Silnylon-Info
This ingenious combination has become particularly popular in the lightweight sector: silicone and nylon (or polyester). The elastic silicone coating and ripstop nylon complement each other to form a fabric with outstanding properties: lightweight, highly tear-resistant, UV-stable, and waterproof. The base fabric made of tear-resistant ripstop nylon is coated on both sides with one or more layers of silicone. This permanently elastic, highly adhesive coating makes the fabric waterproof and increases its UV stability. A very special property of silicone is that it also greatly increases the tear resistance of the already tear-resistant ripstop nylon. If the fabric is damaged by branches, stones, poles, or similar objects, it will not tear completely, even under tension. This allows very lightweight, reliable fabrics to be produced for tents, but also for many other purposes.
Tent fabric made of silnylon
Silicone-coated nylons are used in many areas and are usually produced specifically for this purpose: as spinnaker sails, for paragliders, in stunt kites, in hot-air balloons or even as "slip sheets" in ambulance transport. The properties can vary greatly. For example, silicone-coated ripstop nylons for spinnaker sails or kites are often very stiff, so they flap loudly in the wind and are windproof but often not reliably waterproof. Slip sheets only have a smooth surface and are not required to be waterproof.
All Silnylon fabrics offered by extremtextil under the name "tent fabric" have been specially manufactured for use in tents: the fabrics are reliably waterproof, coated on both sides, and relatively soft, which means they do not "rattle" in the wind. They are also slightly elastic, which prevents peak loads. This combination has proven itself over many years with well-known tent manufacturers such as Hilleberg, MSR, and The North Face. The suitability of other fabrics for tents is mentioned in the product descriptions.
PROCESSING INFORMATION:
Sewing machine:
No special requirements are placed on the sewing machine, except that it should have a smooth, not too "aggressive" feed that does not damage the fabric.
Processing:
Silnylon is generally easy to work with, but the surface can be very smooth and slippery at first. With a little practice—and a few aids—this problem can be quickly remedied. Water-soluble glue sticks such as Pritt or double-sided adhesive tape are very good aids for preventing the fabric from shifting during sewing, as they can be used to temporarily fix the seams in place. The advantage of adhesive tape is that it gives a clean finish, but it should be removed after the first sewing pass, as it can otherwise alter the stretch properties (and increase the weight, if you're really picky). The glue from a glue stick, on the other hand, can simply be rinsed off with warm water once the seam is finished. Paper clips or small sewing clips (Wonder Clips) are also suitable for securing the seam. And, of course, needles can also be used. However, as these leave holes in the fabric, they should be placed in the seam allowance and the resulting holes should be sealed afterwards. Either sharp scissors with micro serrations or a rotary cutter are suitable for cutting.
The seam:
One problem that often occurs with Silnylon is that the seams pull apart under heavy strain. This is influenced by the construction of the fabric and the design of the finished sewn product. In the fabric, a lower thread density has a negative effect on the pulling behavior, but this results in advantages such as a softer feel (and therefore significantly quieter behavior in the wind), lower weight, and higher tear resistance (a paradox in fabrics is that a fabric becomes more tear-resistant when it is more loosely woven).
When sewing, pulling can be prevented by sewing through several layers of fabric if possible. A rolled hem (where 3 layers of fabric are sewn together) is therefore more suitable for hemming than binding with seam tape. A double flat seam has proven to be the best type of seam. This does not completely prevent the seam holes from pulling, but the two seams go through several layers of fabric, so the seam is still very strong even if the fabric is pulled.
To prevent pulling, care should be taken during construction to ensure that the pull is distributed rather than concentrated at specific points. A number of precautions can be taken, in particular by using suitable tensioning points.
Tensioning points:
Eyelets are generally unsuitable as the pull cannot be distributed and the thin fabric is quickly pulled tight. This can be prevented by placing additional layers of fabric underneath. However, it is better to sew on strips (e.g., webbing or ribbed tape). These should either be lined with a stronger fabric (e.g., lightweight tent floor with 90 g/m² or 120 g/m² or nylon, 210 den) or attached to the multiple layers of the hem. To distribute the pull as evenly as possible, the reinforcements at the guy points should be rounded. It is also advantageous to choose a strap that is not too narrow for the guy loops (15-25 mm is suitable), as this increases the contact surface.
Construction:
Silnylon is slightly elastic and stretches slightly when wet. This should be taken into account during construction. When tensioning rigid structures, the Silnylon may give way and sag when wet. Therefore, it should always be possible to retension the fabric.
Needle and thread:
The needle should have as sharp and slender a point as possible, i.e., a jeans or Microtex needle. The thread should be a cotton-polyester corespun (the thread consists of a polyester core wrapped in cotton), e.g. Rasant from Amann in 75 gauge. Ideally, this thread will seal the seam holes in the rain thanks to the cotton coating, which swells when wet. It is important that the thread is sewn with as thin a needle as possible to keep the seam holes as small as possible (depending on the machine and skill in adjusting the thread tension, this is a 70 or 80 needle for the 75 Rasant thread). If the seams need to be sealed anyway or do not need to be waterproof, an 80 or 100 polyester thread is suitable, which produces a robust, long-lasting seam.
Seam sealing:
Unfortunately, only one thing sticks to silicone: silicone. Therefore, seams on silnylon coated on both sides cannot be sealed with PU seam sealants (e.g., Seamgrip or Seamsure) or seam sealing tapes. A thin layer of silicone (e.g., Silnet) applied to the finished seam can seal it so that it also keeps out continuous rain. Whether the seam sealant is applied inside or outside depends on the design: for reinforcements or tension points, it is better to apply it inside, and for pure seams (e.g., ridge seams), it is better to apply it outside so that no water can penetrate the seam in the first place.
