Clamping force | How to calculate the clamping force in injection molding machine | Qsqtech.com

 CLAMPING FORCE: 

Clamping force is an engineering term used in mechanical and manufacturing processes. The meaning of clamping force is to hold one part tightly to another part or keep the parts secure while working in a machine. 

Clamping force is a force that hold one component tightly to another. It is used in many places such as in CNC machines, where clamping force is used to hold the material. Apart from this, clamping force is also used in the automobile industry, clamps are used to hold different parts. 

Clamping force may be exerted by manual or clamping unit of any machine.

 

Here, we will discuss the clamping force in injection molding machine. 

An injection molding machine consists of an injection unit on one side and a clamping unit on the other. The injection unit is used to melt the raw material and inject it into the mold to form a product. The clamping unit plays an important role in the manufacture of molded parts. Clamping unit is used to hold the mold closed while the injection unit injecting the molten plastic material into the closed mold. It includes a drive mechanism for moving a moving platen of the injection molding machine in at least one direction. 

CLAMPING FORCE IN INJECTION MOLDING MACHINE: 

Clamping is very Important role play in injection molding process. Clamping is the force that exerted by the clamping unit of the machine to hold the mold closed. The unit of clamping force is ton and it is also known as clamping tonnage. 

Injection molding machines having its own clamping tonnage capacity. For example, 250 tons capacity of any injection molding machine can applied the clamping force 250 tons on mold. But generally, Clamping force is taken 10% less of tonnage capacity due to safety point of view at the time injection molding process so that we can sustain the mold life.

It is very important to know the clamping force before it apply. Less clamping force can cause the defective parts although extra clamping force on mold can mold damages. 

HOW TO CALCULATE THE CLAMPING FORCE IN INJECTION MOLDING:-

Calculation of clamping force:-

Clamping force= Clamping force constant (kp) * Projected area of product (s)

Every material having its own clamping force constant (kp) value. 

For example:-

Material  Clamping force constant (kp)value PP 0.32 PS 0.32 PA 0.64~0.72 Add glass fiber  0.64~0.72 PE 0.32 ABS 0.30~0.48 POM 0.64~0.72 Other engineering plastic  0.64~0.72

Above constant value isn't the exact value. This is only based of experience.

Formula : 

Clamping force (P)= Clamping force constant (kp) * Projected area of product (S) 

P= kp*S

Where, 

P= Clamping force (T) 

kp= Clamping force constant (t/cm2)

S= Projected area of product (cm2)

Here, The projected area of a product is 410 cm2 and the material is PP, 

then, calculation of clamping force is given below,

Formula - 

P = kp*S

P = 0.32 * 410 = 131.2 (T) 

So a 150 T injection molding machine should be ok for this calculation of clamping force.

Hope! you will understand the topic of clamping force. 

Thanks for visiting 👍