[0001] Object of the invention is a method for treatment ceramic parts, which are used in
the industry of artificial synthetic fibers, for the purpose of recycling or more
precisely controlled process of surface treatment with a view to the processing of
the ceramic part to such a degree that it is achieved, that the ceramic part with
the same purpose, or the same or similar characteristics is re-used in the production
process of synthetic fibers as it has new ceramic part.
[0002] Technical problem presented by the process according to the invention successfully
addresses the recycling process of ceramic parts, especially in the industry of synthetic
fibers, where the ceramic components are present in apparatus and machines for processing
fibers.
[0003] The present invention allows controlled mechanically treating the surface of ceramic
by removing the damaged/modified surface in order to achieve a known end surface.
[0004] Ceramic parts used in the industry of synthetic fibers are usually made from high
quality oxide ceramics, whose share of Al2O3 is about 99.6%. The ceramic materials
are characterized by high mechanical strength, stability at high temperatures (temp.
of the melting point ≥ 2000 °C), low coefficient of thermal expansion and corrosion
resistance. The ceramic parts, which are embedded in the manufacturing process are
exposed to extreme operating conditions, such as high speed running artificial fibers
(filament) to 5200 m/min, temperature from 30 to 80 °C, the quantity of matting agents
( from 0 % up to 1.6 % TiO
2) and the impact of the shape filament (trilobal, round). All previously described
extreme conditions caused by constant changes in the surface of ceramic parts.
[0005] Ceramics is material widely used in fiber industry in the spinning, texturing, covering
and downstream fiber processing. Mainly as Spin finish applicators, Pigtails, Tread
guides ,discs for texturing yarns, Guide discs, working discs and knife discs, Jet
plates, Traverse guides, Eyelets Ceramic, cutters Rollers, birotors, etc. spin finish
applicators Pigtails Jet
[0006] Chemical corrosion, friction, surface wear and electrostatic interaction during the
production process demand ceramic material with high surface quality. Mainly such
ceramics are known as technical ceramics e.g. oxide ceramics Al2O3 purities more than
90% and with different additives to improve physical characteristics. Due to requested
ceramics structure which define high demanding mechanical properties the manufacturing
process is composed of high temperature sintering conditions up to 1800 °C and time
needed up to 200 minutes means high energy consumption. Therefore the ceramics parts
present significant maintenance costs for fiber producers, especially when critical
fibers are produced. Beside maintenance costs of fiber producers the production of
new ceramic parts represent also a big environmental impact as energy consumption
and toxic exhausting gases within sintering process.
[0007] Nowadays fiber producers are forced to be focused on optimizing production yields
and fiber quality. Only constant process conditions and polymer quality can lead to
uniform dyability and efficient downstream processing.
[0008] One of the most critical part of fiber processing equipment found in field of invention
are ceramic parts. Changed / damaged ceramics surface due to fiber production process
leads to non-uniform fiber quality, mainly provokes by different yarn tension and
consequently high temperature.
[0009] The process according to the invention allows that the changed and/or damaged and/or
worn ceramic parts of various sizes and shapes that constitute the waste by-product
of the processes of production and processing of synthetic artificial fibers and similar
processes can be restored by subjecting the specific process of treating the surface
with abrasive means, to reach the final quality of the known structure of the surface.
[0010] The method of the invention allow to altered and/or damaged and/worn ceramic parts
of different sizes and shapes, which are excluded from the production process of causing
a variety of fiber tension, uneven application preparation oil, capillary breakage,
the occurrence of loops in bobin and other physical and chemical changes in the fiber,
which can lead to inhomogeneity of the fiber and a low production efficiency in the
industry of synthetic artificial fibers and similar processes, exposed to controlled
surface treatment by abrasive particles or sand-like particles (such as beads or diamond
particles, or metal balls or particles) and other abrasive material in the form of
spheres or particle, which can be used as a scrubbing agent for the surface treatment
of the ceramic parts in order to achieve the same or very similar surface properties
as a new ceramic works.
[0011] The invention will be explained in detail on the basis of an embodiment and the accompanying
drawings, in which:
Figure 1 show the surface of the ceramic part which is subjected to a treatment with
abrasive particles;
Figure 2 show the controlled passage through the nozzle staticsided ceramic part;
Figure 3 show guided nozzles with vertical and horizontal displacement in relation
to a moving clamped ceramic part (rotating) ;
Figure 4 a comparison of the new, used and updated surface of the ceramic part of
the process according to the invention.
[0012] A ceramic parts A of various shapes and dimensions, with a modified and/or damaged
surface is exposed to controlled process of treating the surface with an abrasive
agent B, that is, abrasive particles, or sand-like particles (such as beads or diamond
particles, or metal balls particles) and many other abrasive materials in the form
of spheres or particles, which can be used as a scrubbing agent for the surface treatment
of the ceramic parts (Figure 1).
[0013] Method of treating ceramic parts A, which is used in the industry of artificial synthetic
fibers, for the purpose of recycling is divided into three main stages, namely:
- preparation of the ceramic part A, where changed/damaged ceramic part A is controlled
with optical or similar magnifying device more than 30 x magnification to verify the
surface of the ceramic part A suitable for processing with abrasive material B. In
this step eliminating broken or damaged ceramic parts which would lead that further
surface treatment would not proper change the ceramics surface to the level of new
one. Method of optical determination can be manual or even upgraded to full automatic
detection of changed/damaged surface of ceramics as cracks, fractures, broken edges,
etc.). Ceramic part A preparation step can be also omitted but this leads to higher
reject at the final treatment and the optical control.
- treatment the surface of the ceramic part A with abrasive material B, where ceramic
part A which was already optically controlled for the readiness of the surface to
be mechanical treated is embedded in the carrier of the sand blasting machine with
the abrasive material B. Machine has to have precise (e.g. electronically) guided
(according pre-set process cycle) nozzle C (Figure (a2)) which with controlled movement
over the static embedded ceramic part A removes changed surface of ceramic part to
the level as new ceramics part is demonstrating. The process can be also driven in
such a way that carrier of the ceramic part A (Figure (a3)) of is moving (e.g. rotating)
and movement of guided nozzle C is in relation of movements in vertical and horizontal
direction to treat the ceramics surface of the ceramic part A.
In a composition of machine settings for processing with abrasive material B (Figure
2 and 3) the following parameters are important;
- (i) inlet angle D of blasting nozzle C which should be between 0 degrees and 180°
according to impact position to the ceramic part A surface,
- (ii) abrasive media B as sand or sand like materials (selection of right dimension,
shape and material structure):
in the invention process two different materials were in use, such as Corundum 220
and Corundum 70, usage of both depending of ceramic parts A final surface properties
were requested,
- (iii) the size of sand basting nozzle C for abrasive media B (size of nozzle between
0.01 mm to 1 cm),
- (iv) speed or time which is needed that the sand blasting machine for processing with
abrasive material B treat particular section of ceramic part surface (time of treating
one surface point of ceramic part A surface and after each further part of ceramics
surface area points among whole ceramics surface is between 0.1s to 3 minutes),
- (v) pressure of the sand blasting device for processing with abrasive material B which
pushes the abrasive particles to the ceramic part A surface to achieve removal of
changed surface of ceramic part (inlet air pressure is more than 2 bar).
- final treatment and optical control where the ceramic part A which was exposed to
surface controlled abrasion is exposed to gentle polishing treatment of treated ceramics
surface (e.g. movements of fine nylon / cotton brushes with direct contact over ceramics
treated surface). After the polishing treatment also ultrasonic treatment is an option
to achieve perfect non-dusty surface of ceramics part A surface (ultrasonic bathing
is not a must but an option to achieving better result in matter of cleanliness of
the ceramics part A surface). Last action is the optical control of the treated ceramics
part with optical or similar magnifying device more than 30 x magnifications to confirm
the ceramics part A surface is in the same condition as new ceramics part.
[0014] Within development of proper method for treating the changed / damaged ceramics surfaces
several different methods were evaluated as;
mechanical brushing of ceramic part A surface (e.g. abrasive rotating discs);
mechanical abrasion of ceramics parts surface (e.g. high speed polishing yarn with
polishing abrasive paste)
protecting or renewing the ceramic part A surface with applying of mechanical resistant
lacquer and backing that lacquer with high temperature up to 1500 °C or process of
polymerization under ultraviolet light.
[0015] Figure 4 shows a comparison of the structure of the new ceramic part and the ceramic
part, which has been treated with the procedure of processing ceramic parts according
to the invention
1. Method of treatment ceramic parts, using in industry of artificial synthetic fibers,
for the purpose of recycling,
characterized in that,
it takes place in three stages, namely: ceramic part (A) preparation, treatment of
the surface of the ceramic part (A) with abrasive material (B) and final treatment
with optical control.
2. Method according to claim 1,
characterized in that,
in the preparation of ceramic part (A), check the manual or automated machined ceramic
part (A) with an optical magnifying device zoom more than 30x, eliminated cracked
or such damaged areas of ceramic parts (A).
3. Method according to claim 1,
characterized in that,
in the processing surface of the ceramic part (A) with the abrasive material (B),
optically inspected ceramic part (A) is inserted in the bed of the apparatus for processing
with abrasive material (B), wherein the device has a precisely controlled, according
to pre-process parameters nozzle (C) which, with controlled directed movement through
static spanning the ceramic part (A), removes the modified surface of the ceramic
part (A).
4. Method according to claim 3,
characterized in that,
the ceramic part (A) is movable or rotating mounted in the device for treatment, or
the ceramic part (A) is static mounted in the bed of the device for treatment and
the nozzle (C) travel over them.
5. Method according to claims 3 or 4
characterized in that,
the angle (D) of sand blasting nozzle (C) for abrasive material (B) is between 0°
and 180° according to impact position of the ceramic part (A) surface,
abrasive material (B) is sand or sand like material such as Corundum 220 and Corundum
70;
the size of sand basting nozzle (C) for abrasive material (B) is between 0.01 mm to
1 cm);
speed or time which is needed for processing with abrasive material (B) is between
0.1 sec to 3 minutes;
pressure of the sand blasting device is more than 2 bar).
6. Method according to claim 3,
characterized in that,
in the final processing of the ceramic part (A) its surface is treated with a gentle
polishing action in the region where the modified surface is removed, and alternatively
use ultrasonic bath, followed by a visual check the machined surface of the ceramic
part (A).