Description:
Field of the Invention

[001] This invention relates to a process for preparing bisected grid line multilayer Tarpaulin and in particular, this invention relates to the process for preparing bisected grid line multilayer Tarpaulin wherein roll is made in sheet form. More particularly, this present invention relates to the process for preparing bisected grid line multilayer Tarpaulin wherein the roll is loaded in the lining unit and the re-grooving is done on the flat film having vertical lines. Furthermore, this invention also relates to the process for preparing bisected grid line multilayer Tarpaulin has the advantages of convenient and reliable in overall installation; and the use and making cost is low.

Background of the invention and the related Prior Art

[002] In general, a tarpaulin has reduced the production cost and improved productivity by multiple-coating low-density polyethylene resin on a layer woven by using high-density polyethylene (HDPE). Recently, there has been taught a process for preparing a tarpaulin by stacking low-density polyethylene (LDPE) resin on one or both surfaces of a layer woven by using HDPE, and compressing and coating it by using a cooling roller and a pressure roller.
[003] The document IN1949DE2013 describes a composition comprises a blend of linear polymer, insecticide, and/ or insect repellent, or in combination, synergist, dispersant, antimicrobial agent, UV resistant agent, flame retardant, fragrance, nano-material which provide functionality to the article after incorporation into the high density thermoplastic polymer containing polyether chain. This composition is extruded into monofilament which in turn woven or knitted into net or fabric and/ or sheet (tarpaulin) for articles. Thus formed articles of invention retain effective amount of the active compounds of blend even after several washings for example 20 washing or ageing for example 7 years and thus articles made from this blend remain effective against common disease vector mosquitoes and other similar type of flying and crawling insects.
[004] The cited document US2015224910 related to a laid fabric suitable to be transformed into a tarpaulin for covering freight trucks, trailers or trucks, more specifically to reinforced tarpaulins for the prevention of deformations during transport with freight trucks, trailers or trucks and the manufacture process of such tarpaulins.
[005] The document CN110485156 discloses a preparation process of double-sided camouflage printed flame-retardant and aging-resistant tarpaulin. The preparation process comprises the specific steps of (1) weaving a fiber layer by adopting high-strength polyester or high-strength nylon as a raw material and adopting plain weaves or lattice plain weaves; (2) desizing, refining, soaping, dewatering, flat laying and shaping the fiber layer to obtain shaped cloth; (3) conducting rolling printing and shaping on the shaped cloth by adopting multi-spectrum paint resistant to strong sun exposure to obtain printed cloth; (4) coating the reverse side of the printed cloth with a flame-retardant layer, and conducting flame-retardant and aging-resistant treatment on a front rubber coating layer to obtain a single-sidedcamouflage printed flame-retardant and aging-resistant cloth; (5) conducting rolling printing on the reverse side of the single-sided camouflage printed flame-retardant and aging-resistant cloth by adopting multi-spectrum paint resistant to strong sun exposure, and then conducting flame-retardant and aging-resistant treatment on the rubber coating layer to obtain the double-sided camouflage printed flame-retardant and aging-resistant cloth. The tarpaulin has the advantages of double-sided printing, superhigh aging resistance, flame retardancy, visible light stealth, infrared stealth, radar wave stealth and the like.
[006] The patent document CN110670371discloses a high-efficiency tarpaulin production process. The high-efficiency tarpaulin production process comprises the following steps: extruding and plasticizing; cutting yarns; winding; warping flat yarns into a plurality of warp shafts by adopting a warping device for tarpaulin; weaving; carrying out film spraying; and packaging. The warping device comprises a warping machine main body, a warping shaft and a creel are arranged on the warping machine main body, a plurality of fixing shafts extending laterally are arranged on the creel, and an outer cylinder body rotating relative to the fixing shafts and a brake device for limiting the outer cylinder body to rotate relative to the fixing shafts are arranged on the fixing shafts in a sleeving manner. According to the high-efficiency tarpaulin production process, pretreatment warping is added between the step of yarn cutting and shaping and the step of weaving to form warp beams with uniform tension, and the monofilament tensions of the different warp beams are consistent. In the weaving step, cloth with high density can be woven by the consistent tension of the warp yarns, meanwhile, the probability of local defects is reduced, the stress on the surface of the cloth is uniform when the surface of the cloth encounters external force, the surface of the cloth can bear high load, and the tensile strength and tearing strength are remarkably improved.
[007] CN113863019 discloses an anti-aging PVC tarpaulin and a preparation process thereof. The anti-aging PVC tarpaulin comprises a base cloth layer and a PVC fabric layer coating the base cloth layer, wherein the PVC fabric layer is prepared from the following raw materials in parts by weight of 70-90 parts of PVC paste resin, 20-30 parts of a plasticizer, 5-10 parts of an anti-aging agent, 3-5 parts of chlorinated paraffin, 3-5 parts of hydrotalcite, 15-25 parts of nano titanium dioxide and 60-80 parts of an organic solvent. The preparation process of the anti-aging PVC tarpaulin comprises the following steps of mixing the PVC paste resin, the plasticizer, the chlorinated paraffin and the organic solvent, then adding the anti-aging agent, the hydrotalcite and the nano titanium dioxide, and uniformly stirring to obtain a PVC fabric mixture; and coating the upper surface of the base cloth layer with the PVC fabric mixture, and drying to obtain the anti-aging PVC tarpaulin. The anti-aging PVC tarpaulin provided by the invention is good in high-temperature aging resistance and migration resistance.
[008] The document CN113863011 relates to the technical field of textile manufacturing, and discloses a flame-retardant tarpaulin and a preparation process thereof. The flame-retardant tarpaulin comprises a polyester filament yarn oxford fabric and a flame-retardant layer attached to an outer layer of the polyester filament yarn oxford fabric; the flame-retardant tarpaulin is characterized in that the flame-retardant layer is prepared from the following raw materials in parts by weight of 70-90 parts of a polyurethane finishing agent, 44-66 parts of a solvent, 25-45 parts of a double-layer microcapsule phase change material, 10-22 parts of ammonium polyphosphate and 3-7 parts of a dispersing agent; and the double-layer microcapsule phase change material is sequentially composed of a polyethylene glycol core material, a graphene oxide secondary outer layer and a polyurea outer layer from inside to outside. A special flame retardant is used in the invention, the firm flame-retardant layer can be formed on the polyester tarpaulin, the flame-retardant layer can form a compact heat insulation layer after being heated, and therefore the flame-retardant performance of the polyester tarpaulin is effectively improved; and the flame retardant used in the invention is efficient, can achieve a relatively good flame retardant effect with a relatively small coating amount, and has almost no influence on the strength of the polyester tarpaulin.
[009] The documents 3047/mum/2015 discloses a closed cell foam made of cross linked polyethylene and also discloses a method to produce the foam. The foam has an enhanced property of providing better thermal insulation and the same is achieved by incorporation of air gaps in the polyethylene foam.
[010] The document 8906/CHENP/2011 describes Method and apparatus for longitudinal orientation of thermoplastic film material (20) comprises a width-reduction zone upstream of the longitudinal stretching zone (9,10) through which the width of the film is gradually reduced so as to allow longitudinal stretching without necking. The width-reduction zone comprises at least two sets of pleating rollers (7,1) comprising intermeshing grooves or discs for pleating the material. The downstream (1) rollers comprise a mini-roller defined by the following measures a) the pitch of the corrugations, measured from middle of tip to middle of each neighbouring tip is 20 mm or less; b) the perimeter from middle of a tip to the middle of each neighbouring tip measured along the corrugated roller surface, divided by the said pitch is in the range between 1,10 and 1,80; and c) the diameter of the mini-roller, measured at the tips of the corrugations, is at the highest 4 times the said pitch. Preferably a pair of mini-roller sets is arranged on opposing sides of the film in reciprocating mounts enabling alternate entwining of the film around one then the other mini-roller. The method allows achievement of high tensile strength, yield point, resistance to tear propagation and puncture resistance, especially for polyethylene and polypropylene films.
[011] 201621011775 describes a foldable and slidable tarpaulin carrier having a light-weight structure and comprising a mechanism for deploying or releasing the tarpaulin carrier on or from the vehicle’s load body. The structure is a moveable hollow tubular tray-like structure having a front extended pivoting arm and a rear extended latching arm; said extended arms transversely disposed on top of the load body and forming part of the tarpaulin carrier base. At either end of the load body, a respective cam guide is provided at the top front end thereof and a respective latching hook is provided on top thereof, disposed away from the cabin and the cam guides at either end of the load body. The extended latching arm is secured in a respective latching hook fitted at either transverse end of the load body for deploying the tarpaulin from the tarpaulin carrier disposed over the load body. The latching arm can be released by slightly moving back the tarpaulin carrier, lifting it above the latching hook and sliding forward to suspend it vertically using the cam guides.
[012] The document 201821013442 discloses a tarpaulin (1) of the present invention comprise a cross laminated multilayered/monolayered polymeric composite film (2) having an improved border (4). Said border (4) is comprised of polymeric composite film layer (2) being sandwiched and sealed between the layers (3) of HDPE laminated woven fabrics or PVC coated film to form composite border (4). Further, the border (4) of tarpaulin (1) is optionally comprised of a layer (2a) of the polymeric composite film (2) being wrapped and coated on either side of the layer (3) of HDPE laminated woven fabrics or PVC coated film to enhance mechanical and tearing strength of the border (4) of the tarpaulin (1). Further, the border (4) is optionally provided with cords/ropes. The tarpaulin border (4) of the present invention has an exceptionally increased mechanical strength, tearing strength; weather resistance, UV light resistance, durability and longer lifespan.
[013] The cited document 202131061699 provides an anti-slip tarpaulin for embankment of water body. The anti-slip tarpaulin comprises warp yarns arranged in longitudinal directions and six weft yarns arranged in lateral direction. The anti-slip tarpaulin is manufactured by using a six shuttle loom machine, wherein a particular type of yarn suitable for the machine is selected from a plurality of available weaving materials. The machine accommodates the warp yarns and the six weft yarns for maneuvering six shuttles in a defined direction. Such directed looming aids in providing the tarpaulin a unique pattern that act as an anti-slip material. The shuttles of the machine, fixed with a first, second, third, fourth, fifth, and sixth weft yarns, are operated in lateral direction by weaving next set of warp yarns in same warp up and warp down pattern. The machine is configured to iteratively weaving thorough the longitudinal direction by using the six shuttles.
[014] The invention consists of certain novel features and a combination of steps hereinafter fully described, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.

Summary of the invention
[015] This invention relates to a process for preparing bisected grid line multilayer Tarpaulin and in particular, this invention relates to the process for preparing bisected grid line multilayer Tarpaulin wherein roll is made in sheet form. More particularly, this present invention relates to the process for preparing bisected grid line multilayer Tarpaulin wherein the roll is loaded in the lining unit and the re-grooving is done on the flat film having vertical lines. Furthermore, this invention also relates to the process for preparing bisected grid line multilayer Tarpaulin has the advantages of convenient and reliable in overall installation; and the use and maintenance cost is low.

Detailed description of the invention with accompanying drawings

[016] For the purpose of facilitating an understanding of the invention, there is illustrated in the preferred embodiment along with accompanying drawings thereof, from an inspection of which, when considered in connection with the following description along with accompanying drawings, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.

[017] The principal object of the invention is to provide a process for preparing bisected grid line multilayer Tarpaulin.
[018] The other object of the invention is to provide the process for preparing bisected grid line multilayer Tarpaulin which comprises;
- Raw materials are mixed and send to the circular die through screw to form the bubble ,
- multilayer film is produced by blown film machine;
- The multilayer film tubular roll is loaded on the grooving unit to form a line design by using groove roller with heat and pressure;
- The tubular roll having line design is cut by a blow of air with mandrel through an angle to make it flat sheet roll having a transverse line;
- Again the transverse flat sheet roll is loaded into the grooving unit to get another line on the roll which intersects the transverse line on roll and form bisected grid line;
- bisected grid line multilayer film is used to form multilayer tarpaulin.

[019] The other object of the invention is to provide the process for preparing bisected grid line multilayer Tarpaulin wherein the tube roll is slit in different range of angle.
[020] The other object of the invention is to provide the process for preparing bisected grid line multilayer Tarpaulin wherein the roll is made in sheet form.
[021] The other object of the invention is to provide the process for preparing bisected grid line multilayer Tarpaulin wherein the tube roll having line design is then cut to make it flat through blow Mechanism using mandral.
[022] The other object of the invention is to provide the process for preparing bisected grid line multilayer Tarpaulin wherein the raw materials are polyethylene, polypropylene, elasto-polymer and other supporting polymers.
[023] The novel features that are considered characteristic of the present invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of certain specific embodiments, when read in connection with the accompanying drawings, in which:

[024] Fig 1- 3 illustrates the design of the process for preparing bisected grid line multilayer Tarpaulin of the present invention;
[025] Fig 4 illustrates the flow chart of the process for preparing bisected grid line multilayer Tarpaulin of the present invention;

[026] The first process to finalize a Raw Material mix along with master batch (Colour) & UV. The material is then mixed and go through gavematric machine through hopper in Barrels then the material passes through screw and goes in circular die. In the circular die with the help of cooling ring the bubble film is formed. The tubular film is there than compressed on the top and winding back down in roll form. In this process film is made.
[027] The roll is then loaded on the lining (grooving unit) to have line impression on the film on machine direction. The line impression is formed in film in this stage ( Fig 1).
[028] The tube roll having line design is then cut to make it flat through blow Mechanism through mandral and it is cut in different range of angle so the film will have transverse angle design. Line shown in sketch below. The roll is made in sheet form.( fig 2)
[029] Again the roll is loaded in the lining unit and the re-grooving is done on the flat film having vertical lines and again a line is formed creating a “ bisected grid line Design” ( Fig 3) .The bisected grid line multilayer film is made.
[030] Without further elaboration, the foregoing will so fully illustrate my invention, that others may, by applying current of future knowledge, readily adapt the same for use under various conditions of service. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention.
[031] Advantages over the prior art:
[032] The process for preparing bisected grid line multilayer Tarpaulin proposed by the present invention has the following advantages over the prior art:
a) It is cost effective.
b) It is user friendly
c) High strength and durable
d) Light weight material
e) Ultra violet protected
f) Water proof film

[033] In the preceding specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

, Claims:We claim:

1) A process for preparing bisected grid line multilayer Tarpaulin which comprises;
-Raw materials are mixed and send to the circular die through screw to form the bubble ,
- multilayer film is produced by blown film machine;
- The multilayer film tubular roll is loaded on the grooving unit to form a line design by using groove roller with heat and pressure;
- The tubular roll having line design is cut by a blow of air with mandrel through an angle to make it flat sheet roll having a transverse line;
- Again the transverse flat sheet roll is loaded into the grooving unit to get another line on the roll which intersects the transverse line on roll and form bisected grid line;
- bisected grid line multilayer film is used to form multilayer tarpaulin.

2) The process for preparing bisected grid line multilayer Tarpaulin as claimed in claim 1 wherein the tube roll is cut in different range of angle .

3) The process for preparing bisected grid line multilayer Tarpaulin as claimed in claim 1 wherein the roll is made in sheet form.

4) The process for preparing bisected grid line multilayer Tarpaulin as claimed in claim 1 wherein the tube roll having line design is then cut to make it flat through blow Mechanism using mandral.

5) The process for preparing bisected grid line multilayer Tarpaulin as claimed in claim 1 wherein the raw materials are polyethylene, polypropylene, elasto-polymer and other supporting polymers.