JPH04121122A - Mulching sheet for fruit tree - Google Patents

Abstract

PURPOSE:To obtain the subject sheet having excellent workability and effective in increasing the sugar content of fruit by densifying one surface of a melt- blown ultrafine fiber nonwoven fabric of a hydrophobic thermoplastic polymer containing a light-shielding substance and setting the water resistance and air- permeability of the sheet to respective specific levels or above. CONSTITUTION:The objective sheet 3 is composed of a melt-blown ultrafine fiber nonwoven fabric sheet 4 made of a hydrophobic thermoplastic polymer (e.g. PE) containing preferably 0.7-15wt.% of a light-shielding substance such as carbon black. At least one surface of the nonwoven fabric sheet 4 is densified and the sheet has a water-resistance of >=500mmH2O and an air-permeability of >=2cc/cm<2>/sec.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a fruit tree mulch sheet that is laid to increase the sugar content of fruit trees.

[Conventional technology]

It has been known that the sugar content of fruits can be increased by restricting the water content of fruit trees and vegetables before they ripen. In order to prevent rainwater from seeping into the base of the plant, a vinyl tonneau mulch sheet is laid down. However, vinyl sheets are not breathable, so if they are spread over the ground, the roots become suffocated due to a lack of oxygen in the ground, which causes root rot and weakens the tree's vigor, resulting in less fruit for the following year and damage to the tree. This may cause the plant to wither and die. Therefore, recently, waterproof, breathable, and moisture-permeable microporous films have been used as mulch sheets for fruit trees. Also, as a multi-sheet, the water absorption rate is at least 100%.
A non-woven fabric made of hydrophilic fibers or a sheet processed from such non-woven fabric is laid down to absorb and release moisture from the ground, drying the ground, and absorbing excess fertilizer and water-soluble substances that accumulate there. JP-A No. 63-216409, JP-A No. 63-21641
It has been proposed in Publication No. 1, etc.

[Problem to be solved by the invention]

The use of conventional mulch sheets has the effect of improving the sugar content of fruits, but because there is almost no ventilation, underground gas and moisture cannot escape, resulting in a lack of oxygen, and the rise in underground temperature causes root pain. This causes a decline in tree vigor. In order to prevent such negative effects, it takes time and effort to remove the mulch sheets depending on the weather conditions, remove moisture from the ground, and suppress temperature rises. In addition, microporous films also have insufficient air permeability, so they are not very promising for labor saving. On the other hand, non-woven sheets made of fibers mainly consisting of hydrophilic fibers have high air permeability and water permeability, and although they are effective to some extent in drying overly wet soil, they do not allow fruit trees to pass through rainwater or dew. Since moisture management is not possible, it is not effective in increasing the sugar content of fruit. The present invention provides a mulch sheet that does not need to be peeled off even when the weather changes, prevents damage to the roots of fruit trees even if left as is, and can improve the precision of fruit picking.

[Means to solve the problem]

The present invention is a melt-blown ultra-fine fiber non-woven fabric sheet of a hydrophobic thermoplastic polymer containing a light-shielding substance, wherein at least one side of the melt-blown ultra-fine fiber non-woven fabric sheet is densified, and the water resistance of the sheet is 50 On+m)1.
20 or more, and has an air permeability of 2 cc/cm''/sec or more, and is a highly air permeable sheet containing a melt-blown ultrafine fiber nonwoven sheet of hydrophobic thermoplastic polymer and a light-shielding substance. A laminated sheet of flexible sheets, the water resistance of the sheet is 500 mm H2O or more,
This is a fruit tree mulch sheet characterized by an air permeability of 2 cc/cff12/sec or more. Hydrophobic polymers forming the melt-blown microfiber nonwoven fabric of the present invention include, for example, polyethylene, polypropylene,
Polybutene, poly-3-methylbutene-11 poly-4-
Polyolefins such as methylpentene-1, ethylene propylene copolymer, ethylene octene copolymer, and ethylene butene copolymer, polyolefin derivatives such as chlorinated polyethylene and fluorinated polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, etc. One or more thermoplastic polymers selected from polyester, polycarbonate, etc. In addition, when melt-blown nonwoven fabric is used as a multi-sheet, the polymer may contain light-shielding substances such as carbon black, titanium oxide,
A powder selected from aluminum oxide, other metal oxides, metal salts, aluminum powder, copper powder, and other metal powders is added in an amount of 0.7 to 15% by weight based on the polymer. These additive powders are preferably selected in consideration of imparting heat retention properties, weather resistance stability, etc. in addition to light blocking properties. When a meltblown nonwoven fabric is laminated with a highly air permeable reinforcing sheet containing a light blocking substance, it is not necessarily necessary to add these light blocking substances to the meltblown nonwoven fabric.
From the viewpoint of spinnability, it is preferable not to add a light-shielding substance to the melt-blown nonwoven fabric. The hydrophobic polymer composition is then melted using conventional melt blown spinning equipment, a volume of molten polymer is expelled from a die, and the molten polymer is passed through a high pressure gas stream with an average fiber diameter of about 0.1 to Spun and conveyed as a 5.0 μm ultrafine fiber stream,
The fiber stream is collected in a collection body to form a melt-blown ultrafine fiber nonwoven fabric. The weight of this nonwoven fabric is an average weight of 100 to 1000 g/+o'' when used as a single nonwoven fabric, and an average weight of
~200 g/m2 melt blown microfiber nonwoven fabric. The obtained nonwoven fabric is calendered on at least one side, then subjected to processing such as press or heat press to densify or partially fuse, and if necessary, a treatment agent is applied to increase water resistance to form a highly water resistant nonwoven fabric sheet. shall be. Melt-blown ultrafine fiber nonwoven fabric sheets can also be used with other highly air permeable sheets, such as short fiber nonwoven fabrics made from regular staple fibers using a wet or dry process, or fabrics such as spunbond long fiber nonwoven fabrics, woven fabrics, and knitted fabrics. , or these fabrics are laminated with at least one type of highly air permeable sheet selected from fabrics in which at least a portion of the fibers are fixed with binder fibers or binder resin. This melt-blown microfiber nonwoven fabric sheet or laminated sheet has a water resistance of 500 mm) 1.0
Above, the sheet satisfies the characteristic values of air permeability of 2CC/Cll12/SeC or higher and moisture permeability of 2500 g/m"/24hr or higher.If the characteristic values of these sheets do not satisfy the above conditions, Even if it is used as a mulch sheet for fruit trees, it is not possible to adequately manage the cultivation area, such as preventing rainwater from penetrating or eliminating excessive moisture in the ground, and it is not possible to improve the sugar content of the fruit or manage shipping. A mulch sheet selected from non-woven fabric sheets or laminated sheets is laid at the base of the fruit tree or at the base and the surrounding ground, but the area and method of laying may be selected as appropriate depending on the cultivation progress and condition of the fruit.Next The present invention will be explained with reference to the drawings. Fig. 1 is a diagram showing the state in which the mulch sheet of the present invention is laid down, where 1 is a fruit tree, 2 is a cultivated area, and 3 is a mulch sheet. 2 is a cross-sectional view of a melt-blown ultrafine fiber nonwoven fabric sheet, 3 is a mulch sheet, 4 is a nonwoven fabric, 5 is a densified part of the nonwoven fabric, and FIG. is a cross-sectional view of a laminated sheet in which a highly air permeable sheet is laminated on one side of a melt blown ultrafine fiber nonwoven fabric sheet, 3 is a multi-sheet, 4 is a nonwoven fabric sheet, 6 is a highly air permeable sheet, and Figure 4 is a melt blown ultrafine fiber nonwoven fabric. A cross-sectional view of a laminated sheet in which highly air permeable sheets are laminated on both sides of the sheet, 4 is a nonwoven fabric sheet, 6.
6' is a highly air permeable sheet.

[Effect]

The present invention is a melt-blown ultra-fine fiber non-woven fabric sheet or a laminated sheet of a melt-blown ultra-fine fiber non-woven fabric sheet and a highly air permeable sheet, which has a water resistance of 500 amH, 0 or more, an air permeability of 2 cc/cm"/sec or more, and a moisture permeability of 2500. By using a material that satisfies the characteristic value of g/wr”/24hr or more as a mulch sheet for fruit trees, it can control fluctuations in ground moisture due to rainwater, etc., without depleting oxygen underground, and improve the By dissipating moisture and suppressing temperature increases, it is possible to adequately manage fruit cultivation areas, and the sugar content of fruits can be improved. Furthermore, since it has light blocking properties, it is possible to suppress the growth of weeds.

【Example】

Next, embodiments of the present invention will be explained with specific examples. Note that parts and percentages in the examples are by weight unless otherwise specified. Water resistance is JIS L-1092r "Waterproof test method for textile products", air permeability is JIS L-10966, 27, l
The air permeability section of Method A “-Test method for patterned fabrics” and moisture permeability are JI
S Z-02 (18 "Moisture permeability test method for moisture-proof packaging materials"
This is the value measured based on. Example l A polymer composition prepared by adding 2 parts of carbon black and 0.8 parts of a weathering stabilizer to polypropylene with a melt index (hereinafter referred to as To!) of 12 g/10 minutes was charged into a melt extruder, and the nozzle diameter was 0.3 mm. Using a die in which holes were arranged in a row at 1 mm intervals and slit-shaped gas outlets were provided on both sides, the melt spinning temperature was 280°C, and the injection gas temperature was 300°C5.
The fibers were spun at a gas pressure of 0.5 kg/cts'' and a discharge rate of 0.2 g/min per spinning hole to form a flow of ultrafine fibers with an average fiber diameter of 3.8 μm.
The microfiber nonwoven fabric was collected on the net-like surface of a collecting device installed at a position of 5 cm to obtain a microfiber nonwoven fabric with an average weight of 21 g/m. This nonwoven fabric was pressed with a calendar roll with a surface temperature of 105°C to form a densified nonwoven fabric On the other hand, M+-1 polypropylene to which 2 parts of carbon black and 0.8 parts of a weathering stabilizer were added was spun to an IL degree of 280.
Melt-spun at °C, taken off using an ejector nozzle, and placed on a collection net a fibrous web with a target weight of 50 g/+w'' (fibrous web-1) and a fibrous web with a target weight of 70 g/w1'' (fibrous web-2). Two sheets of spunbond long fiber nonwoven fabric were obtained by stacking and cascading so that the following was obtained. This spunpond long fiber nonwoven fabric is the nonwoven fabric sheet (1
) is laminated on both sides, heat pressed with a calendar roll, densified and integrated with the nonwoven fabric sheet, resulting in an average weight of 14.
A laminated sheet CI) with a weight of 3g/m" was obtained.
, 2cc/crn”/sec, moisture permeability 7
It had a characteristic value of 250 g/m"/24 hr. The obtained laminated sheet [■] was applied as a mulch sheet to 10 fruit trees each in the upper, middle, and lower parts of a mandarin orange cultivation area on the southern slope of a hilly area. As a result, there was almost no difference in the coloring of mandarin oranges in the cultivated area without laying and the time of coloring.
The fruit has good fatness and the sugar content at harvest was 11 degrees on average in the former, while the average sugar content in the cultivated area under sheeting was 13 degrees.
It was 5 degrees, and sweet oranges were obtained. In particular, the difference in sugar content is large in the lower parts of hilly areas, with an average of 13 degrees Celsius in cultivated areas with soil, compared to an average of 10 degrees Celsius in cultivated fields without soil. Furthermore, no decrease in the vigor of the fruit trees due to mechanical pain was observed. In addition, the laminated sheet (1) maintained sufficient strength to be reusable even after being used for one season. For comparison, a light-shielding silver vinyl sheet made from a mixture of metal powder was placed on 10 fruit trees.
Some fruits were dropped and some had poor ripening, and almost no effect on increasing sugar content was observed. Example 2 The laminated sheet [I] of Example 1 was laid as a mulch sheet on straw in a white peach field to cultivate white peaches. As a result, the rise in soil temperature during mid-summer can be suppressed, moisture can be easily managed, the fruits are thicker, and the average sugar content of normally cultivated white peaches is 1.
The average sugar content of white peaches grown under sheeting was 15 degrees, which was higher than 3 degrees.

【Effect of the invention】

By laying the fruit tree mulch sheet of the present invention at or around the base of fruit trees, it is possible to control rapid changes in the outside air and changes in underground moisture due to rainwater, etc., and to control the cultivation of fruit trees. It is possible to prevent pain, improve the accuracy of fruit pods, and facilitate shipping management. Additionally, since it will not damage the fruit trees even if it is left on the floor for a long period of time, there is no need to lay it down or remove it according to changes in the weather, which saves labor. Furthermore, the light-shielding property suppresses the growth of weeds under the mulch sheet, which reduces the amount of weed work and saves labor.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the state in which the mulch sheet of the present invention is laid, FIGS. 2 to 4 are schematic cross-sectional views of the mulch sheet of the present invention, and FIG. 2 is a cross-sectional view of a melt-blown ultrafine fiber nonwoven fabric sheet. Figure 3 is a cross-sectional view of a laminated sheet in which a highly air permeable sheet is laminated on one side of a melt-blown ultra-fine fiber non-woven fabric sheet, and Figure 4 is a cross-sectional view of a laminated sheet in which a highly air-permeable sheet is laminated on both sides of a melt-blown ultra-fine fiber non-woven fabric sheet. be. 1... Fruit tree, 2... Ground, 3... Multi sheet, 4... Meltblown ultrafine fiber nonwoven fabric sheet, 5... Densified part of nonwoven fabric, 6.6'... Highly breathable sheet .

Claims (2)

[Claims] (1) A melt-blown ultra-fine fiber non-woven fabric sheet of a hydrophobic thermoplastic polymer containing a light-shielding substance, wherein at least one side of the melt-blown ultra-fine fiber non-woven fabric sheet is densified, the sheet has a water resistance of 500 mmH_2O or more, and is breathable. A mulch sheet for fruit trees characterized by a degree of strength of 2cc/cm^2/sec or more. (2) A laminated sheet of a melt-blown microfiber nonwoven fabric sheet of a hydrophobic thermoplastic polymer and a highly air permeable sheet containing a light-shielding substance, the sheet has a water resistance of 500 mmH_
A fruit tree mulch sheet characterized by having an air permeability of 2O or more and an air permeability of 2cc/cm^2/sec or more.