Bottle thread

[deper]

I am designing a molded cap for a sports bottle. I am looking for the physical dimensions of a 28mm bottle thread. Any suggestions where I can find those dimensions?

 

[MikeHalloran]

I hate to admit this, but I've designed a few bottle caps, and always ended up measuring a sample bottle neck to do so.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

I'm with Mike.

Just go out, buy a bottle and measure it.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[richg1]

Hi,

Old-ish thread but I recently came across an SPI document/standard that might be useful. Although I haven't read it myself:

SPI's website is

http://www.plasticsindustry.org/search/index.htm

"AU-124 Dimensions and Tolerances for Plastic Bottles"

From a design for recycling perspective download the "Recyclability by Design" guide from

http://www.recoup.org/business/default.asp.

It is an excellent introduction into designing packaging and similar hi-volume consumer products for recycling.

 

[Wiseco]

Go there :

http://www.closuremanufacturers.org/

Click on the specifications tab.

 

[wgknestrick]

You need the SPI 28MM - SP-400 - specs.

Basically

"T" 1.078 +- .010 (thread DIA)
"E" .984 +- .010 (Neck DIA)

"S" .046 +- .015 (Start of thread from bottle face)
"H" .400 +- .015 (dim from face of neck to bead or shoulder, measured paralell to thread)

.167 Pitch

45deg top thread face angle, 10deg bottom if style "M" thread

.084 thread height

 

[wgknestrick]

Forgot to add, and at least 1 turn of thread.

 

[Wiseco]

Hes aiming a sport bottle so it's surely not a SP-400 thread. SP-400 are mainly for pills bottle, sauce bottle and so on. A sport bottle for me is a bottle that can be opened in a quarter turn of the cap.

 

[deper]

Well, the project continues on.
We did design a 28mm cap but that was for a soda bottle.
Now we are onto a 27mm bottle cap for water. This is truly the sports type cap. Weisco is correct. It has a triple lead thread and opens on about a 1/4 turn.

Now I'm looking for these dimensions!!!

 

[andyhpk]

Sorry to crash this thread. Im a product designer and usually I get a rough model to take to a mold designer, but I have a project for a bottle that will be produced in china and the client wants me to get the CAD files as close to finished as possible. Any suggestions on where I can get a crash course on designing injection molded threads?

I was thinking of buying this book

http://www.amazon.com/Complete-Part...51/ref=si3_rdr_bb_product/103-4395187-9983845

anyone recommend it?

Thanks

 

[richg1]

Hi AndyPK,

Assuming you're using a good 3d CAD package it shouldn't be too much trouble to model the thread accurately. I know ProEngineer has some good tutorials for modelling threads as does Solidworks.

Next step is the actual design. Would recommend looking up the SPI standards and those available at the Closure manufacturers. See above messages for the links.

Finally if all else fails, if you've got an actual bottle thread that you like grab some verniers/calipers and measure them directly.

PS. Word of warning for making anything in China (or anywhere for that matter)...check the mould drawings/cad as I've seen instances where they haven't taken shrinkage into account and have machined plastic molds directly from supplied CAD files. It should be the tool-maker's responsibility but always worth checking...

Hope that helps.

 

[deper]

Andy,

I understand where you're coming from. You're looking for the phsyical dimensions to model in the thread. What I found out since starting this thread is that most molded bottle threads are proprietary to the manufacturer of the bottle. There are some standard dimensions. You can get those at the website that Wiseco menstioned above.

http://www.closuremanufacturers.org.

They told me that if they dont have the dimensions then it must be a proprietary thread. In that case, you will have to measure it.

 

[andyhpk]

Thanks for your help everyone. I got out the calipers and hopefully the sls will work out fine.

Andy

 

[kevindurette]

I'm interested in making a cheap product that uses used 2 liter soda bottles. Which thread is that? Would any standard pipe fitting be a close enough match?

Is it listed here?

http://www.plasticbottle.com/techinfo/spi.html

 

[kevindurette]

I'm interested in making a cheap product that uses used 2 liter soda bottles. Which thread is that? Is that a 28mm 400? Would any standard pipe fitting be a close enough match?

Is it listed here?

http://www.plasticbottle.com/techinfo/spi.html

I measured a 20 oz Sam's Choice water bottle, but the thread pitch came out different.

 

[patprimmer]

Plastics threads are normally quite different to metal threads if any reasonable level of performance is expected.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[mcarey]

wgknestrick

I have to design a custom cap. On your post above for a 28mm -400 bottle, you call out the dimensions for the OD of a bottle thread. I was wondering how you would call out the ID for a cap? Is there a standard someplace? The bottle thread that i need is 58-400.

Thanks,
Meredith

 

[mcarey]

oh and this website has bottle thread dimensions...

http://www.plasticbottle.com/techinfo/spi.html