Silicone Membrane Slitting Machine and Method

Abstract

A mechanism and a method for slitting silicone membranes using automated slitting blades is presented. The pattern of slits in the membrane can be adjusted by using a cutting cylinder comprised of a plurality of circular cutting gears assembled in parallel.

The cutting cylinder is of indefinite length, but in the preferred embodiment is approximately 15″ long and 3″ in diameter. The silicone membrane can range in thickness from 0.005″ to 0.01″ inch.

Claims

1. A slitting machine, the slitting machine comprised of a slitting roller, a backing roller, and a slitting machine frame, the backing roller a cylindrical structure comprised of a firm material, the cylindrical structure possessing a backing roller axle running through the length of the backing roller, the slitting roller comprised of a plurality of cutting gears, each cutting gear is a flat cylinder with an axial hole, each cutting gear possessing a plurality of cutting blades positioned equidistant along the circumference of the cutting gear, each axial hole possessing a circular rim, each cutting gear possessing a registration notch on the rim of the axial hole, said cutting gears of two types, horizontal cutting gears and vertical cutting gears, the vertical cutting gear possessing some of the plurality of cutting blades where the direction of the cutting blades is in parallel with the circumference of the vertical cutting gear, the horizontal cutting gears possessing some other of the plurality of cutting blades where the direction of the blade is orthogonal to the circumference of the horizontal cutting gear direction of the plurality of blades, said slitting roller possessing a slitting roller axle, said backing roller and said slitting roller are of identical length and width, said slitting machine frame comprised of at least an axle rest, a slitting roller nut, a backing roller adjustment device, and a backing roller nut.

2. A method of using the slitting machine of claim 1, comprised of the steps of A) assembling the slitting roller by 1) selecting the pattern of cuts that are to be produced in the slitted silicon nylon matrix (SSNM) or slitted silicon matrix (SSM) material, placing the appropriate horizontal or vertical cutting gears side-by-side on the slitting roller axle, 2) placing the slitting roller into the axle rest and securing the slitting roller with the slitting roller nuts, then B) placing the backing roller into the axle rest by means of the backing roller adjustment device and securing the backing roller with the backing roller nuts, then C) adjusting the backing roller position in the axle rest to the desired distance from the slitting roller by means of the backing roller adjustment device, then D) presenting SSNM or SSM material to the gap between the slitting roller and the backing roller and turning the slitting roller axle with a slitting roller turning means, then E) collecting the slitted SSNM or SSM material and setting it aside, then F) repeating steps D) and E) until the desired amount of slitted material has been produced, then G) cleaning the cutting blades on the cutting gears of the slitting roller with a solution of 70% isopropyl alcohol and water with a microfiber cloth.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0014] FIG. 1. Perspective view of the slitting machine assembled

[0015] FIG. 2. Exploded view of the slitting machine

[0016] FIG. 3. Cross-Section of the assembled slitting machine

[0017] FIG. 4. Perspective view of one horizontal slitting gear

[0018] FIG. 5. Perspective view of one vertical slitting gear

[0019] FIG. 6. Sample pattern for vertically-slitted silicone membrane

[0020] FIG. 7. Sample pattern for vertically- and horizontally-slitted silicone membrane

DETAILED DESCRIPTION

[0021] The SSNM and SSM used by the present invention are similar in composition to earlier skin substitutes in that they each have as a minimum a thin silicone component and optionally an underlying thin knitted nylon component. The present invention possesses “variable porosity” controlled by the clinician; the pore size in the thin, slitted silicone will be essentially zero with no stretch applied to the membrane, in relaxed mode, to a higher porosity proportional to the stretch applied. The present invention possesses a composition of biological coatings applied to both the silicone component and the optional nylon component.

[0022] The slitting machine 101 is shown in perspective view in FIG. 1. There is an exploded view of its components in FIG. 2, and a cross-section view in FIG. 3.

[0023] The slitting machine 101 is comprised primarily of two rollers, the slitting roller 102 and the backing roller 103. When the slitting roller 102 is pressed against the backing roller 103 with an SSM or SSNM membrane between them, it cuts a pattern of slits through the membrane as the slitting roller turning means (not shown) turns the axle 104 of the slitting roller 102.

[0024] This is the fundamental process of the invention, using the blades of the slitting roller 102 to make slits in a length of SSNM or SSM continuously.

[0025] The slit openings are made by the slitting machine 101 after the silicone component has been cured. A perspective view of two of the component cutting gears 112, 113 that can be assembled into the slitting machine 101 slitting roller 102 are shown in FIG. 4 and FIG. 5.

[0026] The cutting gears 112,113 are flat cylinders each with an axis hole 114 cut through their center and a registration notch 115 that is used to assure that the individual gears are oriented correctly to each other when assembled side-by-side into the slitting roller 102. FIG. 4 shows a cutting gear 112 with blades in a horizontal orientation and FIG. 5 shows a cutting gear 113 with cutting blades in a vertical orientation.

[0027] As in FIG. 2, the slitting roller 102 and the backing roller 103 are independent of each other and mounted in the axle rest 125 as shown. In the cross-section diagram, FIG. 3, the slitting roller 102 and the backing roller 103 are shown assembled and pressing against each other.

[0028] SSNM or SSM material is passed between the rollers 102,103 in flat sheets of varying widths. These sheets are between 0.01 and 0.005 inches in thickness. In the case of slitting of the SSNM, the silicone layer is presented to the blades of the slitting roller 102 before the slitting action is performed.

[0029] The means used to turn the slitting roller 102 and thereby to operate the invention can be a hand crank or some motor-driven mechanism. The preferred embodiment of the invention uses a hand crank attached to the slitting roller axle 104. The action of turning the slitting roller 102 draws the SSNM or SSM material under the blades of the slitting roller 102.

[0030] The slitting machine 101 holds the two rollers 102,103 in proximity to each other in the axle rest 125. The slitting roller axle 104 is held in the axle rest 125 by two slitting roller nuts 121. The backing roller 103 is held adjustably in place in the axle rest 125 by the backing roller adjustment device 122 and secured by the backing roller nuts 123. By manipulating the backing roller adjustment device 122, the backing roller 103 can be positioned against the slitting roller 102 at the desired distance.

[0031] The preferred embodiment of the SSNM and SSM after slitting is shown in examples contained in FIG. 6 and FIG. 7. Slits can be made in an alternating orientation, with vertical and horizontal slits, as in FIG. 7, or in a parallel vertical orientation as in FIG. 6.

[0032] The slits made in the silicone are approximately 0.125′ long with a space of 0.50′, between the slits; off-set parallel rows of slits are 0.25″ apart. Rows of slits perpendicular to the above are also 0.125″ long with a space of 0.50″ between the next slit; off-set parallel rows of slits are 0.25″ apart.

[0033] Slitted in the alternating orientation configuration, the silicone/nylon membrane can be stretched in any direction and the slits will open. Porosity therefore increases proportionally to the amount of stretch applied in either direction. Obviously, there is a maximum amount of stretching of the preferred embodiment before the dressing fails.

[0034] In the SSNM, the knitted nylon component would be the thinnest commercially-available mesh, the preferred material nylon. Either 12/1 or 15/1 denier filament would be used to knit the mesh. Alternatively, polypropylene or other filaments used in mesh hernia repair devices could be used. The mesh would be combined with the medical grade silicone as above to produce the structure of the invention.

[0035] The general dimensions of the slitting roller 102 in its preferred embodiment is as follows: the width of each gear 112,113 is 0.180 inches. There are a plurality of gears 112,113 aligned along the slitting roller. In the preferred embodiment, there are 84 gears in the slitting roller 102.

[0036] For the vertical (V) and horizontal configuration, the width of each gear (contains multiple blades either V or H) is 0.180″ and the distance between the center of each blade is 0.180″. There are 84 gears aligned along the cutting cylinder. Each gear has 53 cutting blades. The cutting cylinder is 15.12 inches long. The diameter (D) of the cutting cylinder is 3.0 inches. The circumference (C=Pi×D) of the cutting cylinder is 9.43 inches.

[0037] In a single full rotation of the V+H cutting cylinder cuts an area of 142.56 sq. inches. In this area there are 4,452 slits, each slit is 0.088 inch wide and there is 0.180 inches between the centers of each slit. The number of slits made per square foot of area is 4,464 slits or 31 slits per sq. inch.

[0038] In the V only configuration, the width of each V slit is 0.250″. There are 61 gears on the roller with 37 V blades each. Each gear is rotated 90 degrees from the adjacent gear creating an alternating cutting pattern both along the cutting cylinder as well as around the cutting cylinder.

[0039] A single full rotation of the cutting cylinder cuts an area of 142.56 sq. inches. In this area, there are 2,257 slits, each slit is 0.250″ wide and there is 0.250″ between the centers of each slit. The number of slits made per square foot of area is 2,280 slits or 16 slits per sq. inch.

[0040] As presented, the invention 101 will handle SSNM or SSM material in 15 inch widths and of indefinite length by moving it through the invention 101 at a speed that minimizes the possibility of the material splitting or breaking.

[0041] These are the preferred embodiments of the invention. The technology to create this invention is listed in the preferred embodiments of this invention, but other methods are possible and are within the contemplation of this patent.