One. Basic Definitions

The hat-type fiberglass filter mesh is also known as filter cap or funnel-type filter cap.

● It is made by weaving non-alkali/high silica fiberglass and then forming them through three-dimensional hot pressing.

● Its shape is a reversed cap or conical bowl-shaped.

● It is specifically used to cover the top of the gate cup and the top of the straight pouring channel.

● It is a special filter consumable specifically designed for aluminum alloy low-pressure casting, wheel hubs, cylinder bodies, and piston precision casting.

Two. Core Functionality

1. Physical interception (main filtration function)

Three-layer filtration mechanism for simultaneous purification of aluminum liquid:

1) Mechanical interception: The grid blocks large-sized impurities such as alumina sludge, furnace slag, molding sand, and refractory debris. The interception rate of ≥ mesh-sized impurities is over 95%.

2) Fiber adsorption: The micro pores of the glass fiber strands can adsorb micron-sized impurities. Ordinary flat filter screens do not have a three-dimensional adsorption space, while the three-dimensional structure of the filter cap increases the adsorption capacity by 3 times.

3) Stable flow rectification: Disrupt the impact vortex of the molten aluminum, converting the turbulent flow into laminar flow, thereby eliminating the secondary oxidation of the molten aluminum and preventing the formation of new floating slag. This reduces the occurrence of slag inclusion defects at the source.

2. Casting process suitability for application

1) Low-pressure cast aluminum (for automotive wheels, cylinder heads, pistons): Standard essential consumables. Installed in the gate cup. The molten aluminum is continuously filtered to ensure no air holes, slag holes or cracks in the wheel hubs.

2) Precision cast aluminum with gravity principle: Motor housing, new energy structural components, and aluminum parts for motorcycles. Simplified pouring system, reduced cross-flow channels for slag removal structure.

3) Continuous casting of aluminum rods and ingots: A conical filter cap is installed at the flow channel to filter and purify the molten aluminum water, thereby enhancing the purity of the aluminum profiles.

4) Lost-wax/mold casting aluminum: The wax mold has pre-installed filter caps at the pouring ports. The process of sand coating and firing remains intact without any damage, ensuring stable filtration.

3. Supplementary Function

1) Diversion Buffering: Reduces the erosion of the mold and gate by the high-temperature aluminum liquid, thereby extending the service life of the mold.

2) Simplified cleaning: The gate sludge and the filter screen are completely separated, reducing the grinding and machining allowances for the castings.

3) Re-meltable: The filter screen can be remelted along with the mold material without contaminating the aluminum liquid, and no iron elements are released.

Three. Core Advantages

Compared with Flat Filter Mesh, Stainless Steel Filter Mesh, Ceramic Foam Filter!

1. Unique structural advantage (hood-shaped three-dimensional design)

● Sealing without leakage of slag: The edges are inverted and tightly fitted to the gate cup, with no side leakage gaps. The flat filter plate does not shift, and the molten aluminum flows around from the side without slag leakage.

● Install the zero-fixing parts: Simply place the gate directly, and the mold sand will compress it tightly. No need for clamps or brackets; it is compatible with automated production lines.

● High slag retention capacity: The three-dimensional bowl-shaped cavity stores the slag, making it less likely to clog the net during long pouring processes. It is suitable for large-scale and continuous pouring.

2. Material performance advantages (high silica oxide / alkali-free glass fiber)

● High temperature resistance: Alkali-free glass fiber can withstand 800℃, high silica glass fiber (SiO₂ ≥ 96%) can withstand 1100–1200℃ for a short period of time, suitable for aluminum water casting temperatures of 680–780℃, does not soften or melt and break the fibers.

● Chemical inertness: Free of iron and heavy metals, does not react with aluminum liquid, will not cause excessive iron content in the aluminum liquid or component contamination; Stainless steel filters will leach iron ions, resulting in the scrapping of high-end aluminum alloy castings.

● Extremely low gas emission: The gas emission of the carbonization process filter cap is less than 0.5ml/g, and it will not cause under-chip gas pores in the castings; the ordinary resin filter screen has a large gas emission and is prone to gas shrinkage cavities.

● Resistance to erosion: Molded with phenolic resin, resistant to the impact of high-temperature aluminum liquid. The entire pouring process is free from damage and fibers do not fall off.

3. Production economic advantage

● Reduce scrap rate: It can reduce slagging, porosity and sand holes by 70%, and the quality rate of high-end cast aluminum parts can be increased by 15% to 40%.

● Lower cost: The unit price is much lower than that of ceramic filter sheets. The single-use cost is only one-third of that of ceramics.

● Waste recyclable: The material with filter screens from the gate is directly recycled in the furnace for remelting, with no additional solid waste disposal costs.

● Reduce tool wear: The internal structure of the castings contains no hard slag particles, significantly reducing the wear of the CNC machining tools.

Four. In-kind Shooting