Hi everyone! I hope this is the right area to post this. I am a complete newbie, so please bear with me.

I am trying to modify my PFS-300 impulse sealer. It has a 220v pot that regulates how long to apply heat to a metal strip. I would need a longer heating time to be able to seal mylar bags. Is it possible to change a certain component to lengthen the heating time?

 

Sure... just draw up the circuit and we can tell you what to change. My guess would be that it is temperature controlled, not time.

 

Is this ok?

 

Turning the knob to the maximum makes the "impulse" last about 2 seconds. Minimum is half a second or so.

 

Turning the knob to the maximum makes the "impulse" last about 2 seconds. Minimum is half a second or so.

Is that not enough? If not, then you can increase the resistor in the chain with the pot. Or, you can put a 500k pot on the outside of the sealer (replace the 220k pot) and now be able to vary the time from 0.5 to 4 or so seconds.

 

You could try increasing to the 33 µF capacitor to perhaps 47 µF or 68 µF.

I do advise caution. There may be a possibility of damaging the heater strip or the cover tape with longer heating. You may also find that with the changed timing the shortest time gets too hot for ordinary polyethylene bags.

 

What makes you think that a bag sealer designed for polyethylene (mp 220°F to 360°F) and polypropylene (mp 320°F) will ever get hot enough to seal mylar (mp 500°F)?

 

So-called Mylar (polyester) bags are typically polyester on the outside and polyolefin (polyethylene or polypropylene) on the inside, specifically so they can be heat sealed. The structure does mean it takes a higher temperature and/or a long cycle to assure adequate melting of the inner layer to get a good seal.

 

Understood! I will change the pot to 500k. It would be great to increase the temperature, but I'm guessing this isn't possible for the hardware. Thank you, I greatly appreciate the replies everyone!

 

Understood! I will change the pot to 500k. It would be great to increase the temperature, but I'm guessing this isn't possible for the hardware. Thank you, I greatly appreciate the replies everyone!

Time will increase the temperature. Sneak up on the setting that adequately seals your bags.