vacuuming the jar...

R

RichD

Guest
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

--
Rich
 
On January 3, Jasen Betts wrote:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.
Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

They just top it off with steam instead of air, then as the steam cools
it condenses causing a partial vacuum, the steam is often a side-effect
of the production process.
Click to expand...

duh!
If I didn\'t sleep through my chem classes, I\'d know these things.

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

You left out \"friction\" and \"glue\"
Click to expand...

That\'s possible. But in my experience, I always hear a hiss,
as air enters.

--
Rich
 
On January 3, Jasen Betts wrote:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.
Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

They just top it off with steam instead of air, then as the steam cools
it condenses causing a partial vacuum, the steam is often a side-effect
of the production process.
Click to expand...

duh!
If I didn\'t sleep through my chem classes, I\'d know these things.

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

You left out \"friction\" and \"glue\"
Click to expand...

That\'s possible. But in my experience, I always hear a hiss,
as air enters.

--
Rich
 
On January 3, Jasen Betts wrote:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.
Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

They just top it off with steam instead of air, then as the steam cools
it condenses causing a partial vacuum, the steam is often a side-effect
of the production process.
Click to expand...

duh!
If I didn\'t sleep through my chem classes, I\'d know these things.

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

You left out \"friction\" and \"glue\"
Click to expand...

That\'s possible. But in my experience, I always hear a hiss,
as air enters.

--
Rich
 
On Thursday, January 5, 2023 at 12:35:10 AM UTC-5, whit3rd wrote:
On Wednesday, January 4, 2023 at 7:13:34 PM UTC-8, Fred Bloggs wrote:
On Tuesday, January 3, 2023 at 7:32:29 PM UTC-5, Phil Hobbs wrote:


It\'s often the polymer layer on the sealing surface or the threads.

It is? What polymer layer would that be?
The frequently-seen aluminized seal atop catsup bottles etc.
is a masterpece of electrical engineering. Plastic bottle, plastic cap,
but the seal is an electrical subcircuit, with sticky plastic as output.

https://www.enerconind.com/sealing/cap-sealers/super-seal-jr.aspx
Click to expand...

That\'s pretty fast!
 
On Thursday, January 5, 2023 at 12:35:10 AM UTC-5, whit3rd wrote:
On Wednesday, January 4, 2023 at 7:13:34 PM UTC-8, Fred Bloggs wrote:
On Tuesday, January 3, 2023 at 7:32:29 PM UTC-5, Phil Hobbs wrote:


It\'s often the polymer layer on the sealing surface or the threads.

It is? What polymer layer would that be?
The frequently-seen aluminized seal atop catsup bottles etc.
is a masterpece of electrical engineering. Plastic bottle, plastic cap,
but the seal is an electrical subcircuit, with sticky plastic as output.

https://www.enerconind.com/sealing/cap-sealers/super-seal-jr.aspx
Click to expand...

That\'s pretty fast!
 
On Thursday, January 5, 2023 at 12:35:10 AM UTC-5, whit3rd wrote:
On Wednesday, January 4, 2023 at 7:13:34 PM UTC-8, Fred Bloggs wrote:
On Tuesday, January 3, 2023 at 7:32:29 PM UTC-5, Phil Hobbs wrote:


It\'s often the polymer layer on the sealing surface or the threads.

It is? What polymer layer would that be?
The frequently-seen aluminized seal atop catsup bottles etc.
is a masterpece of electrical engineering. Plastic bottle, plastic cap,
but the seal is an electrical subcircuit, with sticky plastic as output.

https://www.enerconind.com/sealing/cap-sealers/super-seal-jr.aspx
Click to expand...

That\'s pretty fast!
 
On 1/5/2023 7:27 AM, DecadentLinuxUserNumeroUno@decadence.org wrote:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:29c0e39a-
da77-4f88-9ddf-3f4d14e80f25n@googlegroups.com:

onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...



Hey! Do you know what the origin for the Ball Drop in New York City
on New Years Day is?

Neil DeGrasse Tyson does. Cool little vid about it.

https://www.youtube.com/watch?v=6XhRjh4CLtw
Click to expand...

Thanks!
Ed
 
On 1/5/2023 7:27 AM, DecadentLinuxUserNumeroUno@decadence.org wrote:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:29c0e39a-
da77-4f88-9ddf-3f4d14e80f25n@googlegroups.com:

onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...



Hey! Do you know what the origin for the Ball Drop in New York City
on New Years Day is?

Neil DeGrasse Tyson does. Cool little vid about it.

https://www.youtube.com/watch?v=6XhRjh4CLtw
Click to expand...

Thanks!
Ed
 
On 1/5/2023 7:27 AM, DecadentLinuxUserNumeroUno@decadence.org wrote:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:29c0e39a-
da77-4f88-9ddf-3f4d14e80f25n@googlegroups.com:

onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...



Hey! Do you know what the origin for the Ball Drop in New York City
on New Years Day is?

Neil DeGrasse Tyson does. Cool little vid about it.

https://www.youtube.com/watch?v=6XhRjh4CLtw
Click to expand...

Thanks!
Ed
 
On 04-Jan-23 10:58 am, Lasse Langwadt Christensen wrote:
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...
Click to expand...
Indeed, it\'s an essential part of the process. The food has to be hot
enough to be sterile when the lid is put on. That way there\'s nothing
alive inside to make the food go bad.

Sylvia.
 
On 04-Jan-23 10:58 am, Lasse Langwadt Christensen wrote:
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...
Click to expand...
Indeed, it\'s an essential part of the process. The food has to be hot
enough to be sterile when the lid is put on. That way there\'s nothing
alive inside to make the food go bad.

Sylvia.
 
On 04-Jan-23 10:58 am, Lasse Langwadt Christensen wrote:
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...
Click to expand...
Indeed, it\'s an essential part of the process. The food has to be hot
enough to be sterile when the lid is put on. That way there\'s nothing
alive inside to make the food go bad.

Sylvia.
 
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?
Click to expand...

they put the lid on while it is hot ...
 
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?
Click to expand...

they put the lid on while it is hot ...
 
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?
Click to expand...

they put the lid on while it is hot ...
 
RichD <r_delaney2001@yahoo.com> wrote in news:f3bdb417-cf95-450e-
8283-5dae0099519bn@googlegroups.com:

Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

--
Rich
Click to expand...

It is not a full vacuum. Just \'some\' negative pressure. The media
placed into the hot jar is hot and the air during capping is as well.
When it cools, it pulls a \"partial vacuum\" on the head space in the
jar. The same way \"Mason Jars\" work. I did not believe it was that
easy, but it is.

In order to open such a jar, which uses a thick, soft polymer as a
gasket material and does not like to readily realease, Turn it upside
down and rap it sharply on the ass end with the palm of your hand.
If this process worries you, have someone who knows about it show
you. It does not take a very hard rap. Anyway, afterward the lid
comes off easy. The rap of your hand creates a shock wave that
causes a momentary breech of the gasket, freeing it up compared to
its long term sealed position.

Things which are packaged cold can be lidded inside a special
chamber incorporated into the lidding machine.

Carbonated beverages utilize positive pressure, which they
themselves generate in the \"head space\" of the \"pressure vessel\" that
is a soda bottle.
 
RichD <r_delaney2001@yahoo.com> wrote in news:f3bdb417-cf95-450e-
8283-5dae0099519bn@googlegroups.com:

Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

--
Rich
Click to expand...

It is not a full vacuum. Just \'some\' negative pressure. The media
placed into the hot jar is hot and the air during capping is as well.
When it cools, it pulls a \"partial vacuum\" on the head space in the
jar. The same way \"Mason Jars\" work. I did not believe it was that
easy, but it is.

In order to open such a jar, which uses a thick, soft polymer as a
gasket material and does not like to readily realease, Turn it upside
down and rap it sharply on the ass end with the palm of your hand.
If this process worries you, have someone who knows about it show
you. It does not take a very hard rap. Anyway, afterward the lid
comes off easy. The rap of your hand creates a shock wave that
causes a momentary breech of the gasket, freeing it up compared to
its long term sealed position.

Things which are packaged cold can be lidded inside a special
chamber incorporated into the lidding machine.

Carbonated beverages utilize positive pressure, which they
themselves generate in the \"head space\" of the \"pressure vessel\" that
is a soda bottle.
 
RichD <r_delaney2001@yahoo.com> wrote in news:f3bdb417-cf95-450e-
8283-5dae0099519bn@googlegroups.com:

Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

Another thought, a survey of public science illiteracy,
ask: is the lid stuck because it\'s pressurized, or
evacuated? What would be the proportion of replies?

--
Rich
Click to expand...

It is not a full vacuum. Just \'some\' negative pressure. The media
placed into the hot jar is hot and the air during capping is as well.
When it cools, it pulls a \"partial vacuum\" on the head space in the
jar. The same way \"Mason Jars\" work. I did not believe it was that
easy, but it is.

In order to open such a jar, which uses a thick, soft polymer as a
gasket material and does not like to readily realease, Turn it upside
down and rap it sharply on the ass end with the palm of your hand.
If this process worries you, have someone who knows about it show
you. It does not take a very hard rap. Anyway, afterward the lid
comes off easy. The rap of your hand creates a shock wave that
causes a momentary breech of the gasket, freeing it up compared to
its long term sealed position.

Things which are packaged cold can be lidded inside a special
chamber incorporated into the lidding machine.

Carbonated beverages utilize positive pressure, which they
themselves generate in the \"head space\" of the \"pressure vessel\" that
is a soda bottle.
 
On 1/4/2023 6:20 PM, Sylvia Else wrote:
On 04-Jan-23 10:58 am, Lasse Langwadt Christensen wrote:
onsdag den 4. januar 2023 kl. 00.54.51 UTC+1 skrev RichD:
Yesterday, after struggling to open a glass jar,
I resorted to a knife to pry it open. Not for the first time.

Which got me wondering, how do they evacuate the
jar, before screwing on the lid?

they put the lid on while it is hot ...

Indeed, it\'s an essential part of the process. The food has to be hot enough to
be sterile when the lid is put on. That way there\'s nothing alive inside to
make the food go bad.
Click to expand...

Indeed, if one sees a *bulging* container, it may be indicative of
anaerobic bacteria having a picnic.

For \"home canning\" the jars are intentionally designed with lids that
facilitate this process -- the top of the lid is a separate, isolated
surface (from the threaded ring that will eventually secure it to
the jar) so the lid can be loosely attached to still warm jars
and gravity will ensure the top portion adheres to the top of the
jar despite the threaded portion of the lid being \"not tight\".
 
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