Foundry Technology: Design for casting, Study notes of Mechanical Engineering

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EMG 5114 FOUNDRY

TECHNOLOGY

MAY 2025

CHAPTER 6: FOUNDRY MODERNIZATION & AUTOMATION

Major limitations in most foundries

• Safety
  • Higher working temperatures - Workers are exposed to extreme heat, increasing the risk of heat stress and burns
  • Handling molten metal - Molten metal poses severe risks of burns and injuries, requiring meticulous handling and safety protocols
  • Fire and explosion hazards – Furnace charging prone to explosion risks
  • Higher noise levels - Some operations within foundries generate high noise levels, potentially causing hearing damage
• Environmental concerns
  • Air pollution – released toxic fumes, gases
  • Waste management – Disposal of used sand, melt slag

Modernization and automation

❑ Foundry modernization refers to the process of updating and

upgrading the equipment, processes, and technologies used in

foundries to improve efficiency , productivity , safety , and

environmental compliance. This includes the implementation of

advanced materials, state-of-the-art machinery, improved

workflow processes, and enhanced safety measures to bring

foundry operations in line with current industry standards and

technological advancements.

❑ Foundry automation involves the integration of mechanized

systems and robotics into foundry operations to perform

repetitive and hazardous tasks with minimal human

intervention. Automation in foundries aims to increase

production speed , consistency , and precision while reducing

labor costs , minimizing human error , and enhancing workplace

safety

Reasons for modernization and automation

• To workers –

✓ Improved working condition

✓ Ensure a safe , healthy and happy life

• To owners –

✓ Higher productivity & Lower rejection

✓ Improved Quality

✓ Reduction in production cost

✓ Better company image ,Stronger Partnerships

& improved marketing

✓ Keep pace with the changing technology

Areas for modernization and automation

• Material handling
• Pattern making
• Molding and Core making
• Melting, Pouring and Fettling operations
• Pollution Control

Material handling

• Foundry material handling equipment refers to the machinery and tools used to transport, manage, and store materials within a foundry.
• This equipment is essential for the efficient and safe movement of raw materials, molten metal, casting molds, and finished products throughout the foundry process
• Include; Belt conveyors, Bucket elevator, apron conveyor, Flight conveyor, Reciprocating and oscillating conveyors, monorail conveyor, cranes etc. Roller conveyor, pallet conveyor, overhead conveyor, Industrial trucks, robots etc. Belt Conveyor Bucket elevator Roller Conveyor Pneumatic Conveyor Pallet Conveyor

Sand preparation Continuous Mixer - Pivotal type for small to medium size and the mobile type for heavy jobs. Consist of horizontal trough fixed to a column at one end with a rotating shaft with blades around fastened to it .The sand along with the resin and hardener are introduced at one end in the trough in measured quantities using a metering device. As the constituents travel from one side to the other they get thoroughly mixed and the sand grains are uniformly coated with resin. Moldability Controller – Has a slotted vibratory feeder trough and a system of photo electric cells. The controller is positioned at the sand mixer from where a small amount of sand enters the controller. The sand falls onto the vibratory feeder and moves towards the slots .when the sand is dry it falls through the slots and block off the focusing aperture through which the two lights are sources are directed towards the two photocells. The interruption of these light cells opens two water valves in the mixer to add more moisture to the sand. When the required amount of water has been received by the sand, the sand is dispensed. Integrated systems – Where sand preparation with mixed resin sand continuously discharging into a molding box placed on vibratory compaction table, a pattern loop- mould stripping device and a shake out with a reclamation plant Sand Preparation Mixer Continuous Mixer Mobile Mixer

Moulding and core making

Power operated molding machines - These machines use electrical or hydraulic power to automate the process of molding sand into the desired shapes for casting. They significantly reduce manual labor and improve the consistency and quality of molds High pressure molding machines - These machines apply high pressure to compact molding sand around a pattern, creating dense and precise molds. High pressure molding machines are essential for producing high-quality castings with fine details and smooth surfaces Core – blowing machine - Core-blowing machines use compressed air to blow a mixture of sand and binder into a core box, forming the internal shapes and cavities of castings. This equipment ensures uniform core density and reduces defects in the final castings Core drawing machines - Core drawing machines are used to extract cores from the core boxes without damaging them. They are designed to handle delicate cores carefully, ensuring they maintain their shape and integrity for the casting process Continuous core making machines - These machines are designed for high- volume production of cores, continuously mixing, shooting, and curing core sand. Continuous core making machines improve efficiency and throughput, making them ideal for large-scale foundry operations Sand Molding Automated Core blowing machine Molding Machine

Handling casting

• Conveyors used to move casting between the shakeout, fettling and inspection stations
• The separation of castings and sand is almost always done on vibrating machines.
• Shakeout conveyors are used to shake off and segregate sand from castings and to crush the sand lumps without damaging the castings. Vibrating shakeout station

Reclaimed sand preparation equipment

1) Magnetic Separator

• The moulding sand coming from shake out station must be freed of iron particles and foreign matter before being put to reuse.
• The magnetic separator consists of magnetized pulley over which flat rubber or canvas belt rolls.
• As the belt rolls over pulley, the sand and non magnetic particles falls freely.
• The ferrous objects on other hand tend to cling the belt due to magnetization effect and drop off only when the belt has left the pulley.
• The pulley may be permanent magnet type or electromagnet type carrying DC magnetizing coils.

2) Riddle-

• After separation of iron pieces, the sand

usually passed through screen or riddle.

• Pieces of dry sand cores, hard lumps of

sand are eliminated

• Mechanical riddles can screen much faster

than hand riddles.

• There are two types of riddles available
• Operated by compressed air
• Operated by electric motors

Emerging technologies

in metal casting

Robotics and robotic applications

• Many operations that are performed in a foundry are ideally

suited for robotic automation, because they are -

• ‘Three D’s’ - dirty, dangerous and dull
• ‘Three H’s’ - hot, heavy and hazardous
• Robotics and robotic applications are transforming metal casting

foundries by automating repetitive and hazardous tasks,

enhancing efficiency, precision, and safety.

• These technologies enable higher consistency and accuracy in

operations, reduce defects, and improve overall casting quality.

• Additionally, robots equipped with sensors and AI optimize

production in real-time and create a safer working environment

by minimizing human exposure to extreme conditions.

❑ Robotics and robotic applications ❑ Computer simulation of the casting process ❑ Additive manufacturing for pattern and mould making ❑ Industry 4.0 and the smart foundry

Computer simulation of the casting

process

• Computer simulation of the casting process involves using advanced software to model and analyze every stage of metal casting, from mold filling to solidification.
• Simulation includes mold filling and casting solidification, useful for optimizing the design of gating and risering systems respectively. Casting model is the main input for simulation
• This technology allows foundries to predict and prevent defects, optimize mold design, and improve overall casting quality before physical production begins.
• By reducing trial-and-error and material waste, computer simulation enhances efficiency and cost-effectiveness in the casting process.
• Some of the commonly used CAE modelling softwares include CastCAE, Magmasoft, ProCAST, AutoCAT etc.

Industry 4.0 and smart foundry

• Industry 4.0 and the concept of the smart foundry integrate IoT, data analytics, and AI to create highly automated

and interconnected manufacturing environments.

• In smart foundries, real-time data from various stages of the casting process is collected and analyzed to optimize

production, improve quality control, and enhance predictive maintenance.

• This transformation leads to greater efficiency, reduced downtime, and the ability to swiftly adapt to changing

market demands, positioning foundries at the forefront of modern manufacturing advancements.

Pollution Control

Major foundry pollutants

• Dust
• Gases
• Fumes
• Noise Foundry process map Sand (new/old), coal dust, water, energy liquid metal Molding Section Dust, gases, mold forms, used sand Dust, gases, noise, reject mixed sand, surplus sand Dust, gases, surplus sand, noise, rejected molds Energy Gases, organic fumes Patterns, mold forms, sand filling, coatings, energy

Sand mixing

area

Molding

section

Casting area

Shake-out &

Cleaning area

INPUTS Non-Product Finished OUTPUTS

products

Dust and fume control

1. Filter:

• Filter serves for removing gas or air streams by retaining it in or on the porous structure through which the gas flows.
• Porous structure is usually a woven or felted fabric. Filter must be continuously or periodically cleaned or replaced.
• Filters are commonly employed in pattern shops on various wood working machines, such as band saw, circular saw.
• They are also used on cupola collection systems in conjunction with other equipment, such as afterburners, gas cooler, exhaust blower etc.
• Sand reclamation plants also use bag filters for separating fumes from sand grains.

2. Cyclone

• It works on principle of centrifugal separation in which a

vortex motion of particulate matter is created within the

collector.

3. Mechanical collectors

• It collects particulate matter by gravity or

centrifugal force but do not depend upon vortex as

in the case of cyclones.

Centrifugal dust collector