Material Considerations for Successful Demolding
Posted: Sat Dec 28, 2024 9:37 am
Pin Ejectors : These small pins push the part outward. They distribute the ejection force at multiple points, allowing the part to be removed without damaging it.
Sleeve ejectors : These ejectors are applied to cylindrical parts. They surround the part and expel it radially.
Blade ejectors are essential for narrow parts. They eject thin-walled parts without damaging delicate parts of the product.
Stripping Plates: An extended plate contacts all parts of the casting and is suitable for large and delicate products.
Ejector pins pushing the casting out of the mold
Ejector pins pushing the casting out of the mold
Ejection system - Sleeve ejectors
Removal of the part
This process is just as essential as the mechanical ejection system. Proper part removal helps reduce defects and damage. Common techniques include:
Direct Ejection : Often, technicians eject the part directly after ejection by the pin or other mechanisms. This method is mainly applicable to simpler parts with small contact areas or complicated part geometry.
Manual removal : Some parts are complex, fragile and sticky. fan data In this case, technicians remove them manually, using pliers or other hand tools or handling equipment compatible with the line.
Robotic removal : This technique is applied to fully automated molding lines. It involves the use of robotic arms or mechanical manipulators to provide the buoyancy force required to demold the part. This method minimizes the impact of damage and increases the demold rate, especially when manufacturing a large number of products.
One of the most important questions in the demolding process is whether to use thermoplastics or thermosets. Versatile thermoplastics include polypropylene and polyethylene. These plastics can soften at high temperatures but become rigid at low temperatures. Their shrinkage flexibility makes them easy to demold. However, some thermoplastics, such as polycarbonate, can tend to stick to the mold. These products require a release agent to be removed.
Conversely, thermoset materials such as epoxy and phenolic resin are complex to demold after curing. The curing process of these plastics is irreversible. The rigidity and brittleness of thermosets increase the risk of surface destruction or cracking during ejection. Special attention is required when designing mold features and ejection techniques.
Methods to improve demolding efficiency and prevent parts from sticking in the mold include subsequent treatments and coatings of the mold surface. A smooth surface on the mold will make demolding easier. These surfaces have less friction than rough surfaces, making them easier to demold. Some of the substances used include PTFE (Teflon) and nickel or chromium. PTFE makes the part surface non-stick, while nickel or chromium plating provides a hard surface that improves demolding and mold longevity.
In addition, using release agents before each cycle can facilitate the demolding of sticky products. These treatments ensure high-quality parts and increase mold life and manufacturing efficiency.
Sleeve ejectors : These ejectors are applied to cylindrical parts. They surround the part and expel it radially.
Blade ejectors are essential for narrow parts. They eject thin-walled parts without damaging delicate parts of the product.
Stripping Plates: An extended plate contacts all parts of the casting and is suitable for large and delicate products.
Ejector pins pushing the casting out of the mold
Ejector pins pushing the casting out of the mold
Ejection system - Sleeve ejectors
Removal of the part
This process is just as essential as the mechanical ejection system. Proper part removal helps reduce defects and damage. Common techniques include:
Direct Ejection : Often, technicians eject the part directly after ejection by the pin or other mechanisms. This method is mainly applicable to simpler parts with small contact areas or complicated part geometry.
Manual removal : Some parts are complex, fragile and sticky. fan data In this case, technicians remove them manually, using pliers or other hand tools or handling equipment compatible with the line.
Robotic removal : This technique is applied to fully automated molding lines. It involves the use of robotic arms or mechanical manipulators to provide the buoyancy force required to demold the part. This method minimizes the impact of damage and increases the demold rate, especially when manufacturing a large number of products.
One of the most important questions in the demolding process is whether to use thermoplastics or thermosets. Versatile thermoplastics include polypropylene and polyethylene. These plastics can soften at high temperatures but become rigid at low temperatures. Their shrinkage flexibility makes them easy to demold. However, some thermoplastics, such as polycarbonate, can tend to stick to the mold. These products require a release agent to be removed.
Conversely, thermoset materials such as epoxy and phenolic resin are complex to demold after curing. The curing process of these plastics is irreversible. The rigidity and brittleness of thermosets increase the risk of surface destruction or cracking during ejection. Special attention is required when designing mold features and ejection techniques.
Methods to improve demolding efficiency and prevent parts from sticking in the mold include subsequent treatments and coatings of the mold surface. A smooth surface on the mold will make demolding easier. These surfaces have less friction than rough surfaces, making them easier to demold. Some of the substances used include PTFE (Teflon) and nickel or chromium. PTFE makes the part surface non-stick, while nickel or chromium plating provides a hard surface that improves demolding and mold longevity.
In addition, using release agents before each cycle can facilitate the demolding of sticky products. These treatments ensure high-quality parts and increase mold life and manufacturing efficiency.