JPS59224341A - Manufacture of tarpaulin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing tarpaulin.

Conventionally, tarpaulins are made of polyamide, polyester,
The base material is carpet made of synthetic fibers such as polyvinyl alcohol-based synthetic fibers, i.e., 75'r synthetic fiber woven fabric, and polyvinyl chloride (P
It was manufactured by applying a coating such as rubber or rubber. but,
In the case of these tarpaulins, a large amount of plasticizer is mixed in to improve the thermal stability in the drawing process and the thermal stability, physical properties, flexibility, etc. of the product. However, various problems were observed regarding the hygiene of the contents.

For this reason, we changed the coating material from PVA and rubber to ethylene-vinyl acetate copolymer (gVAJ), and used synthetic fiber base fabrics such as polyamide, polyester (PG'R), and polyvinyl alcohol as before, using the calendar method and A product manufactured by the dry simulating method has been proposed.In this case, the problem of hygiene is improved, but when molding by the calendar method using gVA, molding is performed at only 1 low temperature, so the anchoring effect of the single fibers is not sufficient. In addition, in the case of dry 2 laminate, there is no cheap, easy and good processing agent (this causes problems in terms of creep properties and peel strength of the seal part, and is also unsatisfactory in terms of light weight and price). It wasn't something that should have been done.

In addition, in conventional PVO tarpaulins, it has been considered and considered to use polypropylene (PP) or high density polyethylene (HDPR) polyolefin flat yarn cloth for weight reduction and cost reduction. It was not used because it caused problems such as spreading and problems such as a decrease in the strength of the base fabric and cutting during high-frequency sealing.

The present invention solves these problems and improves toughness (extraction residue with boiling n-hebutane (wt%)).
Hail! The base material is a mesh fabric made of isotactic polypropylene with a single fiber fineness of 25 deniers or less, which is made of isotactic polypropylene with a fiber diameter of 96 or more, used as the warp and/or weft, and at least one side of the base material is coated with acetic acid. A method for manufacturing a tarpaulin characterized by bath melting an ethylene vinyl acetate copolymer having a vinyl content of 10 to 30% within a temperature range of 220 to 290C and laminating (hereinafter referred to as melt lamination). It is.

In the present invention, it is essential that the polypropylene resin used for the mesh fabric base material (base fabric) is isotactic polypyrene having a tuffity of 96% or more. If it is less than this, in the tarpaulin of the present invention, not only will the strength decrease after high frequency sealing be large (problems will also occur with weld creep and turbo link league).
There are problems with the practical properties of the tarpaulin, such as heat shrinkage of the base fabric during the coating process.

Regarding the molecular weight and molecular weight distribution of this polypropylene, 1
MFR (melting index n-Q5~151
/ l Omin (same below) 1 MLMFR/MFR (10k!! load melting N number/2-16kl load melting index, measured at 230C) is 13~ which is a guideline for molecular weight distribution.
Preferably, it is 20. If MFR5 or less, there is no problem in terms of strength and creep property, but there are problems in terms of spinnability and drawability, and if MFR15 or more, strength, creep property,
There is a problem with spinnability due to yarn wobbling. Also MLMFR/
If the MFR is less than 15, there will be troubles in the production of PP resin and problems in spinnability due to yarn wobbling.On the other hand, MLM FR/
If the MFR is 20 or more, there are problems in terms of strength and stretchability.

It is essential that the isotactic polypropylene multifilament resin used in the present invention has a single fiber fineness of 25 deniers or less. That is.

In the case of filaments of 25 denier or more, the contact area with the EVA coating is small, and there is a problem with the adhesion between the base fabric and the broken #gvA film, resulting in extremely poor peel strength, welding creep, etc. However, in the present invention, in order to prevent the single fibers from coming apart, the single fibers are heated or a binding agent is applied, but the single fibers can be bundled by any method and used as a woven yarn.

In the present invention, polyolefin cuboline is produced using a mesh fabric formed by using the above-mentioned polypropylene multifilament in one or both of the warp and weft as a base material. In this case, the number of mesh fabrics is not limited, but in the case of plain weave, it is 10 pieces/1nch~3o
Implantation of 1 nch/1 nch is preferable. That is, if the number of implants is 10 or less than 1 nch, there is a problem that misalignment is likely to occur. On the other hand, if the number of implants is 30/1 nch or more, the mesh becomes narrower, the bridging effect of the gVA coating resin layer disappears, and there is a problem in terms of releasability. In addition, in the case of a mesh weave made of warp threads, welding creep in the tarpaulin warp direction is significantly improved, and there are advantages such as no misalignment of the base fabric. In this case, the number of threads to be driven is preferably 5 to 15 threads/1 nch from the viewpoint of weavability and mesh spacing.

In the present invention, a small amount of base fabric (also known as IcV
A needs to have a vinyl acetate content of 10 to 30%; when the vinyl acetate content is less than 10%, problems with high frequency sealing properties occur, and when it exceeds 30%, blocking occurs.

Problems arise with welding creep, etc. Furthermore, the MFR of gVA is not subject to any special restrictions, but the lower the MFR, the better the physical properties such as peel strength. However, if it is too low, there will be a problem in the 2-lamination step, and from this point of view, 1-( is preferably MFR 1 to 20).

In the tarpaulin of the present invention, when ICvA is laminated to the mesh fabric base fabric obtained above.

It is essential to melt-laminate at a high temperature of 220 to 290C, preferably 240 to 270C.In other words, by melt-laminating, the EVA resin enters the bundled woven yarn of 25 deniers or less by heating or a sizing agent, and the single fiber itself This creates a so-called anchor effect and provides adhesiveness between the base fabric yarn and the LLVA layer.

Furthermore, the bridging effect of the mesh weave further increases adhesion.

Conventionally, in the case of the calendar method using EVA, 120 to 150
The anchoring effect of single fibers could not be sufficiently exhibited because it could only be formed into C, and in the case of dry laminate, there was no inexpensive, simple and good processing agent for PP and EVA.

If the above melt lamination temperature is 220C or less, the base fabric and gV
The adhesion of A is poor (there are problems with tarpaulin peel strength, welding creep, etc., and there are also problems with lamination workability.On the other hand, when the melt lamination temperature is 290C or higher, IKVA
The resin decomposes, causing problems with adhesion and workability.

Next, the present invention will be explained with reference to Examples and Comparative Examples. The measurement methods for various test items used in the examples are as follows.

(Welding strength kg / 5 cm) Using high frequency Elder KW2000 made by Kendensha, output 2KW,
Welding pressure 2.5 kg/cm'.

Weld each sample in 12 seconds. The length of the overlap part is 50
%, of which 50% is used during welding. Also, between the chucks 2
00 demon, tensile speed is 200 ttrm/win
shall be.

(2) Weld creep was measured by the method shown in Figure 1. That is, a test piece 3 having a weld portion 2 is suspended from a base 1, and a load M4 is applied to the test piece 3 to measure weld creep. The measurement conditions are as follows.

During welding 30% Width Length 60%L Sample length J20%L 40ky load, left for 50C4B hours, then left for 40C24 hours and measured residual strength. In addition, in the following examples, the intermediate cutting strength is also shown.

(3) Thread withdrawal resistance (kt/2 yarns) Make three notches 5 on the sample as shown in Figure 2, and measure the yarn pullout resistance by pulling the sample from side to side (as indicated by the arrows in the figure).

The other numbers in the figure indicate dimensions, and the unit is ■. The tensile speed was 200 m/m.

(4) Peel strength The test piece having the weld portion 6 was pulled from the left and right sides in the manner shown in FIG. 3, and the peel strength was measured. The measurement conditions are as follows.

Welder width 5Qvrra Length 30g Distance between chucks 200mm Tensile speed 200mm/m1n (5) Tear strength Compliant with JIS Z f 651. By single tank method.

(6) Tensile strength , u:j　z　1　<S　Compliant with 51.

Example 1 VFR is 8.5, MLMFR/MFR is 14. Isotactic polypropylene with a toughness of 97.0% is produced using a 40%φ extruder and a 1.5$φ125 hole nozzle.
Extrusion temperature c, c2c3c4 nozzle 200 23.0 260 290 290C1 Spun the undrawn yarn at a spinning speed of 200 m/win and a cooling air temperature of 18C, then use a hot four-wheel drawing machine to spin the undrawn yarn,
It was drawn 8.74 times at a drawing temperature of 150C and a drawing speed of 200X to obtain a multifilament of 651,000 denier and a single filament fineness of 15 denier.

The strength of the obtained multifilament was 8.84Ii/(1).

The multifilament obtained above is used as a warp.

It was used for the weft and woven on a plain weave base fabric with a number of threads of 17 x 17 threads/1 nch on a Toyota Sulzer 110-inch loom, and the base fabric had a vinyl acetate content of 18.5%, wx5.
．． The tarpaulin with a thickness of 0.85♂ was obtained by pasting both sides (300 μm on one side) on 51/1°0 ethylene acetate vinyl at a JR type speed of 10 m/min.

As shown in Table 1, a tarpaulin with good welding creep, peel strength, thread pull-out strength, and bath bonding strength was obtained.

Example 2 Two multifilaments used in Example 1 were bundled,
This is used as the weft, and the warp is PP/HD manufactured by Konyoshi Kako Co., Ltd.
Using PE1500 denier flat yarn, 10 x 2 warp yarns/110 inch loom equipped with Toyota Sulzer splitting device.
1 nch, 8 wefts/1 nch Karami mesh base fabric and none.

EVA was laminated onto this base fabric under the same conditions as in Example 1 to obtain a tarpaulin with a thickness of 0.92%.

As shown in Table 1, a tarpaulin was obtained which had particularly good bath creep in the vertical direction and also had very good other physical properties.

Comparative Example 1 A multifilament with a single yarn fineness of 40 denier was obtained under the same conditions as in Example 1, but the strength of the obtained multifilament was 8.2Ji/11.

This multifilament was used for the warp and weft, and woven on a plain weave base fabric with a number of threads of 17 x 17 threads/1noh using a 110-inch loom manufactured by Toyota Sulzer. 9710 minutes of ethylene vinyl acetate copolymer manufactured by Mitsubishi Heavy Industries, Ltd.
Using a 0%φ extruder with a tie width of 1600% and a laminator, the resin temperature was 260C and the molding speed was 10 m/mi.
Double-sided adhesive (300μ on one side) with n, thickness 0-85'X,
obtained a tarpaulin.

As shown in Table 1, there were no problems with tensile strength, but there were problems with welding creep (and problems with peelability and thread pullability).

Comparative Example 2 Isotactic polypropylene having MFR of 8.7, MLMFR/MFR=20-5, and toughness of 93.1% was spun under the same conditions as in Example 1, but at a draw ratio of 7.3 times.

There were no problems with spinning or drawing. Increase the strength to 15.8. F
/d.

A tarpaulin with a thickness of 0.82% was obtained in the same manner as in Example 1. As shown in Table 1, problems are seen in terms of tensile strength and bathing creep.

Comparative example 6 The resin temperature during laminator is 190C.

A tarpaulin was also obtained in the same manner as in Example 1 except that the molding speed was 5 m/min.

As shown in the Ml coating, welding creep was poor compared to Example 1 (problems were observed in peelability and thread pullability).

Comparative Example 4 zvA'4g on polyester base fabric: A! Various physical properties were sub-determined for a commercially available tarpaulin made of 1tlt.

As shown in Table 1, a problem was observed in bath coat creep.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the solution layer creep test, FIG. 2 is an explanatory diagram of the stringing liquid resistance test, and FIG. 3 is an explanatory diagram of the peel strength test. 1... Base, 2... Weld part, 3... Test piece,
4... Load, 5... Notch, 6... Part of welder %rF IB craftsman Showa Denko K.K. patent attorney Yoshihiro Sato Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] The base material is a mesh fabric in which less than one strand of marten isment is used for the warp and/or weft. At least one side of the base material has a vinyl acetate content of 10 to
30% ethylene vinyl acetate copolymer from 220 to 290
Bath melt within the temperature range of C. A method for producing tarpaulin, characterized by laminating it.