pressure measurement in the test system

[AgeOfEmpire]

Hi Friends,

Could you give some information about this problem. I work on polymer processing and I have a simple test system. This system consist of heated reservoir and a piston. Polymer is filled in reservoir and heated when is melted. then polymer flows through small hole. In this system, pressure value is read a constant point in the reservoir. My problem is that pressure value is continuously drop at this point. I know that pressure should drop in reservoir but I dont understand why pressure value is different at the constant point using a constant piston speed. I should think so viscosity of polymer is changing because of some parameters.

If you have any suggestion I will be pleased.

 

[MikeHalloran]

You are using a grease- purged pressure gage, right?



Mike Halloran
Pembroke Pines, FL, USA

 

[AgeOfEmpire]

Hi MikeHalloran

My test system like a capillary rheometer which is used to determine polymer melt behaviour in the processing conditions and I use a pressure transducer to read the pressure in the reservoir.

 

[MikeHalloran]

... and you've verified that the polymer is in liquid form at the transducer face, right?



Mike Halloran
Pembroke Pines, FL, USA

 

[AgeOfEmpire]

Yes, polymer melt conduct pressure transducer in the reservoir.