1) Yarn

The majority of electrical insulating sleeving Varflex produces is braided with fiberglass yarns purchased, exclusively, from Advanced Glassfiber Yarns (formerly known as Owens-Corning). This yarn is purchased in single strands composed of continuous multi-filament fibers. It is received in, what is referred to because of its appearance, a large “milk-bottle” package with 0.7 turns per inch in the Z (reverse) twist direction ready for “uptwisting” on our twist frames.

2) Uptwisting

In this first operation, we “uptwist” or increase the number of twists per inch in the yarn (in the same Z-twist direction) to a pre-established 4.0 turns per inch to achieve a uniform product which will process more smoothly. The material, which is now on a double-flanged plastic bobbin, is now ready for plying on our ply frames.

3) Plying

In this operation, two or more yarns are “plied” by twisting the strands in an opposite S (forward) twist direction into a multiple-end yarn product. The primary reasons for plying are to produce a “balanced” yarn and to increase its diameter and tensile strength. Upon completion of this step, the yarn again is in a “milk-bottle” package and it is now ready for winding.

4) Winding

The next step in yarn processing takes place in our Winding Department where the plied yarns are transferred to “braider packages” suitable for use on the braiding machines. The winding is also used to combine different yarn constructions which give us the ability to braid a variety of sleeving sizes ranging from a #28 - #30 AWG wire size to a 6” I.D.

5) Braiding

Varflex has braiders in a variety of sizes ranging from small 8-carrier units, generally used to braid very fine yarns, to some with as many as 144 carriers used to braid larger-sized sleevings with inside diameters up to 6 inches.

In the braiding operation, one-half of the carriers (spindles on which the wound “braider packages” are mounted and rotate) travel in a clockwise direction while the other half travel counterclockwise, all following a figure-eight pattern. This interlacing process transforms the wound yarn into a continuous tubular braid or sleeving.

Although most sleeving is produced in standard wall thicknesses, heavy walls, as well as double- and triple-wall constructions, are available. Varflex can also perform custom overbraiding on customer-supplied wire, cable, hose, and a variety of other items, thereby eliminating a costly step in the customer’s manufacturing processes.

6) Braid Stock

Our Braid Stock Department is where we keep upwards to 10 million feet of untreated braid in 40 standard types and sizes enabling us to process and ship orders more quickly than our competitors. A close examination of some braided material would reveal fine, hair-like projections, or “spikes”, protruding from the braid. These actually are broken filaments of glass which must be removed.

7) Normalizing
(Heat Cleaning)

Normalizing is a proprietary heat cleaning process that not only singes the braid to remove the “spikes” we have just mentioned, it also removes a controlled amount of the sizing, or lubricant, introduced during the yarn manufacturing process thereby providing for better adhesion of the subsequent application of various insulating compounds.

8) Coating
(Tower Rooms)

The tower rooms, which get their name from the tower-like structures which actually are huge vertical ovens, are where the braid receives any one of a variety of treatments or coatings designed to satisfy specific electrical, thermal, chemical and/or physical requirements.

After the braid is coated, the sleeving is drawn up, in continuous lengths, through the oven where a precisely-controlled temperature cures the coating to a tough, yet flexible, finish. Our large-sized coated sleevings are available in 3 to 6 foot lengths only and are both coated and cured utilizing a batch-type process.

9) Inspection/Packaging

This is the final step in the manufacturing process. Even though various quality checks and tests have taken place at stages prior to this, during this phase, every inch of sleeving we produce is examined for defects and imperfections.

Here also is where sleeving is packaged, or put up, on spools, in coils or 36” lengths in accordance with customer specifications. Should a customer have a requirement for short pieces cut to a particular length, these too can be supplied to very close cutting tolerances.

Once the sleeving has been inspected and put up, it is appropriately marked, packed and shipped to its destination ready to become an essential component in any of a vast array of demanding applications and end-use markets.