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Machines that produce the chain stitch...?

Started by baileyuph, April 07, 2015, 05:34:53 am

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baileyuph

April 07, 2015, 05:34:53 am Last Edit: May 14, 2015, 06:19:46 pm by DB
The chain stitch is seen often but never reproduced in my business.  Some I see are more substantial looking (during tear down and disassembly) which provoked the question about possible differences.

I see the chain stitch in many products; clothing, upholstery on furniture and autos, I believe even some canvas cover work.

Hence, are they all made with only one thread?  I mean possibly more than one top thread or?

The concept of no bobbin is aluring in many respects but the general understanding chain stituches are not as strong or perhaps easier to unsew.  Seems inordinate that they are so widely used, during project repair/teardown/unseaming, whatever sometimes they appear to have held up fairly well.  

I wonder what all the considerations/risks are in using them.  It would be interesting to grasp more when judgement is good to use them and when bad to use them.

The benefit of getting rid of a bobbin constraint is appealing, particularly in manufacturing.

Doyle


bobbin

Chain stitch machines are uniformly fast, the need for a bobbin is eliminated (a looper replaces the bobbin and is fed by a cone of thread).  The only single thread chainstitch machine I have seen is the blindstitch machine.  This is the machine that does the stitch that invisibly keeps hems in place in clothing work.  It's also used to invisibly attach interfacing on constructed men's clothing (sport coats).  I am not familiar  with "bag closers", but you'll know the stitch if you purchase grain for livestock or dry dog/cat food.  I've never seen one, but the stitch is basically the same as that of a blindstitch.  How much variation can you have with one thread, afterall?

Sure, a chainstitch can be "undone" with a site specific break in the process, but the same can be said for the lockstitch.  How much stress a seam sees will also affect the likelihood of seam failure.  A properly adjusted chainstitch is really very strong... much of its strength lies in its ability to "give" and "stretch" when tension is put on the seam.  A lockstitch is actually a lot less able to "give"; it's for that reason that you don't see it in fabrics that feature "memory yarns" (stretch fabrics).  A very resilient topstitch can be obtained with a coverstitch machine.  Chainstitch machines comprise the biggest portion of industrial sewing machinery for the reasons explained above. 


baileyuph

May 10, 2015, 02:48:27 pm #2 Last Edit: May 10, 2015, 02:53:09 pm by DB
More insight, thanks Bobbin.  I, as all, see the chain stitch in upholstery, particularly in listings attached to covers in furniture and auto.  My experience goes way back and ever since the beginning they have been around.  Never saw a chain stitch machine, if did, didn't know it.

Matter of fact, currently redoing a reproduction original interior in a 1957 Chevy now and it reminds me of the chain stitch, as it is used on every seat in the car but not where it is visable.  The idea in this type of work is to make everything back to original as best can for the cars are judged pretty hard at national shows.

So, what I have learned is there are different machines used, some with more threads than others.  Interesting!  I do have a serger in the business and believe me, you better learn how to use it to be effective.  I remember in early use that - just threading is an important step.  Very durable machine.

Yes, as stated ,they can be quite strong and seldom leave any sewing wrinkles.

When this car, current project, is finished the next restoration, likewise back to original as possible will be a 1963 Pontiac, so those chain seams will get looked at.  

Diversified on this front, always something challenging and I never get a job I don't like, some make me think a bit but that is how we learn.

Thanks for the response,

Doyle

bobbin

I would think a chain stitch would be a very useful machine when working with vinyls, as it would provide a nice amount of stretch and would allow the fabricator to produce a very closely fitted cover and could be pulled on and coaxed into perfect shape with the use of some heat. 

I'm presently doing a cockpit on a very nice picnic boat (18 cushions, seats have knee rolls, and the backs are graduated, large lumbar cushion, smaller shoulder support above).  I am working with a Spradling vinyl and I was thinking about this thread as I was topstitching the cushions; thinking that the "give" in a seam would be nice as the covers must be closely fitted to give a pleasing result.  I have the Stidd seat left to recover.  This has been the year of vinyl for me. 

wizzard

If you want to see the practical advantages of a sewing machine which produces a chain stitch I would recommend you go to a reputable commercial sewing machine shop where they have a machine like the one your question set up for sewing.
Use one of your vinyl materials and check if you feel comfortable in use such a machine.

I have in my shop two machines which use a chain stitch. Both are used for sewing binding on carpets. One is portable, the other one is a union special table top machine.
Yes it's great, one does not have to worry about a bobbin refills and both threads run of a big spool. Normally I use a 69 nylon threat but also a strong comparable monafilement or even a nice cotton one.
Machine sews very fast, no comparison to my walking foot machine, but don't forget I rarely use it to sew anything round mostly just straight.
In my case the union special has a slight zig-zag stitch but it can be converted to straight stitch too.
Opening the chain stitch seam is quite easy too, just to pull the right thread and there everything goes. I never had the issue that
the sewing would open up on its own due to abuse.
Personally I don't see any real advantage to use such a machine for upholstery, except maybe industrial mass production.
Even the large upholstery shops in the automotive industry use most of the time a walking foot machine.

baileyuph

Yes, it is apparent that the chain stitch is ideal in mass production of some products.  I do a lot of auto upholstery repairs and the chain stitch is used in manufacturing auto interiors for sewing listings to the cover.  These listings and other sewing where chain stitching is used is not seen. 

The chain stitch increases efficiency - thus profits - for the obvious reason you stated, saves time servicing a bobbin.

Another dimension of auto interior work, I do, is auto restoration, where the entire interior is replaced back as close to original as possible/practical.  Since this activity involves recreating the original interior back to original as can, again the chain stitch is involved in the upholstery installed.  Most of this work I am referring, the restoration shop does not fabricate the seat covering, we install the seat upholstery that is available from after market manufacturers.  There are business reasons for this scenario, every thing is about money.  My shop can fabricate but the mass production approach is cheaper.  That is why we usually do not fabricate or make those cover requirements.

The chain is interesting, I guess it is the thing of getting away from bobbin refills.

Your comment about chain stitching along the edge of carpeting - could you explain why the chain stitch is used.  Or is what you talking about is the same of the serging and over locking so typical seen on home carpets and even in some older auto carpets?

I have seen carpets bound with the portable and stationary sewing devices.  That type of sewing, home carpets and the like, I have seen them managed on an air lift table - which makes it easier/possible for the operator.

Perhaps, carpet edging is something you do?  If so, what is your set up?

Doyle

gene

QuoteI am not familiar  with "bag closers", but you'll know the stitch if you purchase grain for livestock or dry dog/cat food.


I've shown many folks over the years, including my wife who buys big bags of bird feed, how to take the thread and pull the entire stitch apart.

If I remember correctly the 3 thread serger stitch can come apart by cutting one thread.

We've had discussions a few times on this forum over the years about how we could retire rich if we invented a way to eliminate the bobbin thread.

gene
QUALITY DOES NOT COST, IT PAYS!

bobbin

It's the two thread overlock that can be removed in one go if you break the stitching in the proper location.  It's for that reason that swimwear and lingerie is rarely constructed with a 2 thread over lock.  You have to break a 3 thread overlock on the needle thread every 12-15 inches and pull it out to release the two looper threads; this is what makes the 3 thread overlock preferable to seaming memory yarn fabrics together. 

wizzard

Quotecould you explain why the chain stitch is used

The machine I use is a Union Special heavy duty machine with two additional pullers to pull the carpet through the machine.
The stitch is a slight zig zag stitch on top and a straight stitch line on the bottom, this setup holds the binding the best way possible to the carpet. We even use serging tape which replicates the serging on the carpet.
NC Carpet in NJ produces this machines. Not cheap but one of best in the industry
Additional we use several attachments from 3/4inch to 5inch size to accommodate all kind of binding tapes.
We don't use an airtable due to size restriction in our workroom. All is needed are two 12foot section of roller conveyors on which the carpets rolls.
The machine just pulls the carpet through, all the operator has to do, see that the carpet edge is close to the binding shoe.
With this set-up I could run up to 60ft per minute through without bobbin, so speed is what counts as well as a perfect stitch every time.
This is a very heavy duty well build machine on which one can sew almost any carpet for binding. We use it even to sew all kinds of sisal carpets.




baileyuph

Very interesting Wizzard, that business has changed since my much earlier explanation of how carpet edges were treated or prepared.  Back then, if I understood correctly, edges were serged, bound (or binded), or overlocked.  In addition, fringes were in vogue and important (relatively expensive - again if my recall is correct).

Thanks for identifying the machine, given a chance, maybe I can look it up and at least see a picture of one. 

That wrap and secure procedure sounds like a fast, efficient way to do the job.  Certainly fast, can't believe the rate you gave, 60 feet per minute.  I am understanding that there is prep time for the wrapping before securing by sewing.

Things change, for sure.

Do you work for or are part of the company?

Thanks again,

Doyle

wizzard

QuoteDo you work for or are part of the company

this is part of my upholstery business 
Quoteprep time for the wrapping before securing by sewing

yes, there is quite some preparation of squaring the carpet to the correct size, then if the carpet has a high pile one should bevel the carpet with a beveler so the binding wraps nicely around the carpet.
There are also special machines like sergers or machines which are only suited to apply fringe to the carpet. But note that each of this special machines is quite expensive and so one has to analyze if there is a return of investment in buying such a specialized machine.
In my case, I decided on a union special which does everything I need and with a little bit
tinkering it does everything.
Quoteback then, if I understood correctly, edges were serged, bound (or binded), or overlocked

Note: it really did not change much, only the machines are upgraded to work faster, more precise and are easier to operate due to electronic controlled motors.
The technique is mostly the same

baileyuph

I love carpet prepared with an appealing fringe placed over a beautiful hardwood floor but smaller than room size to display the floor around the perimeter or sides.  The higher quality carpet (burlap backing) has been my preference.  Carpet backing has changed, apparently to keep cost down.  Like everything else, price sells and with that quality is challenged. 

You are right about business analysis to support business decisions.  The process never ends.  There are always decisions small business must make regarding what dimensions of the business or related business to seek.  To keep seeking more usually requires decisions about expansion in more ways.. shop space, employees, etc.

Given time I will run a querry on the carpet machines you are using.  I like equipment.

I have been involved more so in auto carpet, particularly in auto restoration support and it is a marval to see perfectly bound auto carpet which the best equipment does enable.  Comparing the binding operation with manual methods certainly makes one appreciate equipment and higher technologies.

Interesting stuff Wizzard.

Doyle