DE960418C - Blasting agent for cleaning any work piece from adhering surface layers - Google Patents

Description

Blasting agent for cleaning any workpieces from adhering surface layers The cleaning of any workpieces from adhering surface layers was previously done mainly by scraping, brushing or tapping by hand, as all other cleaning processes that rely on a mechanization of this. Aimed at the operation, not the in almost all cases necessary avoidance of attack of the surface guaranteed. So had to z. B. to this day for cleaning cylinder heads from Oil coal always relied on human labor. In the last Years have been introduced to mechanize these operations fall back on the blasting process. To avoid attacking the surface abrasives such as hardwood shavings, nutshells or even plastic in grained The mold is placed in a stream of air and thrown onto the workpiece. These abrasives, all of which have a very low specific weight and very low hardness, however, have some significant drawbacks for the work process. That's how it is lifespan the wood and nutshell abrasives are extremely low and the procurement sufficient quantities are not guaranteed with increasing demand.

The plastic blasting media have a much longer service life on, however, are so expensive that their use in all cases where not the technical effect makes their use absolutely necessary, uneconomical will. As a result of the low grain weight, they are necessary for the work process required kinetic energy with the low mass of the grain very high impact velocities required, which can only be achieved in the compressed air flow. But with that the Use of these blasting media in modern, compressed air-free, according to the centrifugal wheel principle working machines, the maximum impact speed of which today is around 8o to 100 m / sec is impossible.

Attempts to use abrasives with a higher specific weight or higher To use service life, especially on a metallic and mineral basis, as they are for other work processes, e.g. B. zuin cleaning castings, today in considerable Extensive use has not led to any useful result because the Effect of this abrasive in normal grain sizes is too aggressive and itself in the case of soft materials, such as B. aluminum, leads to an attack on the workpiece. This attack. can be reduced by appropriate refinement of the grain will; at the same time, however, there is a reduction in the kinetic energy and the same phenomena appear as in the case of vegetable blasting agents. In addition, the fineness of the grain makes it difficult to separate properly during the work process accumulating dust from the abrasive and thus the recovery of the abrasive and an economical way of working.

The invention consists in the advantages of both types of blasting media, d. H. the work piece-friendly effect of the plastic and the economic efficiency of the metallic or mineral blasting abrasive, in such a way that that in a suitable plastic material metallic or mineral blasting media finest grains can be embedded, creating a relatively large grain with a 'correspondingly high specific weight and, secondly, the proportion the very expensive plastic largely reduced in favor of the cheap co-formulants will.

As a plastic binder, any cold or hot cast or thermoplastic can be used Commercially available plastic can be used by suitable aftertreatment or admixtures hardened to the degree of hardness suitable for the abrasive grain can be; any fine-grained or powdered metal, such as iron, Copper lead. Aluminum etc., and any natural or artificial mineral such as corundum, Quartz, etc., are suitable. The selection of the plastic depends first of all on his Strength properties after processing, secondly. According to its price and thus its economic efficiency, and thirdly after the processability and the Binding ability of the fillings listed above.

The selection of co-formulants based on the material as well as the grain shape and size depends on the intended use. So you will z. B. If necessary, use a relatively coarse-grained corundum or angular Hartgußgranulat for hard adhering combustion residue on steel parts, while ektromotorenteilen for normal contamination of El in which protection of the insulation must be noted soft metallic co-formulants, such as fine-grained aluminum or copper is used.

If necessary, other plastics can also be used as co-formulants, which as a result their low strength as a binding compound or as a pure grain are uneconomical, Find use when the technical effect makes it desirable. As co-formulants there may also be mixtures of the individually listed substances, e.g. B. Chilled cast granulate and corundum, or. Quartz and plastic powder, in question. Furthermore can to increase the strength of the starting material, co-formulants are added to the working effect of the grain has no influence and only increases the strength Have effect such. B. Perlon or glass fibers.

The manufacture of the material, in terms of its technology, nothing in itself New offers are made in such a way that one adds suitable chemicals or by suitable physical treatment for hardening or kneading the synthetic resin mixed with the co-formulant in an appropriate ratio and over conventional, commercially available granulating devices in a granular material with Grain sizes between 0.1 and 5 mm, depending on the intended use, converts. In connection this can be followed by chemical or physical treatments that may be necessary for the hardening of the binder is required. The selection of the appropriate grain size depends on the intended use and the machine in which the work process is carried out should take place, d. H. according to the impact speed, the impact angle, the Radiation density, etc.

Claims (1)

PATENT CLAIM: Blasting abrasive for cleaning any workpieces from adhering surface layers, characterized in that the abrasive grain is granular with a size of 0.1 to 5 mm and with a cylindrical, cube-shaped, spherical or other shape from a mixture of a plastic and a metallic, mineral substance Form or a plastic such as Perlon or glass fiber.