JPS5846333B2 - "ro" kafu - Google Patents

Description

[Detailed description of the invention] The present invention relates to Sawa Tsusho.

More specifically, the present invention relates to Sawa Tsusho, which is particularly suitable for use in food manufacturing processes, in which a network structure made of fibril fibers and a net-like material are fused together.

Conventionally, various textile or non-woven fabrics have been used in sawa-tsusho used in food manufacturing processes and the like.

Of these, woven fabrics are the most widely used, but they are generally expensive, and if they become clogged, they are usually washed and used repeatedly.

At this time, care must be taken to prevent the debris remaining on the cloth from rotting, and for this reason, it is desired to develop a cloth suitable for disposable use.

Another disadvantage of woven fabrics is that threads may come off during use, and this system may be mixed into liquid F, impairing the quality of food products.

On the other hand, nonwoven fabrics made of short fibers have food hygiene problems due to the use of binders such as rubber latex, and nonwoven fabrics made of long fibers produced using the so-called spunbond method do not have uniformity when made into thin sheets. It is difficult to obtain a suitable density, and the strength is also insufficient, making it impossible to obtain sufficient strength for use as Sawa Tsusho.

An object of the present invention is to provide a sawa-tsusho that does not have the above-mentioned drawbacks found in conventional products.

In other words, by providing an inexpensive Sawatsusho that is uniform, does not pull out threads, and has sufficient strength, and by making it disposable, it solves the problems in food hygiene management that occur especially during the food manufacturing process. It's about trying.

The present inventors have focused on the development of a p-commerce system that simultaneously achieves these objectives. , at least two types of polyethylene having different melting points as other constituents, and
A composite structure obtained by selecting a net-like material stretched in a uniaxial direction and having a multi-layered cross-section and fusing and integrating the two is particularly suitable for food manufacturing. We have discovered that the problems of conventional Sawa Tsusho can be solved all at once, and have completed the present invention.

That is, the present invention provides a network in which fibril fibers are interconnected and have a random structure, which is obtained by melting and foaming a mixture of a thermoplastic resin and a blowing agent, and taking it under a draft. A net-like material (8) made of at least two types of polyethylene having melting points different from those of the structure (4), stretched in a uniaxial direction and having a multilayer structure in cross section.
characterized in that the low melting point polyethylene layer of the net-like material [F]) is fused to the fibril fibers of the network structure (4) made of a thermoplastic resin having a higher melting point than the net-like material [F]). It is a filter cloth.

The mesh structure (4), which is one component of the filter cloth of the present invention, is different from the net-like material (B), which is the other component.
) is made of a thermoplastic resin that has a higher melting point than polyethylene, which has a lower melting point, and has a random structure in which fibril fibers are interconnected.

The thermoplastic resin that is the material for the network structure (4) is as follows:
For example, thermoplastic synthetic resins such as polyethylene, polypropylene, polystyrene, polyamide, and polyethylene terephthalate are preferably used.

Among these, polyolefin resins such as polyethylene and polypropylene are particularly preferred materials because they provide high fusion strength with polyethylene, which is the material of the net-like material [F]).

As mentioned above, the network structure (4) has a random structure in which fibril fibers are interconnected, but fibril fibers are fine fibers with an irregular shape that have a branched structure or a twisted structure. Also, the term "interconnected" refers to a state in which these fine fibers are bonded to each other at branched parts, forming a network structure, and there are no loose single fibers.

Such a mesh structure (4) is, for example, disclosed in Japanese Patent Application Laid-open No. 1986-
As described in Japanese Patent Publication No. 47170 and Japanese Patent Publication No. 49-3458, a thermoplastic resin and a blowing agent are mixed and kneaded, melted, foamed and extruded, and then taken under a suitable draft. Therefore, it can be easily manufactured.

The product produced by the above method is particularly excellent in quality uniformity and surface coverage, and is therefore particularly suitable for use as the network structure of the present invention.

Furthermore, the network structure (1) manufactured as described above is as follows:
Fibril fibers are interconnected and have a random structure,
The fibril fibers are intricately intertwined and have uniform quality without being thick or thin like thin spunbond nonwoven fabrics, so it not only has excellent surface coverage but also
It also has the advantage of high filtration efficiency.

The network structure (1) of the present invention has a basis weight of about 3
? /m'' or more, particularly about 5?/d or more is preferably used.

The basis weight is about 3 f? For those smaller than /yj,
It tends to have poor surface coverage as a filter cloth, has insufficient strength, and tends to be difficult to handle in the fusing process described later.

However, the mesh structure (
4) does not necessarily consist of a single sheet, but rather preferably consists of a plurality of sheets stacked one on top of the other, about 2 to 12 sheets, and for this reason, the basis weight of the single sheet of the network structure (4) The meaning of is not definitive.

Moreover, the net-like material [F]) which is the other component constituting the filter cloth of the present invention has at least two different melting points.
made of polyethylene and stretched in the longitudinal direction;
It is a net-like material whose cross section has a multilayer structure.

As polyethylenes having different melting points, low-density polyethylene, medium-density polyethylene, high-density polyethylene, etc. are conveniently used because they are easily available.

However, polyethylene here refers not only to homopolymers, but also to copolymers of ethylene and other comonomers, as long as their properties, especially fusion properties with the network structure (4), are maintained. ing.

A combination of low density polyethylene and high density polyethylene is particularly preferably used as the above melting point polyethylene forming the net-like material [F]).

The above-mentioned net-like material [F]) of the present invention imparts a strength reinforcing effect to the network structure (4), which does not necessarily have sufficient strength to be used alone as a filter cloth. ) to ensure an effective filtration area.

Therefore, the size, number, etc. of the meshes [F]) are appropriately determined depending on the purpose of use of the filter cloth, taking these points into consideration.

The net-like material of the present invention has at least two different melting points.
It can be manufactured easily and with good productivity by, for example, processing a film with a multilayer structure obtained by multilayer extrusion of a type of polyethylene and then uniaxial stretching.

These multilayer extrusions are carried out by a known method such as extrusion of a multilayer film using a commonly used extruder having a multilayer T-die.

Further, a film obtained by uniaxially stretching this film is produced by a known method such as stretching with a hot roll using a continuous stretching and defibrating machine.

A uniaxially stretched film having a multilayer structure is processed into a net-like material by, for example, making cuts regularly or irregularly therein and widening the film in a direction intersecting the cuts.

Such processing is carried out, for example, by making incisions with a rotary cutter having regularly arranged blades and defibrating with a needle drum having a large number of needles.

Sawatsusho, which has the composite structure of the present invention, has the above-mentioned network structure ω
and the net-like material 03) are fused together in polyethylene having a lower melting point forming the net-like material Q3).

For example, when the polyethylene forming the net-like material (B) is high-density polyethylene and low-density polyethylene, the network structure (4) and the net-like material (B) are made of low-density polyethylene having a lower melting point. It is fused by.

In its simplest form, the p-commerce of the present invention consists of one mesh structure (4) or a plurality of mesh structures (4) and one net-like material.

Such sawa-tsusho has its main strength in the uniaxial direction (stretching direction) of the net-like material, and exhibits strength sufficient to withstand normal sawa-tsusho.

Another aspect of the present invention is that the mesh structure holder) and a plurality of net-like objects are overlapped and fused with the stretching direction perpendicular or oblique to each other. It is.

Such a sawa-tsusho is suitably used as a sawa-tsusho that requires balanced vertical and horizontal strength, and as a sawa-tsusho that has higher strength.

Furthermore, another aspect of the present invention is a network structure (
A net-like material) is present on both sides of 1) and is fused.

Such a sawa-tsusho is used as a sawa-tsusho whose mesh structure (4) is not exposed and has higher strength.

The manufacture of Sawa Tsusho having the above-mentioned composite structure of the present invention can be carried out, for example, by overlapping the network structure (4) and the net-like material [F]) and bonding them together by thermocompression using a known thermal calendar roll laminator or the like. This is preferably carried out.

Thermocompression bonding means bonding by applying pressure in a heated state, and this operation involves bonding the mesh structure (4) and the net-like material [F]
), preferably at a temperature slightly lower than the melting point of the polyethylene having a lower melting point forming the net-like material (8) that mediates the fusion with the polyethylene.

By doing this, the polyethylene with a higher melting point that forms the net-like material (B) maintains the strength of the uniaxially stretched film, so the net-like material [F]) acts as a reinforcing net, and the main material Gives strength to the flow of inventions.

Note that if the temperature is too low, sufficient adhesive strength cannot be obtained, while if the temperature is too high, the polyethylene on the high melting point side will stretch back, resulting in a decrease in strength.

Moreover, as a net-like material, the net-like material [F]) of the present invention
In contrast, when a single piece of polyethylene is used, the net-like material is stretched back during the thermocompression bonding process as described above, reducing the strength for reinforcement. The purpose of reinforcement with objects is not achieved.

In the Ogero thermocompression bonding during production of Sawa Tsusho of the present invention, a net-like material (B) in which a layer made of polyethylene with a lower melting point forms at least one outer layer is used, and It is desirable to overlap the network structure (B) on the outer layer side.

For example, in the case of manufacturing Sawa Tsusho in which the net-like material (B) is present on both sides of the network structure (4), a polyethylene layer with a higher melting point is used as the net-like material and a polyethylene layer with a lower melting point is used as the intermediate layer. A three-layer, uniaxially stretched film having a multilayer structure with polyethylene layers as both outer layers is produced, and a net-like material processed from the film is used.

The composite structure of the present invention provides a balance between excellent sewage performance, sewage material, and required strength.

Therefore, by using the sawa-tsusho of the present invention, it is possible to carry out uniform and stable sawa-tsusho, and there is no contamination with thread waste etc. originating from the sawa-tsusho of foodstuffs, etc., and it has sufficient strength. It can be used for a wide range of purposes as Tamesawa Tsusho.

For example, it is suitably used in sawatsusho used in the food industry such as tofu manufacturing process and brewing process.

In addition, it can also be used as a pruning bag for tea, soup stock, etc.

In addition, the sawa-tsusho of the present invention can not only be used to separate solids and liquids as described above, but also use its sewage function to make bags and fill them with oxygen scavengers, deodorants, etc. It can also be used to separate solids and gases by preventing solids from dispersing in gases.

It can also be used to prevent dust in airflow.

The implementation is shown below.

In the examples, parts are by weight.

Example 1 Polypropylene (Mitsui Noblen BJHH-G) 100
and 1.5 parts of azodicarbonamide, extruded through an inflation die with a 0.5% slit using a 90%φ extruder, and wound up under conditions of a swelling ratio of 2 and a draft ratio of 4. A network structure (4) having a basis weight of 6.5 P/m was obtained.

On the other hand, high-density polyethylene (HIZEX 3300F)
Then, low-density polyethylene (Mirason 10) was extruded into a multilayer film with a total thickness of 50 μm using a 90%φ extruder having a multilayer T die, and the film was wound up.

Next, this multilayer film was defibrated using a continuous stretching and defibrating machine (Toshiba Machine 5F-102) while being stretched 4.5 times with a hot roll.

While expanding this defibrated film to twice its width, the low-density polyethylene side became the network structure obtained by the foaming extrusion method (
4) The four layers were laminated so as to be in contact with each other and fused by thermocompression using a thermal calendar roll heated to 120° C.** to obtain a composite laminated structure.

The basis weight of this product was about 30 g/-.

When this composite laminated structure was used in the soy milk squeezing step in the tofu production process, very good and high quality tofu could be obtained.

The findings during the tofu manufacturing process are shown in Table 1 below.

For comparison, Table 1 also lists findings when using other Sawa Tsusho.

For comparison purposes, a 10-layer heat-embossed sheet (foam defibrated sheet), a valve sheet-like material (8 layers thick), and a spunbond nonwoven fabric sheet (2 layers thick) were used.

In addition, these comparisons are as follows.

The 10-layer heat-embossed sheet (foamed defibration sheet) was prepared in Example 1.
Ten sheets of polypropylene network structures with the same basis weight of 6.52 layer m' as used in were laminated, and the roll surface temperature was set to 120
It is manufactured by thermocompression bonding with an embossing roll having a canvas pattern at ℃.

Basis weight, 6s? /rrl. A commercially available valve sheet for tofu production was used as the valve sheet (thickness: 8 mm).

Basis weight about 600 f? / m”.

As the spunbond nonwoven fabric sheet (thickness 2 mm), a commercially available spunbond nonwoven fabric (trade name: Yu7nel, manufactured by Mitsui Petrochemical Spunbond ■) consisting of continuous filaments of polypropylene was used.

Basis weight 100'? /m”.

Claims (1)

[Claims] 1 A network structure (1) in which fibril fibers are interconnected and have a random structure, obtained by melting a mixture of a thermoplastic resin and a blowing agent, extruding the foam, and taking it under a draft. and a net-like material (B) made of at least two types of polyethylene having different melting points, stretched in a uniaxial direction and having a multi-layered cross-section, the net-like material (6) having a low melting point. A polyethylene layer is fused to the fibril fibers of the network structure (4) made of a thermoplastic resin having a higher melting point than the polyethylene layer.