How bulbs and globes are vacuumed and sealed?

  • Thread starter CognitiveNet
  • Start date
In summary, the process of sealing a plasma globe or light bulb made of glass involves creating a long neck where a vacuum pump can be attached, pumping out the air, heating the neck until it becomes soft, and then using a tool to squeeze it closed while the vacuum is still intact. It is important to seal it after the air has been pumped out because the sealing process makes it impossible for air to get in or out.
  • #1
CognitiveNet
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How can a plasma globe or a light bulb made of glass be sealed after the air has been removed by a vacuum pump?
 
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  • #2
You first make it with a long neck where the vacuum pump is attached. Then you heat the glass of the neck until it becomes soft, closes the neck and seals the bulb.
 
  • #3
Is it sealed before or after the air is pumped out?
 
  • #4
CognitiveNet said:
Is it sealed before or after the air is pumped out?

Think it through! (Hint, the process of sealing makes it impossible for air to get in or out...)
 
  • #5
What a strange question! If you seal it before you pump the air out, you no longer have a way to pump the air out!

The point is this- you mask a long thin glass neck, pump the air out, then, while the neck is still attached to the vacuum pump, with the vacuum still good, you heat the neck until it is soft, and use some tool to squeeze it closed.
 
  • #6
CognitiveNet said:
Is it sealed before or after the air is pumped out?

I am glad I was not the only one who thought that question was odd.
 

1. How are bulbs and globes vacuumed?

Bulbs and globes are vacuumed using specialized equipment that removes all the air and gases from inside the bulb or globe. This creates a vacuum, which is necessary for the proper functioning of the bulb or globe.

2. Why are bulbs and globes vacuumed?

Bulbs and globes are vacuumed to prevent the filament or electrodes from burning out quickly. Without a vacuum, the filament or electrodes would quickly oxidize and burn, rendering the bulb or globe useless.

3. How are bulbs and globes sealed?

Once the vacuum is created, the opening of the bulb or globe is sealed using electrodes or a glass stem. This ensures that no air or gases can enter the bulb or globe, maintaining the vacuum inside.

4. Why are bulbs and globes sealed?

Bulbs and globes are sealed to maintain the vacuum inside and prevent any outside elements from entering, which could damage the filament or electrodes and affect the performance of the bulb or globe.

5. How are bulbs and globes tested for vacuum and seal?

Bulbs and globes are tested for vacuum and seal using specialized equipment that measures the pressure inside the bulb or globe. If the pressure is not at the desired level, the bulb or globe is rejected and not used for production.

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