Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
  • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
  • B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
  • B24D3/346—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties utilised during polishing, or grinding operation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
  • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
  • B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties

Definitions

• the invention relates to an abrasive body with abrasive grain, such as corundum, a binder which is a curable organic or inorganic system, for example plastic, such as phenolic resin, and fillers which are at least partially abrasive.
• abrasive grain such as corundum
• a binder which is a curable organic or inorganic system, for example plastic, such as phenolic resin, and fillers which are at least partially abrasive.
• additives in the grinding media that either improve the adhesion of the abrasive grain in the bond (adhesion promoters, e.g. silanes or coatings that improve adhesion, e.g. frits with melted metal oxides, ceramic coatings, etc.).
• additives make production easier, for example, either by improving the flowability of the abrasive material or by reducing the internal friction during pressing.
• Halides e.g. lead chloride, fluorspar, cryolite, etc.
• chalcogenides e.g. pyrite antimony sulfides, zinc sulfide, molybdenum sulfide, selenides, tellurides, etc.
• low-melting metals e.g. lead, tin, low-melting mixture metals
• high pressure lubricants e.g. graphite, boron nitride
• an optimal abrasive filler must have favorable transition temperatures, favorable film-forming properties and chemically reactive cleavage products, that it and its secondary products should have the lowest possible toxicity and therefore high MAK values, that it should be inexpensive and that it should be processed in abrasive products must be possible.
• the applicant's AT-PS 366 944 discloses the use of hygroscopic fillers which have very good grinding properties.
• the disadvantage of these fillers is that in practice they have to be encased, which on the one hand is labor-intensive and thus expensive and on the other hand reduces the volume of the active grinding fillers which can be introduced into the grinding compound.
• a special object of the invention is to introduce fillers into an abrasive body of the type mentioned at the beginning which have the same effect as toxic fillers, e.g. Have lead, as well as the grinding active cooling properties of hygroscopic fillers e.g. ZnCl2 without being hygroscopic.
• chlorides are provided which are not hygroscopic. Expensive protective measures such as coating with organic substances can therefore be dispensed with. As already mentioned, this also has the advantage that there is more grinding-active filler in the grinding compound per unit mass. Due to the limited ability to bind and the amount of phenolic resin, it is not possible to incorporate unlimited amounts of fillers into the abrasive compound. The volume of the grinding-active fillers in the grinding wheel is therefore reduced by a casing.
• the filler according to the invention is described in its use in a conventional phenolic resin-bonded grinding wheel with corundum as the abrasive grain.
• three metal salts were fused together, ground and sieved to create the filler according to the invention, namely the salts were melted and the molten liquid was poured onto a metal plate, where it cooled very quickly, and after hardening, the mixture was ground to obtain the to form new filler.
• the preferred grinding mixture for a cutting wheel for cutting structural steel is a mixture of 70% by weight KCl and 10% by weight of ZnS and 10% by weight MnS. The particles were melted. The melted mass, which was then hardened on a steel plate, was ground in a cross beater mill and sieved to a fineness of 24 o mesh US standard (63 my).
• a first disc was produced, in which lead chloride (Pb Cl2) was used as the only grinding active filler in a conventional manner.
• This grinding wheel was the directional grinding wheel in relation to which the results of the other grinding wheels were measured.
• a second grinding wheel was also produced in a conventional manner, K2 Mn Cl4 being introduced as a hygroscopic, non-toxic, active filler.
• a third cutting disc was provided with the filler according to the invention described above.
• the cutting discs were manufactured as shown below.
• the mass of the binders used in these three cutting discs consisted of phenolic resin and the fillers.
• the phenolic resin was split. 82% by volume of the total phenolic resin was used in the form of a novolak hexa mixture and the rest in the form of a liquid resol.
• binder mixture which consists of the dry resin powder and the fillers.
• the binder mixture compositions for the three disks were as follows:
• Dry binder mixtures were prepared by mixing the above components.
• the grinding wheel mixture was made by placing the corundum in a mixer.
• the liquid phenol resol was poured onto the corundum and the mixer was operated until the corundum grains were coated with the liquid resol.
• the premixed powdered binder mixture was placed in a second mixer and the abrasive grain wetted with liquid resin was mixed in until all of the abrasive grains were coated.
• the mixture was then sieved to order Remove lumps and stored for twelve hours.
• the deposited mixture was pressed into disks with a diameter of 600 mm and a thickness of 7.5 mm.
• Two type 93160 reinforcement fabrics were placed in each pane.
• the slices were then hardened for 36 hours, the max. Temperature of 175 ° was maintained for six hours.
• the hardened disks were subjected to an explosive test and checked for imbalance and dimensions. All discs corresponded to the standard values.
• the filler according to the invention gives the lead chloride equivalent performance factors with the same cut quality and about 36% better results than with hygroscopic manganese fillers.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Polishing Bodies And Polishing Tools (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8199730

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Family Applications After (1)

Country Status (1)

Cited By (1)

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Citations (5)

Family Cites Families (6)

• 1988
  • 1988-12-30 EP EP88121884A patent/EP0375803A1/fr not_active Withdrawn
• 1989
  • 1989-06-21 EP EP19890111276 patent/EP0379633A3/fr not_active Withdrawn

Patent Citations (5)

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