Dacron
IF boats with Dacron sails
Dacron is the brand name of the manufacturer DuPont registered in the 1950s for a fiber made of the polyester polyethylene terephthalate (PET).
Dacron is used in a variety of ways, for example for textiles, in medicine, among other things, as suture material and for vascular prostheses, for bow tendons or in sailing.
Sailing
In sailing Dacron is used to produce sailcloths used. Due to its properties (good handling, long durability) and its good price-performance ratio, it is the most frequently used raw material for sails.
Treatment of Dacron cloths
| term | meaning |
|---|---|
| Annealing | Polyester fibers are heated so that the shrinkage creates a stronger woven bandage. |
| Coating | Resins of the cloth to improve the fiber composite. |
| MF | Abbreviation for sails that are coated with melamine resin. |
| HTP | Abbreviation for sails that are coated with polyurethane resin. Use mainly for regatta sailors. The surface becomes harder but also more sensitive, which leads to a shorter service life |
| Warp-oriented fabric | Using special yarns and tensions, fabrics that are optimized for the intended use can be produced in a targeted manner |
| Weft-oriented fabric | The first fabrics had greater tension in the warp direction than in the weft thread and were therefore less stretchy in the warp direction. |
| Balanced cloth | Evenly resilient cloth in warp and weft directions |
Types of dacron cloths
| Type | description |
|---|---|
| Balanced | For low aspect sails with a very long foot; Luff to foot ratio ≤ 2: 1 |
| All purpose | For moderate low aspect sails: weft-oriented cloths, luff to foot ratio 2.5: 1 |
| Strong fill | Extremely weft-oriented fabric for high aspect sails with a short foot. Luff to foot ratio 3: 1 |
| Square cloth | In addition to the fabric, a grid of thicker polyester threads is woven in. (Ripstop pattern) Mainly used for regatta sails. For example, the polyester fiber Pentex is used for this. |
| Hydra Net | Process of the cloth manufacturer Dimension Polyant. Firmly woven polyester cloth into which a mesh made of polyethylene fibers (Spectra or Dyneema ) is woven. The resin content can be reduced with the same rigidity. |
Sail cut
Tracks are cut rounded at the edges so that the profile is shaped after sewing together.
| Sail cut | criteria |
|---|---|
| Crosscut | Lanes are aligned at right angles to the leech. The greatest forces therefore run across the seam. The cheapest and therefore most popular sail cut. Less waste than with radial sails. |
| Bi-radial section | Lanes run load-oriented, i.e. radiate from the clew and the sail head to the center of the sail. Load introduction into the sail runs along the seams.
Different fabrics can be used in the individual sections. |
| Tri-radial section | Further development of the bi-radial section, with additional fabric strips as a third direction from the sail neck to the center of the sail. |
| Combi Cut | Development of Beilken Sails especially for furling genoa. Horizontal tracks in the front area and chain-oriented vertical tracks in the stressed leech segment lead to better load transfer, especially in the reefed state. |
processing
| Width of the sail tracks: | Typical width: 91.4 cm up to 1.4 m. Dacron sails get the profile through the seams. -> More seams means a better profile and higher costs |
| Zigzag seam | 3 rows of zigzag seams. Easier method, inexpensive, risk of being torn open. |
| Six-stitch seam | With the six-stitch seam, the needle passes through the fabric layers up to 6 times and connects the upper and lower thread. This seam is 2.5 times stronger than zigzag. Thread damage only ribs to the next knot. |
| Small corner reinforcement | Small doublings cut to form a sail only achieve insufficient load transfer. -> star-shaped wrinkles and waves in the sail |
| Parachute fan reinforcement | Load-oriented, large-area reinforcements for good and harmonious load application |
| Tear drop reinforcement | Similar effect to the parachute fan, but easier to manufacture
Chafing protection Additional patches on stressed parts such as stag riders, battens, etc. |
| Doubling | Basically made of the same material as the underlying cloth to avoid different stretching behavior. |
| Batten pocket | Ends of the batten pockets should be reinforced to prevent piercing when killing the sail. The elastic in the batten pocket should keep the batten under constant pressure. |
Criteria for choosing a sail
| Type of sail: | High aspect, low aspect, furling etc. |
| Sailing area: | Mediterranean, Baltic Sea etc. |
| Purpose: | Regatta, cruiser etc. |
| Cloth specification: | z. B. Fix the proposal by the sailmaker and in writing |
| Width of the sail tracks: | typical width: 91.4 cm up to 1.4 m. Dacron sails get the profile through the seams. -> More seams means a better profile, slightly higher weight and higher costs |
| processing | Previously 3 rows of zigzag is replaced by a six-stitch seam. The latter has 2.5 times the strength of zigzag. |
medicine
Dacron is used as a non- absorbable suture material or for the manufacture of vascular prostheses .
Individual evidence
- ^ DuPont website , accessed November 16, 2011.
- ↑ Tim Baker: The Bible of Traditional Bow Making, Volume 3, p. 248 . Verlag Angelika Hörnig, 2005, ISBN 978-3-9808743-9-7 . Online: limited preview in Google Book search
- ^ Website of Fritz-Segel , accessed on November 16, 2011.
- ↑ Marc André Reymond, Hans Lippert , Norbert P. Haas: Specialist examination in surgery: In cases, questions and answers, p. 126 . Elsevier, Urban & Fischer Verlag, Munich 2007, ISBN 978-3-437-23241-1 . Online: limited preview in Google Book search.
- ↑ Wolfgang Hepp, Helmut Kogel: Gefäßchirurgie, p. 705 . Elsevier, Urban & Fischer Verlag, Munich 2006, ISBN 978-3-437-21841-5 . Online: limited preview in Google Book search.