MOLDING
Fountain Foundry uses a variety of molding techniques depending on size and production volume. From automated match-plate molding for high volume to loose molding for prototypes, Fountain Foundry has the equipment and knowledge to produce the castings you need with an emphasis on controlled cost and consistent quality!
MATCH-PLATE MOLDING
The principle of the matchplate, meaning pattern plates with two patterns on each side of the same plate, was developed and patented in 1910, fostering the perspectives for future sand molding improvements.
In the early 60's, Hunter Automated Machinery Corporation launched its first automatic flaskless, horizontal molding line applying the matchplate technology, and it is widely used today, including at Fountain Foundry.
Automated matchplate molding's great advantage includes inexpensive and easy to change pattern tooling, thus letting us quickly switch between long series or short series castings.
EQUIPMENT WE USE:
- Hunter Automatic- 14x19, 18x20, and 20x24 (18x20 is adaptable to 16x20 & 14x19)
COPE & DRAG
The terms cope and drag refer respectively to the top and bottom parts of a two-part casting flask, used in sand casting. The flask is a wood or metal frame, which contains the molding sand, providing support to the sand as the metal is poured into the mold.
In the simplest sand casting procedure, the drag is placed upside down on a board, around a pattern of the part to be cast. The pattern is a model of the desired casting. Talcum powder is often dusted over the pattern to aid in the removal of the pattern. Sand is sifted over the pattern until the model is covered by a few inches of sand. More sand is then dumped into the drag, and rammed with a wooden wedge, or mechanically vibrated to pack the sand down. The sand is then struck level with the top edge of the drag, using a wooden or metal strake. A board is then placed on top of the drag and the drag is flipped over.
Then, the cope is placed on the drag, and dowels (or pins) are put in the sand to make holes for the sprue and one or more risers. Talcum powder and sand are again sifted over the pattern, and rammed to fill the cope. The pins are then carefully pulled out of the sand. The critical part of the operation is to separate the cope and drag to remove the pattern. The pattern may be vibrated with a powered vibrator, or the pattern, and maybe the cope and drag flask, will be lightly tapped with a small hammer. The pattern is lifted from the sand, leaving a molding cavity. A passageway for metal to enter the mold, called a "gate", is then cut from the sprue hole to the void left by the pattern, and a runner is cut from the sand to allow metal to flow into the riser.
The flask is then put back together, and metal can be poured into the mold. The metal will flow down the sprue, into the mold cavity, and back up the riser (of which there may be several). Once the metal has cooled enough to solidify, the flask can then be separated again, and the sand removed to reveal the rough casting. The rough casting is separated from the sprue and riser(s) either by sawing them off, or just breaking the thin metal of the gates and runners.
In some cases the part design is more complicated, and intermediate flasks and mold sections are needed between the cope and drag. These sections are called cheeks.
EQUIPMENT WE USE:
BMM CT-6's, SPO Rollover
FLASK SIZES:
14x19 to 42x42
COPE & DRAG INSERTS:
24x27, 30x38, and 42x42
LOOSE MOLDING (PROTOTYPES ONLY)
CORE PROCESSES & EQUIPMENT
WHAT ARE CORES?
Cores are used to generate hollow cavities or internal features which cannot be formed using a pattern alone. They are generally made of sand, however some processes use permanent cores made of metal.
To produce cavities within the casting, negative forms are used to produce cores. Cares are inserted into the casting box after removal of the pattern.
With a completed mold at the appropriate moisture content, the box containing the sand mold is then positioned for filling with molten iron,. After being filled with liquid metal the box is set aside until the metal is sufficiently cool to be strong. The sand is then removed, revealing a rough casting. As iron is generally heavier than the casting sand, the casting flask is often covered with a heavy plate to prevent floating the mold. Floating the mold occurs when the pressure of the metal pushes the sand above the mold cavity out of shape, causing the casting to fail.
OUR CORE PROCESSES:
Oil Sand, Shell, CO2, SO2, Pep-Set, Furan Warmbox
OUR CORE EQUIPMENT:
Shalco U-180’s, Redford 44A, 16, 22, CB-5, CB-10
BP6A, Dep 100, Carver Batch & Continuous Mixers
Core Process & Equipment
