| 1. | An antislip tarpaulin, comprising: a woven cloth layer formed by weaving polyethylene ; and a coating layer coated on one or both surfaces of the woven cloth layer, wherein a plurality of twisted split yarns are aligned on the coating layer on at least one surface at predetermined intervals. |
| 2. | The antislip tarpaulin of claim 1, wherein the split yarns twisted in two pieces are extended in the longitudinal direction of the woven cloth layer. |
| 3. | A method for manufacturing an antislip tarpaulin, comprising the steps of: supplying a woven cloth layer formed by weaving polyethylene ; supplying a plurality of split yarns twisted in two pieces to the woven cloth layer so that the split yarns can be aligned on the woven cloth layer at predetermined intervals ; and spreading a coating agent on the woven cloth layer, and compressing and coating the resultant layer through a cooling roll and a pressurizing roll. |
BACKGROUND ART In general, when construction materials such as timber and steel or various agricultural products are heaped, a tent is covered to protect heaped products from strong wind, raindrops or snow. Tarpaulins used for a waterproof tent are classified into PVC (polyvinyl chloride) tarpaulins and PE (polyethylene) tarpaulins according to used materials. Here, the PVC tarpaulin is prepared by coating PVC on both surfaces of a PET woven cloth comprised of multi-filament yarns, and the PE tarpaulin is prepared by drawing HDPE (High Density Polyethylene) films to be a woven cloth,
and laminating LDPE (Low Density Polyethylene) resins on both surfaces of the woven cloth.
The tarpaulin for the tent is generally waterproof, to protect the heaped products from frost, rain or snow, and has sufficient strength not to be torn by wind.
*The tarpaulin for the tent shows excellent waterproof and strength properties, but its surface is not anti-slip processed. In the case that products wrapped up in the PE tarpaulin are laminated in multiple layers, they may be easily slipped even by a slight external force because of the property of the coated LDPE. Therefore, it is very difficult to laminate the products wrapped up in the tarpaulin in multiple layers. Especially, when timbers are covered with the PE tarpaulin, they may not be sufficiently waterproof, and workers may be injured due to the slippery surface.
In order to solve the foregoing problems, Korean Utility Model Reg.
No. 234912 applied on March 19, 2001 and registered on June 7,2001 by the present applicant discloses an anti-slip tent which improves a surface friction force by adhering an anti-slip film on the surface of the tent, and embossing the surface of the anti-slip film in a multiple number. That is, the anti-slip tent includes a tent main body comprised of PVC or PE, and an anti-slip layer formed on at least one surface of the tent main body for
enhancing a friction resistive force.
Although the surface friction force is enhanced by adhering the anti-slip film on the surface of the tarpaulin by lamination, or compressing and coating an anti-slip material thereon, and embossing the surface of the anti-slip layer in a multiple number, there is a limit to improve the surface friction force. Accordingly, a tarpaulin having a much higher friction force is required in weather conditions of heavy snow or rain.
On the other hand, both surfaces of the PE tarpaulin are covered and coated by using the same material (LDPE) and method. The PE tarpaulin is intended to restrict drainage and air permeability as much as possible according to its intrinsic use. However, when the PE tarpaulin is used for a green cover of a lawn stadium or golf practice range in winter, the low air permeability and water flow have detrimental effects on lawn.
So as overcome the aforementioned disadvantages, the present applicant applied an anti-slip tarpaulin with air permeability and water flow for registration on January 3,2002 under Korea Patent Application No.
2002-197. The tarpaulin includes a woven cloth layer formed by weaving polyethylene, and a multiple pore coating layer formed by coating a resin composition including LDPE or ethylene-vinylacetate resin as an essential element and hydrizodicarbon amide or azodicarbon amide as an auxiliary
element on one or both surfaces of the woven cloth layer, wherein a plurality of pores are formed on the multiple pore coating layer at least one surface.
The anti-slip tarpaulin with air permeability and water flow can be used for a green cover for a lawn stadium or golf practice range in winter due to its air permeability and water flow, maintaining its intrinsic functions.
In addition, the anti-slip tarpaulin can be used for a cover for wrapping up products laminated in multiple layers or protecting timber in a logging site due to its waterproof and anti-slip functions.
The anti-slip tarpaulin provides excellent air permeability and water flow by the plurality of pores formed on the coating layer, but reduces the friction force for preventing slipping.
DISCLOSURE OF THE INVENTION An object of the present invention is to provide an anti-slip tarpaulin and a method for manufacturing the same which can prevent slipping accidents from occurring, by coating a strong friction force structure on at least one surface of the tarpaulin.
In order to achieve the above-described object of the invention, there is provided an anti-slip tarpaulin including: a woven cloth layer
formed by weaving polyethylene ; and a coating layer coated on one or both surfaces of the woven cloth layer, wherein a plurality of twisted split yarns are aligned on the coating layer on at least one surface at predetermined intervals.
In addition, a method for manufacturing an anti-slip tarpaulin includes the steps of: supplying a woven cloth layer formed by weaving polyethylene ; supplying a plurality of split yarns twisted in two pieces to the woven cloth layer so that the split yarns can be aligned on the woven cloth layer at predetermined intervals; and spreading a coating agent on the woven cloth layer, and compressing and coating the resultant layer through a cooling roll and a pressurizing roll.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flowchart showing sequential steps of a method for manufacturing an anti-slip tarpaulin in accordance with the present invention; Fig. 2 is a process view showing sequential steps of the method for manufacturing the anti-slip tarpaulin in accordance with the present invention ; and Fig. 3 is a plane photograph of the anti-slip tarpaulin in accordance
with the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION An anti-slip tarpaulin and a method for manufacturing the same in accordance with the present invention will now be described in detail with reference to the accompanying drawings.
In order to maintain an intrinsic function of a tarpaulin for a tent for protecting heaped products and improve a friction force on the surface of the tarpaulin, twisted split yarns are inserted into a coating layer coated on one surface of the tarpaulin.
The split yarns are prepared by forming flat tape yarns by dividing a HDPE resin into a few pieces and drawing them, and splitting the flat tape yarns a few times in the longitudinal direction. So as to improve strength, the split yarns are twisted a few times into one piece. Here, one piece of split yarn can be used, but more preferably, two pieces of split yarns are twisted to enhance the strength and friction force.
The twisted split yarns are aligned and coated on a polyethylene woven cloth at predetermined intervals.
As disclosed in detail in Patent Application No. 2002-197, in accordance with a general method for manufacturing a PE tarpaulin, an
HDPE woven cloth which is a main material of the tarpaulin is woven, and the woven cloth is positioned on an unwinder to be fetched. The woven cloth fetched from the unwinder is transferred to a pressurizing roll of a first extruding unit and a second extruding unit. A coating agent is supplied to the woven cloth through a T-die so that both surfaces of the woven cloth can be compressed and coated.
In order to improve the surface friction force, the twisted split yarns are supplied as shown in Fig. 1.
That is, when the polyethylene woven cloth is supplied (S10), the twisted split yarns are supplied from a krill die to the polyethylene woven cloth (S20). The woven cloth is coated with the coating agent discharged through the T-die (S30), to obtain the anti-slip tarpaulin (S40). During the process, the coated woven cloth is transferred to coat the other surface after removing frictional heat according to a cooling process (S35).
Fig. 2 is a process view showing the method for manufacturing the anti-slip tarpaulin in accordance with the present invention. A plurality of bobbin axes 12 (four bobbin axes in this embodiment) are fixed to a krill stand 10 at a predetermined angle, and the split yarns 16 twisted in two pieces are wound around bobbins 14 rotatably mounted on the bobbin axes 12 to be fetched. Here, a tension roller 18 is positioned between a guide
roller 20 and the krill stand 10 to prevent the split yarns 16 unwound from the bobbins 14 from getting tangled.
The split yarns 16 fetched along the guide roller 20 under proper tension are aligned at predetermined intervals through an interval control plate 22. Thereafter, the split yarns 16 are extended and aligned on the polyethylene woven cloth supplied from the unwinder at predetermined intervals in the longitudinal direction, and the compression coating process is performed thereon by using the coating agent supplied from the T-die.
Preferably, an LDPE mixed resin can be used as the coating agent.
That is, the LDPE mixed resin uniformly mixed in a dry mixer for a predetermined time is supplied into a hopper of the first extruding unit, and molten and mixed by an extruder. Then, the resin extruded into high temperature mobile films through the T-die is spread on one surface of the polyethylene woven cloth supplied from the unwinder, and coated on the woven cloth under pressure through the cooling roll and the pressurizing roll of the first extruding unit.
The resin is transferred to the second extruding unit, and an LDPE mixed resin supplied in the same manner is compressed and coated on the other surface of the woven cloth, to prepare the anti-slip tarpaulin. The completed product is wound around a winder in a roll type.
Fig. 3 is a plane photograph of the anti-slip tarpaulin in accordance with the present invention.
Referring to Fig. 3, the plurality of twisted split yarns are aligned on the polyethylene woven cloth at predetermined intervals, and a plurality of protruding units are formed on the woven cloth as large as a diameter of the split yarns, to maximize the surface friction force. Preferably, the split yarns have a thickness of about 2200 denier. Here, two pieces of split yarns are twisted, and thus a thickness of the split yarns is about 4400 denier. The plurality of twisted split yarns are coated at predetermined intervals in the longitudinal direction of the tent, and thus a height of the tent increases by the diameter of the split yarns, to improve the friction force.
INDUSTRIAL APPLICABILITY As discussed earlier, in accordance with the present invention, two pieces of split yarns are extended and aligned on at least one surface of the tarpaulin for the tent at predetermined intervals in the longitudinal direction, and the plurality of producing units are formed thereon, which enhances the surface friction force to prevent slipping accidents.