Frequently Asked Questions

Why did Epoch merge with Double E?

Double E produces quality web handling accessories including core chucks, core shafts, safety chucks, brakes, slitting equipment, core cutters, and rollers. Adding Epoch rollers to the Double E product line adds even more depth to the comprehensive service that converters enjoy when working with Double E. Double E's extensive support team enhances customer service.

What are the benefits of balancing a roll?

It minimizes machine vibration, noise, web flutter, and bearing wear. It also minimizes the effect of critical speed.

When is it acceptable to only static balance a roll?

If the roll is very short in relation to its diameter or if the running speed is very slow (below 100 rpm).

Why can a roll never be perfectly balanced?

In practice, the perfect balancing cannot be achieved because some inherent unbalance will remain. The best one can do is to reduce this unbalance to a certain acceptable level.

When is a roll balanced, is weight added or removed?

It can be either. Most of the time, Epoch adds weight to the roll.

If weight is removed, what location on the roll is it removed from?

When weight is removed, it is removed from the end of the roll by drilling holes in the end.

If weight is added, what location on the roll is it added to?

When weight is added, it is added on the inside of the tube near the ends. Weight is added to the middle of the roll if it is "whip" balanced.

What material is the balance weight made of?

The materials used are lead and a two-part epoxy called Dynaweight.

What is ISO G6.3? What does it mean?

It is an ISO 1940-1 Balance Quality Grade. The numerical value of "G" is equal to the vibration velocity mm/sec (6.3 mm/sec = .25 in/sec) of a freely suspended rotor.

How was it that Epoch chose ISO G6.3 quality grade to use for idler rolls?

The ISO 1940-1 recommends paper machinery rolls and print rolls to be balanced at this grade.

What is the fastest speed Epoch can currently balance up to?

5500 FPM.

Is there an extra charge to balance at a higher speed?

Yes, the charge is figured on a case-by-case basis. The charge is related to the extra time required to perform this balance.

Why does Epoch use custom built balancing machines?

Typical balancing machines made to handle long rolls (+140" long) are made to balance to a certain sensitivity based on the customary weight of a metal roll of that size. Composite rolls present a special set of conditions which require higher sensitivity than most industrial roll balancing machines are able to handle due to their light weight. Epoch has balancing machines to handle a full range of idler rolls sizes, lengths, and weights.

What is the percent of grease fill for our standard bearings?

SealMaster ERX bearings have 10%-15% of the grease a standard bearing would have. Standard bearings have a 40%-60% grease fill.

What type of grease are these bearings filled with?

Andok B grease.

What is the maximum temperature that these bearings can withstand?

180 to 200 degrees Fahrenheit.