JPH0365256B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a bag-like body used for fenders, etc., and more specifically, a bag-like body that is lightweight and has excellent durability, particularly for use in fenders, floats, etc. The purpose of the present invention is to provide a method for manufacturing a bag-like body suitable for such cases.

Traditionally, the method of manufacturing ship fenders is as follows:
A method of forming fenders using synthetic rubber has become popular, but fenders manufactured using this method have drawbacks such as being heavy and inconvenient to transport and handling, as well as being expensive. It had

Therefore, instead of the above method, using a foam as a core material,
Attempts have been made to coat the surface with a resin such as FRP (fiber-reinforced plastic) or to integrate synthetic fibers by attaching them to the surface using an adhesive.

However, not only are the processes involved in both manufacturing methods complicated, but the fender materials manufactured using these methods are also prone to resins, synthetic fibers, etc. that peel off due to oil adhesion, impact, etc. However, it had the disadvantage of poor durability.

Furthermore, when manufacturing floats for use in fishing nets, oil fences, etc., attempts have been made to use a method using foam as the core material, similar to the method described above, but in this case as well, the manufacturing process is complicated and , floats produced by that method had the same drawbacks as the fender described above.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method of manufacturing bag-like bodies used for fenders, and it is possible to produce bag-like bodies for fenders etc. that are lightweight and have excellent durability. The purpose is to provide a method for manufacturing the body.

The manufacturing method according to the present invention includes a thermoplastic material inside a steam-permeable bag formed of a fabric or knitted fabric knitted or woven to a roughness that does not allow foamed resin particles to pass through but allows steam to pass through. filling the bag with foamed resin particles, supplying steam from the outside of the bag through the woven or knitted fabric of the bag, and thermally expanding the foamed resin particles inside the bag with the steam to form a foam; It is characterized in that the bag is filled with the foam.

Hereinafter, using this invention, a bag-like body 1 as shown in FIG. 1 (perspective view) and FIG. 2 (cross-sectional view), that is, a bag-like body 1 in which the inside of the bag 10 is filled with a foam 20, will be constructed. The case of manufacturing will be explained in detail based on FIGS. 3 to 5 showing the main manufacturing process.

First, a bag body 10 made of woven or knitted fabric such as synthetic fiber is prepared. The texture of the woven fabric or the stitch of the knitted fabric does not allow the foamed resin particles a described below to pass through,
It is woven or knitted so coarsely that it allows steam to pass through. This bag 10 was originally a cylindrical body with both ends open, and a rope 31 with retaining rings 30, 30' connected to the upper and lower ends was inserted into the bag.
With the retaining ring 30' protruding from the lower end of the bag body 10, the lower end opening is closed by squeezing with the cap 11 or the like, leaving only the upper end open (see FIG. 3). The overall length of the rope 31 is determined so that the retaining ring 30 will protrude when the upper end opening of the bag body 10 is closed by squeezing with the cap 11 or the like.

Now, the bag 10, which is open only at the top end, is filled with foamed resin particles a (see FIG. 4).
The material for the foamed resin particles a is a polyolefin resin such as polyethylene or polypropylene as a core, a styrene monomer and a catalyst for polymerizing the monomer are absorbed into the core, and the styrene monomer is polymerized within the core. Accordingly, a material in which at least a portion of a polyolefin resin and a polystyrene resin are graft-bonded (the graft bond portion is 1% or more of the total amount of the polyolefin resin and the polystyrene resin) is used.

Then, the foamed resin particles a are made into foamable resin particles (trade name: PIOCELAN (grafting rate: 4%), manufactured by Sekisui Plastics Co., Ltd.) by adding a foaming agent,
After foaming the particles to form pre-expanded particles,
The bag 10 is filled as described above. The foamed resin particles a are heated and fused together as described below, and the resin has elasticity, restorability,
It has excellent oil resistance and is particularly suitable for fenders.

Now, as described above, the bag 10 filled with the foamed resin particles a is stored in the steam chamber 40 after closing the upper end opening with the cap 11 or the like with the retaining ring 30 protruding. (See Figure 5). Steam is supplied into the steam chamber 40 from a supply port (not shown), and the steam passes from the outside of the bag 10 in the direction of the arrow in the figure through the holes of the woven or knitted fabric of the bag 10. By supplying it into the body 10,
The foamed resin particles a filled in the bag 10 are heated and expanded to form a foam 20 as shown in FIG. 2, and the bag 10 is filled with the foam 20 to form the bag 1. Manufacture.

Note that this invention is applicable to a bag body 1 as shown in FIG.
It can also be applied to the case of manufacturing a product in which a plurality of 0's are arranged in a row. In this case, the connection portions of each bag 10 may be communicated with each other, and the communication portions may also be filled with foam.

In addition, as the material for the foamed resin particles a, in the above-mentioned examples, polyolefin resin and polystyrene resin were partially graft-bonded, but other thermoplastic foamed resin particles such as polypropylene and polystyrene may be used. It's okay.

Furthermore, the present invention can be applied to bags having various shapes such as square tubes in addition to the above-mentioned cylindrical shape, and can also be used for fishing nets, fishing nets, etc.
Various types are possible, such as floats for oil fences.

As detailed above, when manufacturing a bag-like body for use in fenders, etc. by the method of the present invention, the bag formed of woven or knitted fabric is filled with foam, so it is light and lightweight. It is possible to manufacture a bag-like body that is convenient to transport and handle. In addition, to fill the bag with foam, steam is supplied from the outside of the bag to the thermoplastic foam resin particles filled in the bag through the holes of the woven or knitted fabric of the bag. As a result, the foam is thermally expanded as it is to form a foam, so the foam can conform to the bag without any problem, making it possible to manufacture a bag-like body with good integrity very easily and at low cost. . Furthermore, the manufactured bag-shaped body can reliably prevent chipping of the foam, etc., and has an excellent shape-maintaining effect, and is particularly suitable for use as a fender material to which strong pressure is repeatedly applied.

Therefore, it can be said that the present invention provides a method for easily manufacturing a bag-like body that is lightweight and has excellent durability, and is particularly suitable for use as a fender.

[Brief explanation of drawings]

The figures illustrate embodiments of the present invention; FIG. 1 is a perspective view showing a bag-like body according to the present invention, FIG. 2 is a cross-sectional view, and FIGS. FIG. 6 is a sectional view showing the main process, and a perspective view showing a modified example of the bag-like body according to the present invention. 1... Bag-like body, 10... Bag body, 20... Foam, 30, 30'... Retaining ring, a... Thermoplastic foam resin particles.

Claims (1)

[Scope of Claims] 1. Thermoplastic foam inside a steam-permeable bag formed of a fabric or knitted fabric that is coarsely knitted or woven to a degree that does not allow foamed resin particles to pass through but allows steam to pass through. Filling the bag with resin particles, supplying steam from the outside of the bag through the woven or knitted fabric of the bag, thermally expanding the foamed resin particles inside the bag with the steam to form a foam, and forming the foam. A method for producing a bag-like body for use in fenders, etc., characterized in that the bag body is filled with a body. 2. The method for manufacturing a bag-shaped body used for fenders, etc. according to claim 1, wherein the foam is made of a resin in which a polyolefin resin and a polystyrene resin are at least partially graft-bonded.