung von Schleifbandrollen nach Patentanspruch 1, dadurch gekennzeichnet, dass die besagten Schleifmittelkörner auf elliptische Bereiche abgelagert werden.
8. Verfahren zur Herstellung von Schleifbandrollen nach vorstehenden Patentansprüchen,
dadurch gekennzeichnet, dass es einen dritten Schritt des Aufsprühens von Harz mit dem anschließenden Schritt
der Trocknung umfasst.
1. Procédé pour la réalisation de bobines de ruban abrasif, comprenant la phase d'étalage
(S1) d'une couche de résine adhésive de base sur un support ou ruban flexible (F),
la phase de distribution ou dispersion (D) de granulés abrasifs, la phase de séchage
(E1) de la résine avec l'adhérence conséquente des granulés abrasifs, la phase d'étalage
(S2) d'une deuxième couche de résine de liaison, la phase de séchage (E2) de la deuxième
couche de résine, caractérisé en ce qu'il comprend une ou plusieurs gabarits (M) aptes à obtenir le dépôt sélectif des granulés
abrasifs dans des zones délimitées par des bandes linéaires, de bord à bord, sans
granulés abrasifs, lesdites bandes constituant, durant l'utilisation de la bande abrasive,
des voies de déchargement pour le matériau abrasif, et où lesdits granulés abrasifs
sont déposés sur des zones polygonales, tels que des zones rhomboïdales, des zones
triangulaires, des zones rectangulaires, des zones hexagonales ou des zones elliptiques,
de manière à ce que lesdites bandes sans granulés abrasifs soient inclinées par rapport
à la largeur de la bobine de ruban abrasif de manière à faciliter l'élimination du
matériau abrasé de la zone comprise entre la bande abrasive et la surface à traiter,
et où la distribution desdits granulés abrasifs se vérifie par électrodéposition.
2. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdites bandes sans granulés abrasifs comprennent des portions plus grandes.
3. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdits granulés abrasifs sont déposés sur des zones triangulaires.
4. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdits granulés abrasifs sont déposés sur des zones rectangulaires.
5. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdits granulés abrasifs sont déposés sur des zones hexagonales.
6. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdits granulés abrasifs sont déposés sur des zones polygonales.
7. Procédé pour la réalisation de bobines de ruban abrasif selon la revendication 1,
caractérisé en ce que lesdits granulés abrasifs sont déposés sur des zones elliptiques.
8. Procédé pour la réalisation de bobines de ruban abrasif selon les revendications précédentes,
caractérisé en ce qu'il comprend une troisième phase de pulvérisation de résine avec la phase conséquente
de séchage.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description