CHAIN WITH ENDLESS BRAIDED CHAIN-LINK

Abstract

The invention relates to a chain comprising a plurality of interconnected chain-links wherein at least one chain-link comprises a braided core comprising a first primary strand comprising polymeric elongated elements wherein the polymeric elongated element has a tenacity of at least 1.0 N/tex wherein the braided core is braided from at least 2 consecutive turns of the primary strand. The invention also relates to a braided endless shaped element suitable as chain-link for said chain. The invention further relates to a chain wherein the chain has a tenacity (Ten) in N/Tex and a combined titer of the 2 legs of the chain-link comprising polymeric elongated elements (T) in MTex, with Ten0.50*T.sup.0.05.

Claims

1. A chain comprising a plurality of interconnected chain-links wherein at least one chain-link comprises a braided core comprising a first primary strand, the first primary strand comprising polymeric elongated elements wherein the polymeric elongated elements have a tenacity of at least 1.0 N/tex, wherein the braided core comprises at least 2 consecutive turns of said first primary strand.

2. The chain of claim 1, wherein the braided core comprises at least 3, preferably at least 4 more preferably at least 6 consecutive turns of the first primary strand.

3. The chain of claim 1, wherein the braided core comprises one or more further primary strands wherein said braided core comprises at least 2 consecutive turns of each of the one or more further primary strands, preferably at least 3 consecutive turns, more preferably at least 4 and most preferably at least 6 consecutive turns of each of the one or more further primary strand.

4. The chain of claim 3, wherein the first primary strand comprises a first polymeric elongated element and the one or more further primary strands comprises one or more further polymeric elongated element, whereby the polymers of the first and the one or more further elongated elements are of the same type, preferably the first primary strand and the one or more further primary strands comprise polymeric fibers of the same type, even more preferably the first primary strand and the one or more further primary strands comprise polymeric yarns of the same type.

5. The chain of claim 4, wherein the first primary strand comprises a first polymeric elongated element and the one or more further primary strands comprises one or more further elongated elements, wherein at least one of the one or more further elongated elements differ from the first polymeric elongated elements, preferably the at least one further elongated element differ from the first polymeric elongated element by at least one property selected from the list consisting of material, tenacity, yarn titer, filament titer or creep rate.

6. The chain of claim 1, wherein the polymeric elongated element of the first primary strand and/or further primary strand has a tenacity of at least 1.2 N/tex, preferably at least 1.5 N/tex, more preferably at least 2.0 N/tex, even more preferably at least 2.2 N/tex and most preferably at least 2.5 N/tex.

7. The chain of claim 1, wherein the first and/or further primary strand is a twisted or laid strand, a braided strand, a tendon of parallel yarns, or a woven strand.

8. The chain of claim 1 comprising at least one braided or laid primary strand, wherein at least 2 terminal ends of the at least one braided or laid primary strand are connected together with a splice.

9. The chain of claim 1, wherein at least one chain-link, preferably all chain-links comprise a cover, wherein at least one primary strand or at least one braided core, preferably all primary strands or all braided cores are sheathed with a cover.

10. The chain of claim 1, wherein the polymeric elongated elements are at least partially coated with a thermoset or thermoplastic polymer.

11. The chain of claim 1, wherein the braided core has a cross-section of between 5 mm.sup.2 and 5 dm.sup.2, preferably between 10 mm.sup.2 and 3 dm.sup.2, more preferably between 50 mm.sup.2 and 100 cm.sup.2.

12. The chain of claim 1, wherein the chain has a tenacity of at least 0.50 N/tex, preferably the chain has a tenacity of at least 0.55 N/tex, more preferably at least 0.60 N/tex, even more preferably 0.65 N/tex and most preferably at least 0.70 N/tex.

13. The chain of claim 1, wherein chain has a static strength of at least 300 kN, more preferably at least 1000 KN.

14. A chain comprising a plurality of interconnected chain-links, wherein at least one chain-link comprises polymeric elongated element, wherein the polymeric elongated element has a tenacity of at least 1.0 N/tex and wherein the chain has a tenacity (Ten) in N/Tex and a sum of titer of the 2 legs of the chain-link comprising polymeric elongated elements (T) in MTex, with Tenf*T.sup.0.05, wherein f is 0.50, preferably 0.55, more preferably 0.60.

15. A braided endless shaped element suitable for the braided core according to claim 1 comprising at least 2 turns of a first primary strand comprising a polymeric elongated element, wherein the polymeric elongated element has a tenacity of at least 1.0 N/tex.

Description

EXAMPLES AND COMPARATIVE EXPERIMENT

Comparative Experiments

[0047] The chain-links of the comparative experiments are constructed according to the example as disclosed in WO2013/186206 whereby for comparability the load bearing Dyneema SK75 in the narrow weave was substituted by Dyneema DM20, a 1760 dtex yarn having a tenacity of 32.0 cN/dtex produced and supplied by DSM Dyneema, The Netherlands. This narrow weave, or strip, employed in the comparative examples has a titer of 272800 dtex and a nominal breaking strength of about 39 kN.

[0048] Comparative Experiment 1 and 2 were constructed by interlacing 3 chain-links produced according to the comparative experiment in WO2013/186206, each of the 3 chain-links consisting of 8 and 12 turns of the DM20 narrow weave respectively, the 2 ends of each narrow weave of each chain-link being stitched together. Further properties and the maximum break load (MBL) of the 2 chains are reported in Table 1.

[0049] In Comparative Experiment 3, a chain according to Example II of document WO2008/089798 has been produced. The chain had 4 engaging loops of 16 Dyneema SK75 yarns of 1760 dtex, produced and supplied by DSM Dyneema. This chain was fixed by air-splicing. Accordingly, each loop was formed from an air-spliced multifilament yarn bundle of 161760 dtex (28160 dtex) with a diameter of about 4 mm and a theoretical strength of 9856 N of the yarn bundle. Further properties and the maximum break load (MBL) of the chain are reported in Table 1.

EXAMPLES

Example 1

[0050] A primary strand was braided from a total of 12 sub-strands, each sub-strand consisting of 715 Dyneema DM20 1760 dtex yarns as employed for the narrow weave of the Comparative Examples. Accordingly, the primary strand was a braided rope construction of 127151760 dtex (2217600 dtex) with a diameter of about 20 mm and a strength of 400 kN. A single length of about 20 m of said primary strand was used to construct a first chain-link by starting from an end of the 20 m primary strand and forming a loop of about 3 m length (1 m diameter). With the remainder of the primary strand a total of 11 further loops were formed along the first circle in such a way that the 12 loops form a first chain-link braided from these 12 loops of the single primary strand whereby the pitch of the braid was about 10. The two free ends of the primary strand were buried inside the braided chain-link construction. An alternative description of the braided chain-link would be a 12-lead 4-bight braid. The second and third chain-link were formed from 2 further 20 m lengths of the primary strand in a process as described for the first chain-link with the difference that the first loop and the further loops were passing through the center of the first chain-link, hence forming a chain consisting of 3 interlaced chain-links. The chain was subjected to a break load test. The primary strand (20 mm rope) broke twice without showing substantial slip of the deteriorated chain-link. Even with the primary strand fractured in 3 sections, the chain-link retained its total strength. The chain failed upon the third breakage of the primary strand of one of it links. Further properties and the maximum break load (MBL) of the chain of Example 1 are reported in Table 1.

Example 2

[0051] A chain construction similar to the one of Example 1 was prepared with the difference that the braided primary strand was braided from 12 sub-strands each sub-strand consisting of only 4 Dyneema DM20 1760 dtex yarns resulting in a braided rope construction of 84480 dtex with a diameter of about 5 mm and a strength of about 20 kN. From said primary strand braided chain-links with a diameter of about 0.3 m have been prepared, starting from about 4 m of said primary strand for each chain-link. Further details and MBL of the chain are reported in Table 1.

Example 3

[0052] A chain similar to the chain of Example 2 was prepared and further coated by impregnating it with an aqueous suspension of a very-low density polyethylene plastomer commercially available as as Queo (supplier Borrealis GmbH), dried for 24 hours at room temperature, resulting in a weight increase of about 20 wt %. Subsequently each of the braided chain-links was heat set for 7 minutes and 120 C. at 2 t load (about 10% of the MBL of the link). Details and break performance of the chain is provided in Table 1.

TABLE-US-00001 TABLE 1 Maximum break load and tenacity of chains 2 legs of Chain Basic strand Turns cores MBL tenacity [tex] (Loops) Legs [Mtex] [kN] [N/tex] Comp. 1 Weave: 8 2 0.436 217.1 0.50 27280 Comp. 2 Weave: 12 2 0.655 329.8 0.50 27280 Comp. 3 MF* Yarn: 16 2 0.005632 2.8 0.50 176 Example 1 Rope: 12 2 5.32 3081 0.58 221760 Example 2 Rope: 8448 12 2 0.203 137.25 0.67 Example 3 Rope: 8448 12 2 0.203 166.4 0.86 MF* Yarn = multifilament yarn (tex)