Positioning your sealing head

Sealing head positioning is critical to successful sealing. The power of the electromagnetic field reduces with by square of the distance, meaning that if you double the distance between the seal and the head you only have 1/4 the sealing power!

Standard Sealing Heads

The optimal distance between the sealing head and the cap is 1/8 inch. The caps must also be centered in the tunnel or under the head. Proper positioning is illustrated in the figure at right.

In addition, the sealing head must be square with the cap or conveyor surface (equal height at all corners). This provides even heating and reduces potential problems. This can be done by placing a capped bottle under each end of the head and adjusting the gap to 1/8 inch. The side to side elevation adjustment (leveling) can be done in the same manner.

To help ensure an equal 1/8 inch sealing head gap, Enercon offers a free gap gauge to make setting up your unit easier. Request your free gap gauge today!

Tunnel Sealing Heads

A series of custom sealing heads has been developed by Enercon to address the more difficult task of heating liners, which are deeply recessed in their closure. Examples of these closures are pointed (yorker) spouts and push-pull valves. Furthermore, many of these closures are used on higher speed filling lines, which require more aggressive heating for the seal to occur. The recessed foil liner is more distant from the electrical field established by the conventional flat or tunnel sealing head, therefore, Enercon recommends the extra deep tunnel as illustrated.

The nature of these designs requires the field to be near the bottom of the tunnel opening. In fact, very little field exists near the top of the tunnel. The field is concentrated at the bottom of the opening making it more efficient in the heating process. Therefore it is always necessary to position the closure near the bottom of the opening.

To facilitate the correct placement of the foil liner, two horizontal scribe marks are used to establish boundaries for the liner position. Optimum sealing will occur when the liner is positioned between the established scribe marks. It should be apparent that this sealing head design will accept both high profile closures as described and the more conventional style.

All-in-One Sealing Heads

In many instances, multiple cap sizes will be run on the same power supply. The All-in-One Sealing Head and Pivot Kit allows for moving the sealing head to accommodate various size caps without having to exchange the sealing head. The All-in-One sealing head can be pivoted in approximately seven (7) degree increments to four different positions. The chart below indicates the desired position for each liner size. The pivot assembly brackets serve to guide the sealing head rotation to provide the proper angle for each liner size shown in the table. The knurled locking knobs serve to lock the sealing head in place.

Position Description
1 20 - 38mm
2 43 - 58mm
3 63 - 89mm
4 100 - 120mm

Proper alignment of the All-in-One Sealing Head is critical, use the following steps for proper set up.

  1. First align the power supply and sealing head over the conveyor with the sealing head in the #1 position. The mount / cart must be secure.
  2. Align and gap the product to the sealing head using the same criteria used for a Flat Sealing Head ensuring the cap runs centered along the entire length of the sealing head.
  3. Choose the proper pivot position for the cap size to be run and pivot the sealing head to that position, Refer to table above.

NOTE: Check alignment whenever the pivot angle is changed to ensure proper sealing.

No tools are required to change the position of the sealing head. Loosen both of the knurled locking knobs, one at each end of the sealing head. Rotate the sealing head to the proper position for the cap size in use. Center the proper indicator line on the locking knobs at each end of the sealing head and hand tighten the locking knobs.


A standard Enercon flat sealing head seals freshly packed oysters. The sealing head is position 1/8" above the closure