PLC for small-scale production

[Sophia]

Hi! I'm wondering if PLCs are used for small-scale production.
I've got four machines doing different things with textiles, and I'm exploring the idea of automating the process.
I would be grateful for your advice!

 

[cardosocea]

Of course they are. There's a wide variety of PLCs with different capabilities used to automate simple and complex machinery.

If you give us an idea of the process we may even be able to easily pinpoint the easiest/best solution to go with.

 

[parky]

Yes, from simple things like label applicators, simple filling of trays, heating water, sorting hardware like screws, sealing boxes the list is endless. small PLC's are reasonably cheap & come with small I/O counts i.e. 6 in 6 out to perhaps over 500 I/O.

 

[I_Automation]

I've built and encountered small machines that only did one thing that were run by a PLC.


Pneumatic cylinder pushed out a dowel pin
Torque driver put a self tapping screw into a hole to a certain depth
Punch punched a hole in a part that couldn't be done in the press
Test fixture checked for a hole then sprayed a dot of ink to show it was checked
Thread tested for deep tapped holes
Flip frame lifted panels off a conveyor and stacked them on a magazine
A test fixture had an inspection camera to check a weld nut for being there and not being on backwards, good parts could pass into the bin


Lots of small machines out there with a mini or micro PLC, Plus with the price of the Automation Direct Click PLC's so cheap there will be a lot more

 

[mikeexplorer]

I have also done a few small scale projects. One just replaced an old mechanical counter that was used to measure the liquid level in storage tanks. (A replacement counter was $5,000!)



Recently I did one that has a few inductive proximity sensors that is positioned after a bailer. (installs the metal wire handle on a 1 gallon can) if the wire is missing, lights up an alarm light and stops the conveyor.



Nowadays there are several inexpensive PLC's that are great for small scale projects.

 

[parky]

I remember doing a small project to detect if the shape/size of those bars of soap you get in hotels was correct i.e. no broken edges & height was correct etc. it consisted of a conveyor with a jig on it that had about 7 or 8 fibre optic photocells, it would check the height, length, width & corners were ok, if not reject it, the system worked at high speed you could only see a blurr of the soap bars on the conveyor it was fun getting it right at one point had these little soap bars flying everywhere.

 

[I_Automation]

Nowadays there are several inexpensive PLC's that are great for small scale projects.

+1

If you compare the price of a small PLC to the cost of a few relays and sockets, then compare the programming time vs the wiring time a PLC is less and faster

 

[JRW]

Sophia
What is your textile process?
We may be able to give you some ideas

 

[arpus4KM]

Hi! I'm wondering if PLCs are used for small-scale production.
I've got four machines doing different things with textiles, and I'm exploring the idea of automating the process.
I would be grateful for your advice!

Lots of good reasons to use a PLC for a small function process that needs variability or automation.

we have a couple of "oem" processes that only have 4 inputs (2 switches and a start and stop), and 2 outputs. it could be done with some physical timers and extra relays, but at the cost of a small PLC these days, it makes no sense not to use them. by the time the PLC becomes obsolete, you'd have the time to recreate the program and implement with a new cheap option that would do the same thing.

 

[Sophia]

Thank you so much for your responses and assistance!
I sew clothes and other products. At the moment, I have two machines dedicated to applying prints onto fabric.
Additionally, I'm looking to buy the following equipment one for folding clothes and sealing bags, and another for cutting fabric.
It would be convenient to manage these operations using a PLC. I'm also keen to know if it's feasible to analyze the number of operations and finished products, storing that data within the program itself, or if I should handle it separately.

 

[I_Automation]

It would be convenient to manage these operations using a PLC. I'm also keen to know if it's feasible to analyze the number of operations and finished products, storing that data within the program itself, or if I should handle it separately.

In almost all of my programs I at least keep a log of how many parts/cycles were done in its lifetime. Currently I have PLC's showing over 10 million parts.

Logging good/bad quantities is also done.

If you just want to see the values on a HMI to write them down then using the PLC is okay.


If you want an archive you can make sure the PLC's have Ethernet capabilities and have an HMI that does data logging. Small PLC's with Ethernet can be as low as $80 extra above a standard PLC.

I have more then once used the Excel function available in AdvancedHMI to log to excel spreadsheets, with an external USB port to the computer and a shortcut to the log folder to open Explorer to copy the logs to the flash drive.

 

[parky]

PLC's are not really designed for storing data but as I_automation has stated, use an HMI, this gives you graphical control over the process, most are capable of storing data for later retrieval, you can even use recipes to load pre-defined patterns or what ever the process is. again many HMI's have the ability to retrieve data stored on perhaps a flash card for local viewing or copy to a pc for analasis by other programs like Excel etc.

 

[JesperMP]

Runtime meters and counters can definitely be logged and stored in the PLC.

I have to mention that if you change a manual way of producing something to that it happens automatically, then you are creating a 'machine' (*), and then the Machinery Directive applies. Essentially you have to perform a risk assessment, decide safety measures, validate, document, test.
You would need someone who knows about the MD, it is way too difficult for someone jumping into it without previous knowledge.
I think you are an employer. If that is the case and an accident happens and the MD has not been followed, you can get into serious trouble.

Dont want to be a buzzkill, but it is better you are forewarned before deciding.

* edit: In this case it may be an 'assembly of machinery'. But that doesnt change that the MD must be followed.
If you have to modify the machinery to get them to work automatically, then it may be that the machines original CE mark and EU Declaration of Conformity are no longer valid.

 

[Sophia]

Thanks everyone for your advice! You helped me a lot!

 

[Circiter]

there's basically nothing you can't program with a PLC. Here in belgium we even use it in houses to control lighting..

So basically the posibilities are endless