Re: How to control the heating & temperature of glue container of the lamination mach
It's likely your heating element is switched on for a while, then switched off for a while. It's the most efficient use of power.
The thermostats I've seen (the ones connected to mains power or house heating systems) are either on or off. They contain a bimetallic strip which might be coiled, or straight, or slightly curved.
Some have contacts at the end which open and close, depending on temperature. Or the coil tilts a mercury switch. I believe modern digital thermostats contain a relay.
Does your thermostat have a bimetallic spring inside? Could glue have gotten splashed on it? That wouldn't be hard to fix.
The thermostat may or may not carry mains voltage. It's hard to be sure what it means that yours reads 63 ohms at a setting of 1 or more. That may be the value when it calls for heat. Whereas 0 ohms at 0 position means it doesn't call for heat?
Anyway if it has really gone bad, then you might check as to whether another appliance might contain a replacement. Example, roaster oven, slow cooker, coffeemaker, hot plate, laboratory equipment, etc.
If you are good with electronics, there's the idea of using an inexpensive thermistor, op amp, and relay.