CA1076785A

CA1076785A - Rovings

Info

Publication number: CA1076785A
Application number: CA275,368A
Authority: CA
Inventors: Ernst Horoldt
Original assignee: Zinser Textilmaschinen GmbH
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 1976-04-03
Filing date: 1977-04-01
Publication date: 1980-05-06
Also published as: NL7703384A; CH607827A5; DE2614523C3; FR2346472B2; DE2614523A1; DK144677A; JPS52121551A; FR2346472A2; IT1114771B; BR7702069A; LU77057A1; DE2614523B2; GB1535885A; BE853213R

Abstract

Abstract of the disclosure:
A roving having a cohesion length of 15 to 500 meters and consisting of a strand of untwisted and unsized staple fibers.
having a total titer of from about 1,000 to 30,000 and, wrapped around said strand, a filament yarn having an elongation at break of less than 50 % and a titer of less than 15 dtex, the number of windings being in the range of from 20 to 300 per meter, has especially favorable properties when filaments of cross-linked polyesters are used for wrapping.

Description

107~7~.~3 This invention relates to an improvement in the manufac_ ture of rovings by using filaments of cross-linked polyesters for wrapping around the sliver of staple fibers.
In Copending Application Serial No.237 146 filed October 6, 1975 by Fritjof Maag et al., a roving has been proposed that consists of a sliver of staple fibers and at least one filament yarn wound round the staple fibers. This roving is distinguished by the fact that the staple fibers are untwisted and unsized and have a total titer of approximately ~ 10 1000 to 30,000 dtex, preferably 2,500 to 15,000 dtex, and that ;;- the filament yarn has an elongation at break of less than 50%,preferably less than 25%, that the filament yarn has a titer of less than 50 dtex, preferably less than 15 dtex, and that the roving has a cohesion length of 15 to 500 m, preferably 30 to ~ ?
300 m, and that the number of windings is 20 to 300, preferably 30 to 100 per meter.
Surprisingl~, it has now been possible to ascertain taht these rovings with their excellent properties are obtained ~3 in an especially advantageous manner by using as the filaments that are wound round the staple fibers those produced from crosslinked polyesters, monofilamenta preferably being used.

., ~

~, -~,"' .

'.'~ ' ~ ,' ' :

: " ;, . ..

Particularly favourable results are obtained if the polyester is polyethylene terephthalate that contains up to 0.03 to 1.5 per cent by weight, preferably up to 1 per cent by weight, especially up to 0.05 t~ c~ff~ y~i~wei~htiof'a crds~
linking agent calculated on the pure polyethylene terephthalate.
The polyesters preferably contain as crosslinking agent silicon compounds, for example, of the formula (X20)mtsio2)n~
in which X represents a hydrogen atom, a monovalent organic radical or an atom equivalent of a metal, n represents an integer and m an integer between 0 and 2n. These compounds, and the method and manner in which t7~produce polyesters cross-linked therewith, are described in German Auslegeschrift 12 37 727.
In another preferred embodiment, the polyesters are obtained using esters and/or salts of compounds of the ~l general formula '!'.~, O OH
,, 1~ 1 HO - P - CH2 - CH2 - Si - OH - xH2O, '~ OH OH

. .
, in which x represents 1.5 or a number below 1.5 or even 0, 20 wherein the ester groups are ~he radicals of lower aliphatic alcohols having 1 to 4 carbon atoms and the salt groups are the ions of alkali metals. The manufacture and use of these ~ compounds are described in German Patent Specification No.

; 1 720 647. .

, I
... . .

. . .
. .
:;

. . .
_3 . .
', .

107~;78S

Another possibility of crosslin~ing the polyesters consists in using polyfunctional, purely organic compounds.
Suitable crosslinking components are, for example, pentaerythritol, dipentaerythritol, glycerin, sorbitol, trimethylol ethane, trimethylol propane, trimethylol butane, trimethylol hexane, 1,3,5-trimethylol beneze, 1,3,5-tripropylol benzene, 1,3,5-tributylol benzene, 1,2,fi_hexantriol, 2,2,655_tetramethylol cyclohexanol, hemimellitic acid, trimellitic acid, trimesic acid, prehnitic acid, mellophannic acid, pyromellitic acid, .

mellitic acid and functional derivatives thereof, such as, for example, methyl, ethyl and propyl or phenol esters. Also suitable are 5~hydroxyisophthalic acid, 4_hydroxyisophthalic ~, acid, 2,5-dihydroxyisophthalic acid, 2,5-dihydroxyphthalic acid and functional deriva~ives thereof, such as, for example, the esters with an aliphatic alcohol, such as methyl, ethyl and propyl alcohols, or aromatic phenol esters. These permanent - crosslinkers may also be used in admixture with the silicon compounds which produce only a temporary crosslinking effect.
The winding filaments comprising crosslinked poly_ ;~
esters have to a great extent the properties that are required ... . .
;~ for the winding filaments described in the aforesaid specification:
they must impart to the sliver of untwisted staple fibers sufficient strength for the processing, but must tear when ~- strained during the fine yarn production, i.e. they must not -have too high an elongation. Filaments of crosslinked polyesters ' exhibit this combination of properties ideally. -; Advantageously, in the case of small, colored slivers, ., -~, ", ~ , .
. ', : :
_4_ , .. . . .
.. . . . . . .

non-matter winding filaments can be used.
The quantities both of the permanent and of the temporary crosslinkers depend heavily on the number of - functional groups contained therein.
As disclosed in applicant's copending Canadian Application Serial No. 237,146, the staple fibers consist of spinnable natural or man-made fibers and may be selected from the group of wool, cotton, viscose, polyester, polyamide, polyacrylonitrile, polyolefin and polyurethane fibers.
The following examples serve to illustrate the ~; invention.
~ Examples `~ The modified, crosslinked polyethylene tereph-thalates were prepared in accordance with a discontinuous :;.
process as follows:

Interchange of ester radicals:

Glycol and dimethyl terephthalate are introduced in the ' :!
ratio of 1 : 2.2 in~o a heatable pressure tank provided with an agitator. The catalyst Mn-acetate and the crosslinker are added at 140-150C.
The interchange of ester radicals is carried out without pressure by heating up to 165-220C within a period of 2.5 to 3 hours. The methanol released is drawn off by way of a distillation column heated to 70-75C. Subsequently, at a tank temperature of 220C
and a column temperature of 195C, approximately .~
., , ", .. .
- .
. - .

2.0-2.5 1 of glycol is distilled off. The condensation catalyst (antimony trioxide) and the sta~ilizer (phosphorous acid) are then added.
Polycondensation:
The reaction solution at 225-230C is forced into a condensation autoclave. There then follow, under nitrogen, heating to 240C and the commencement of the evacuation stage.

. . i ~ ' .
:~, .

, , .
.'j ' ' . '.' ., , ~
~1, ':

,, . ::
'i . .- ' .' ,~: -~ - 5(a~ - I

., ~. I

. . . . .. . .. .

~0767BS

After 105 minutes the complete vacuum of 0.1 mm Hg has been reached, whilst the temperature is increased to 240-275C.
The viscosity of the melt is measured by resistance to stirring.
The condensation time is 2.5-3.5 hours. The removal of the polymer melt is carried out under nitrogen.
~ le 1: Crosslinker according to German Patent 1 720 647 Polymer preparation:
0.03 percent by weight of manganese acetate . 4 H20 related to DMt 0.008 percent by weight of Sb203 0.4 percent by weight of TiO2 0.6 percent by weight SIP (silicon polyester) produced according to German Patent l 720 647 `. specific viscosity: 0.535 softening point: 2B8.5C.
Spinning:
The polymer was spun from an extruder through a 2-hole ' nozzle with a hole diameter of 250 u, at a nozzle temperature of 265C and a nozzle draw-off of 1800 m3min. The spun fila-ments were wound onto a bobbin in the form of a monofilament and stretched by a stretch-twisting machine (Zinser* 16 S model) -~ in the ratio of l : 3.1 at a galette temperature of 90C and an iron temperature of 120C.
;~ A monofilament with a strength of 34 g/tex and an `~ elongation at break of 8% was obtained. The thread titer was j appr~ximately 8 dtex. The monofilaments obtained were used, - as in the above Specification for winding round a roving.
The results were rovings with the properties given therein.
* denotes trade mark ,~ '~ ' .

.

,:: .

~xample 2: Crosslinker: trimethylol propane Polymer preparation:
0.03 percent by weight of manganese acetate . 4H20 0.015 percent by weight of phosphorus acid 0.03 percent by weight of antimony trioxide 0.4 percent by weight of TiO2 0.3 percent by weight of trimethylol propane specific viscosity: 0.620 softening point: 257C.
Spinning:
The spinning was carried out analogously to that in Example 1 at a nozzle temperature of 2qOC and a stretching ratio of 1 : 3.65. The thread strength is 32 g/tex at an elongation of 14% and an individual thread titer of 5 dtex.
Winding this monofilament round a roving in accordance with the above Specification resulted in wound rovings having `: ~
the advantageous properties quoted therein.
. .
: Example 3: Crosslinkers: pentaerythritol .~ Polymer preparation:
20 0.02 per cent by weight of manganese acetate . 4H2O
`~` 0.01 percent by we;ght of phosphorous acid 0.03 percent by weight of antimony trioxide :. 0.4 percent by weight of TiO2 0.2 percent by weight of pentaerythritol specific viscosity: 0.61 ~:~
softening point: 258.5C.

. I ~
.;~
., _7--: .

~pinning:
The spinning was carried out analogously to that in Example 1 at a nozzle temperature of 270C and a stretching ~ ratio of 1 : 3.8. The thread strength is 34 g/tex at 20%
: elongation and an individual thread titer of 7 dtex.
The results of winding round a roving were as according to the above Specification.

.

: .
. ~ , ,"~, ':

~ " ' .

; .

,.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED OR DEFINED AS FOLLOWS:

1. A roving having a cohesion length of 15 to 500 meters consisting of a non-consolidated strand of un-twisted and unsized staple fibers, having a total titer of from about 1,000 to 30,000 dtex and at least one filament yarn wrapped around said strand, the yarn having an elongation at break of less than 50% and a titer of less than 50 dtex and being wrapped around the strand from 20 to 300 times per meter, characterized in that the filament comprises a crosslinked polyester filament yarn.

2. A roving as claimed in claim 1, in which the filament is a monofilament.

3. A roving as claimed in claim 1 in which the polyester is polyethylene terephthalate, which contains 0.03 - 1.5 percent by weight of a crosslinking agent, calculated on the pure polyethylene terephthalate.

4. A roving as claimed in claim 1, claim 2 or claim 3 in which the polyester is polyethylene terephthalate, which contains 0.05 to 0.7 percent by weight of a crosslinking agent, calculated on the pure polyethylene terephthalate.

5. A roving as claimed in claim 1, claim 2 or claim 3 in which the polyester is crosslinked using at least one compound of the group of esters and salts of compounds of the general formula wherein x represents 1.5 or a number below 1.5 and x may represent 0, wherein the ester groups are the radicals of lower aliphatic alcohols having 1 to 4 carbon atoms and the salt groups are the ions of alkali metals.

6. A roving as claimed in claim 1, claim 2 or claim 3 in which the polyester has been crosslinked with a com-pound of the formula (X2O)m(SiO2)n' wherein X represents a hydrogen atom, a monovalent, organic radical or an atom equivalent of a metal, n represents an integer and m represents an integer between O and 2n.

7. A roving as claimed in claim 1, claim 2 or claim 3 in which the polyester has been crosslinked with a polyfunctional alcohol or a polyfunctional organic acid.