CA2175110A1

CA2175110A1 - Polyolefin line

Info

Publication number: CA2175110A1
Application number: CA002175110A
Authority: CA
Inventors: Roger B. Cook
Original assignee: Berkley and Co Inc
Current assignee: Berkley and Co Inc
Priority date: 1995-04-27
Filing date: 1996-04-26
Publication date: 1996-10-28
Also published as: DE69605235T2; ATE186954T1; US6148597A; EP0740002B1; JPH0998698A; EP0740002A1; US5540990A; DE69605235D1; DK0740002T3; JP3669527B2

Abstract

Monofilament lines are made from twisted gel spun polyolefin yarns that are heated and stretched under conditions sufficient to fuse adjacent filaments into a line having monofilament characteristics and high tenacity.

Description

POLYOLEFIN LINE

FIELD OF-THE INVENTION
The present invention relates to the stretching of braids or twisted and plied 5 yarns made of high tenacity, ultrahigh molecular weight filaments, fibers or yarns.
BACKGROUND OF THE TECHNOLOGY
Ultrahigh molecular weight, high tenacity filaments based on spun polyolefins are described in numerous patents, published patent applications, and technical articles.
Exemplary references include Kavesh et al. US 4,413,110; Smith et al. US 4,344,908;
Smith et al. 4,422,993; Kavesh et al. US 4,356,138; Maurer EP 55,001; Harpell et al.
US 4,455,273; Kavesh et al. US 4,897,902; Neal US 5,277,858; and Kirkland et al.WO 94/00627.
These filaments are generally made from linear polyethylene or polypropylene chains of a molecular weight of at least 400,000, a tenacity of at least 15 grams per denier (g/d), a tensile modulus of at least 500 g/d (nylon monofilaments are about 20-50 ! I g/d), a melting point of at least 140 C, have high abrasion resi.ct~nce, low stretch, high to~lghnesc, good dimensional and hydrolytic stability, and high resict~n~-e to creep under sl-st~in~ loads. The yarns are opaque and white in appea~ ce. Such yarns are commercially available from Allied-Signal, Inc., Morris, New Jersey as SPECTRA
20 fiber and from DSM, NV, Netherlands under the name DYNEEMA. The fil~mentc in these commercial yarns has a significantly higher molecular weight than 400,000.Both SPECTRA and DYNEEMA fil~mentc are fi~n-l~mentally made in the same way. A solution cont~inin~ polyethylene gel swelled with a suitable solvent is spun into filaments of high molecular weight polyethylene. The solvent is removed, and the25 resulting yarn is stretched or "drawn" on one or more stages. In general, such filaments are known in the art as "gel spun polyolefins" with gel spun polyethylene being the most commercially sold.
Monofilament fishing lines of high molecular weight, gel spun polyolefin filaments in sufficient diameter are not commercially available. The most likely reason Attorney Docket No. 47941 2 1 ~5 1 1 U

is that the filament manufacturing process involves quantities of solvent that must be removed from the filament following its formation Thicker filaments would hinder the efficiency and completeness of the solvent removal process and aversely affect the strength of the finished filament. In addition, there are concerns for the degree of S lilllplless such lines might have as well as the h~nllling characteristics of such lines in real fishing conditions.
Fishing lines must be reasonably limp to be effective under the conditions of normal fresh and salt water fishing. For example, the bending modulus of nylon monofilaments is within the range from about 15-50 g/d. The high molecular weights 10 characteristic of gel spun polyolefins, however, make the line unacceptably stiff at the diameters geneMlly required for fishing lines, if such lines could be produced.
Monofilaments from such materials would not wind onto a conventional reel easily and would be difficult to tie into knots, such as those used to secure a lure to the line, without we~kening the line and jeopardizing the quality of the knot.
It would be desirable to have a fishing line from gel spun polyolefins that was sufficiently limp like monofil~m~nt~ to use for fresh and salt water fishing with conventional fishing equipment and lures.
Fishing lines made from braids of gel spun polyethylene yarns have been introduced into competition with conventional braided fishing line materials (generally 20 polyesters) and nylon monofil~m~nt lines. The higher strength of such braidedpolyethylene lines is a distinct advantage. Such braids can, however, exhibit some disadvantageous characteristics.
Monofilament lines are generally more preferred for bait casting, spinning, and spin casting. Monofilaments have a round, firm structure that makes for more 25 convenient h~n(11ing. The stiffer nature of the line and the smoother surface combine to reduce drag during the cast and enable longer casts while providing a better release from a fishing reel. Monofilament lines do not entrap water and do not present an outer surface that is vulnerable to snags and entanglement.

Attorney Docket No. 47941 2 2175~ ~0 Braided lines can also have the tendency to fray at the end of the line. When tied into a knot, this "tag end" frays to create a fuzzy protrusion that can adversely affect the-appearance and acceptability of a lure when fishing. In addition, braided lines made from gel spun polyethylenes cannot be cut cleanly with a co~ ession type of line 5 ~ clipper that is commonly in use among anglers. The braid must be cut with a scissors or other type of shearing device to ensure that all filaments in the braid are severed evenly.
It would be desirable to have a line with the high tenacity of gel spun polyolefin lines that is more monofilament-like in its h~ntlling characteristics, i.e., the line has a firm structure like that of a monofilament, exhibits a lower diameter than a braid, does not saturate with water, and reduces or elimin~t~s the problems associated with end fraying and the difficulties of cutting the line. I
Braided or twisted lines made of gel spun polyolefin yarns are also characterized by an opaque white color (i.e., no light tr~n~miftivity). White is not, however, the 15 ~ plefelled color for use in a fishing line. Ihere is a belief that white lines are too visible below water and will tend to scare fish from a bait or lure.
It would be useful to have a process for providing a gel spun polyolefin line that exhibited a nonopaque appedldnce, preferably a translucent to more ~deq~ ely hide the line when under water.
SUMMARY OF THE INVENTION
It is an objective of the invention to provide a yarn from gel spun polyolefins that exhibits low end fraying and cutting characteristics similar to conventional monofilaments.
i It is another objective of the invention to provide a fishing line made from gel spun polyolefin filaments that is stiffer than a twisted or braided line yet sufficiently stiff to exhibit reel h~n-lling (loading and unloading) characteristics like monofilament lines.
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Attorney Dockct No. 47941 3 217jl 10 It is a further objective of the invention to provide a fishing line from gel spun polyolefin that is at least partially translucent and less visible in water than previous opaque white lines from gel spun polyolefin.
In accordance with this and other objectives of the invention that will become S apparent from the description herein, lines according to the invention are made by a process comprising: exposing an opaque braided or twisted line made from gel spun polyolefin filaments to a temperature within the melting point range of said polyolefin for a time sufficient to at least partially fuse the contact surfaces of adjacent f1l~ment~.
For gel spun polyethylene, the temperature is preferably within the range from about 150-157 C.
Lines made according to the invention impart desired h~nrlling characterislics of monofilament in ultrahigh molecular weight, gel spun polyolefin braided or twisted lines while affording the benefits of high strength characteristic of the gel spun polyolefin materials. Casting is improved over braids. The line exhibits a harder, stiffer, lower 15 ' friction surface than braids or twists which leaves the reel and moves through the guides I with less drag. The line also exhibits low fraying and is easier to cut with conventional clippers. The low stretch character of the reslllting line tran~l~tes into a fishing line with a high degree of sensi~ivily.
DETAILED DESCRIPTION OF THE INVENTION
20, Gel spun polyolefin yarns are braided or twisted into a line and then subjected to a further ~llelchillg at an elevated temperature within the melting point range of the filament material that is sufficient to at least partially fuse t_e contact surfaces of the individual filaments within the yarn into a line having monofil~m~nt-like characteristics.
The unfused surfaces permit the line to retain filament mobility and limpness while the fused surfaces secure the individual filaments to plevelll end fraying and permit cutting with conventional compression cutting devices.
The conditions of the fusion process according to the present invention are selected to be high enough and for a sufficient residence time to soften the filaments and allow them to fuse at least partially within a braided or twisted line structure.

Attorney Docket No. 47941 4 ~ 21751il3 Conditions useful for the surface fusion process include a temperature or series of oven temperatures within the melting point range of the filament polymer that allows for adequate fusion during the exposure period. The temperature is preferably within the range from about 150 C up to about 157 C for high molecular weight, gel spun 5 ~ polyethylene yarns exhibiting a relaxed melting point range of 138 to about 162 C at a 20C/minute scan rate. Residence times during which the line is exposed to thefusion temperature are within the range from about 6 seconds to about 150 seconds.
Although a higher degree of fusion is achieved by increasing the temperature, there is a corresponding loss in tenacity as the fusion temperature (e.g., the set point temperature 10 of the heating ovens) is increased.
It should be noted that the effect of increasing temperature appears to predominate over the length of the residence time at the applied fusion temperature. In other words, a change in oven temperature will have a more pronounced effect than a change in residence time through the fusion ovens.
Following the fusion process, lines according to the invention change their appearance from an initial, opaque white color (0% light tr~n~mi~ion) characteristic of the virgin filaments into a nonopaque appea~ ce. In particular, the filaments take on a translucent, milky, or subst~nti~lly l~ alelll surface having a range of light tr~n~mittivity from about 1% to about 100%, preferably within the range from about 20 1 2% to about 50%. Such an increase in light tr~n~mi~sion helps to conceal the line undel ~al~r.
Only the outer surface of the filaments should soften and begin to fuse as seen by an increase in light tr~n~mi~.~ion as the degree of fusion progresses. The change in light tr~n~mi~sion is visible to an observer as the line exits from an oven between 25 unheated stretching rollers or as it leaves a heated stretching roller. As the light tr~n~mi~ion character of the outer surfaces increases (i.e., the line becomes more clear), however, the line becomes stiffer and more like a monofilament. The fused surface contacts provide the line with monofilament-like character in terms of low end fraying and convenient cutting with crushing style clippers.

Attorney Docket No. 47~41 5 The line is also heated while stretching (sometimes referred to in the art as "drawing") the line under tension that is preferably applied continuously. The stretching-tension provides a number of benefits: (1) tension prevents loss of tenacity at the fusion telllpelalul~s; (2) tension preserves or increases the tenacity of the fused 5 ! structure relative to the unfused braided or twisted line; (3) tension helps to compress the structure radially for better fusion; and (4) tension prevents melting.
Preferably, the temperature, residence time, and stretching ratio at the selected temperature are chosen to provide a line exhibiting some degree of light tr~n~mi~sion and a tensile modulus within the range from about 230 g/d to about 780 g/d with a 10 tenacity of at least 15 g/d, and more preferably a tenacity of at least 25 g/d. Significant reductions in the line tenacity indicate that the combinalion of temperature and residence time are too high and are resl-lting in loss of filament orientation.
A simple test can be used to determine whether adjacent fiber surfaces are fusing. Line with a sufficient number or conce,lL,aLion of surface fused fibers is 15 ~ mounted on a slide. A perm~n~nt marker is held vertically and contacted at a stationary position for 5-10 seconds. A regular, braided line will wick color from the marker into the line surface. A sufficiently fused line will not wick color from beyond the contact area.
Altelllalively, an optical microscope can be used to observe whether the 20 I filaments or yarns will readily se~dlale when subjected to coll~ ,ssion. Tn~lfflciently fused lines will readily separate. Sufficient fusion exists when the line does not readily separate and a series of compression/tension cycles is needed to begin to separate the filaments or yarns from the line.
~ Preferably, the present fusion conditions also include an overall stretching ratio 25 from one or more stages of stretching to preserve or increase chain orientation. Such stretching ratios are generally within the range from about 1.01 to about 2.5 and preferably a ratio within the range from about 1.35 to about 2.2.
The fusion process conditions place the outer surface temperature of the filaments at or within the melting point range of the polymer in the filaments so that At~orney Docket No. 47941 6 ' I filament surfaces begin to soften and fuse at contact points along the outer surfaces of the filaments. The fusion conditions are chosen to m~int~in a line tension reflective of centerline- chain reorientation and avoid loss of filament orientation.
The non-opaque outer surface of the gel spun polyolefin line of the invention is5 better capable of blending into the background colors under water without colorants. A
clear outer surface is most able to be self-camouflaging. If colored, the improved transmission of light provides an outer surface that is more readily colored than the virgin opaque, white surface.
The lines of the invention may be made from colored yarns, colored after 10 braiding or twisting, or after fusion according to the present invention. Penetrating coloring solutions that can be employed in the color-imparting process include: aqueous solutions of ethylene-acrylic acid copolymers, low molecular weight polyethylenes, low molecular weight ionomers, high molecular weight ionomers, and polyurethanes; and dyes or pigments in organic solvents or mineral oils (especially those with a molecular weight of 200-700 that will penetrate the filament). A preferred coloring agent is an aqueous solution cont~ining ethylene-acrylic acid copolymer cont~ining a blue or green dye or pigment.
Coloring agents can be applied by passing the line of the invention through a bath cont~ining the coloring solution at room temperature, e.g., a temperature within 20 the range from about 20 C to about 25 C, although higher tempelalu,es can be used if desired. Thereafter, the coated line is dried and the coloring agent set by passing the coated line through an oven m~int~in~ l at a temperature within the range from about 100 C to about 130Q C.
The gel spun polyolefin yarns used in the invention are preferably made from 25 filaments of ultrahigh molecular weight, high tenacity polyethylene or polypropylene.
Such filaments are characterized by a molecular weight of at least 400,000 and more preferably at least about 800,000; a tenacity of at least 15 g/d; a tensile modulus of at least 500 g/d; and a melting point of at least 140 C. See, Kavesh et al. US Patent Attorney Docket No. 47941 7 ;: i Nos 4,413,110 and 4,551,296 the disclosures of which are herein incorporated by reference.
The polyolefin can contain one or more fillers. Exemplary fillers include I ll magnetic materials, electrically conductive substances, substances with high dielectric " constant, and mixtures thereof can be used if desired. Specific examples include 5 I calcium carbonate, barium carbonate, m~gnPsium carbonate, clay, talcum, mica, feldspar, bentonite, al-lmin-lm oxide, m~gn~sil-m oxide, tit~nillm dioxide, silica, gypsum either uncoated or coated with another material to enhance the bond between the polymer and the filler, e.g., stearic acid or acrylic acid. See, Maurer EP 55,001.
Braided lines according to the invention are made with conventional braiding 10 1 equipment and 3-16 discrete yarns braided about a central axis. The braid tightnf~
(measured in picks per inch") is adjusted to provide a limp line of good surface quality according to the prevailing standards of the line manufacturer. The braids used as feed to the present fusion process preferably exhibit a size within the range from about 100 denier to about 3000 denier and more preferably within a range from about 200-800 denier.
Twisted lines of the invention can be made from either single, twisted yarns or in 24 ply, torque-bal~n~d structures. Preferably, the line is twisted to produce a neutral net twist, i.e., the twisted fibers will remain i~ lwil~ed even when free of tensile loading. In the conventional language of the art, single yarns are twisted in a z" direction, while 24 of these z-twisted yarns can then be plied together in t_e sn (opposite) direction. The z pitch and s" pitch are chosen to balance the torque of each twist. Twists are measured in terms of twists-per-inchn (tpi) or ~twists-per-metern (tpm). Like the braids, twists used as feed to the present fusion processpreferably exhibit a size within the range from about 100 denier to about 3000 denier and more preferably within a range from about 200-1200 denier.
One or more outer coating materials can be applied to the surface of the line, yarn, or filament to enhance the fusion process between the fiber polymer of adjacent filaments. Such coatings include mineral oils (e.g., heat transfer grade mineral oils with an average molecular weight of 250-700) paraffin oils, and vegetable oils (e.g., Attorney Docket No. 47941 8 coconut oil). Contact between the line or yarn and the coating material can be performed under ambient conditions (e.g., 20-25 C) or under elevated temperatures (e.g., up to about 100-150 C or higher). Mineral oil acts as a plasticizer that enhances the efficiency of the fusion process permitting the fusion process to be performed at 5 lower temperatures. Such enh~nre~l ef~lciency is exhibited regardless of the structure into which the filaments, yarns, or lines is made, e.g., fabrics, composites, or ballistic apparel.
EXAMPLES
The following examples were performed in one of two heated production lines 10 made with three ten foot ovens wherein the last two ovens are end-to-end and stretching rollers are located after the first oven and following the last in the "double length"
oven. Unless otherwise stated, all temperatures are in degrees Celsius.
Examples 1-9 Braided and twisted lines made from yarns of gel spun polyethylene filaments 15 were prepared and subjected to the fusion process of the present invention. Total draw ratios were within the range of 1.8-1.9 with a higher draw ratio on the first roller than on the second. Each of the examples formed a line with monofilament-like characteristics and good tenacity values. (For comparison, conventional polyester-based braids generally have tenacity values of less than 8, usually about 6-7 g/d, and nylon 20 braids exhibit tenacity values of about 5-6 g/d.) Examples 8 and 9 were performed with braided lines that were previously coated with ethylene acrylic acid copolymer resin (EAA) cont~ining a green pigment. A summary of the conditions and results are shown in Tables 1 and 2.

Attorney Docket No. 47941 9 21 /Sl lO

Table l Construction Braid Braid Braid Braid Il (2x100,2x200) (4x200) (4x200)(2x100, 2x200) Initial Denier645 860 860 645 Rate (fpm) 30 30 30 30 Ovenl Temp 150 150 150 150 Oven 2 Temp 155 154 154 154 Draw Ratio 1 1.4 1.4 1.5 1.5 Draw Ratio 2 1.36 1.36 1.27 1.27 Total DR 1.9 1.9 1.9 1.9 Final Denier 332.2 449.8 445.4 333.7 Elongation (%)3.3 2.7 2.6 3.1 Break Strength (Ib) 20.9 25.8 27.2 23.6 15 I Knot Strength (Ib) 14.7 18 20.4 17.4 Tenacity (g/d)28.5 26 27.7 32.1 Attorney Docket No. 47941 10 Table 2 6 7 ~ (EAA)9 (EAA) Construction Braid Braid Braid Braid Braid (4x100), (3xS0, Ix100) (4xS0) (4x200) (4x200) Initial Denier 430 260 295 945 945 Rate (fpm) 30 30 30 20 20 Ovenl Temp 150 150 150 152 150 Oven 2 Temp 154 154 154 154 152 Draw Ratio 1 1.4 1.4 1.4 1.4 1.4 Draw Ratio 2 1.36 1.36 1.36 1.286 1.286 Total DR 1.9 1.9 1.9 1.8 1.8 Final Denier 225.9 141.2 114.2 524.6 513.3 Flo~tinn (%) 2.9 2.9 3.1 3 2.8 Break Strength (Ib) 15.7 9.7 8 28.1 31.2 Knot Strength (Ib)12.1 7.6 5.6 16.5 20.8 15 , Tenacity (gld) 31.5 31.2 31.8 24.3 27.6 Differences in braid construction and line size did not adversely affect the nature of the fusion process. Tenacity values were within acceptable ranges and variances.
Examples 10-13 In examples 10-13, mineral oil was used as a plasticizer and fusion el~h~l~r-er. In examples 10 and 12, the mineral oil contained a dye. In examples 10-13, the braided lines were dipped in mineral oil for about 1 second and wiped with a squeegee toremove excess oil. Oil was observed to wick into the braid immediately upon contact with the oil. The line then fed to and through the fusion line ovens and rollers, a time period during which the oil was believed to continue to penetrate into the yarns of the braid. If used, mineral oil within a range from about 1% to about 30%, preferably about 1-25%, and more preferably within the range of about 1-20% should be used as measured by heptane extraction of the final, processed line. Table 3 reports the results.

Attorney Docket No. 47941 1 1 ., ~ f ;
~J l~

Table 3 - (19.3% Min. Oil)(12.7% Min. Oil)(12.7% Min. Oil)(14.6% Min. Oil) Construction Braid Braid Braid Braid (4x200) (2x100,2x200)(2x100,2x200) (2x100,2x200) Initial Denier 860 645 645 645 Rate (fpm) 20 20 20 10 Ovenl Temp 152 148 148 148 Oven 2 Temp 154 152 152 152 Draw Ratio 1 1.4 1.4 1.4 1.4 Draw ~atio 2 1.286 1.36 1.36 1.36 Total DR 1.8 1.9 1.9 1.9 Final Denier 569.4 372 380.4 374 Elongation (%) 1.9 2.5 2.5 2.3 Break Strength (Ib)17.1 22 21.8 20.6 Knot Strength (Ib) 9.4 16.6 16.4 16.1 Tenacity (g/d) 13.6 26.8 26 25 The mineral oil did improve the ease of fusion and the quality of the monofilament characteristics in the res~lltin~ line. The plasticized line was more flexible and well fused. The tenacity values were, however, somewhat lower although 20 ! still acceptable.
Example 14 A braided yarn of gel spun polyethylene was stretched at a draw ratio of 1.9:1 at 152 C. The structure became semi-fused but could be delamin~ted back to the original four yarns by cyclic abrasion over a sharp corner. For comparison, the braided yarn of 25 the same material was then passed through a heat transfer grade mineral oil (avg. MV
of 350), then stretched and processed at 152 C. The braid became fused, greatly- reducing del~min~tion characteristics and nearly m~int~ined the properties of the drawn, braided structure..

Attorney Docket No. 47941 12 l, 2 1 7 5 i 1 0 ; Example 15 Twisted yarns of gel spun polyethylene filaments of single ply and four ply constructions with an initial denier of 400 were drawn at a ratio of 1.3-1.4 at 152 C.
The drawn structure was loosely fused and was easily del~min~t~d by flexing the S 1 structure. For comparison, single ply and four ply structures of the same materials and size were then passed through the mineral oil bath used in example 14, stretched, and processed at 152 C. The twisted structures became completely fused and m~int~ined most of the desired properties in the original twisted structures yet adding a monofilament-like h~nflling characteristic.
Example 16 Untwisted gel spun polyethylene yarns were stretched at ratios of 1.3-1.45:1 at 152 C. The yarn showed little signs of fusion. For comparison, untwisted yarn was passed through the mineral oil of example 14, stretched, and fused at 152 C. The yarns formed a fused structure with monofilament-like h~ntlling characteristics and 15 nearly the strength of the original stretched yarn.
Examples 17-18 In examples 17, a line was made from four yarns by twisting and plying. The resl-lting line exhibited a neutral twist and was used as feed to a fusion process according to the invention. Table 4 reports the process conditions and physical 20 characteristics of the resllltinp fused line.

Attorney Docket No. 47941 13 ~ 1 75~ ~ O
;' Table 4 - Construction Twist 4x100, twist 700 t/m z", ply 350 t/m "s"
Initial Denier412.4 5 I Rate (fpm) 25 Ovenl Temp 148 Oven 2 Temp 154 control Draw Ratio 1 1.4 Draw Ratio 2 1.268 10 , Total D~ 1.8 Final Denier 235.2 412.4 Elongation (%) 3.1 4.2 Break Strength (Ib) 12.5 21.6 Knot Strength (Ib) 8.3 15.5 15 i Tenacity (g/d)24.1 23.8 The lines made from twisted yarns fused well and did not exhibit a loss of tenacity. Reductions in break strengths were due to a drop in the line denier from 412.4 to 235.2.
20 j The examples prese~ d herein are intended for illustration purposes only and are not intended to act as a limitation on the scope of the appended claims.
, Attorney Docket No. 4 /941 14

Claims

1. A process for making a fishing line containing gel spun polyolefin filaments, said process comprising:
exposing a braided, twisted, or twisted and plied fishing line made from yarns of gel spun polyolefin filaments to a temperature within the melting point range of said polyolefin for a time sufficient to at least partially fuse adjacent filaments.

2. A process according to claim 1 wherein said process comprises:
exposing said line to said temperature for a time sufficient to increase the light transmittivity of said filaments.

3. A process according to claim 2 wherein said process comprises:
exposing said line to said temperature for a time sufficient to make said filaments a milky white color.

4. A process according to claim 2 wherein said process comprises:
exposing said line to said temperature for a time sufficient to make said filaments substantially transparent.

5. A process according to claim 1 wherein said process comprises:
exposing a twisted line made from filaments containing gel spun polyethylene to said temperature.

6. A process according to claim 1 wherein said process comprises:
exposing a braided line made from filaments containing gel spun polyethylene to said temperature.

7. A process according to claim 1 wherein said process further comprises:
stretching said line at a stretching ratio within the range from about 1.01 to about 2.20.

8. A process according to claim 1 wherein said process comprises:
exposing a braided, twisted, or twisted and plied line that is coated with a plasticizer in an amount within the range from about 1% to about 30% by weight.

9. A process for making lines with monofilament characteristics from filaments made of gel spun polyolefins, said process comprising:
twisting a plurality of yarns made from a gel spun polyolefin filaments into a line with a neutral net twist;
exposing said line to a temperature within the range from about 150° C to about 155° C for a time sufficient to fuse at least a portion of adjacent filaments into a fishing line having monofilament characteristics.

10. A process as in claim 9 wherein said process comprises:
exposing said line to said temperature for a time sufficient to increase the light transmittivity of said filaments.

11. A process according to claim 10 wherein said process comprises:
exposing said line to said temperature for a time sufficient to make said filaments exhibit a milky white color.

12. A process according to claim 10 wherein said process comprises:
exposing said line to said temperature for a time sufficient to make said filaments substantially transparent.

13. A process according to claim 9 wherein said process comprises:
exposing said line made from filaments containing gel spun polyethylene to said temperature.

14. A process according to claim 9 further comprising:
coating said line with a plasticizer before exposing the line to said temperature.

15. A process according to claim 14 wherein the coating step comprises:
coating said line with about 1-30% by weight of a mineral oil.

16. A yarn made of gel spun polyolefin filaments with characteristics of a monofilament, said line comprising:
at least two gel spun polyolefin filaments that have been braided or twisted together and then exposed to a temperature within the melting point range of said polyolefin filaments for a time sufficient to at least partially fuse surfaces of adjacent filaments.

17. A yarn according to claim 16 in which said filaments have been twisted together with a neutral net twist and then exposed to said temperature for a time sufficient to make said filaments translucent.

18. A yarn according to claim 17 wherein said yarn is exposed to said temperature for a time sufficient to make said filaments substantially transparent.