U.S. patent application number 14/037459 was filed with the patent office on 2014-08-28 for unbalanced hybrid cords and methods for making on cable cording machines.
This patent application is currently assigned to E I Du Pont De Nemours And Company. The applicant listed for this patent is E I Du Pont De Nemours And Company. Invention is credited to Clifford K Deakyne, Brian R. France, Mark Allan Lamontia, David William Litchfield, NATHAN W. LOVE.
Application Number | 20140237983 14/037459 |
Document ID | / |
Family ID | 50193633 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140237983 |
Kind Code |
A1 |
LOVE; NATHAN W. ; et
al. |
August 28, 2014 |
Unbalanced Hybrid Cords and Methods for Making on Cable Cording
Machines
Abstract
A hybrid cord formed from a plurality of component plies wherein
at least one of the plies has a length that is from 1 to 50 percent
longer than the other plies and a method of providing a cord with
predetermined twist and component ply lengths.
Inventors: |
LOVE; NATHAN W.; (Richmond,
VA) ; France; Brian R.; (N. Chesterfield, VA)
; Lamontia; Mark Allan; (Landenberg, PA) ;
Deakyne; Clifford K; (Wilmington, DE) ; Litchfield;
David William; (Midlothian, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
E I Du Pont De Nemours And Company |
Wilmington |
DE |
US |
|
|
Assignee: |
E I Du Pont De Nemours And
Company
Wilmington
DE
|
Family ID: |
50193633 |
Appl. No.: |
14/037459 |
Filed: |
September 26, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13778595 |
Feb 27, 2013 |
|
|
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14037459 |
|
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Current U.S.
Class: |
57/238 ;
57/58.52; 57/58.7; 57/58.86 |
Current CPC
Class: |
D01H 1/10 20130101; D02G
3/04 20130101; D01H 1/02 20130101; D02G 3/28 20130101; D02G 3/48
20130101; D07B 1/025 20130101 |
Class at
Publication: |
57/238 ;
57/58.52; 57/58.7; 57/58.86 |
International
Class: |
D02G 3/28 20060101
D02G003/28; D01H 1/02 20060101 D01H001/02; D01H 1/10 20060101
D01H001/10; D02G 3/04 20060101 D02G003/04; D07B 1/02 20060101
D07B001/02 |
Claims
1. A hybrid cord, comprising a plurality of plies, wherein at least
two of the plies are of unequal ply length regardless of the twist
of the plies and at least one of the plies has a length that is
from 1 to 50 percent longer than the other plies and the plies
comprise yarns selected from the group consisting of continuous
filaments, staple spun yarns and stretch-broken yarns
2. The cord of claim 1, wherein the component plies are polymeric
or metallic.
3. The cord of claim 1, wherein at least one of the plies has a
length that is from 1 to 35 percent longer than the other
plies.
4. The cord of claim 1, wherein at least one of the plies has a
length that is from 1 to 25 percent longer than the other
plies.
5. The cord or claim 2, wherein the polymeric plies are selected
from the group consisting of m-aramid, p-aramid, polyazole, nylon,
polyester, polyethylenenaphthalate, rayon, UHMW-PE and carbon.
6. The cord of claim 5, wherein the polyazole is
polyoxadiazole.
7. The cord of claim 5, comprising at least one p-aramid ply and at
least one nylon ply.
8. The cord of claim 5, comprising at least one p-aramid ply and at
least one m-aramid ply.
9. The cord of claim 7, wherein the shortest length ply is
nylon.
10. The cord of claim 8, wherein the shorter length ply is
m-aramid.
11. The cord of claim 8, wherein the p-aramid ply is from 4 to 5
percent longer than the m-aramid ply.
12. A method of providing a hybrid cord with predetermined twist
and component ply lengths comprising the steps of. (i) identifying
the desired cord twist multiplier and component ply lengths, (ii)
identifying the number of component plies and the composition of
each ply, (iii) providing a cabling machine, (iv) setting the
desired twist level for the hybrid cord into the cabling machine,
(v) setting the desired tension level for the component piles, (vi)
feeding the plies into the cabling machine, and (vii) producing a
cabled cord having the desired twist multiplier and component ply
lengths.
13. The method of claim 12, wherein the component plies have zero
twist.
14. The method of claim 12, wherein the component plies all have
the same twist.
15. The method of claim 12, wherein at least two of the component
plies have a different twist.
16. A product made by the method of claim 12, wherein the component
plies have zero twist.
17. A product made by the method of claim 12, wherein the component
plies all have the same twist.
18. A product made by the method of claim 12, wherein at least two
of the component plies have a different twist.
20. An elastomeric reinforced hose, comprising the hybrid cord of
claim 1.
Description
BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to producing twisted hybrid
cords.
[0003] 2. Description of Related Art
[0004] Different types of materials, for example one having a
higher modulus and one having a lower modulus, are often used
together in hybrid cords for applications such as tire
reinforcement. When forming a plied cord, it is common to use
different twist levels in the high-modulus ply and the low-modulus
ply to account for the difference in modulus between the two
materials, or in order to achieve a desired cord response. This
currently cannot be achieved on cable corders because they do not
form cords in the same manner as ring twisters. Although hybrid
cords can be made on cable corders, the cord behavior that can be
achieved is limited to that of a balanced twist cord, that is, a
cord where the high-modulus and low-modulus ply lengths are the
same in which case there is only one response for any given twist
level. When an unbalanced hybrid is required, it is currently made
on ring twisters. Cable corders provide a tremendous productivity
advantage, so it would be desirable to make both balanced and
unbalanced hybrids on such machines considering that the unbalanced
hybrids are more common than perfectly balanced twist hybrids.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 depicts a prior art cable corder.
[0006] FIG. 2 depicts a front view of the inventive cable
corder.
[0007] FIG. 3 depicts a side view of the inventive cable
corder.
[0008] FIG. 4 is a graph showing load vs. elongation at break.
SUMMARY OF THE INVENTION
[0009] The invention pertains to a hybrid cord comprising a
plurality of plies, wherein at least two of the plies are of
unequal ply length regardless of the twist of the plies and at
least one of the plies has a length that is from 1 to 50 percent
longer than the other plies.
DETAILED DESCRIPTION OF THE INVENTION
[0010] By hybrid cord we mean a cord consisting of at least two
plies in which at least one ply has a different modulus from the
other plies. As an example, one ply can be para-aramid and the
other ply can be nylon. The plies may also be of the same
composition, but of different modulus.
[0011] By zero ply twist we mean the amount of twist that could be
measured in a ply if it were removed from a cord without untwisting
the cord. By ply length we mean the length of the ply if it were
removed from the cord without untwisting the cord.
[0012] When two yarn plies are to be combined in the cable cording
process, the plies run through a regulator. The regulator may
consist of two pulleys on one side connected by solid axles to two
pulleys on the other side. The regulator helps assure the plies are
entering the cord twist machine at the same rate. FIG. 1 shows
generally at 10 a prior art regulator comprising pulleys 11
connected by axles 12. The diameters of the pulleys are all the
same. FIG. 2 shows generally at 20 a regulator comprising pulleys
14a connected by axles 15 to pulleys 14b. The two pulleys 14a on
side 1 are of a larger diameter than the pulleys 14b on side 2,
thus the ply traveling through side 1 will enter the cord faster
than the ply from side 2. This is because the pulleys on both sides
are connected by a solid axle and must rotate at the same speed.
The larger circumferences of the pulleys on side 1 (as opposed to
the pulleys on side 2) create a longer path for the ply to wrap
around and therefore convey more ply for each rotation of the
pulleys. FIG. 3 is a side view of FIG. 2 and shows the path of a
ply 13 around the larger diameter pulleys 14a. A second component
ply follows a similar path around the smaller diameter pulleys 14b
(not shown). Thus at least two of the plies are of unequal ply
length regardless of the twist of the plies. In one embodiment,
this invention is to use a series of pulley sizes to create
unbalanced hybrid cords. By sending a high modulus ply over larger
pulleys and a lower modulus ply over the smaller pulleys, the high
modulus ply will be longer than the other ply in the cord
structure. The ratio between pulley sizes will dictate the ratio
between ply lengths. If the pulleys for the high modulus ply are
25% larger in diameter than the pulleys for the low modulus ply,
the former will be roughly 25% longer than the latter.
[0013] In addition to matching the behavior of unbalanced,
ring-twisted hybrid cords at cable corder productivity levels, the
quality of the cord can also be improved. When large differences in
twist between high modulus plies and low modulus plies are made on
ring twisters, the highly twisted low modulus ply provides a
tremendous amount of residual torque in the cord. If the difference
in length is achieved on a cable corder using different size
pulleys, such residual torque in the low modulus ply will be
minimized or absent. This will allow for more neutral cords and
cords that should be easier to control in manufacturing.
[0014] The hybrid cord can be made of a plurality of plies, wherein
there is zero twist in the plies and at least one of the plies has
a length that is from 1 to 50 percent longer than the other plies
or 1 to 35% longer or even 1 to 25% longer. The amount of
differential length between the plies is selected to suit specific
performance requirements. In some embodiments, the hybrid cord has
a linear density of from 500 to 5000 denier. In some other
embodiments, the hybrid cord has a linear density of from 1000 to
3500 denier. The hybrid cord may be made from polymeric plies such
as meta-aramid, para-aramid, polyazole, nylon, polyester,
polyethylenenaphthalate (PEN), rayon, polypropylene,
ultra-high-molecular weight polyethylene (UHMW-PE) or carbon. A
suitable polyazole is polyoxadiazole such as is available under the
tradename Arselon from OJSC SvetlogorskKhimvolokno, Svetlogorsk,
Belarus. The hybrid cord may also be made from metallic plies.
[0015] The hybrid cord may comprise a single ply of a high modulus
material and a single ply of a low modulus material, such as at
least one p-aramid ply and at least one nylon ply, wherein the
shortest length ply is nylon. The hybrid cord may even comprise at
least one p-aramid ply and at least one m-aramid ply wherein the
shorter length ply is m-aramid.
[0016] In preferred embodiments, the plies comprise filamentary
yarns that can be continuous, partly discontinuous or discontinuous
such terms being well known in the textile art. An example of a
partly discontinuous yarn is a stretch-broken yarn. An example of a
discontinuous yarn is a staple-spun yarn.
[0017] In one embodiment of this invention, the p-aramid ply is
from 2 to 7 percent longer than the m-aramid ply, preferably from 3
to 6 percent longer or more preferably from 4 to 5 percent longer.
A hybrid cord of this construction formed into a woven or knit
fabric is particularly suitable for use in components that are
subject to burst pressure testing at low temperatures such as room
temperature and fatigue testing at high temperatures such as 175
degrees C. An example of such a component is a turbocharger hose
where the cords provide structural reinforcement to an elastomeric
material. Similar applications may be found in other mechanical
rubber goods applications such as conveyor belts and tires. In
other embodiments, a p-aramid ply may be from 3 to 5 percent longer
than a polyoxadiazole ply or a polyoxadiazole ply may be from 1 to
10 percent longer than a m-aramid ply.
[0018] The plies may have the same or different twist. In some
embodiments, the plies have zero twist.
[0019] The pulleys may be adapted to fit any cabling machine such
as those available from Oerlikon Saurer, Charlotte, N.C. or Verdol,
Valence, France or Aalidhra Textile Engineers Ltd., Surat,
India.
[0020] In one embodiment, the invention is also directed to a
method of providing a cord with predetermined twist and component
ply lengths having the steps of [0021] (i) identifying the desired
cord twist multiplier and component ply lengths, [0022] (ii)
identifying the number of component plies and the composition of
each ply, [0023] (iii) providing a cabling machine, [0024] (iv)
selecting appropriate size pulleys for the regulator of the cabling
machine such that the pulleys on side 1 are larger than the pulleys
on side 2 so as to provide the desired component ply length in the
cord, [0025] (v) setting the desired twist level for the hybrid
cord into the cabling machine, [0026] (vi) feeding the plies into
the cabling machine, and [0027] (vii) producing a cabled cord
having the desired twist multiplier and component ply lengths.
[0028] Another embodiment pertains to a method of providing a
hybrid cord with predetermined twist and component ply lengths by
adjusting tension leads to force a length differential that
accomplishes the goal outlined above wherein the size of the pulley
is increased. This embodiment comprises the steps of:
[0029] (i) identifying the desired cord twist multiplier and
component ply lengths,
[0030] (ii) identifying the number of component plies and the
composition of each ply,
[0031] (iii) providing a cabling machine,
[0032] (iv) setting the desired twist level for the hybrid cord
into the cabling machine,
[0033] (v) setting the desired tension level for the component
piles,
[0034] (vi) feeding the plies into the cabling machine, and
[0035] (vii) producing a cabled cord having the desired twist
multiplier and component ply lengths.
[0036] In this embodiment, a cabling machine of FIG. 1 may be used
with a yarn tension device (not shown) located before each yarn
feed-in pulley. Several types of tension devices are available on
the market and are suitable for use.
[0037] In both of the methods described above, the component plies
can have various combinations of twist. For example, the plies can
all have zero twist; the component plies all have the same twist;
or least two of the component plies can have a different twist.
EXAMPLES
[0038] The following examples are given to illustrate the invention
and should not be interpreted as limiting it in any way.
Sample Preparation
[0039] The para-aramid yarns used were Kevlar.RTM. K29 1100 dtex
available from E.I. DuPont de Nemours and Company, Wilmington,
Del.
[0040] The nylon yarns used were PA66 1400 dtex available from
Invista, Wilmington, Del.
[0041] Cords were formed on an Oerlikon Allma CC3 cable cording
machine with each cord comprising one p-aramid yarn and one nylon
yarn. All of the cords had a twist multiplier of 6.5. One cord had
both component yarns of equal length from passing both yarns over
pulleys of equal diameter. Other cords had p-aramid yarns of a
length 5%, 10% and 20% longer than the nylon yarns from using
pulleys in which the diameter of the pulleys over which the
p-aramid yarns passed were respectively of 5%, 10% and 20% greater
diameter than those over which the nylon yarns passed. The cords
were then tested for mechanical performance on an Instron.RTM.
universal test machine model 5500. The test method was ASTM
D885-07. Load vs. elongation at break profiles for the examples are
shown in FIG. 4.
[0042] The curves in FIG. 4 demonstrate how the behavior of hybrid
cords can be modified with different pulley ratios without changing
the twist level of the cords. For the example of a
Kevlar.RTM./nylon hybrid, 100/100 denotes that the diameter of the
pulley over which the Kevlar.RTM. yarn was the same as the diameter
of the pulley over which the nylon yarn was fed. Kevlar.RTM./nylon
hybrid, 105/100 denotes that the diameter of the pulley over which
the Kevlar.RTM. yarn was fed was 5% larger than the diameter of the
pulley over which the nylon yarn was fed and similarly for the
other curves in FIG. 4. In certain tire applications higher
elongations and lower initial modulus are desired and can be
achieved by using a larger pulley for the Kevlar.RTM. ply.
* * * * *