JPS6366936B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a hexagonal-shaped net-like body formed by twisting synthetic resin filaments. More specifically, the present invention relates to a method for manufacturing a hexagonal-shaped mesh body made of synthetic resin and having good mesh regularity and excellent strength and durability. The tortoise-shell-shaped reticular body having the mesh shape shown in Fig. 1 has two or more of its six sides made up of twisted sides X, so it has superior strength than a normal quadrilateral reticular body, and can be used outdoors. It is widely used in applications such as fences and seafood farming. A variety of devices have been developed to manufacture such hexagonal mesh bodies, but a typical example is a device that produces multiple filaments, as shown schematically in the zone in Figure 2. 5, 5' attached to the inlet rail 1 and the outlet rail 1', the half-split gear 2,
The half-split gears 2, 2' are inserted between the through holes 6, 6' of the inlet rail 1, and are rotated mutually in the entrance rail 1 and moved laterally. An example of such a device is to knit the net-like body 10 by twisting filaments using half-split gears 2', 2' which rotate in the opposite direction to the above. However, this device is originally a device for manufacturing wire mesh made of metal filaments, and when manufacturing synthetic resin nets using this device, the filaments before knitting can be plastic-processed. It is necessary to preheat to a certain temperature, and usually an electric heater 4 is provided as in the zone shown in FIG. 2, or a hot air zone 3 is provided between the rails 1 and 1'. However, when manufacturing a tortoiseshell-shaped network from filaments such as synthetic resin monofilaments using such equipment, shrinkage of the filaments themselves, imbalance in the force applied to twisting, and variations in preheating temperature occur. This causes distortion in the mesh twists and non-uniformity in the size and shape of the mesh, resulting in problems in that not only the regularity of the mesh is poor, but also the mesh is susceptible to distortion and deformation. Therefore, although the conventional tortoiseshell-shaped mesh obtained from synthetic resin filaments is superior in durability to so-called tortoiseshell-shaped wire mesh in that it does not cause rust or corrosion,
The reality is that it is inferior in strength and mesh regularity. Therefore, the present inventors conducted intensive studies with the aim of obtaining a tortoiseshell-shaped network made of a synthetic resin filament with an excellent balance of mesh regularity, strength, and durability. The present invention was achieved by discovering that the above object can be effectively achieved by strictly controlling the manufacturing conditions. That is, the present invention provides a method for manufacturing a tortoiseshell-shaped network body having at least two twisted sides by alternately twisting a plurality of synthetic resin filaments. Transition temperature~
After preheating to the temperature of the melting point, twisting and knitting this under tension, the net-like body is heat-set in a relaxed state,
The present invention provides a method for producing a hexagonal-shaped reticular body, which is characterized in that it is then rapidly cooled. The synthetic resin filaments used as materials in the present invention include polyamide resins such as nylon 6, nylon 66, nylon 610, nylon 612 or mutual copolymers thereof, polyethylene terephthalate,
Polyester resins such as polybutylene terephthalate or copolymers thereof, polyhalogenated vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyolefin resins such as polyethylene and polypropylene, or mutual blends of these resins. It is a filament that has heat shrinkability and heat fixability, such as a monofilament obtained by spinning and drawing a thermoplastic resin. It should be noted that these resin materials can of course contain conventional additives such as dyes, pigments, heat resistant agents, light resistant agents, weather resistant agents, algae resistant agents, flame retardants, and lubricants. There are no particular restrictions on the thickness of filaments such as monofilaments made of these resin materials, but usually
It can be selected from the range of 0.3 to 5 mm depending on the application. However, it is important that the synthetic resin filament used in the present invention is drawn and unfixed yarn that has not been drawn and heat set.If undrawn yarn is used, the strength of the twisted sides of the mesh This is not preferable because only a weak and easily deformable network can be obtained. Furthermore, when drawn and heat-set yarns are used, the force required for knitting the net-like body, especially for twisting, increases, and in some cases, cracks may occur in the net-like body.
Therefore, the use of unfixed yarn gives favorable results from the viewpoint of thermal history and power saving. Next, the manufacturing conditions for the tortoiseshell-shaped reticular body of the present invention will be explained with reference to FIG. First, when subjecting the synthetic resin filament materials 5, 5' to the zone (knitting section) of the apparatus shown in FIG. 2 for twisting and knitting, the filament is preheated to a temperature between its glass transition point and melting point. However, it is important to immediately twist and knit it under tension. If the preheating temperature is below the glass transition point of the filament, the force applied to twist the filament will increase, and the plastic workability of the filament will be insufficient and the twists will loosen, resulting in a decrease in the strength of the network. If it exceeds the melting point, the tension state cannot be maintained, and the shape and dimensions of the network become non-uniform, resulting in a decrease in regularity, and the strength of the network is also significantly reduced, which is not preferable. Note that this preheating can be efficiently performed by the hot air zone 3 using a heater 4 provided in the zone or a hot air circulator (not shown). It is also important that the filaments are kept under tension during twisting; if the filaments loosen, the shape of the strands may become uneven, causing the mesh to become distorted or the strands to loosen. This is not preferable because the size and shape of the mesh become non-uniform and the regularity is significantly impaired. The tension state of such striae is, for example, the second
This is achieved by adjusting the rotational speed of the half-split gear 5' of the zone and the rotational speed of the net guide roll 7 as shown in the figure. Next, the knitted net-like body 10 is sent to the zone (heat-setting section) shown in FIG. 2, but it is important that this heat-setting is carried out with the net-like body in a relaxed state. In other words, the purpose of this heat setting is to apply uniform heat contraction to the mesh to remove distortion and to prevent the twisted edges from untwisting. This is not preferable because the shrinkage becomes non-uniform, the strength decreases, and the material becomes easily distorted and deformed during use. The relaxed state of the net-like body 10 is achieved, for example, by adjusting the rotational speed of the net guide rolls 7 and 7', as shown in FIG. In addition, the heat fixation treatment can be carried out by passing the mesh through a hot air circulation bath, or by passing the mesh through a heating medium tank 8 as shown in Figure 2.
This method is carried out by dipping the net-like body in water and passing it through, but the latter method is more preferable since uniform heat setting can be expected. The heat setting temperature can be arbitrarily selected depending on the characteristics of the material, but it is usually preferably a temperature between the glass transition temperature and the melting point of the material, and slightly higher than the preheating temperature. In addition, when using a heating medium tank, the appropriate time for dipping the mesh is 10 to 60 seconds. The net-like body organized and heat-set in this way is then rapidly cooled in the zone (quenching section) shown in Figure 2, and this rapid cooling is essential to eliminate unevenness and uneven mesh on the surface of the net-like body. This is the process. The mesh during quenching may be in either a tense or relaxed state, and examples of quenching means include spraying cooling water from a shower 9 as shown in FIG. 2, and immersing and passing the mesh in a cooling water bath. can be adopted. Also, water is suitable as a cooling medium.
The temperature of the cooling water is preferably below room temperature, particularly 0 to 20°C. The tortoiseshell-shaped net-like body thus produced through each process of the present invention is washed and dried as necessary, and then rolled up into a product. Moreover, the twists on the twisted sides are tight and uniform, and it has excellent strength and durability, making it useful for various uses such as outdoor fences and seafood cultivation. The present invention will be further explained below with reference to Examples. Example Polyethylene terephthalate monofilament with a diameter of 3 mm (glass transition point: 70°C, melting point 255°C)
Using the equipment shown in Figure 2, the first
Shape as shown (thread diameter approx. 2.7 mm, mesh spacing 50 mm and 10
When manufacturing a tortoiseshell-shaped mesh body with a width of cm and a mesh size of 2), the stretching of the material, the heat-setting state, the preheating conditions, the knitting mesh conditions, and the heat-setting conditions were variously changed as shown in Table 1.
The properties of each obtained network were evaluated. The monofilament was preheated by heating the rail with an electric heater 4 attached to the exit rail 1' in FIG. 2, or by circulating hot air at a specified temperature in the hot air zone 3. The preheating time was set at a constant monofilament passage time of 30 cm/min.
The length of the electric heater or hot air zone was determined so that the time of contact with the electric heater or the time of passing through the hot air zone at this speed met the conditions shown in Table 1. When knitting the net, the net guide rail 7 and the half-split gear 2'
The tension or relaxation of the monofilament or net was maintained by adjusting the rotational speed of the net guide rails 7 and 7' during heat setting. The heat setting conditions were as follows: passing through a heated water bath 8 at 90 to 98°C for 15 seconds, and water cooling after heat setting was performed by pouring water at 20 to 25°C onto the net guide roll 7'. The evaluation criteria for the obtained reticular bodies are as follows. 1 Mesh normality Indicates the number of normal meshes out of 10 meshes. 2 Knitting property Indicates the degree of ease of twisting monofilaments. 〇…Can be easily twisted. △…Difficult to twist. ×…Twisting is extremely difficult. 3. Twisting fixity 〇 Indicates the condition of the twisted edges of the net: Twisted tightly and evenly. △...There is some looseness. ×... Significant loosening and distortion. 4 Tensile strength: Measured according to JIS L-1070 5 Tensile elongation: Measured according to JIS L-1070 6 Cracking resistance Indicates the number of meshes in which the yarn is cracked among 10 meshes. The manufacturing conditions and evaluation results for each network are also shown in Table 1.

[Table] From the results in Table 1, it is clear that No. 8, whose material, preheating, knitted mesh, and heat setting conditions were within the specified ranges of the present invention, had extremely excellent properties.

[Brief explanation of drawings]

FIG. 1 is a plan view of a tortoiseshell-shaped reticular body, and FIG. 2 is a schematic diagram of an apparatus used in the method of the present invention. 1, 1' - inlet (exit) rail, 2, 2' - half-split gear, 3 - hot air zone, 4 - electric heater, 5,
5'~linear object, 6,6'~through hole, 7,7'~net guide roll, 8~heating medium tank, 9~shower, 10
〜Reticular body, 〜Knitted net zone, 〜Heat fixation zone,
~Quick cooling zone.

Claims (1)

[Claims] 1. In a method for manufacturing a tortoiseshell-shaped network body in which at least two sides are made up of twisted sides by alternately twisting a plurality of synthetic resin filaments, the stretched and unfixed filaments are first heated to a temperature between the glass transition temperature and A method for producing a tortoiseshell-shaped net-like body, which comprises preheating the net to a melting point temperature, twisting and knitting the net-like body under tension, heat-setting the net-like body in a relaxed state, and then rapidly cooling the net-like body.