Small part hot plate welding.

Small part hot plate welding.

Application:-Weld two small plastic parts with the hot plate welding method. Write the PLC program for the hot plate welding process using a ladder diagram language.

Diagram:-

Explanation:-

Hot plate welding the method is a popular method for plastic part welding in the plastic industry. Generally, two parts are melted at a certain temperature and joint together in this method. We can use this method for two plastic parts welding.

 

PLC program:-

Write the ladder program for the above application using ladder diagram language. Here for ladder logic, we can use any supported PLC system like S7-1200, S7-300, S7-1500 or any other PLC which can support this instruction. For PLC logic we need digital inputs and outputs.

For our application start switch is digital input and valves are the digital output. To define digital input address and output address as per the below explanation,

Digital inputs:-

Start switch S1=I0.0

Hot plate forward limit=I0.1

Hot plate reverse limit=I0.2

Digital Output:-

Hot plate forward=Q0.0

Hot plate reverse=Q0.1

Top servo forward=Q0.2

Top Servo Reverse=Q0.3

    Network 1:-Hot plate forward

Network 2:-Hot plate forward reset

Network 3:-Servo forward on

Network 4:-servo forward reset

Network 5:-servo revere on and hot plate reverse on

Network 6:-Hot plate reverse off

Network 7:-Servo reverse off

PLC program Explanation:-

In network 1, Start switch (I0.0) is pressed, hot plate forward output (Q0.0) will on and hot plate moves forward.

In network 2, in this network when the hot plate will move till its forward limit, once hotplate forward limit achieved, hot plate forward output (Q0.0) will be off.

In network 3, Servo motor forward (Q0.2) movement will on when hotplate achieves its limit.

In network 4, Servo motor (Q0.2) will be off when its set distance limit achieved.

In network 5, both the function will happen simultaneously, when melting time is over hotplate and servo motor will start to move reverse.

In network 6, hot plate reverse output will be off when its reverse limit is achieved.

In network 7, Servo reverse command will be off when its set distance value is achieved.