Baoding Ningxin New Material Co., Ltd.

Baoding Ningxin New Material Co., Ltd. Manufacturer of foundry molten metal filters including fiberglass mesh filter, silica mesh filter and ceramic foam filter, extruded ceramic filter, etc..

Reasons for Filtering:The Ceramic Filters are used to filter metals like aluminium, cast iron, copper, steel, and their ...
31/07/2015

Reasons for Filtering:

The Ceramic Filters are used to filter metals like aluminium, cast iron, copper, steel, and their alloys. These metals in their molten state contain metallic and non-metallic inclusions:
Metallic inclusions are the residues of metallic additions or improperly dissolved metallic additions or inoculants.
Non-metallic inclusions occur in two types:
A. Exogenous inclusions
They are introduced from the outside. They can be the lining material of the furnace, ladle, or, mould material introduced as a result of erosion.
B. Endogenous inclusions
They are formed internally and occur due to liquid metal oxidation while pouring or as a by-product of metallurgical reactions. They are found, in particular, as oxides and sulphides.
The Effects of Inclusions in Castings can cause following defects:
POOR SURFACE QUALITY - The inclusions, impair the appearance of the casting surface and need considerable machining tolerance. They even react with the mould material, increasing surface roughness.
DETERIORATION OF MECHANICAL PROPERTIES - The inclusions that form on the grain boundaries as films, damage large areas of metal structure. As a result mechanical properties like ductility and fatigue strengths will decline considerably.
POOR MACHINABILITY - The non-metallic inclusions are harder and therefore difficult to machine. This leads to the deterioration of the machined surface, reduced cutting performance and considerable reduction of tool life.
CASTING LEAKAGE - The inclusions in the castings act as conduits for pressure, which penetrates through the cast walls leading to leakage in pressure loaded castings.
GAS BUBBLES - The gas bubbles occur by the reaction of inclusions with the metal or can act as nuclei for bubble nucleation during solidification. This can be avoided by getting rid of the inclusions.

Filtration effect of Foam Ceramic Filter:Filtration: reduce the impurities which could lead to the casting defects (incl...
31/07/2015

Filtration effect of Foam Ceramic Filter:

Filtration: reduce the impurities which could lead to the casting defects (inclusions).
Elimination of bubbles in metal.
Regulate and homogenize the metal flow, reduce the oxidation, improve casting quality.

Increase castings yield rate by 5 –10%
Reduce castings reject rate by 15 –30%
Improve castings Compressive strength and rigidity by 5~10%
Improve castings bending resistance strength by 5~8%
Simplify the gating system
Improve the machining performance of castings.

How is ceramic foam filter produced?The Ceramic Foam Filters have the same inherent shape as that of the polyurethane fo...
31/07/2015

How is ceramic foam filter produced?

The Ceramic Foam Filters have the same inherent shape as that of the polyurethane foam media. They are highly efficient, have an open pore and a reticulated structure with a very high volume of porosity- in excess of 90% - and very high surface area to trap inclusions.

The Ceramic Foam Filters are manufactured by impregnating the base polyurethane foam media with ceramic slurry and baking it at very high temperatures. During this process the base FPCP media melts away and the ceramic skeleton structure remains.

In these filters the molten metal takes a tortuous path, leading to the removal of very small inclusions by attraction and adsorption to the internal ceramic pore surfaces.

Development of foundry filterSetting filter in gating system of casting is the technology in recent 20 years. In the beg...
31/07/2015

Development of foundry filter

Setting filter in gating system of casting is the technology in recent 20 years.

In the beginning people use oily sand or green sand to make sand core with hole, it is usually square or round with thickness 10–20mm and it can be used after drying.The filter is usually set above or below the sprue and runner with performance of filtration,but oily sand or green sand can not endure high temperature molten metal so the use of filter is limited.

Later,fiberglass and metal filter are extensively popularized and also they are easy to use and cheap,but the high temperature resistance capacity and filtration performance is not so ideal so the widely use is limited.

Along with the development of science and technology and better requirement of the metal purity one new type of Foam Ceramic Filter are applied in foundry industry and it brings a qualitative leap for filtration of molten metal.

E-glass fiberglass mesh filter for aluminum filtration are specially designed and woven for the diffusion and filtration...
31/07/2015

E-glass fiberglass mesh filter for aluminum filtration are specially designed and woven for the diffusion and filtration of aluminum.High twisted yarns are used to control strand diameters and resist flattening or distortion under pressure from contact with molten metal. The integrity of the weave pattern is maintained by the use of phenolic resin, and by the use of leno or Plain construction in high density.

31/07/2015

USING SILICA MESH TO HELP ON REMOVING RISER AND GATING PARTS

High silica fiberglass mesh was originally introduced as the filtration media for removing impurities from molten metals. Another very useful application is to be used for riser knock-off or degating knock-off.

NX-RiserBreakers generally consist of a cut disc of silica mesh filter material that is embedded directly into the inner wall of a shell or sand-based breaker core.This RiserBreaker is then typically attached to the bottom of any variety of riser sleeve(exothermic,shell-based,etc.) and then placed into the pattern.If there is a concern about the riser "flow", a small feeder hole is cut in the center of the silica mesh to ensure the molten metal flow is adequate.The primary benefits in using RiserBreakers include an upper temperature threshold of 1620°,complete rigidity (no deflection into casting),and the ability to be used for most of all ferrous and non-ferrous metals like non-ferrous, grey iron,ductile iron,low-carbon and Manganese steel etc..

ADVANTAGE:
-Readily fit to most common riser sleeves
-No deflection into casting
-Knocks-off easily with minimal force
-Cost-efficient de-risering
-Center hole for flow rate management
-Use in standard riser feeder application or as part of direct-pour sleeve

RISER REMOVAL:
There are three hole sizes available for silica mesh:1.5x1.5mm,2.0x2.0mm and 2.5x2.5mm.
Among them, 2.0x2.0mm and 2.5x2.5mm is the most common ones for riser removal. These 2 weaves offer the good percentage of open area which allows for proper metal feed to the casting.The material is available to foundries as flat fabric, or it can be purchased in die-cut pieces. In either case,for riser removal applications, it is common practice to cut a small hole through the silica mesh. This permits any impurities which may be trapped on the mesh surface during pouring, to flow up into the riser. This small opening also ensures effective feeding by the riser, while still facilitating good riser break off, and minimizing fabric sagging.Silica mesh has been found to be most effective as a breaker material when used with neck down riser sleeves. In many applications, the silica mesh can replace breaker cores with much lower cost - insertion of the fabric by itself or in conjunction with a breaker core.

FILTRATION & RISER/GATING PARTS REMOVAL:
In direct pour applications, where the riser also serves as the point of metal entry,silica mesh may serve two purpose:acting as both a molten metal filter, and a riser knock off plane.

HOW TO APPLY:

Silica mesh may be fastened to insulating or exothermic riser sleeves by nailing or gluing the fabric to the base of the sleeve.Although silica mesh can withstand pouring temperatures to 1620°C, it will become soft when contact with molten metal.Therefore, it is recommended that a riser pad of 1/4"-3/8" be used to prevent a mesh imprint on the casting's surface.

Abrasive wheel cutting is eliminated when using silica mesh for a breaker material.While the effectiveness of silica mesh, in terms of riser knock-off characteristics, is still largely dependent upon the ductility and temperature of the metal at the time of riser removal, in most cases, including ductile iron castings, 100% de-risering is achieved during shake-out operations.Also the large risers are simply removed by impact with a mallet or hammer of sufficient size. This procedure is normally followed by a minor grinding operation to remove the riser pad and achieve final casting cosmetic standards.

Address

Baqie Industrial Zone, Tang, Hebei
Baoding
071000

Telephone

86-312-8925702

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