US3867810A

US3867810A - Spliced tow and process for making spliced tow

Info

Publication number: US3867810A
Application number: US437858A
Authority: US
Inventors: Jan Meertens; Antonius H J Merkx
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1974-01-30
Filing date: 1974-01-30
Publication date: 1975-02-25
Anticipated expiration: 1992-02-25

Abstract

The ends of two tows or ropes of continuous filaments are overlapped and spliced together with a pneumatic tow-splicer or other means for interentangling the filaments, the sides of the tows are folded over adjacent to the splice to cover filament ends, and the filaments are interentangled with the tow-splicer to secure the folded over portions of tow. A strong, compact towsplice is obtained that is suitable for direct tow-to-sliver break-processing or for wet-drawing and crimping operations.

Description

United States Patent [191 Meertens et a1.

SPLICED TOW AND PROCESS FOR MAKING SPLICED TOW Inventors: Jan Meertens, Dordrecht; Antonius H. J. Merkx, Hank, both of Netherlands E. l. du Pont de Nemours and Company, Wilmington, Del.

Filed: Jan. 30, 1974 Appl. No.: 437,858

Assignee:

US. Cl 57/142, 28/7212, 57/159 Int. Cl. B65h 69/06, D02j 1/08, D02g 3/22 Field of Search 57/22, 142, 159; 28/72.12,

28/722 F, 1 CF, 1.4

References Cited UNITED STATES PATENTS 2/1967 Rosenstein 57/22 Feb. 25, 1975 3,339,362 9/1967 Dodson, Jr. et al. 57/159 3,379,002 4/1968 Rosenstein 57/142 3,458,905 8/1969 Dodson, Jr. et al. 57/22 X 3,619,868 11/1971 Dibble 57/22 UX Primary ExaminerJohn Petrakes [57] ABSTRACT The ends of two tows or ropes of continuous filaments are overlapped and spliced together with a pneumatic tow-splicer or other means for interentangling the filaments, the sides of the tows are folded over adjacent to the splice to cover filament ends, and the filaments are interentangled with the tow-splicer to secure the folded over portions of tow. A strong, compact towsplice is obtained that is suitable for direct tow-tosliver break-processing or for wet-drawing and crimping operations.

3 Claims, 8 Drawing Figures SPLICED TOW AND PROCESS FOR MAKING SPLICED TOW BACKGROUND OF THE INVENTION This invention relates to textile tow or rope splicing techniques and the resulting spliced product. By textile .tow or rope, hereinafter called tow, is meant a group of essentially parallel continuous textile filaments which individually are of textile deniers but in aggregate total several thousand denier and in come cases hundreds of thousands denier.

During some steps in the production of textile tow from various synthetic polymers, such as polyacrylonitrile, finite lengths of tow are collected in containers, lagged, andthen a multiplicity of containers placed in a creel so that several tows are withdrawn and processed in parallel as a large aggregate tow. Since the length of tow in each container is-limited and may vary from container to container, splicing is required in order to achieve continuous processing. In other instances, such as for direct conversion of tow to staple sliver, it may be necessary to combine at least two large tows prior to conversion, e.g., when using a Turbo Sta pler (Turbo Machine Co., Landsdale, Pennsylvania) or a Seydel Stretch Break Converter (Seydel & Co., Germany). Component tows are usually furnished in finite lengths. Splicing in this case is also necessary to enable continuous processing. Conditions existent in various processing steps place demands on such tow-splices for not only high strength (e.g., to withstand high drawing forces) but also low volume (e.g., to pass through crimping with adjacent unspliced tow).

In the past, many types of splices and splicing techniques have been disclosed which involve sewing the splice with separate strands, adding adhesive to the splice area, or interentangling tow filaments in the splice area with pneumatic or mechanical means, but the disclosed splices have been too voluminous or too weak to satisfy the above requirements. Dodson et al. U.S. Pat. No. 3,339,362 discloses a process for joining tows to form a continuous tow by placing the end of a tow A over the end of atow B so that the filamentsof tow A rest on top of the filaments of tow A with filaments of tow B to form a splice with opposed jets of air. Gagnon U.S. Pat. No. 3,308,520 discloses a similar process except that the filaments are mechanically interentangled by punching felting needles repeatedly through the overlapped ends of tow.

SUMMARY OF THE INVENTION The present invention is an improvement in the general process described above; of placing the end of-a tow A over the end of a tow B so that the filaments of tow A rest on the filaments of tow B and interentangling the filaments of tow A with the filaments of tow B to form a preliminary splice. In accordance with the improvement, the assembly is then stretched laterally adjacent to the splice, one edge of the tows is folded over toward or to the other edge of the tows to form an overlap at one side of the splice, the filaments are interentangled at the overlap, the operation is repeated to form an overlap in the tows on the other side of the preliminary splice, and the filaments are interentangled at this overlap. The process provides a strong, compact, tow-splice. A stronger splice is provided when the filaments are interentangled at several locations and in more than one direction, as illustrated subsequently.

The invention provides compact splices in wet tow which remain intact during wet-drawing at least about 4.5X followed by crimping. For this purpose, the splice can be made in wet tow and water lost during pneumatic interentanglement of filaments can be replaced by spraying the spliced tow with water. The invention provides compact splices in dry tow which are suitable for direct tow-to-sliver break-processing.

BRIEF DESCRIPTION OF DRAWINGS FIGS. 1A through ID are schematic representations of several steps involved in splicing an assembly of two tow ends by one embodiment of the invention; and

FIG. 2 is a schematic diagram of a second embodiment of the splice, with FIGS. 2A, 2B, and 2C providing sketches of cross-sectional views through zones A, B, and C, respectively, of the splice of this type.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS Turning first to FIGS. 1A through 1D, the sequence of steps employed to provide the tow-splice of the first embodiment illustrating this invention are seen to corn prise the following. In FIG. 1A, the terminal portion of a first tow 10 is placed on a flat table with its end 1012 to the right, and that of a tow 20 is placed so that it rests on top of the first tow but with its end 20e about 40 centimeters to the left of end We The thus overlapped tows are grasped with both hands by an operator with one hand approximately at the location 20e and the other at the location We. This assembly is then placed .in a pneumatic tow-splicer (such as that disclosed in Dodson et al. U.S. Pat. 3,339,362) and a diagonal preliminary splice is made from point I on one edge of the assembly to point II on the other edge. In the illustrated embodiment, two parallel passes are made close together to provide a double diagonal preliminary splice.

Next, as shown in FIG. 1B, the end portions beyond the splice are then cut along lines parallel to and adjacent to the diagonal splice so that now the cut end of tow 20 is shown by a full diagonal line 20c and that of tow 10 by a dotted diagonal line l0e', since it is on the underside of the assembly. The next step is illustrated by FIG. 1C wherein the tow assembly is grasped first at point I, stretched transversely without incurring splits in the tow, folded sidewise across the top of the remaining tow, and placed down on a point I directly across from the original tow point I. A similar cross-fold is made by grasping the tow at point II, stretching it sidewise and folding it over to position II', directly across the assembly. This new assembly is now placed back in the pneumatic splicer and two

splices

30, 31 are made directly across the assembly at the location of the first foldover and two

similar splices

32, 33 are made at the location of the second foldover, To complete this splice, pneumatic splices are made across the assembly starting well to the left of the first foldover such as at line 40 in FIG. 1D and additional parallel, transverse, spaced splices (e.g., 41 and 42) are made along the entire length of the folded portions and beyond as illus hated by the transverse lines 40, 41', and 42'. This last set of splices (40, 41, 42, 40', 41', and 42') are typically spaced over a length of about 60 centimeters.

When this splice is made on wet tow, it is often necessary to further moisten the tow after this splicing has been completed by spraying with water over the length of the splice and adjacent lengths that may have become partially dried.

Another tow-splice and splicing process embodying this invention is illustrated in FIG. 2. In this case, the terminal portions of first and

second tows

110, 120 are laid down with the end 1l0e of the first tow on the right and end 1202 of the second to the left and on top. The entire overlap is made approximately 30 cm. long. The assembly is spread flat and each tow manipulated so that the tows are of equal width. This assemblage is grasped as before with both hands flat on the overlap, one to the left and the other to the right of the middle, and the thus held assembly placed in a pneumatic splicer of the type referenced above. Approximately three spaced splices are made directly across the assembly near its middle, as shown by lines 115, and then cross diagonal splices are added between the ends of the other splices as shown by the lines 116. The assembly can now be released. A double foldover is carried out by pulling the edges transversely and then folding the assembly up over and partially across the assemblage from each edge. One set of foldovers is located to the left of the initial splice and spaced so that the actual end le of tow 120 is covered by the foldovers. This firstset of foldovers is now pneumatically spliced with a series of transverse and cross

diagonal splices

140 and 141.

Next, the assembly is turned upside down and a similar double foldover structure made on the right in a position to enclose end 110e. This is next spliced as described for the left hand set of foldovers.

The configuration of the completed tow splice is, further evident from the cross-sectional views of FIGS.

2A, 2B, and 2C. Thus, the left hand foldovers enclose two 120 inside tow and the right hand foldovers enclose tow 110 inside tow 120, since the assembly was turned over before these latter foldovers were made.

The technology of this invention has been found to provide compact tow-splices that successfully pass through the steps of wet-drawing at least about 4.5X followed by crimping. Furthermore, dry splices according to this invention have been found to process satisfactorily through direct tow-to-sliver break-processing.

We claim:

1. In the process for joining tows to form a continuous tow by placing the end of a tow A over the end of a tow B so that the filaments of tow A rest on top of the filaments of tow B and interentangling filaments of tow A with filaments of tow B to form a splice, the improvement for forming a strong, compact tow-splice, wherein the improvement comprises forming a preliminary splice, stretching the assembly laterally from one edge adjacent to one side of the preliminary splice, folding this stretched portion of the assembly over toward its other edge to form an overlap at one side of the preliminary splice, interentangling filaments at this overlap, similarly folding the assembly near the other side of the preliminary splice to form a second overlap at the other side of the preliminary splice, and interentangling filaments at this second overlap.

2. A process as defined in claim 1, wherein the filaments are further interentangled at intervals along the assembly at the location of the preliminary splice and said overlaps.

3. Tow-spliced as defined in claim 1.

Claims

1. In the process for joining tows to form a continuous tow by placing the end of a tow A over the end of a tow B so that the filaments of tow A rest on top of the filaments of tow B and interentangling filaments of tow A with filaments of tow B to form a splice, the improvement for forming a strong, compact towsplice, wherein the improvement comprises forming a preliminary splice, stretching the assembly laterally from one edge adjacent to one side of the preliminary splice, folding this stretched portion of the assembly over toward its other edge to form an overlap at one side of the preliminary splice, interentangling filaments at this overlap, similarly folding the assembly near the other side of the preliminary splice to form a second overlap at the other side of the preliminary splice, and interentangling filaments at this second overlap.

3. Tow-spliced as defined in claim 1.