DD140435A1 - METHOD FOR DISCONNECTING CERAMIC MASSES, IN PARTICULAR UNSATURATED OXID CERAMIC MASSES - Google Patents

Description

_ "_ 210 6 73

Title of the invention

Process for separating ceramic masses, in particular unsintered oxide ceramic masses

Field of application of the invention

The invention relates to a method for separating ceramic masses, in particular extruded unsintered oxide ceramic masses, as used in industrial ceramics application.

Characteristic of the known technical solutions

Generally known is the separation of extruded ceramic masses by single or multiple wire cutters. These separation processes are predominantly used in the heavy clay industry, - since they sufficiently meet the existing requirements with regard to the cutting accuracy and cut surface quality. Occurring slight deformations of the mass strand are meaningless for the final product.

Due to the required accuracy and quality of the cut surfaces in the case of oxide ceramic masses, it is necessary for them to perform a grinding of the cut surfaces after sintering «

"2- α ι ν σ /%>

This additional process step is ineffective and also causes relatively high material waste.

Furthermore, it is known to separate extruded rods of oxide ceramics with great slenderness after sintering by grinding. While this method of separation ensures good cut quality, the bars often warp during sintering, requiring them to be burnished.

Decisive disadvantages of this separation process are the large processing effort and material waste due to the accumulation of remnants as well as the difficult reprocessing of the contaminated material waste.

Furthermore, separation processes have become known / in which divided by high-speed water jets materials

become. ·

Thus, DD-PS 111 655 describes a method for separating hard rock. In order to achieve a useful quality of cut and to avoid water retention, shortly after the nozzle opening of the radiator, a water-insoluble additive, preferably fine-grained crushing sand, is added to the cutting jet. The tendency of the same to turbulence and early breaking is to be reduced by a wholly or partially soluble in water additive, which is particularly suitable substances with long chain molecules.

This proposed for the separation of hard rock method also has the known disadvantages, with the addition of fine-grained crushing sand should be problematic. A method of cutting soft absorbent material by liquid jet is disclosed in DT-AS 1 94'9 "583.

An adverse fluid intake of the interfaces to. cutting material is to be avoided in that the jet speed is 36Ο to 1 200 m / s and the selected cutting speed due to the

, 21O 6 73

standing cutting heat evaporation or evaporation of the remaining liquid in the cutting area guaranteed.

The cutting fluid is preferably water or an aqueous solution. If the cut surfaces are adversely affected by dissolution processes, the use of an easily evaporable organic liquid is suggested.

It is also known to use high velocity liquid jets for mining mining, metal cutting or similar materials

 An application of liquid jets for separating unsintered oxide ceramic compositions has not been previously known. ,

Object of the invention

The aim of the invention is to make the separation of unsintered oxide ceramic masses more productive, with the material waste occurring should be low and readily treatable.

Explanation of the essence of the invention

The object of the invention is to develop a separation process which ensures sufficient cut surface quality without additional processing of the same and which eliminates contamination of the waste material.

closes.

According to the invention the object is achieved in that by an unsintered oxide ceramic mass strand one or more Flüssigkeitsstrahlen.mit a jet velocity of at least 100 m / s and a diameter of 0.05

.30 · to -0.5 mm and such feed cutting speed

-4- 210 6 73

be guided, which causes an excess of liquid at the cutting area and thus avoids an increase in the melt temperature over a permissible maximum safe.

Another feature of the invention is that a 0.5 to 4 percent aqueous solution of the binder of the oxide ceramic composition is used as the cutting fluid, whereby a significant improvement in the quality of cut "and the edge strength of the cut parts can be achieved.

To be particularly advantageous, it has been found that the liquid jet with a jet velocity of 300 m / s and a diameter of 0.2 mm with a feed cutting speed between 1 to 10 mm / s is passed through the strand of mass.

embodiment

The invention will be explained in more detail below using an exemplary embodiment.

Oxide ceramic compositions are mixed with a plasticizer consisting of binders and lubricants to produce dimensional stability and compressibility. Aqueous polyvinyl alcohol solutions which are volatile at temperatures of about 70 ^° C. are frequently used as binders. Any further heating of the oxide-ceramic mass during the separation process must therefore be excluded.

be closed «·

For separating the strands of the oxide ceramic mass formed in known manner, a 1 to 1.5 percent aqueous solution of the binder is fed to a nozzle via a high-pressure pump system known per se, wherein the cutting fluid flows at a jet velocity of 300 m / s. , The emerging liquid jet is guided through the mass strand at a feed cutting speed of 1 to 10 mm / s and in this case has a diameter

- 5

of about 0.2 mm. The joint width, thus can be kept very small and is about 0.2 to 0.4 mm, whereby the resulting material waste remains very low. Corresponding to the selected beam parameters results in a feed cutting speed im'abementioned area in which the cutting area, supplied liquid süberschuß causes the cooling of the oxide ceramic mass and an increase in the melt temperature above the critical limit, for example 70 * C, safely avoided. In order to further increase the effectiveness in separating the mass strands, it is possible to simultaneously guide a plurality of liquid jets through the mass strand to be separated.

The technical-economic effects of the method according to the invention are that with minimal Werkstoff'abfällen and avoiding contamination of the same a post-processing of the parting surfaces and grinding the separate workpieces no longer required and thus a significant increase in productivity 20-reach.

The preparation of the remaining material waste,. which has special significance in the sometimes very valuable oxide ceramic materials, presents no difficulties, so that material losses are essentially excluded. ,

Claims (3)

Claim of invention. 1. A method for separating ceramic masses, in particular unsintered oxide ceramic masses, characterized in that one or more liquid jets are performed by a mass strand with a jet velocity of at least 100 m / s and a diameter of 0.0 5 to 0.5 mm, wherein the feed cutting speed is selected so that a recooling of the mass takes place by means of a liquid excess supplied to the cutting area. 2. The method according to item 1, characterized in that a 0.5 to 4 percent aqueous solution of the binder of the oxide ceramic composition is used as cutting fluid. 3 · Procedure according to point 1 «. and 2., characterized in that the liquid jets preferably have a jet velocity of 300 m / s and a diameter of 0.2 mm.