The following series of ideas occurred to me while holding a loose thread on my jacket, and trying to decide whether to try breaking it on the spot, or to wait until I had a pair of scissors handy.
The manufacturing of clothing is still largely a low tech industry (unlike the making of the fabric itself), where rooms of poorly paid workers cut and sew together garments (I’ve linked to some articles below, some of which have great photos showing what a modern sweatshop looks like).
The dexterity involved in making clothes that actually look good, combined with the already low unit cost, have deterred manufacturers from automating the process with expensive machinery or robots.
Most of the existing material that I’ve found on high tech manufacturing has focused on the use of robotics to replace people. This is a high cost approach, and I don’t thing it is feasible. I’ve also found some material on welding seams that is a parallel process to what I describe below. Its also quite possible that others have had the identical set of ideas, but that I simply couldn’t find any material on the subject online. As per the usual – I have no idea if I’m actually being original or not. If I am, there’s probably ample material here for a few patents.
Clothing is essentially held together by friction. Threads are pushed through fabric and interlocked on the other side by a sewing machine. The act of actually tying off these threads would be a time wasting and expensive proposition for most clothes. This means that the only thing holding the stitches together is the friction between the threads and the cloth. That’s good enough, for the most part, so why bother improving on it?
My first idea actually does improve on the strength of the individual stitches, but wouldn’t be a huge economic improvement. Consider it a building block though.
The concept is this: why not weld the threads together, so that they don’t slip?
Materials like nylon are frequently seam-welded by either lasers or chemical reactions in extremely cheap garments like dollar-store ponchos, or for things like awnings. The results don’t look aesthetically pleasing though, and they aren’t necessarily much stronger than sewing the fabric together. The primary goal is typically waterproofing.
What if, instead, we were to sew the fabric together, using a slightly modified sewing machine, with a small laser that welds the threads together on one side?
As you can see in the image, sewing would still be a manual process, but the strength of the stitches would be improved, and the garment should (theoretically) be more durable.
We would also need to be careful that the welding process doesn’t sever the thread, since this would require re-feeding the sewing machine.
This would be a relatively cheap addition to a sewing machine though, and would be an advancement in a technology that hasn’t changed much in a century.
Can we improve on this process further though?
3D printers use a small extruder that pushes out plastic in order to form shapes. What if we made one small enough that it could be used as a needle? The sewing machine would have a stock of nylon, or some other plastic, and would form the thread by pushing it out of the tip of the needle on the fly. The stitches would then be welded by a laser.
This still doesn’t sound like an economic improvement, does it? The process would still require a room full of people, plus the addition of expensive new sewing machines. The third step, below, will connect the dots.
What if we were to build something like a lever press, but with a row of extruder needles built into it? This would allow us to “sew” an entire seam at a time.
With a bit of refinement, this process could allow garments to be stamped out of a press in a single mechanical action. Picture large sheets of fabric running through a machine that resembles those used to stamp out steel parts. The sewing and cutting could happen at the same time, and many garments could be made simultaneously with parallel presses.
Some advantages of this approach:
Once the initial investment in equipment is made, garments could be made extremely rapidly, and at a very low unit cost.
The equipment, while more expensive than a sewing machine, would be less costly than robots.
Fewer people would be needed. The manufacturing could therefore be done anywhere for roughly the same cost.
The resulting clothes would (theoretically) be stronger and more durable.
As with seam welding, seams would be flatter, and perfectly aligned (the press can be configured with a precise shape), and every garment would be identical.
Unlike the seam welding approach, however, the resulting garments would still resemble today’s sewn clothes, and quality control would be easier since there would still be a thread holding the fabric together (it is apparently hard to QA a welded seam).
The equipment could be designed to be configurable, such that new types of garments (or different sizes) could be made by the same machine, with little effort to re-configure between manufacturing runs.
The process could be optimized to use less fabric and thread, resulting in further savings.
Time to make the garment industry high tech?
An ebook on Google Books on transforming the garment industry – http://books.google.ca/books?id=BrRM5pSWsNQC&printsec=frontcover#v=onepage&q&f=false
Wikipedia article on the garment industry in Bangladesh. The photos at the bottom are particularly interesting – http://en.wikipedia.org/wiki/Bangladeshi_RMG_Sector
Article about fabric welding techniques: http://fabricgraphicsmag.com/articles/0908_f2_welding.html
Another article on fabric welding: http://www.teonline.com/knowledge-centre/fabric-welding.html