KR870000442B1 - Multi-monofilament's producing method - Google Patents

Abstract

Multi-monofilaments were obtd. from sheath-core type multithreading of high density polyethylene(HDPE) [or linear low density polyethylene(LLDPE), below 135≰C of fusion point poly propylene(PP) or its mixt. i.e. low f.p. polyolefin resin! and up 150≰C of f.p. PP. (A) 1.5-7.0 of fusion fluidity index ratio of low fusion point polyolefin resin and up 150 C of f.p. PP and (B) 30:70-60:40 of sheath-core multiple ration filaments are stretched by 6-9 times. Prepg. filaments has thermo-adhesive and improved strength.

Description

Manufacturing method of composite monofilament

The present invention relates to a method for producing a composite monofilament (hereinafter referred to as "composite MF") having heat adhesiveness and excellent strength. More specifically, a low melting polyolefin resin component on the sheath side and a polypropylene having a high melting point on the core side (hereinafter referred to as high melting point pp) are used. It is a manufacturing method of polyolefin resin "composite MF" which melt-extrudes using a mold | die mold | die, draws after solidification after cooling, and has excellent heat adhesiveness and excellent strength.

In general, a monocomponent monofilament (hereinafter, commonly referred to as MF) formed by melt extrusion of a polyolefin resin, stretching after cooling, and the like, has excellent mechanical strength, chemical resistance, corrosion resistance, water resistance, moldability, and the like. It is widely used for processing of marine materials such as fisheries, insect nets, windbreak nets, golf nets, shading nets, filters and civil engineering sheets.

By the way, land nets are mainly used by knitting, and its mechanical strength is a practical feature, but the longitudinal cross-section of the knitted fabric (hereinafter referred to as `` mesh '') is Since it is not bonded and relatively free, the net products are shifted due to the net mesh during knitting and the execution of net products or practical conditions.

On the other hand, the netting technology of nets obtained by using a special rotary tool, directly formed into a net by melt extrusion, and stretched in the longitudinal direction again to the net or net molded article bonded to the mesh. However, these monofilaments (hereinafter, referred to as "MF") are extremely limited because they have a very low strength of 1.5 g / d or less, in comparison with the MF strength of each longitudinal and horizontal strand of a net composed of MFs of 3 g / d or more. There is a problem that can be applied only to the packaging for simple light weight.

In addition, in the nonwoven fabric field, in recent years, a composite fiber having a heat-sealable function has been used to form a cloth and then heat-treated to heat-bond the mesh part for various purposes. Since the fineness of fibers is very thin, usually 1 to 30 denier, the fineness generally used as MF is thicker than 100 denier, and when using a composite fiber, it is necessary to make the fiber aggregate, which makes processing complicated. As a result, the cost is very high.

It is an object of the present invention to provide a method for producing a composite MF having excellent heat adhesion, excellent strength, no curl, and no delamination.

That is, the present invention is a high density polyethylene (hereinafter referred to as "HDPE") or linear low density polyethylene (hereinafter referred to as "LLDPE") or polypropylene having a melting point of 135 ° C or less (hereinafter referred to as "low melting point pp") or A mixture of these low melting point polyolefin resins and melting points

HDPE and polypropylene (hereinafter referred to as "PP") used in the present invention are both ethylene or a homopolymer of propylene, a copolymer with propylene butene-1 or the like mainly ethylene, or ethylene or butene mainly propylene. The copolymer with -1 etc. can also be used preferably. In addition, additives such as stabilizers such as antioxidants, ultraviolet absorbers and the like, additives such as lubricating agents, antistatic agents and chlorinating agents, which are usually added to the polyolefin resin, can be added to these polymers or mixtures thereof. have.

In the present invention, the mixing method in the case of mixing and using HDPE, LLDPE, low melting point PP, or the like as the seed component is possible with conventional apparatuses and methods such as an extruder, a Banbury mixer, a tangler mixer, a Hensiel mixer, and the like. In addition, the compound extrusion method or apparatus can be extruded using a known technique such as extrusion using two extruders and a parallel or seed core compound die. However, in the present invention, the spinning, stretching stability and stretching of the composite MF It is preferable to use a seed-core type composite tool which is advantageous in terms of poor peeling properties of the interface layer of the seed-core component.

In the present invention, the high melting point PP and the low melting point PP in terms of FR ratio are ASTM-D.

The high melting point PP (MFR) of the high melting point PP used on the core side of the composite MF is generally in the range of 0.3 to 15 used in the MF, but its melting point requires 150 ° C or more, The FR ratio with the low-melting-point polyolefin resin component of the de side becomes remarkable in the effect of this invention at 1.5 or more and 7 or less. In other words, when the melting point of the core component is 150 ° C. or lower, the strength, which is the basic performance of the core component, decreases, and furthermore, the shrinkage property is increased, and shrinkage deformation becomes severe at the time of heat setting after knitting on the net. When the FR ratio is 1.5 or less, the radiation and elongation are unstable, and the net heat adhesiveness is inferior. When the ratio is 7 or more, the fluidity in the nozzle of the seed component and the core component is different, and the difference in crystallization behavior between the two components ( The stress-strain caused by the volume shrinkage difference of the sheath-core layer in the process of cooling or solidification from the molten state is increased, and the unextruded yarn is curved or large at the nozzle exit. It becomes an ice sheet and the bag property deteriorates. In addition, the difference in stretching stress applied to the sheath-core component is large, the stretching cutting or the stretched yarn is easily curled, the stretching trouble easily occurs.

The low-melting polyolefin resin used as the seed component is a component obtained by imparting adhesiveness by heat fusion to the composite MF, and the effect is remarkably sufficiently obtained by using HDPE, LLDPE, and low-melting point PP alone, but these are two or more kinds. Even if it mixes and uses, the effect similar to the effect used independently is shown, It is preferable to combine the component in this case with what has the same fluidity. Use low melting point PP as the seed ingredient

80 degreeC or more is preferable and, as for melting | fusing point of low melting-point polyolefin resin, 100 degreeC or more is more preferable.

The composite ratio of the seed / core of the seed component and the core component is preferably in the range of 30:70 to 60:40. If the seed component is 30% or less, the radiation and elongation tends to be poor, and furthermore, the thermal adhesive component of the composite MF decreases, and the bonding force of the net joint of the net becomes weak, which is not preferable. On the other hand, when the core component is 40% or less, the strength, which is a basic element that the core component takes on, is lowered, which is undesirable.

In the present invention, stretching is usually possible with a general apparatus and method adopted by MF, and the stretching ratio thereof is suitably 6 to 9 times. In the case of the composite MF, since the strength is structurally lower than that of the MF, the strength is low at 6 times or less, and the strength is sufficient at 9 times or more, but the compatibility of the interface between polymers unique to the composite structure is insufficient. Due to this, the difference in the stretchability of the seed-core component becomes remarkable, and troubles such as flaw or peeling of the seed component occur in the stretching process, and are easily curled after stretching, so that the winding state in the winding process is poor or collapse of the winding. It is unpreferable because it causes the bad smell trouble of the back.

In addition, the apparatus and method for the purpose of improving the shrinkage of the drawn yarn after the stretching process.

The composite monofilament of the present invention can usually be suitably used for scraping of 100 to 1,000 denier.

The composite MF obtained according to the present invention usually maintains strength characteristics for each MF and combines thermal adhesiveness. The net product obtained by heat-treating the net product knitted by using such composite MF by heat roller or heating calender or hot air or steam treatment is generally a net product made of MF. It becomes net product which is hard to produce eyes gap of mesh part while keeping strength every time. Hereinafter, the present invention will be described in Examples and Comparative Examples. In addition, the code | symbol in a criterion of evaluation and a table | surface is as follows.

1) MJ: melt flow index of polyethylene resin (ASTM-1238 (E), that is, the weight of the sample extruded for 10 minutes under the condition of orifice hole diameter 2.092 ± 0.002mm, temperature 190 ℃, and load 2.160g in g number Shown)

2) MFR: melt flow index of polypropylene resin (same as 1) except temperature is 230 ℃); According to ASTM D-1238 (L).

3) FR ratio; MI (MFR for low melting point PP) and MFR measured in ratios of melt flow index of the seed component and the core component [1) and 2)

4) composite ratio; The weight ratio of the seed-core component obtained by extruding the seed-core component alone and measuring the weight per unit time of the undrawn yarn thereof.

5) radioactive. Extruded Unstretched State

○: normal

△: undrawn yarn bends at nozzle exit

X: Undrawn yarn bends at the nozzle exit, making spinning impossible

6) Extensibility. Evaluated in stretching state. Also,

* Table indicates that stretching is not possible

(Circle): It is normal also in a drawing yarn or a drawing process.

(Triangle | delta): A drawer turns into a white image.

X: It is easy to generate | occur | produce a winding trouble by extending | stretching cutting or curled image.

7) Peelability of Composite MF... Intermediate Separation of Seed-Core Components

(Circle): It does not peel even if it tries to remove a seed layer forcibly.

(Triangle | delta): Although it peels when a seed layer is forcibly removed, there is normally no problem.

X: It is easy to peel in an extending winding process.

8) Heat setting method of products on the net. The net product manufactured by the conventional method using the composite MF was left to stand for 1.5 minutes in a hot air heating tank of 140-150 degreeC.

9) Composite MF Strength after Thermal Bond Processing. Evaluate composite MF from net-bonded products with mesh neck and measure tensile strength.

(Circle): It is larger than 4.0 g / d. △: 3.0 to 4.0 g / d ×: less than 3.0 g / d

Note) Tensile strength measurement conditions

Tensile tester; Teshiron IV type made by Dongyang Baldwin Corporation; 23 ℃

Between shanks; 200mm humidity; 50%

Tensile velocity; 200mm / min

10) Adhesion of the mesh part of the product on the net: Measure the adhesive strength of the mesh part

○: adhesive strength is greater than 300g

△: adhesive strength of 100 to 300g

X: adhesive strength is less than 100 (those which are attached once but have weak adhesiveness are included).

Example 1 and Comparative Example 1

Two extruders with a diameter of 40 mm and a diameter of 1.5 mm each have a melting point of 161 DEG C and various MFRs as a core component, HDPE or LLDPE with different MI as PP, or a PP having a melting point of 128 DEG C. It is used as a composite ratio of melt-extruded and cooled by using the seed-core type composite mold of mm, the extrusion temperature of the core side to 260 ° C, the extrusion temperature of the seed side to 240 ° C, and the temperature of the composite mold to 260 ° C. A 50-50 seed-cored composite non-drawn yarn is obtained. This was stretched 5 to 10 times with a wet heating stretching apparatus to obtain various composite MFs of 450 deniers. The results for the radioactivity and stretchability of the extruded undrawn yarn and the peelability between the seed and core layers of the composite MF at this time are shown in the first table. After weaving into a net-like product having a fabric density of 5 slits / 25 mm × 5 slits / 25 mm using various MFs manufactured by the above process, heat-setting for 140 minutes in a hot air heating bath at 140 ° C. The results of evaluating the thermal adhesiveness and the remaining strength of the composite MF are shown in Table 2.

In these tables, a high melting point PP of 161 ° C is used as the core component, and HDPE or LLDPE or

Example 2 and Comparative Example 2

As the core component, PP having a melting point of 161 DEG C and an MFR of 3.1 was used alone, and HDPE, LLDPE or PP having a melting point of 128 DEG C was used alone, and spinning was carried out under the same conditions as in Example 1, and various compound ratios were obtained. A phosphorous-cored composite undrawn yarn is obtained. This was stretched by the wet heating drawing apparatus to obtain 450 denier composite MF. The thermal adhesiveness and the self-presence strength of the net-like product were evaluated in the same manner as in Example 1 for the radioactivity and the stretchability of the undrawn yarn at this time and the obtained composite MF. The results are shown in Table 3.

In Table 3, the composite ratio of the seed-core component was in the range of 30:70 to 60:40, and was found to be excellent in the heat adhesiveness and the residual strength of the net-like product by the radial stretching stability and the composite MF.

Example 3 and Comparative Example 3

PP having a melting point of 161 ° C. and a MFR of 3.1 as a core component and a low melting PP point having a MFR of 15.5 and a different melting point as the seed component were used alone and in Example 1, respectively.

In the case of using low melting point PP as the seed component in Table 4, when the melting point becomes 135 ° C or higher, the heat adhesiveness and residual strength of the adhesive property remain large due to the heat fixation conditions of the net product. It has been found that the higher the heat adhesion property becomes, the higher the heat setting temperature in order to improve the thermal adhesion property. On the contrary, the strength of the composite MF after the heat adhesion processing becomes too low.

Example 4

After mixing PP with melting point of 161 ° C and MFR of 3.1 as core component, HDPE, LLDPE or PP with melting point of 128 ° C in Hensiel Mixer at a ratio of 1: 1, and extruded with 40mm diameter extruder It evaluates similarly to Example 1 using a mixed resin as a seed component. The results are shown in Table 5.

In Table 5, it was found that even when the seed component was a mixture of HDPE, LLDPE and low melting point PP, it had the same effect as the single component.

Example 5 and Comparative Example 4

Table 6 shows the results of evaluating PPs having the same MFR and different melting points as core components, HDPE, LLDPE, or PPs having a melting point of 128 ° C. alone, as in Example 1, respectively. It was.

In Table 6, when the melting point of the core component is 150 ° C. or lower, thermal adhesiveness is not a problem, but it is found that the decrease in the residual strength is remarkable.

Claims (1)

High density polyethylene, linear low density polyethylene or polypropylene having a melting point of 135 ° C. or lower or a mixture of low melting point polyolefin resins having a melting point of 150 ° C. or higher and a polypropylene having a melting point of 150 ° C. or higher are formed in a seed-core type using the former as the core and the latter as a core. A composite monofilament unstretched yarn obtained by spinning, wherein the melt flow index ratio between the low melting point polyolefin resin component and the polypropylene component having a melting point of 150 ° C or higher is 1.5 or more and 7.0 or less, and the composite ratio of the seed / core is 30:70 to 60: A method for producing a composite monofilament having heat adhesiveness and excellent strength, characterized by stretching 40 to 6 times 9. [Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

Images