Armadillo - Vibration and Shock Control

ARMACEL

<< back to Products

Introduction

Moulded from a high neoprene content elastomer
ARMACEL pads have been engineered to give
excellent isolation while offering good lateral stability.
The off set design of the pad allows the elastomer to
flow under load there by eliminating any stiffening
effect with large area pads.
Pads are available in thicknesses of 8 mm and 13mm
each in 25, 50 and 70 durometer hardness.

Pad Loadings

	Max load	Max Load	Thickness
Armacel 25	25psi	0.18 N/mm	8mm
Armacel 50	50psi	0.36 N/mm	8mm
Armacel 100	100psi	0.70 N/mm	8mm
Armacel 200	200psi	1.40 N/mm	13mm
Armacel 300	300psi	2.10 N/mm	13mm

Chemical Properties

The high Neoprene content of ARMACEL gives excellent
resistance to most common oils, solvents and steam.
If an application is to be exposed to specific conditions
hybrid elastomers are available on request. Please contact
the Engineering department at ARMADILLO VSC.

Application of Theory

In applications where the disturbing frequency is low the
Natural Frequency of the isolator is critical. To reduce the
Natural Frequency of an isolator the static deflection must
be increased. Armacel pads are specifically designed to
be “stacked” Increasing the vertical height of a support
bearing will increase the static deflection which in turn
lowers the Natural Frequency. See later chart for
indication of Natural Frequencies of multiple pads.
The offset cell design of Armacel allows for easier flow of
the elastomer there by offering larger deflection with the
corresponding improvement in isolation.

Armacel

Armacel Selection

It is critical that the correct grade of ARMACEL is selected
for the application to ensure the highest degree of isolation.

Required:
Total mass to be isolated.
The disturbing Frequency
Bearing area which comes into contact with the floor.

Imperial Example
Machine weight 15,000 lbs
Bearing area 6 supports at 6” square = 1296” square.

Running Speed 1350 RPM (22.5 Hz or cycles per second)

10,000 lbs 1,666
6 Supports =1,666 lbs per 36 area of foot = 46.3 psi

Use Aramcel 50.

Table or statistics

Increasing the Isolation

There are applications when either the disturbing frequency is
very low or a high degree of isolation is required. In these
situations Armacel has been designed so it can be stacked in
multiple layers. Stacking the material gives a greater deflection
and corresponding reduction in Natural Frequency. (See table
one)

The voids in the surface of Armacel allow the elastomer to flow
easily under load giving greater deflection and a lower natural
frequency.

To increase the stability of multiple stacks rigid inter leaves are
added every third layer of Armacel. Multiple layer bearings are
bonded together to form a completed isolation bearing.

If bearings are placed directly beneath machines or channel
steel work narrower than the width of the bearing, additional
steel spreader plates may need to be added.

To ensure bearing stability, good design practice dictates the
stack height must not exceed the width of the bearing.

Natural Frequency

By increasing the number of layers of Armacel, the Natural
Frequency of the isolator can be reduced. (See table two)

For assistance with applications using Armacel, please call the
engineering department at ArmadilloVSC.