JPH0140783B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressurized coating apparatus for forming a primary coating on the outer periphery of an optical fiber.

As is well known, glass optical fibers such as quartz-based and multi-component optical fibers are coated with a resin such as rubber or plastic immediately after spinning.

For coating in this case, it is considered advantageous to use a pressure-type coating device that can increase the optical fiber linear speed, and a typical pressure-type coating device for optical fibers is
By concentrically combining the inner nipple and the tip die through a cylindrical holder,
A ring-shaped resin flow path having a uniform width in cross section is formed between the inner and outer peripheries of these nipples, the holder, and the die, and a resin supply port communicating with the resin flow path is opened on the circumferential surface of the holder. It is formed by

To coat optical fiber with this,
Liquid resin is supplied under pressure from the resin supply port to the resin flow path, and the optical fiber is passed from the nipple to the die to form a primary coating of the liquid resin on its outer periphery, and then a matching coating is applied by appropriate means. It is hardened with

However, in the case of the above-mentioned coating means, although it is a pressure type, it is not possible to increase the resin pressure unlimitedly considering the characteristics of the optical fiber, and therefore the resin supply pressure is lower than that with plastic extrusion molding means etc. The pressure must be kept at a low pressure of 10 kg/cm ² or less, and as a result, the pressure loss of the resin flowing in the resin flow path has a large effect, causing a so-called short pass phenomenon in which a large amount of the coating resin flows through the supply port side of the resin flow path, causing light There was a problem that a coating of uniform thickness could not be obtained around the outer periphery of the fiber, resulting in uneven thickness.

The present invention has been made to solve the above problems, and its configuration will be explained below with reference to illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a pressure-type coating device disposed below a spinning device (not shown), and in this coating device 1, an inner nipple 2 and a tip die 3 are connected to each other via an outer holder 4. are combined.

The nipple 2 is fitted and fixed to the holder 4 by a nipple presser 6 screwed onto the upper part of the holder 4, and both 2 and 4 exhibit an eccentric state as described below, but this eccentric state is set optimally. Therefore, the nipple 2 housed in the holder 4 can be rotated and adjusted around its vertical axis, and the adjusted state is adjusted between the positioning hole 5a on the nipple 2 side and the positioning hole 5b on the holder 4 side. It can be fixed with a stop pin 5c inserted therein.

In this case, it is preferable to provide a plurality of positioning holes 5a, 5b, or both at intervals in the circumferential direction on the outer periphery of the body of the nipple 2 and on the outer periphery of the upper surface of the holder 4, respectively. When either the hole 5a or the positioning hole 5b is made singular and the other is made plural, the stop pin 5c may be fixed to the single hole 5a or hole 5b.

On the other hand, the die 3 is fitted into a fitting hole 7 formed at the tip of the holder 4.
It is fixed with a die presser 8 screwed to the bottom of the
These nipples 2, dies 3, and holders 4 are arranged concentrically, and 9 in the figure is a die holder 8.
The opening of the optical fiber f installed vertically is shown.

A resin flow path 13 is formed between the outer circumferential surface 10 of the tip side of the nipple 2, the inner circumferential surface 11 of the holder 4, and the inner circumferential surface 12 of the die 3. A resin holder 14 is connected to the base end of the holder 4, and one or more resin supply ports 15 communicating with the resin holder 14 are opened on the circumferential surface of the holder 4.

This resin flow path 13 consists of a cylindrical portion 13a and a conical portion 13b having a V-shaped cross section following the cylindrical portion 13a.
The conical portion 13b is formed at the distal end 10a of the outer circumferential surface 10 on the nipple distal end side so that the gap g is approximately uniform.
The tip 11a of the holder tip side inner circumferential surface 11 and the die inner circumferential surface 12 are formed concentrically, and the inlet hole 2' at the tip of the nipple 2 and the outlet hole 3' at the tip of the die 3 are also concentric with each other. There is.

On the other hand, the cylindrical part 13a of the resin flow passage 13 is an eccentric passage part in which the gap G extends in the axial direction, narrowing the supply port side G' and widening the opposite side G'', as clearly shown in FIG. Therefore, the proximal end 10b of the outer circumferential surface 10 on the distal end of the nipple is formed eccentrically by L with respect to the proximal end 11b of the inner circumferential surface 11 on the distal end of the holder. The connecting portion between the tip portion 10a and the tip portion 10a is inclined from the supply port 15 side to the opposite end side.

Therefore, in order to coat the optical fiber f using this device, the optical fiber f spun by a spinning device (not shown) is pulled from the entrance hole 2' of the nipple 2 to the exit hole 3' of the die 3, as in the conventional method. At the same time, the liquid resin is passed through the resin supply port 1 into the resin flow path 13.
It is sufficient to supply the resin under pressure from the resin flow path 1.
As described above, the cylindrical portion 13a of No. 3 is an eccentric passage portion with the supply port side narrowed, so that if a large amount of resin flows on the supply port side of the flow path 13, it will not get stuck and will flow to the conical portion 13b. It flows uniformly in the circumferential direction and coats the outer periphery of the optical fiber f with a uniform thickness through the exit hole 3' of the die 3. After that, the coated optical fiber is placed in an ultraviolet curing furnace or a heating type curing furnace. The coating resin is then cured.

Note that the degree of eccentricity in the eccentric passage can be adjusted by relative rotation between the nipple 2 and the holder 4, and in this case, the positioning hole 5a, the positioning hole 5b, and the stop pin 5c can be used as means for fixing the adjusted state. In addition, in an embodiment in which a plurality of these holes 5a and 5b are provided, the hole 5
a or hole 5b serves as a guide for adjustment.

Furthermore, when a plurality of resin supply ports 15 are provided on the circumferential surface of the holder 4 at intervals in the circumferential direction,
Liquid resin can be supplied into the resin flow path 13 from an arbitrary number of resin supply ports 15, and in this case, if each supply port 15 is provided with a needle valve type throttle valve mechanism that can be opened and closed freely, the resin can be stored in an unused state. resin supply port 15
can be easily closed and the amount of resin supplied can be adjusted.

Of course, the eccentricity mentioned above, the number and position of the resin supply ports to be used are set appropriately according to the viscosity of the resin, the coating thickness, the volume of the resin flow path, etc. By taking these adjustment measures, various coating conditions can be adjusted. Optimum conditions can be obtained depending on the conditions, and uniform coating can be achieved over a wide range.

As explained above, in the present invention, a die is attached to the tip of a cylindrical holder, a nipple is housed inside the holder, and the nipple, holder,
In a pressurized coating device for optical fiber, in which a resin flow path is formed between the inner and outer peripheries of the die, and a resin supply port that communicates with the resin flow path is opened in the holder, a part of the resin flow path is provided. Since an eccentric passage is formed by mutual eccentricity between the nipple and the holder, it is possible to prevent the short pass phenomenon of the coating resin as in the conventional case, and it is possible to coat the outer circumference of the optical fiber with a uniform thickness. Furthermore, coating can be performed at high linear speed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of a pressure-type coating device according to the present invention, and FIG. 2 is a sectional view taken along the line -- in FIG. DESCRIPTION OF SYMBOLS 1... Pressure type coating device, 2... Nipple, 3... Dice, 4... Holder, 13... Resin flow path, 13a...
Cylindrical portion of resin flow path (eccentric path portion), 15...supply port.

[Claims]

1. A method of manufacturing a flame shielding glass panel comprising at least one layer of intumescent material sandwiched between two structural sheets of the panel, said method comprising forming said layer and securing the sheets. The method includes forming an assembly comprising at least one sandwiched layer comprising an intumescent material at least partially in the form of particles and the two structural sheets, the intumescent material being applied to the edges of the assembly in a degassing step. and heat and/or pressure conditions that homogenize the particles in the layer into the foam to form a continuous layer, bonding the structural sheets through the foam. A method for manufacturing a flame shielding glass panel characterized by: 2. The method of claim 1, wherein at least one of the foamable layers is comprised of a material that is at least to a large extent by volume in the form of particles. 3. According to any one of claims 1 to 2, at least one of the foamable layers comprises a granular material held together by a binder, such as water or an aqueous solution of foamable material. Method described.