FLEXIBLE ABRASIVE MEMBER WITH PERMANENT ONE WAY MOULD AND METHOD OF MAKING SAME

Abstract: A flexible abrasive member comprising a backing layer to which a t one side an attachment is mounted and to which at the other side deposits are adhered consisting of abrasive particles and bonding material, such as a resin, wherein a permanent one way mould is attached to said other side of the backing layer substantially encircling said deposits, wherein said mould may extend along at least part of the height of said deposits, wherein said mould comprises a through hole substantially in the middle of said mould, wherein said mould is made of a synthetic material, such as a flexible foam material, and a method of making said flexible abrasive member.

Description: Flexible abrasive member with permanent one wav mould and method of making same. Description The invention relates to a flexible abrasive member comprising a backing layer to which at one side an attachment is mounted and to which at another side deposits are adhered consisting of abrasive particles and bonding material such as a resin. Such abrasive members are used for coarsegrinding or polishing hard materials like stone, glass, concrete and ceramic by example. It is known in the art to produce such abrasive members by using moulds in which resin or other bonding materials, comprising abrasive particles, are being poured or sintered. These moulds may be made of metal or synthetic material. Preferably, these abrasive particles may be diamond particles. The moulding techniques known in the art comprise at least one mould suited for either multiple use or one time use. In case of one time use the mould is lost and does not fulfill any function in the method of making the abrasive member anymore, nor in the performance of the abrasive member itself. Losing this mould causes this moulding technique to be expensive, especially in case of mass production of the abrasive members. In case moulds suited for multiple use are being used, these moulds must be made of hard-wearing material such as hardmetal. Both applying such expensive material and forming the mould cause this moulding technique to be expensive, although typically suited for applying in mass production techniques. Moreover, such these moulds are suited for only one product form. Slight or great alterations concerning product form result in the need for new moulds. In producing flexible abrasive members with moulding techniques there is a need for a flexible, fast and cheap method, which not thereby affects the current performance of the abrasive members. One object of the invention is to provide a flexible abrasive member produced by a moulding technique much cheaper and faster to operate than moulding techniques known in the art, used for making flexible abrasive members. This object is achieved according to the invention by a permanent one way mould which is attached to the other side of the backing layer substantially encircling the deposits, wherein the mould may extend along at least part of the height of the deposits. This mould may have circular, rectangular or any fancy shape suitable for the purpose of the abrasive member. A typical advantage of the present invention is the possibility to produce moulds of any simple or complex shape much cheaper and easier than in the known methods. The mould as well as the deposits may be made of any ceramic, metal, resin or synthetic material as well as graphite, glass, quartz or sand. According to another aspect of the invention a fill-in mould has been provided substantially extending along the rest of the height of the deposits, which height is not being convered by the primary mould. The main purpose of the fill-in mould is to fill the space between the top surface of the primary mould and the plane supported by the top surfaces of the deposits desired. According to another aspect of the invention the mould comprises a through hole substantially in the middle of the mould. By example, this hole forms the area not suited for abrading purposes when applying rotating abrasive members where the axis of the hole is the axis of rotation. This through hole may also be present in the backing layer and the attachment. This hole may be provided for several purposes. By example, an axle may be put through or coolant may be supplied through. According to another aspect of the invention the mould is made of a synthetic material. Preferably, this material is a flexible foam material, such as "Plastozote" made by the British Petroleum corporation in sheetform from 1-50 mm thickness. The flexibility of the abrasive member is for a great deal determined by the flexibility of the mould. Particularly flexible abrasive members are required when grinding or polishing curved shapes, as in the case of optical lenses and complex shaped products as a body out of stone or marble. According to another aspect of the invention the synthetic material is a spongetype foam holding water or coolant. This presents the advantage that water or other type of coolant is no longer needed for cooling purposes at the machine when applying the abrasive member. The invention relates not only to the abrasive members such as herein referred to and described, but also to the method whereby such abrasive members are produced or from which these abrasive members resulted. According to another aspect of the invention the method of making the flexible abrasive member according to the invention, comprises the steps of: providing a mould with a particularly desired external shape and one or more openings; attaching the mould to the surface of said backing layer at the side of said backing layer opposite the attachment; adhering the deposits in the openings provided in the mould to the backing layer and/or the mould. This method preserves the mould. After moulding the mould permanently present on the product, supports the deposits and conducts heat away. This moulding technique is much cheaper and faster to operate than moulding techniques known in the art, used for making flexible abrasive members, specifically because the mould is not lost, after moulding the mould has a function in the product making other arrangements for the same purpose redundant, and after moulding the mould does not have to be taken away, cleaned, greased and prepared for the following sequence. According to another aspect of the invention the method of making the flexible abrasive member may comprise the step of applying heatshrinkage in or after one of the steps mentioned above, for the mould to obtain a desired thickness. By heatshrinkage not only the thickness of the mould can be adjusted, the openings present in the mould material can be adjusted also. The latter influences the flexibility of the mould and the capacity for containing water or other type of coolant. According to another aspect of the invention the method of making the flexible abrasive member may comprise the steps of: providing a fill-in mould with a particularly desired external shape and one or more openings corresponding to the openings of the primary mould; positioning said fill-in mould on top of the surface of said primary mould; before adhering the deposits in the openings provided in said primary mould and the corresponding openings in said fill-in mould, to the backing layer and/or the primary mould and said fill-in mould. According to another aspect of the invention the method of making the flexible abrasive member may comprise the step adhering the fill-in mould to the surface of said primary mould. According to another aspect of the invention the method of making the flexible abrasive member may comprise the step of applying heatshrinkage in or after one of the steps mentioned above, for the fill- in mould to obtain a desired thickness. By heatshrinkage not only the thickness of the fill-in mould can be adjusted, the openings present in the fill-in mould material can be adjusted also. The latter influences the flexibility of the mould and the capacity for containing water or other type of coolant. According to another aspect of the invention the method of making the flexible abrasive member, the external shape of the mould and one or more openings in the mould are provided by punching a sheet material. According to another aspect of the invention the external shape of said mould and one or more openings in said mould may be provided by punching or cutting a sheet material. According to another aspect of the invention the external shape of the fill-in mould and one or more openings corresponding to the openings in the primary mould are provided by punching or cutting a sheet material. According to another aspect of the invention the fill-in mould is positioned on top of the surface of said primary mould prior to punching or cutting the external shape of the mould and/or the openings corresponding to the openings in said primary mould. The invention also relates to the apparatus and composite features thereof wherein and/or whereby the process or processes is or are carried out for producing the abrasive member or abrasive members herein described. The invention will be further elucidated referring to an embodiment of the invention shown in the drawings, wherein: Figure 1 shows an embodiment of the invention in perspective from the side and top; Figure 2 shows an other embodiment of the invention in perspective from the side and top. In figure 1 a flexible abrasive member 1 according to the invention is shown, comprising a backing layer 2 to which at one side 3 an attachment 4 is mounted and to which at the other side deposits 6 are adhered consisting of abrasive particles 7 and bonding material 8 such as a resin, and a permanent one way mould 9 attached to said other side 5 of the backing layer 2 substantially encircling the deposits 6. In the embodiment of figure 1 the permanent one way mould 9 extends all along the height of the deposits 6. In the left part of figure 1 a fill-in mould 13 has been provided on top of the surface of the primary mould 9. The fill-in mould 13 extends along the rest of the height of the deposits 6, which height is not being convered by the primary mould . The fill-in mould 13 has a particularly desired external shape and one or more openings corresponding to the openings 12 of the primary mould 9- In figure 2 a flexible abrasive member 1 according to a further aspect of the invention is shown, comprising the same items as the exemplary embodiment shown in figure 1. In the embodiment of figure 2 the permanent one way mould 9 extends along part of the height of the deposits 6. Both in figure 1 and 2 the flexible abrasive member 1 comprises a through hole 10, 11 substantially in the centre of the member 1 through the permanent one way mould 9 and through the backing layer 2 and the attachment *. respectively. Although not shown in the drawings, the permanent one way mould 9 may extend not only along at least part of the height of the deposits 6 but beyond the height of these deposits 6 also. Although not shown in the drawings, the through hole 10, 11 may be absent or may be a blind hole not extending all through the height of the member 1.

Claims: C L A I M S 1. A flexible abrasive member (1) comprising a backing layer (2) to which at one side (3) an attachment (4) is mounted and to which at another side (5) deposits (6) are adhered consisting of abrasive particles (7) and bonding material (8) such as a resin, characterized in that a permanent one way mould (9) is attached to said other side (5) of the backing layer (2) substantially encircling said deposits (6), wherein said mould (9) may extend along at least part of the height of said deposits (6). 2. A flexible abrasive member according to claim 1, wherein a fill- in mould (13) has been provided substantially extending along the rest of the height of said deposits (6), which height is not being convered by said primary mould (9). 3. A flexible abrasive member according to claim 1 or 2, wherein a through hole (10) has been provided substantially in the middle of said mould (9) . 4. A flexible abrasive member according to claim 1-3. wherein a through hole (11) has been provided substantially in the middle of said backing layer (2) and attachment (4). 5- A flexible abrasive member according to claim 1-4, wherein said mould (9) is made of a synthetic material. 6. A flexible abrasive member according to claim 5. wherein said synthetic material is flexible foam material. 7. A flexible abrasive member according to claim or 6, wherein said synthetic material is a spongetype foam holding water or coolant. 8. A method of making a flexible abrasive member (1) according to claims 1-7, comprising the steps of: providing a mould (9) with a particularly desired external shape and one or more openings (12); attaching said mould (9) to the surface of said backing layer (2) at the side (5) of said backing layer opposite said attachment (4); adhering said deposits (6) in the openings (12) provided in said mould (9) to the backing layer (2) and/or said mould (9) • 9. A method of making a flexible abrasive member according to claim 8, wherein said mould (9) obtains a desired thickness by applying heatshrinkage in or after one of said steps. 10. A method of making a flexible abrasive member (1) according to claim 8 or 9, comprising the steps of: - providing a fill-in mould (13) with a particularly desired external shape and one or more openings corresponding to the openings (12) of the primary mould (9) ; positioning said fill-in mould (13) on top of the surface of said primary mould (9); before adhering said deposits (6) in the openings (12) provided in said primary mould (9) and the corresponding openings in said fill-in mould (13), to the backing layer (2) and/or said primary mould (9) and said fill-in mould (13). 11. A method of making a flexible abrasive member according to claim 10, wherein said fill-in mould (13) is adhered to the surface of said primary mould (9) • 12. A method of making a flexible abrasive member according to claim 10 or 11, wherein said fill-in mould (13) obtains a desired thickness by applying heatshrinkage in or after one of said steps. 13. A method of making a flexible abrasive member according to claim 8-12, wherein said external shape of said mould (9) and one or more openings (12) in said mould (9) are provided by punching or cutting a sheet material. 14. A method of making a flexible abrasive member according to claim 10-13, wherein said external shape of said fill-in mould (13) and one or more openings corresponding to the openings (12) in said primary mould (9) are provided by punching or cutting a sheet material. 15- A method of making a flexible abrasive member according to claim 14, wherein said fill-in mould (13) is positioned on top of the surface of said primary mould prior to punching or cutting the external shape of the mould and/or the openings corresponding to the openings in said primary mould (9)-

Inventors: FERRONATO SANDRO GIOVANNI GIUS, FERRONATO, SANDRO, GIOVANNI, GIUSEPPE
Applicants: FERRONATO SANDRO GIOVANNI GIUS, FERRONATO, SANDRO, GIOVANNI, GIUSEPPE
Application year: 1995
Main classification: B24D18
IPC codes: B24D3, B24D7, B24D18