US2985911A - Spinnerettes - Google Patents

Description

May 30, 1961 E. J. GRISET, JR

SPINNERETTES Filed June 29. 1959 INVENTOR. Ernesf J. Gr/sef, Jr

J Un t S a e Pa SPINNERETIES Ernest J. Griset, Jr., Bound Brook, NJ., assignor to Ethicon, Inc., a corporation of New Jersey Filed June 29, 1959, Ser. No. 823,468

2 Claims. (Cl- 18-8) general practice to force an aqueous dispersion of swollen collagen fibrils through a spinnerette, having a plurality of orifices in the face thereof, into a dehydrating medium which converts the material passing through each orifice to a filament. As the filament-forming collagen emerges from the orifices, the dehydrating medium will cause the swollen collagen fibrils to set, by'removing the solvent therefrom.

All spinnerettes are not suitable for use in the extrusion of a collagen dispersion since the individual collagen fibrils effect the flow properties of the dispersion. Tangles .of collagen fibrils and fibrils at an angle to the longitudinal axis of the filament being extruded will tend to clog up the spinnerette and cause breaks, unless the spinnerette is specially designed for the specific purpose. It has been, previously noted, however, that if-thedispersion' is extruded through a relatively long tube or capillary, the individual fibrils tend to become aligned in the direction of extrusion. By way of example, a tube of 10-20 centimetres in length is mentioned as appropriate in the Salo Patent No. 2,598,608 and it is indicated that such a spinnerette maintains the maximum degree of longitudinal orientation of the fibrils in the extruded filament and thereby increases the ultimate strength of the finished fiber.

I have now discovered that the long capillary tubes may be dispensed with if the spinnerette is manufactured within certain critical dimensions to provide an inlet orifice having a larger diameter than the outlet orifice.

To operate satisfactorily, the spinnerette should be so constructed that:

(l) The diameter of the orifice inlet is approximately the length of the collagen fibrils that are present in the dispersion or about 0.035 inch.

(2) the diameter of the orifice outlet is about 0.018 inch.

(3) each orifice has a straight cylindrical section at least 0.045 inch in length and an inlet portion defined by conical walls which form an angle of about 15 to the axis of the orifice.

The invention has, for its principal object, to provide a spinnerette for the extrusion of a multifilament from a dispersion of swollen collagen fibrils that is small in size.

A further object of the invention is to improve a spinnerette for spinning a collagen dispersion, thereby reducing the number of breaks that occur during the spinning process.

It is also an object of this invention to provide apparatus for the production of multifilament collagen having a large number of filaments which will provide a 7 Patented May 30, rest lice 2 relatively free access of fluid to each of the filaments as it is formed.

Another object of this invention is to provide a spinnerette of improved construction for the production of multifilament collagen.

The present invention is a multifilament spinnerette in which the spinning orifices are disposed in concentric circular rows and separated from one another by imperforated portions of the spinnerette face. It accordingly comprises an article of manufacture possessing the features, properties and relative dimensions which will be exemplified in the article hereinafter described and the scope of the invention will be indicated in the claims.

The invention is best understood in conjunction with the eccompanying drawing, in which: J

Figure 1 is a top plan view of a spinnerette.

Figure 2 is a side elevation of the spinnerette illustrated in Figure 1, partly in section.

Figure 3 is an enlarged view, in section, which trates a single orifice of the spinnerette.

Thespinnerettee is a shallow cup having a fiat exterior face 11 and a flange 12 for reinforcement and conveni ence in mounting. The spinnerette may be formed ofany suitable material which will resist the corrosive efiects of the collagen dispersion and of the coagulating or dehydrating medium. The face 11 of the spinnerette is proillusvided with a plurality of orifices 13 extending therethrough, which orifices have a diameter, indicated in Figure 3 is a legend a, of about 18 mils. The orifices 13, of which there may be a total of from about 40 to about 500 or more in the face of the spinnerette, are

' i arranged in rows extending outwardly from a point at the center of the face 11, almost to the outer edge thereof. Each orifice has a straight cylindrical section, indicated in Figure 3 by the legend b, at least 0.045 inch in length and an inlet portion definedby the conical walls which form an angle of about 15 to the axis of the orifice. t

diameter of the inlet portion indicated in Figure 3 by the legend 0, is approximately the length of the collagen fibers in the dispersion, or about 0.035 inch.

The distance between individual orifices is quite critical since a feather-like growth will be formed at the spinnerette surface while spinning the collagen dispersion. Any large feathers that are formed will result in discontinuity and poor tensile strength in the dried and stretched multifilament. If the concentric circular rows of individual orifices are separated by a distance identified in Figure 2 by the legent d of about 0.035 inch, the feathers that may form are quickly carried away by the closely adjacent filaments. If the separation is appreciably more than 0.035 inch, the feathers will grow in size and frequently cause breakage of the extruded filament.

As stated above, the distance b may not be less than 0.045 inch for good spinning; thus reducing this distance to 0.015 inch results in a spinnerette that will not operate with collagen dispersions and if the distance is increased to 0.030 inch, the spinning is poor because of numerous nozzle breaks.

An outlet diameter b, of about 0.018 inch, is optimum for the best all-around spinning results. If the diameter of the outlet is increased in excess of 0.020 inch, the filaments as extruded are difiicult to dehydrate and soft. Reducing the diameter below about 0.018 inch results in numerous nozzle breaks.

The spinnerette of the present invention may be formed of any non-corrosive metal such as nickel, platinum, silver or alloy thereof, or of non-metallic materials such as 3 e.g., by punching, grinding, drilling, or a combination of these methods.

The following example, which is not limited, is given so as to make the invention more easily understood.

Example I A spinnerette having 197 orifices is constructed as shown in Figure 1. Each orifice has an outlet diameter of 0.018 inch and the orifices are positioned as follows:

RowNo. Diameter, No.01

1n. Holes In this particular spinnerette, the outlet area of each orifice is 0.0002545. The total combined area of 197 orifices, therefore, is 0.0501322. The area of the circle defined by the last row (0.560 inch diameter) is 0.24630. Therefore, the ratio of the surface area of the spinnerette to the total combined outlet area is about 5, or

.4 (2) the dehydrating bath volume may be smaller and (3) less line pressure is required.

What is claimed is:

1. A multi-orifice spinnerette for use in the extrusion of a dispersion of collagen fibrils to form a collagen multifilament, all of the orifices being arranged in circular rows spaced apart by a distance of about 0.035 inch to 0.040 inch, said orifices consisting of an outlet portion about 0.018 inch in diameter with a straight cylindrical wall at least 0.045 inch in length and an inlet portion defined by conical walls having an angle of taper of about 15, the diameter of the inlet portion being about 0.035 inch.

2. A multi-orifice spinnerette for use in the extrusion of a dispersion of collagen fibrils to form a collagen multifilament, all of the orifices being arranged in concentric circular rows, the orifice in each row being spaced an equal distance apart, .each of said orifices having an outlet about 0.018 inch in diameter and an inlet diameter of about 0.035 inch, all of the orifices having a straight cylindrical wall at least 0.045 inch in length, and a total combined outlet area according to the relationship where A; is the area of the circle defined by outermost row of orifices and A is the total combined outlet area of all orifices.

References Cited in the file of this patent UNITED STATES PATENTS 1,967,798 Witte July 24, 1934 2,266,363 Graves Dec. 16, 1941 2,514,189 Spencer et al. July 4, 1950 2,848,737 Poetter et al.- Aug. 26, 1958 FOREIGN PATENTS 493,608 Germany Mar. 10, 1930 155,735 Switzerland July 15, 1932

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