Abstract
The present invention relates to a composite elongated body (3), comprising high performance polyethylene HIPPE filaments (2) having a tenacity of at least 0.6 N/tex and a polymeric composition throughout (10) the composite elongated body, wherein the polymeric composition comprises a thermoplastic ethylene copolymer and a lubricant; and wherein the thermoplastic ethylene copolymer is a copolymer of ethylene and wherein said polymeric composition has a peak melting temperature in the range from 40 to 140 C. measured in accordance with ASTM E794-06. The present invention further relates to a lengthy body, an article and a crane comprising the composite elongated body: a method of manufacturing a composite elongated body: a method of manufacturing a lengthy body; and use of a polymeric composition.
Claims
1. A composite elongated body, comprising high performance polyethylene HPPE filaments having a tenacity of at least 0.6 N/tex and a polymeric composition throughout the composite elongated body, wherein the polymeric composition comprises a) a thermoplastic ethylene copolymer; and b) a lubricant; and wherein the thermoplastic ethylene copolymer is a copolymer of ethylene and wherein said polymeric composition has a peak melting temperature in the range from 40 to 140 C., measured in accordance with ASTM E794-06.
2. A composite elongated body according to claim 1, wherein the high performance polyethylene HPPE filaments are provided as a yarn, said yarn comprising at least two HPPE filaments having a tenacity of at least 0.6 N/tex.
3. A composite elongated body according to claim 1, wherein the lubricant is a wax.
4. A composite elongated body according to claim 3, wherein the wax is synthetic wax or a plant wax.
5. A composite elongated body according to claim 3, wherein the wax is a polyethylene wax, a polypropylene wax, beeswax, carnauba wax or a Fischer-Tropsch wax.
6. A composite elongated body according to claim 1, wherein the lubricant is a polymeric dispersion.
7. A composite elongated body according to claim 6, wherein the polymeric dispersion is a dispersion of a polyurethane or an acrylic, or a hybrid of a polyurethane and an acrylic.
8. A composite elongated body according to claim 1, wherein the lubricant comprises: a synthetic grease or oil; a mineral grease or oil; an inorganic solid such as graphite or molybdenum disulfide; a ceramic such as a ceramic lubricant or ceramic coating; or any combination thereof.
9. A lengthy body comprising the composite elongated body as defined in claim 1.
10. The lengthy body according to claim 9, wherein the lengthy body is a strand, a cable, a cord, a rope, a belt, a strip, a hose or a tube.
11. An article comprising at least one composite elongated body as defined in claim 1 and/or comprising at least one lengthy body, wherein the article is a synthetic chain, a sling, a tendon, a net or a personal protection item.
12. A crane comprising a sheave and the rope according to claim 10.
13. A method of manufacturing a composite elongated body comprising the steps: a) providing a coating composition, wherein the composition comprises a thermoplastic ethylene copolymer and a lubricant; b) providing a yarn comprising at least two HPPE filaments, the filaments having a tenacity of at least 0.6 N/tex; c) applying the coating composition to the yarn to obtain a coated yarn; and d) elevating the temperature of the coated yarn to obtain the composite elongated body, wherein the high molecular weight thermoplastic ethylene copolymer is a copolymer of ethylene and wherein said thermoplastic ethylene copolymer has a peak melting temperature in the range from 40 to 140 C.
14. The method according to claim 13 wherein in step d) elevating the temperature causes the coating composition to dry and the thermoplastic ethylene copolymer to melt.
15. A method of manufacturing a lengthy body comprising the step of assembling at least two composite elongated bodies as defined in claim 1 to form the lengthy body, preferably the lengthy body is a rope, such as a laid or braided rope.
16. A method of manufacturing an article comprising the step of providing the lengthy body and/or the composite elongated body according to claim 1 and producing the article, wherein preferably the article is a net, a synthetic chain, a personnel protection item or a glove.
17. A method of lifting and/or placement of an object comprising the steps a) providing a rope as defined in claim 10; b) connecting the rope to the object to be lifted; and c) using the rope to lift and/or place the object.
18. Use of the polymeric composition as defined in claim 1 to reduce abrasion of a rope, a synthetic chain or a belt comprising such composition, wherein the rope, synthetic chain or belt comprises high performance polyethylene HPPE filaments having a tenacity of at least 0.6 N/tex.
Description
FIGURE DESCRIPTION
[0324] FIG. 1a schematically depicts a cross section of a yarn (1) comprising high performance polyethylene HPPE filaments (2) having a tenacity of at least 0.6 N/tex.
[0325] FIG. 1b schematically depicts a yarn (1) comprising high performance polyethylene HPPE filaments (2) having a tenacity of at least 0.6 N/tex having a length dimension (Ld) which is much greater than a transverse dimension (Td) of width and of thickness.
[0326] FIG. 1c schematically depicts a cross section of a composite elongated body according to the invention comprising high performance polyethylene HPPE filaments (2) having a tenacity of at least 0.6 N/tex and a polymeric composition throughout (10) the composite elongated body. The composite elongated body comprises said polymeric composition, more specifically the polymeric composition is present in between the filaments of the composite elongated body. The polymeric composition is present throughout the cross-section of the composite elongated body and in intimate contact with the at least one filament, i.e. with the individual filaments. In an even more preferred embodiment the polymeric composition impregnates the filaments; in other words: the polymeric composition is present throughout the cross-section of the composite elongated body. Hereby is understood that the polymeric composition is present in between substantially all the filaments of the composite elongated body. Preferably at least 50% of the surface of the filaments of the composite elongated body in contact with the polymeric composition, more preferably at least 70% and most preferably 90% of the filament surface is in contact with the polymeric composition. A way to look at this may be via a microscopic image of a cross section of the composite elongated body and see which % of the filament surface is in contact with the polymeric composition. FIG. 2 schematically depicts a Cyclic bend-over-sheave (CBOS) test set-up for a 5 mm rope. Details are given below in the METHODS. FIG. 2B depicts a schematic see through of the inside of the schematic frame (24) in FIG. 2A. F represents the direction of the Tension (MPa).
[0327] FIG. 3 schematically depicts a Cyclic bend-over-sheave (CBOS) test set-up for a 21 mm rope. Details are given below in the METHODS.
[0328] FIG. 4 schematically depicts a fairlead abrasion test set-up. Details are given below in the METHODS.
[0329] FIG. 5 schematically depicts a cross section of a composite elongated body (53) according to the invention comprising high performance polyethylene HPPE filaments (52) having a tenacity of at least 0.6 N/tex and a polymeric composition throughout (50) the composite elongated body. In an embodiment the composite elongated body may have cross section having a rectangular shape (54), an oval shape (52), a circular shape (55), a hexagonal (56) or an octagonal shape.
[0330] FIG. 6 schematically depicts an embodiments of a chain according to the invention. The chain (60) comprises at least two interconnected chain links (61). The chain link comprises a strip (62). The strip is typically a narrow webbing comprising at least at least two composite elongated bodies (not shown in detail). The strip of material in this embodiment forms a plurality of convolutions of said strip, the strip having a longitudinal axis and each convolution of said strip comprising a twist along the longitudinal axis of said strip, said twist being an odd multiple of 180 degrees. Such a chain link is described in the published patent application WO2013186206, incorporated herein by reference. By a convolution of the strip is herein understood a loop thereof, also called a winding or a coiling, i.e. a length of said strip starting at an arbitrary plane perpendicular to the longitudinal axis of the strip and ending in an endless fashion at the same plane, thereby defining a loop of said strip. The term plurality of convolutions may also be understood herein as coiled into a plurality of overlapping layers. Said overlapping layers of the strip are preferably substantially superimposed upon one another but may also present a lateral offset. The convolutions may be in direct contact to each other but may also be separated. Separation between the convolutions may for example be by a further strip of material, an adhesive layer or a coating. Preferably, the chain link in the chain according to the present invention comprises at least 2 convolutions of the strip of material, preferably at least 3, more preferably at least 4, most preferably at least 8 convolutions. The maximum number of convolutions is not specifically limited. For practical reasons 1000 convolutions may be considered as an upper limit. Each convolution of the strip of material may comprise a twist of an odd multiple of 180 degrees along its longitudinal axis; preferably the odd multiple is one. Said twist of an odd multiple of 180 degrees will result in a chain link comprising a twist of an odd multiple of 180 degrees along its longitudinal axis. The presence of said twist in each convolution of the strip of material results in a chain link with a single outer surface. Another characteristic of said construction may be that the lateral surfaces of a first end of the strip of material are superimposed on either side by the convoluted strip of material. It was observed that said twist results in a construction such that the convolutions lock themselves against relative shifting. Preferably, at least 2 convolutions of the strip of material are connected to each other by at least one fastening means.
[0331] FIG. 7 schematically depicts an embodiment of a chain according to the invention. The chain (70) comprises at least two interconnected chain links (71). The chain links comprise at least at least two composite elongated bodies (not shown in detail).
[0332] FIG. 8a represents an example of a knotless warp-knitted net (Raschel Knotless net) (80), comprising cords (81), each cord comprises a single composite elongated body (81), the cords form mesh legs (indicated with ovals 85) and joints. The joints are formed from intermingled cords (indicated within ovals 82 and 83: two mesh legs are formed into a joint). The mesh size (length) is indicated by arrow (84). In another embodiment the cord comprises at least two composite elongated bodies, typically 2 to 3 composite elongated bodies.
[0333] FIG. 8b shows schematically that mesh size (84) of a knotless net is measured as the length between the 2 opposite joints of a stretched mesh.
[0334] FIG. 9 schematically depicts a rope (90) according to the invention comprising laid strands (91), the strands comprise at least three composite elongated bodies (not shown in detail) according to the invention. The outer surface of the rope is indicated with 92.
[0335] FIG. 10 schematically depicts a rope (100) according to the invention comprising twelve braided strands (101), the strands comprise the composite elongated body (not shown in detail) according to the invention. The outer surface of the rope is indicated with 102.
[0336] FIG. 11 shows a SEM picture of a surface of a composite elongated body.
[0337] FIG. 12 is described in the METHODS under Tensile properties of HPPE filaments.
[0338] FIG. 13 is described in the METHODS under Coefficient of Friction.
METHODS
[0339] Titer was measured by weighing an arbitrary length of yarn or filament, respectively. The titer of the yarn or filament was calculated by dividing the weight by the length and is reported in either tex or dtex expressing the weight in gram per 100,000 m or 10,000 m respectively. The length of yarn or filament measured is typically 50 meters. [0340] Heat of fusion and peak melting temperature have been measured according to standard DSC methods ASTM E 793-85 and ASTM E 794-06, respectively, at a heating rate of 10 K/min for the second heating curve and performed under nitrogen on a dehydrated sample. In such DSC measurement a part of the full composite elongated composition (including HPPE filaments) can be measured. The peaks from HPPE and coating are sufficiently well separated so the Tm and heat of fusion of coating can be determined directly. [0341] Coating percentage The amount of polymeric composition in the composite elongated body according to the invention (coating percentage) may be determined as follows. [0342] A sample of 1.0 gram of composite elongated body is taken. The polymeric composition in the sample is extracted from the composite elongated body via a warm Soxhlet extraction: refluxing with toluene containing 5% acetic acid (150 ml), for 16 hours. After extraction the remainder of the sample is dried for 2.5 hours at 80 C. in vacuum. By weighing the sample before and after the extraction process, the coating percentage can be calculated using the following formula:
[00001] [0343] In which M_after_extraction is the mass of the sample after extraction and drying as described above and M_before_extraction is the mass of the sample before extraction and drying as described above. [0344] Density The density of the polymeric composition is measured according to ISO 1183-04. The density of the thermoplastic ethylene copolymer is measured according to ISO 1183-04. [0345] Immersion method (A) and more preferably density gradient column method (B) are suitable for the present products. It is noted that ISO 1183-1:2004 covers three methods, and that the skilled person will be able to select, depending on the sample to be tested, suitable sample preparation technique and method. The skilled person would know that if he/she is faced with a finished product, he/she needs to obtain the polymeric composition before doing the density measurement. It is part of the skills of the skilled person to, depending on what the finished product looks like, determine how to obtain and prepare a sample of the polymeric composition and thereafter based on what the sample looks like select the appropriate way to measure the density. For example the polymeric composition may be scraped off from the composite elongated body and measured. Depending on what the scraped off product looks like, any of the corresponding methods listed in the ISO 1183-2004 may be used. [0346] It is noted that the density of the thermoplastic ethylene copolymer will typically be provided by the supplier will provide this information e.g. in the specification of the product. [0347] IV: the Intrinsic Viscosity is determined according to method ASTM D1601 (2004) at 135 C. in decalin, the dissolution time being 16 hours, with BHT (Butylated Hydroxy Toluene) as anti-oxidant in an amount of 2 g/l solution, by extrapolating the viscosity as measured at different concentrations to zero concentration. [0348] Tensile properties of HPPE filaments: filament tenacity and filament tensile modulus: [0349] Determination of filament linear density and mechanical properties is carried out on a semiautomatic, microprocessor controlled tensile tester (Favimat, tester no. 37074, from Textechno Herbert Stein GmbH & Co. KG, Mnchengladbach, Germany) which works according to the principle of constant rate of extension (DIN 51 221, DIN 53 816, ISO 5079) with integrated measuring head for linear density measurement according to the vibroscopic testing principle using constant tensile force and gauge length and variable exciting frequency (ASTM D 1577). The Favimat tester is equipped with a 1200 cN balance, no. 14408989. The version number of the Favimat software: 3.2.0. [0350] Clamp slippage during filament tensile testing, preventing filament fracture, is eliminated by adaption of the Favimat clamps of the Favimat according to FIG. 12. [0351] The upper clamp 121 is attached to the load cell (not shown). The lower clamp 122 moves in downward direction (D) with selected tensile testing speed during the tensile test. The filament (125) to be tested, at each of the two clamps, is clamped between two jaw faces 123 (442 mm) made from Plexiglass and wrapped three times over ceramic pins 124. Prior to tensile testing, the linear density of the filament length between the ceramic pins is determined vibroscopically. Determination of filament linear density is carried out at a filament gauge length (F) of 50 mm (see FIG. 12), at a pretension of 2.50 cN/tex (using the expected filament linear density calculated from yarn linear density and number of filaments). Subsequently, the tensile test is performed at a test speed of the lower clamp of 25 mm/min with a pretension of 0.50 cN/tex, and the filament tenacity is calculated from the measured force at break and the vibroscopically determined filament linear density. The elongational strain is determined by using the whole filament length between the upper and lower plexiglass jaw faces at the defined pretension of 0.50 cN/tex. The beginning of the stress-strain curve shows generally some slackness and therefore the modulus is calculated as a chord modulus between two stress levels. The Chord Modulus between e.g. 10 and 15 cN/dtex is given by equation (1):
[00002] [0352] where: [0353] .sub.10=elongational strain at a stress of 10 cN/dtex (%); and [0354] .sub.15=elongational strain at a stress of 15 cN/dtex (%). [0355] The measured elongation at break is corrected for slackness as given by equation (2):
[00003] [0356] where: [0357] EAB=the corrected elongation at break (%) [0358] EAB (measured)=the measured elongation at break (%) [0359] .sub.5=elongational strain at a stress of 5 cN/dtex (%) [0360] CM (5:10)=Chord Modulus between 5 and 10 cN/dtex (N/tex). [0361] Tensile properties of HPPE yarns: tensile strength (or tenacity) and tensile modulus (or modulus) of a yarn are defined and determined on multifilament yarns as specified in ASTM D885M (1995), using a nominal gauge length of the yarn of 500 mm, a crosshead speed of 50%/min and Instron 2714 clamps, of type Fibre Grip D5618C. On the basis of the measured stress-strain curve the modulus is determined as the gradient between 0.3 and 1% strain using a pretension of 0.2 cN/tex. For calculation of the modulus and strength, the tensile forces measured are divided by the titre, as determined above; values in GPa are calculated assuming a density of 0.97 g/cm.sup.3 for the HPPE. [0362] Tensile strength and tensile modulus at break of the thermoplastic ethylene copolymer may be measured according ISO 527-2. [0363] Short chain branches per 1000 total carbon (SCB/1000TC): [0364] is determined by NMR techniques and IR methods calibrated thereon. As an example the amount of methyl, ethyl or butyl short side chains are identical to the amounts of methyl side groups per thousand carbon atoms contained by the UHMWPE as determined by proton 1H liquid-NMR, hereafter for simplicity NMR, as follows: [0365] 3-5 mg of UHMWPE are added to a 800 mg 1,1,2,2-tetracholoroethane-d2 (TCE) solution containing 0.04 mg 2,6-di-tert-butyl-paracresol (DBPC) per gram TCE. The purity of TCE is >99.5% and of DBPC>99%. [0366] The UHMWPE solution is placed in a standard 5 mm NMR tube which is then heated in an oven at a temperature between 140150 C. while agitating until the UHMWPE is dissolved. [0367] The NMR spectrum is recorded at 130 C. e.g. with a high field 400 MHZ NMR spectrometer using an 5 mm inverse probehead and set up as follows: a sample spinrate of between 10-15 Hz, the observed nucleus-1H, the lock nucleus-2H, a pulse angle of 90, a relaxation delay of 30 sec, the number of scans is set to 1000, a sweep width of 20 ppm, a digital resolution for the NMR spectrum of lower than 0.5, a total number of points in the acquired spectrum of 64 k and a line broadening of 0.3 Hz. [0368] The recorded signal intensity (arbitrary units) vs. the chemical shift (ppm), hereafter spectrum 1, is calibrated by setting the peak corresponding to TCE at 5.91 ppm. [0369] After calibration, the two peaks (doublet) of about equal intensity are used to determine the amount of methyl side groups are the highest in the ppm range between 0.8 and 0.9 ppm. The first peak should be positioned at about 0.85 ppm and the second at about 0.86 ppm. [0370] The deconvolution of the peaks is performed using a standard ACD software produced by ACD/Labs; [0371] The accurate determination of the areas A1.sub.methyl side groups, hereafter A1 of the deconvoluted peaks used to determine the amount of methyl side groups, i.e. A1=A1.sub.first peak+A1.sub.second peak is computed with the same software. [0372] The amounts of methyl side groups per thousand carbon atoms, is computed as follows:
[00004] [0373] wherein A2 is the area of the three peaks of the methyl end groups which are the second highest in the ppm range between 0.8 and 0.9 and are located after the second peak of the methyl side groups towards increasing the ppm range and wherein A3 is the area of the peak given by the CH2 groups of the main UHMWPE chain, being the highest peak in the entire spectrum and located in the ppm range of between 1.2 and 1.4. [0374] Minimum creep rate of yarns may be determined as described in the published patent application WO2016001158. In particular as described in the section Stabilizing creep and minimum creep rate in the fibers of WO2016001158. The minimum creep rate of the yarns has been derived therein from a creep measurement applied on multifilament yarns by applying ASTM D885M (1995) standard method under a constant load of 900 MPa, at a temperature of 30 C. and then measuring the creep response (i.e. strain elongation, %) as a function of time. The minimum creep rate is determined by the first derivative of creep as function of time, at which this first derivative has the lowest value (e.g. the creep rate [1/s] of the yarn is plotted as function of strain elongation [%] of the yarn in a so-called known Sherby and Down diagram.) [0375] Coefficient of friction The set-up of the equipment to measure the coefficient of friction is schematically depicted in FIG. 13a. FIG. 13b depicts a cross section of one of the sheaves from FIG. 13a, the cross section is given along the X-Y area in FIG. 13a. The coefficient of friction of a 5 mm diameter rope (131) with respect to metal was measured by running the rope in a machine over two sheaves (132, 133) made from tool steel 1.2709 (roughness Ra 0.2150.002 (n=3)), one of which was blocked (132) to prevent rotation (see FIG. 13). Water of 23 C. ran through the blocked sheave (132), the Relative Humidity in the room was 50%. Sheave diameter (D) of each of the sheaves (132, 133) was 99 mm. The radius of the groove (136) of each of the sheaves was 3 mm. A force was applied between the two sheaves using two pneumatic cylinders (134, only one is shown) both connected to opposite sides of the freely rotating sheave (133) such that the rope was loaded with a load of 3750 N. The rope was then moved over the sheaves at a speed of 2750 mm/min by means of a slider (135) to which the rope is connected, and which slider is moved along the Y-axis. The force required to move the rope was measured, and using Eq 1 the coefficient of friction was calculated
[00005] [0376] Where is the coefficient of friction, F.sub.braid is the force in the braid (3750 N), and F.sub.measured is the measured force required to move the rope over the stationary and moving sheave at the defined speed. [0377] Before measuring the coefficient of friction, the rope was loaded to 7750N for 60 seconds by means of increasing the pressure in the pneumatic cylinders and subsequently unloaded by means of increasing and decreasing pressure in the pneumatic cylinders to remove constructional elongation. Subsequently, the measurement of the coefficient of friction was performed by moving the slider (135) 350 mm down and thereafter 350 mm up. This is one cycle. For each rope 3 cycles were measured. The average force during the second cycle was used to calculate the coefficient of friction. [0378] CBOS 5 mm test (test set-up is schematically depicted in FIG. 2): 6 bends per machine cycle, rope diameter 5 mm, D/d 10, Tension 510 MPa (Load: 30% Minimum Breaking Load), in wet environment (water cooling: ambient temperature water sprayed (FIG. 2a-item 25) at bending zone area of the top sheave (21). [0379] The cyclic bending over sheave (CBOS) performance was tested. Within this test the rope (20) is bend over three rolling sheaves (21, 22, 23) each having a diameter of 50 mm. The three sheaves were positioned in an upside-down V-formation on a frame (24). The rope was placed over the sheaves in such way that the rope has a bending zone at each of the sheaves. The rope was placed under a specific load (30% MBL). The frame with the sheaves is cycled back and forth (indicated with an< >arrow arrow (G) during which the rope is exposed to cyclic bending over sheaves until the rope reaches failure (=break). One machine cycle represents the frame with the sheaves going back and forth once. This means that one machine cycle represents 6 bends (3 bends a time). The stroke length (L, see FIG. 2c, is the distance from start(S) to end (E)) of the rope was 45 cm long. The cycling period was 5 seconds per machine cycle. [0380] One machine cycle contains a straight bend) (90 at A, reverse bend) (180 at B, followed by straight bend) (90 at C. Rope is alternately bend in opposite directions, one full cycle exists of 4) (90 straight bends and 2 (180) reverse bends. One full cycle is 2 stroke lengths long. [0381] Cyclic bend-over-sheave (CBOS) 21 mm-A test (test set-up is schematically depicted in FIG. 3): rope diameter 21 mm, D/d 20. CBOS test: the bend fatigue of the rope was tested by bending the rope over a sheave. This is schematically depicted in FIG. 3. The test rope (30) was configured in an endless loop construction, meaning both rope ends have been connected with use of a splice termination. The loop had a circumference of about 6.5 m. The splice termination (often referred also to as a tucked splice) had an amount of tucks of 9 per rope side. Both splice-ends were not tapered. This loop was positioned over the large sheave on top (traction sheave (31)) and small bending sheave (32) in the bottom of the machine. [0382] The rope was placed under load (Tension 280 MPa (this is 18% of the MBL)) and cycled back and forward over the sheave, at a stroke speed of 210 m/min, until the rope reached failure. Each machine cycle produced two straight-bent-straight bending cycles of the exposed rope section, the double bend zone. The double bend zone was approximately 14 times the diameter of the rope. The bending cycle time was 12 seconds per machine cycle (1 cycle is back and forth), in dry environment (no water cooling). The pause was 1 second between each cycle reversal. The pre-load for bedding in the rope was 5 times 14.5 metric tons. [0383] Cyclic bend-over-sheave (CBOS) 21 mm-B test: the same as for CBOS 21 mm-A above but with Tension 370 MPa. [0384] Fairlead 10 mm test: rope diameter 10 mm, 2 abrasion cycles per machine cycle, 36 seconds per machine cycle-C2 fairlead (DIN 81915) D/d 20, Tension 380 MPa (Load: 25% MBL), in dry environment (no water cooling). [0385] The fairlead abrasion performance was tested. This is schematically depicted in FIG. 4. Within this test the rope (40) is moved under a specific load (1800 kg) over a fairlead (41). One machine cycle represents the rope being pulled over the surface back and forth once. The rope was cycled back and forth until failure. The cycling period was 36 seconds per machine cycle. The stroke length of the rope was 56 cm long.
EXPERIMENTS
The following examples are given by way of non-limiting reference only.
Materials
[0386] Paramelt Aquaseal X2050 (also referred to as X2050 herein) is a water based dispersion, formulated with unplasticized high molecular weight thermoplastic ethylene copolymers, which is totally solvent free. Solids content 44%, pH 11, a milky white liquid, with a Viscosity (Dynamic @ 20C) of 150 mPas. This thermoplastic ethylene copolymer has a melting peak at 76.7 C. and heat of fusion of 21.9 J/g. It was purchased from Paramelt Veendam B.V., Veendam The Netherlands.
[0387] Michelman Michemprime MP2960 is a water-based copolymer dispersion having pH of 11-12 and a non-volatile content of 16.5-17.5%. It was purchased from Michelman SARL, Windhof, Luxembourg.
[0388] BYK Aquacer 2650 is a non-ionic emulsion of carnauba wax in water. It comprises 30% non-volatile matter and has a pH of 4.5. It was purchased from BYK Netherlands B.V.
[0389] BYK Aquacer 2700 is an emulsion comprising a Fischer-Tropsch wax at a pH of 9.5. It was purchased from BYK Netherlands B.V.
[0390] NeoCryl A-668 is an anionic acrylic styrene copolymer emulsion, supplied as 45% solids in water. It was purchased from BYK Netherlands B.V.
[0391] DSM NeoRez R-2180 is an aliphatic, self-crosslinking polyurethane dispersion in water, having a pH of 7.3 and a solids content of 35%. It was acquired from DSM Coating Resins B.V. Waalwijk, Netherlands.
Manufacturing of the Coating Compositions for Ex. 1-6
The thermoplastic ethylene copolymer and the lubricant were mixed by adding the lubricant to the ethylene copolymer at room temperature and stirring for 15 min.
Manufacturing of the Comparative Coating Compositions for Comp. Ex. 1 and Comp. Ex. 2
The comparative coating composition was prepared by diluting the ethylene copolymer by water in the amount of 1:1.
Manufacturing of a Composite Elongated Body
A HPPE yarn (Dyneema 1760 SK78, yarn tenacity 34.5 cN/dtex, filament tenacity 37 cN/dtex, Modulus 1190 cN/dtex, from DSM Protective materials BV, The Netherlands) was impregnated by dipping in the coating composition. The wetted yarns were fed first through a die and then in seven passes through a hot air oven with a length of 6 meters with an inlet speed of 50 m/min and an outlet speed of 50 m/min. The oven temperature was set at 110 C. The obtained dried monofilament-like product each contained about 15 mass % polymeric composition and 85 mass % was fibrous material (filaments).
Manufacturing of a 5 mm Rope
The composite elongated body was used to produce 5 mm ropes (rope having 5 mm diameter), each having 48 single yarns divided over 12 strands. The rope contained 12 strands, (round) braided in 6 clockwise oriented strands and 6 counter-clockwise oriented strands, each strand contained a 20 turns per meter twisted assembly of 4 monofilament-like products, braiding pitch was 7 times the diameter of the rope.
Manufacturing of a 10 mm Rope
The composite elongated body was used to produce 10 mm ropes (10 mm diameter). Each rope contained 12 strands, (round) braided in 6 clockwise oriented strands and 6 counter-clockwise oriented strands, each strand contained 18 turns per meter twisted assembly of 20 monofilament-like products, braiding pitch was 7 times the diameter of the rope. This way Rope Examples 1 to 6 and Comparative Examples 1 and 2 were made.
Fairlead Test
The ropes from Rope Examples 1 to 6 and Comparative Examples 1 and 2 were subjected to the Fairlead 10 mm test as described above.
Table 1 reports the Fairlead test results.
TABLE-US-00001 TABLE 1 Polyethylene Solids copolymer ma- Fairlead Example base trix:solids Coefficient abrasion No. matrix Lubricant lubricant of friction cycles Comp. X2050 None N/A 0.13 11.5 Ex. 1. Ex. 1. X2050 Aquacer 1:1 0.10 25 2650 Ex. 2. X2050 NeoRez 3:7 0.13 26 R-2180 Ex. 3. X2050 NeoCryl 1:3 0.11 28 A-668 Ex. 4. X2050 NeoCryl 1:1 0.12 18 A-668 Comp. MP2960 None N/A 0.13 23.5 Ex. 2. Ex. 5. MP2960 Aquacer 1:1 0.12 48.3 2700 Ex. 6. MP2960 Aquacer 1:1 0.07 29 2650
The results indicate that presence of a lubricant together with a polyethylene copolymer base matrix leads to a reduction in the coefficient of friction. Further, the presence of a lubricant together with a polyethylene copolymer base matrix improves the abrasion resistance of a coated elongated body. Further, coating with MP2960 improves abrasion resistance more than coating with X2050. When the coating comprises a higher proportion of solids in the lubricant than solids in the matrix, the rope has a further improved abrasion resistance.
