Words of Widsom: Cross-training hot-runner controls

Surprisingly, molders can significantly cut back on downtime and gain a competitive edge by such straightforward steps as standardizing on 12-zone increments of hot runner controls for all molds of less than 60 zones, and standardizing on one type of cable and connector for all hot runner molds.

A common scenario in many molding plants is the need to juggle schedules. Many molders don?t know in advance which tools they will be running on any given day.

Juggling mold schedules can mean juggling hot runner controls. If you find out today that starting later this week you need to bring a mold out of storage and put it into production on a press that?s been idle, will you have a control, cables, and connectors ready to go, or will the lack of these result in downtime?

Most custom molders have a lot of active and semi-active hot runner molds, in some cases hundreds of them. It seems like a daunting task to replace the hot runner controls, mold connectors, and cables in your shop, and it is. To make this a less onerous task, however, leave the old molds alone?but start now to put standard equipment on new tools.

The Power of 12

Our experience has shown that 12 is the preferred number of control zones, cables, and connectors. Almost all of the leading hot runner suppliers have already standardized on 12-zone wiring patterns. The main difference among the brands is that they use different styles of cables and connectors.

The most commonly used connector is probably the PIC/MTC 12G D-M-E standard. These connectors are fine for most applications, but their power-side crimp pins are relatively fragile. Gammaflux recommends using the HBE-24 style connector with molded-in pins for durability.

How many controls do you need? This is a common question. The answer depends on the number of molds in your shop, how often they run, and what your scheduling is like.

Some molders dedicate a hot runner temperature control to a specific mold; some, to a specific molding machine; and some use ?floaters,? meaning the control is mobile and can be moved around the shop and used on many machines or molds. All of these methods are fine, but for the ultimate flexibility, we recommend the ?floaters? method.

It is often not necessary to dedicate a hot runner control to a machine or mold, although this may be preferable for molds of 60 zones or more. For molds smaller than 60 zones, you can ?cross-train? your controls to work with any number of machines and molds in your plant. With the controls, cables, and connectors standardized, you will have a built-in backup plan. Any control can control any mold up to its maximum number of zones.

Your hot runner controls should take up as little floor space as possible. The Gammaflux TTC hot runner control is floor-standing on casters, has a compact footprint, and works for molds up to 60 zones. For smaller applications, the LEC hot runner controls are stackable in 12-zone increments. This provides the ability to stack controls to match the specific mold they?ll be working with, while not occupying extra floor space.

The Plan

Start today with a plan to standardize your controls, cables, and connectors. This ?cross-training? of your equipment will save you invaluable time and money down the road. Eventually, all of your controls and molds can be compatible. Our recommendations: