Impact Drop Tower

Major components 

• 

General introduction: 

Drop tower allows to measure several properties of polymers at dynamic conditions including: 

• Impact strength (KJ/m²) 
• Toughness (J.m^-3)
• Energy absorption (J.kg^-1)
• Ductility level (elongation percent)
• Transition temperature (°C)

Machine capabilities: 

Light-weight drop energy range	2.6 to 826 J
Medium-weight drop energy range	4.6 to 945 J
Heavy-weight drop energy range	25 to 1603 J
Maximum impact velocity	20 m/s
Spring assisted acceleration	Yes
Light-weight drop weight range	2.7 – 14.7 kg
Medium-weight drop weight range	4.7 – 23.7 kg
High-weight drop weight range	24.2 – 80.5 kg
Maximum drop height	1.25 m (49 in)
Measurement of drop weight	Electrical with strain gauge load cell
Load cell full-scale	90.7 kg
Load cell accuracy	+/-2 % of actual load
Drive speed	1600mm/min

How does it work? 

• Connect the main power cable between controller and power supply and set the power switch to 1 (on). 

• The instrument requires compressed air of 85-95 psi (580-650). 

• Set the velocity detector: 

1. Install the specimen into the support fixture 
2. Move the drop weight down until the tup touches the specimen slightly. 

• Zero the drop weight 
• Loosen the knob holding the velocity detector 
• Move the velocity detector and make sure the bottom of detector is aligned with the bottom edge of the flag. 
• Tighten the knob to secure the velocity detector 
• Release the drop weight

Velocity recommendations based on international standards: 

ISO:      4.40m/s                      1 m height 

ASTM: 3.33m/s (10.94 ft/s)   0.575 m height 

             6.35m/s                       2.056m height

• Zeroing the weight: 

Before commanding the system to move to a particular height, establish a zero point for the position of tup and drop weight. 

1. Close the chamber door 
2. Drive the drop weight down until the tip of tup is close to the surface of specimen. 
3. Press “Zero Position”

• Software: 

1. Make sure the drop weight is correctly zeroed.
2. Type in the value of height, velocity, or energy that you wish to achieve
3. Click go to the drop height (or velocity or energy) button. The drop weight moves to that position.  
4. Press and hold the ARM button on control panel, after 3 seconds, while continuing to hold the ARM button, press Fire.