RO128688B1 - Thermally-insulating textile reinforcement for soil mulching - Google Patents

Description

The invention relates to a heat-insulating textile reinforcement, with 3D structure, opaque, permeable to air and water, made for efficient mulching of the soil cultivated in rows in the field, in greenhouses and solariums.

In the specialized literature we know world-wide patented technical solutions, which refer to materials for mulching agricultural crops and which fall into the following categories: a) biodegradable / perforated polymeric films; b) paper products; c) non-woven fabrics and d) composites, with the mention that each of the products in categories a) - c) are often also composite structures. Thus, the international patent application WO 2006100799, "Agro-Horticultural Soil Cover Film", refers to a film with selective transmission of the solar radiation from the visible (reflected, not reaching the ground) and infrared (absorbed, to warm the cold soil). ), with the help of tungsten-based microparticles, which is useful in the spring, but totally not recommended during the summer; Thermo-insulating mulching diminishes the seasonal thermal oscillations of the soil. Also, WO 2007091944, "Cultivation Sheef", describes the creation of a biodegradable substrate that retains water, biocides or nutrients to transmit to plants, consisting of natural fibers (paper, cardboard), based on a hydrophobic layer, respectively from a paper made from wood-treated fibers homogenized with wax. And the international patent application WO 2006076057, "Apparatus and Methodologies for Fertilization, Moisture Retention, Weed Control, and Seed, Root, and Plant Propagation", describes a non-biodegradable non-woven plan to stimulate germination, growth and logging of plants and trees, associated suppressing the development of weeds, made up of at least one of the following natural fibers: human hair; animal hair; coconut fiber; seagrass; cotton; corn silk; swamp muscle and, optionally, synthetic fibers, reinforced by intersecting, water or air, with the role of creating or remaking a crop punctually, by providing water and fertilizers to plants. Application WO 2006047093, "Composite Fabric with Controlled Release of Functional Chemicals", presents a composite structure consisting of an air and water permeable nonwoven, preferably of polyolefinic nature, with a thermoplastic resin network glued to the exposed face, in which it is introduced a functional chemical compound, which diffuses from the resin, into the liquid that passes through the non-tissue within a preset time. Another technique used is that of patent application RO 127863 A2, which describes a composite made of a textile reinforcement woven from monofilamentary polyethylene yarns, with 1 ... 3 layers and a coating degree of 23,2 ... 45%, laminated with molten polyethylene adhesive on the surface of a polyethylene film with 2..3 layers, which form cylindrical air bubbles, with a diameter of 30 mm and a height of 12 mm, in which the stationary air represents 75% of the volume of the film with 2 layers. and 95% of the volume of the 3-layer film. Patent application CN 1245634 (A) describes the application of polyethylene and polystyrene foams, respectively, to the production of heat-insulating films for use in making greenhouses or mulching layers, while patent FR 2596244 describes a mulching material that ensures a unidirectional permeability, constituted. from an artificial or natural agglomerate and limestone, to which expanded polystyrene granules can be added which are meant to improve the thermal insulation conferred by the mulching layer.

The technical problem that the invention solves is to improve the thermal insulation properties, permeability and mechanical strength, but also to print an ecological character on the reinforcement for the resulting mulching.

The heat-insulating textile reinforcement made for mulching according to the invention removes the disadvantages mentioned by the fact that it consists of knit fabrics of high density polyethylene, polypropylene or polyester yarns, containing open cavities at one end, with dimensions between 50 ... 150 mm in longitudinal direction. and 200 ... 700 mm in the transverse direction, in which expanded polystyrene granules with specific mass 16 ... 640 kg / m ³ are closed,

RO 128688 Β1 having a thermal conductivity of 0.02 W / mK, by longitudinal wetting and seaming with 1 wear-resistant polyester yarn, with a density of length Nm 30/3, and the cavities are made of double-layer knitting of polymeric yarns mentioned monofilamentation and are separated some 3 from the other by single-layer knit sections of the same polymeric yarn.

Numerous advantages are obtained by applying the invention, such as: 5

- easy handling, by applying heat-insulating textile reinforcement to the soil by repeated rolling / rolling in the cultivated area; 7

- by mulching the soil with the opaque thermal insulation reinforcement, the access of sunlight is blocked and the germination of harmful plants is prevented; 9

- the possibility of reusing the reinforcement in 2 ... 3 successive cycles leads to a reduction of the production costs (for water, fertilizers, herbicides, labor, classical agricultural operations) 11 and to the protection of the ground covered from the field by the direct actions of the atmospheric factors with effects erosion on the fertile soil layer. 13

The heat-insulating textile reinforcement, made for the efficient mulching of crops during 24 ... 36 months, is made by introducing a light, opaque, 15 thermal insulation material resistant to photodegradation, for example expanded polystyrene granules with specific mass.

16 ... 640 kg / m ³ and remarkable thermal conductivity, 0.02 W / mK-0.03 kg / m ³ , in sufficient quantity to fill the cavities arranged transversely to the length of the composite, with optional dimensions in longitudinally, for example 50 ... 150 mm, and transversely, 19 for example 200 ... 700 mm, in correlation with the distances between rows of the main horticultural crops, and opened at one end of a textile reinforcement, knitted or high density polyethylene, polypropylene or polyester UV-stabilized yarn 21 monofilament yarn for 24 ... 36 months, formed by alternating knit / woven portions with mono-23 structure and doubled, longitudinally (technical solution preferably) or by bending a monolayer, woven or knitted textile material, and forming open cavities at one end by sewing 25 in a transverse direction, compared to the longitudinal direction of the composite (technical solution posi ball, but which requires a greater volume of labor), with the role of permanent retention of the 27 heat-insulating granules in a convenient 3D dimensional form, depending on the requirements of the crop, more precisely the distances between the rows of the main vegetable crops (20 cm: salad , spinach; 29 50 cm: beans, celery; early cabbage; 60 cm: potatoes, pumpkin; 70 cm: tomatoes, peppers, cucumbers, eggplants, autumn cabbage). 31

After filling the cavities with granules, whose compatibility with the placement of the composite in contact with the cultivated soil has been verified previously (by spectrophotometric analysis 33 of the aqueous extract obtained by intense and prolonged mechanical agitation of the granules in water), with the help of some metal funnels. dimensions have been correlated with the dimensions of the 35 cavities of the reinforcement, and their immediate provisional closure (with needles), to allow the manipulation of the semi-finished product, until the filling and definitive closing of all the cavities with granules, the definitive restraint is proceeded. of the heat-insulating material granulated in the reinforcement cavities, by longitudinal surfacing and sealing with / without white velcro zipper 39 cm 2.5 cm, using wear-resistant polyester thread (Nm 30/3), both of the reinforcement edge which includes all the ends open cavities, as well as the opposite ones, with c the closed cavities 41 of the cavities so that the heat-insulating composite made has mechanical resistance in use. 43

The length of the composite made corresponds to the length of the rows of mulched plants and is adjusted by transverse thermal cutting, followed by the surfilation and cutting of 45 both thermally cut ends, to ensure its mechanical resistance in use, with the observation that the manufacturing operations (triplock threading and longitudinal framing 47

RO 128688 Β1 bilateral; thermal cross-cutting, followed by triplock surfacing and cross-cutting at both ends) results in the transformation of the two components (granules and textile reinforcement with cavities) into a made-up textile insulating composite, after which the separation of the components is no longer possible without destroying the structure of the composite.

Washing the heat-insulating composite made is very important to remove any trace of unwanted substance, technologically / accidentally deposited on the composite and which could potentially affect the mulched soil, and this is done for 30 minutes, at room temperature, by immersing it intermittent stirring, in an aqueous solution of detergent (3 g / l), followed by repeated rinsing, centrifugation and free drying, which occurs very quickly, as all the components of the composite are hydrophobic (reinforcement monofilament yarns, expanded polystyrene granules, polyester yarn), then rolled.

The thermal insulation textile composite made by mulching is mounted by rolling on the floor, in the longitudinal sense of the rows of plants, on both sides of their stems, with / without closing the velcro zipper between successive plants on the row, so as to cover the soil well. between the rows of plants and prevent the penetration of sunlight at the level of the soil, in order not to determine: a) its temperature increase and the physical loss of the water supply, by evaporation, and b) the illumination of the soil, which determines the germination and development of the plants competing with the agricultural culture (weeds), by consuming nutrients and water administered for the development of crop plants.

The heat-insulating textile composite made of mulch, according to the invention, is permeable to air and water, but the textile reinforcement does not impregnate with water, but dries quickly, so that the stems, leaves, flowers and fruits of plants vulnerable to contact with soil impregnated with water, for example, salad, strawberries, etc., are protected (against rotting) by the dry surface of the thermal insulating mulching composite, which is an efficient, environmentally friendly technical solution, without labor consumption and other materials, at a low cost price, usable during a 3 ... 6 successive crops, as compared to: a) chemical weed control, by herbicide, with the related labor and chemical consumption; b) physical control of weeds, by fracking, with the mention that, in the case of naturally tilled soils, with the reduced tendency of compaction, it is possible the succession of the crops with the minimum digging manpower.

In order to achieve the thermal insulation textile reinforcement for mulching according to the invention, several aspects were followed:

- selection of the chemical nature of the components of the made thermal insulating textile composite (high density polyethylene; polypropylene; polyester; polystyrene), of the form (a. monofilamentary yarns for knitting or weaving the reinforcement, in order to avoid impregnation of the reinforcement by the adsorption of the water between the capillaries. polypropylene yarns; b. expanded polystyrene granules; c. knitted / knitted reinforcement with cavities created directly by the alternate mono- and double-knit structure of the knitting / weaving or indirectly, by bending and sewing in a transversal way a monostrated, woven / knitted textile material ) and their properties (a. permeability to air and water, as well as the soil; b. hydrophobic character, so that the water is not retained by the composite exposed to the sun, but transmitted to the soil; c. thermal insulation, due to the air included in the expanded polystyrene granules, which determines the maintenance of a relative temperature constants, which diminish the tendency to evaporate water from the soil; d. UV stabilization of polymers from monofilaments and mechanical strength of textile-yarn structures, reinforcements, sewing thread, to ensure the durability of the composite for 18 ... 24 months; e. the ecological character of the components and the composite, ensured by the use of monofilaments in which the additives are embedded in the polymer, not on the surface of the wires; by spectrophotometric testing of the aqueous extract to confirm the absence of unwanted, harmful substances for soil or plants, deposited on granules, before using the granules to fill the reinforcement cavities; by repeatedly washing and rinsing the made composite, before installing it on the ground);

RO 128688 Β1

- elaboration and realization of the structures of the textile reinforcements, whose cavities have dimensions between 50 ... 150 mm, in the longitudinal sense of the composite, and whose widths are correlated dimensional with the recommended distances between the rows of the main vegetable crops (200 mm: salad, spinach ; 500 mm: beans, celery; early cabbage; 600 mm: potatoes, pumpkin; 700 mm: tomatoes, peppers, cucumbers, eggplants, autumn cabbage), and whose production technologies (knitting, weaving, making) aim synergistically to obtain a heat-insulating composite of mulch that can withstand (as UV stabilization; as mechanical resistance) for 3 ... 6 successive cycles of culture, for 18 ... 24 months;

- experimental confirmation of the functionality and reliability (no deterioration) of the thermal insulating textile composite made of mulching, under real conditions of use at USAMV Bucharest (figure), both in the hot season (May-October), in the solarium and in the field, mounted on a tomato cultivation, as well as in the cold season (October-December), mounted on a salad culture, inside the unheated double insulated enclosure. In this last agrotechnological configuration, the most relevant instrumentally measured values were recorded, according to the data in the example, which confirms the functionality of the mulching composite.

The figure represents a heat-insulating textile reinforcement made for mulching and a heat-insulating textile reinforcement made for facilitating the movement of personnel along the plants with partial mulching effect.

The following is a non-limiting example of embodiment of the invention, in connection with the figure.

Example

The agrotechnological parameters measured instrumentally in the experimentation of the thermal insulating textile composite made for mulching, with reinforcement from the recycled fabric with a coverage degree of 55%, under real conditions of use at USAMV Bucharest in the cold season, on a salad culture established in the double insulated area, with and without thermal insulation, at the same date and at the same time:

Characteristics Value minimum ° C Value maximum ° C The difference absolute Minimum-maximum ° C Remarks Outside sun temperature, ° C 1 6 5 Sunny solar temperature 1, ° C 4 8 4 Solar soil temperature 2 in the area without thermal insulation, ° C 6 11 5 Reference for assessing the thermal insulation effect of the composite Solar soil temperature 2 in the area with thermal insulation, ° C 9 13 4 Minimum value greater than 3 ° C, maximum value greater than 2 ° C, absolute difference less than 1 ° C, which confirms the thermal insulation effect

Characteristics Value minimum % Value maximum % Absolute difference minimum max,% Remarks Exterior soil moisture,% 45 85 40 Solar soil moisture 1,% 55 90 35

RO 128688 Β1

Table (continued)

Characteristics Value minimum % Value maximum % Absolute difference minimum max,% Remarks Solar soil moisture 2 in the area without thermal insulation,% 75 95 20 Reference for assessing the effect of maintaining soil moisture Solar soil moisture 2 in the area with thermal insulation,% 85 99 14 Minimum value greater than 10%, maximum value greater than 4%, absolute difference smaller (-6%), which confirms obtaining the effect of maintaining soil moisture

The textile composite made to facilitate the movement of the staff along the rows of plants for carrying out the maintenance operations of the crops, without slipping or loading the mud shoes, is a particular application of the thermal insulating textile composite of mulching, since it has a partial effect of mulching (partially prevents the development of weeds in areas covered with extruded polystyrene plates), associated with its main function, to constitute a stable and resistant surface with a width of 260 mm, easy to mount and dismantle from the ground, by roll-rolling. The stability of the surface for the movement of the workers, especially on the soil impregnated with water, has been experimentally confirmed and was obtained with the help of the structure of the textile reinforcement woven, knitted or made, with a width of 290 mm, which has double open portions at one end with the size 60 mm longitudinally, alternating with monolayer portions with a size of 30 mm, and with the help of sets of 7 extruded polystyrene plates, with a length of 245 mm, a width of 45 ... 48 mm and a thickness of 7 x 3 mm, inserted into cavities and retained indoors by triplock threading and perimeter sealing, to be durable in use for 12 ... 24 months (figure).

Claims (1)

Thermal insulation reinforcement for soil mulching, characterized in that it consists of 3 knit made of monofilamentary yarns of high density polyethylene, polypropylene or polyester, containing open cavities at one end, with dimensions between 50 ... 150 mm in 5 longitudinal directions and 200 ... 700 mm transversely, in which expanded polystyrene granules with specific mass 16 ... 640 kg / m ³ are closed, having a thermal conductivity of 0.02 W / mK, 7 by surfilation and longitudinal shear with wear-resistant polyester yarn, with a density of Nm 30/3 length, and the cavities are made of double-layer knit from the mentioned mono-9 filament polymeric yarns and are separated from each other by portions of single-layer knit of the same polymeric yarns . 11