JPH0119340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a horticultural laminate film, particularly a film made by welding a reinforcing film to a crystalline film having low tear strength in the stretching direction.

《Background of the invention》 For example, as a method for improving the quality of fruits,
As seen in Publication No. 33947, a crystalline plastic film in which a devitrified film having a large number of microscopic voids of 500μ or less is placed under the fruit at the enlargement stage, ripening stage, or harvesting stage. There is.

The plastic film used in the quality improvement method may be made of, for example, polyester, polyamide,
A film made of polyethylene or polypropylene that has been crystallized or a film obtained by mixing several percent to several tens of percent of inorganic particulate matter or other incompatible polymers in the polymer is forcedly stretched again. This produces minute cracks between resin crystals or between the resin and the inorganic particulate matter.

This film not only reflects medium-wavelength light, but also reflects short-wavelength ultraviolet rays, such as 290 to 390μ, well, while reflecting little long-wavelength infrared rays, so it does not color fruits during the growing stage. It has the favorable advantage of brightening.

However, on the other hand, the above-mentioned film has extremely low tear strength in the stretching direction, and has the property of being easily torn off, which poses an obstacle in practical use.

As a method for improving such strength, it has been considered to laminate a reinforcing film on the back side of the film.

In this case, a reinforcing film is extruded onto the film using a T-die or the like, and is continuously pressed with a laminating roller.

However, it has been confirmed that when the reinforcing film is integrally laminated over the entire surface of the film, the reinforcing film is easily torn along the axial direction along with the stretched film.

This is considered to be because the reinforcing film is extruded in a stretched state along its axial direction and is easily torn because it is integrated with the stretched film having low tear strength.

In order to solve this problem, for example, the reinforcing film may be laminated in a state perpendicular to the Nobunaka film, but in this case, the lamination work is interrupted every time the reinforcing film is laminated perpendicularly to the Nobunaka film. As a result, continuous lamination cannot be performed, resulting in extremely inefficient and unproductive results.

<<Object of the Invention>> The object of the present invention is to provide a horticultural laminate film which is strong and capable of continuous lamination for the above-mentioned stretched film having low tear strength in the stretching direction.

<Structure and Effects of the Invention> In order to achieve the above objects, the present invention provides a reinforced horticultural laminate film in which a reinforcing film is welded to a crystalline film having low tear strength in the stretching direction. The film is characterized by having a discontinuous welding surface along the longitudinal direction.

That is, according to the laminate film of the present invention, the crystalline film tends to tear along the stretching direction, but because the welded surface of the reinforcing film welded to the back surface is discontinuous along the stretching direction, , the propagation of the tear is prevented by the non-welded surface,
This results in an extremely strong laminate film.

Therefore, when the laminated film according to the present invention is applied to a film for improving the quality of fruits as described above, it has extremely high tear strength during actual use, so it can be used repeatedly and does not need to be handled with care. It has advantages such as being economical.

<<Description of Examples>> FIGS. 1 and 2 show a laminating apparatus suitable for producing a laminated film according to the present invention, in which a stretched crystalline plastic film 1 is wound up on a roll stocker 2. At the same time, the plastic film 3 is constantly extruded from the T-die 4 to a predetermined thickness and width, and is welded and laminated together by a pair of pressure rollers 5 and 6, and a take-up roller 7,
It is taken up at 8, wound up on a winding roller 9, and stored there.

The crystalline plastic film 1 may be made of polypropylene, polyethylene, polyester, polyamide, etc., and the reinforcing plastic film 3 may be appropriately selected from polypropylene, polyethylene, polyester, polyamide, etc.

The surface of one of the laminating rollers 5 and 6 has a large number of round hole-shaped recesses 5a and 5a.
... are integrally formed, whereby the laminated films 1 and 3 are integrally welded in a discontinuous manner, leaving the recessed portions.

FIG. 3 shows a laminated film with the discontinuous portion left behind. When this laminated film is torn, the adhesive portion A is easily torn in the stretching direction of the crystalline plastic film 1; Since there is no adhesion at all in the gap B, the propagation of the tear stops in the gap B, and independent tearing forces are applied to the reinforcing film 3 and the crystalline film 1, but the reinforcement Since the tearing force is applied to the film 3 independently, it exerts its reinforcing effect, and therefore, the propagation of the tear is completely stopped in the non-welded area, so that there is no tearing overall. become.

In the embodiment, a large number of round non-welded portions are formed, but for example, cross-shaped non-welded portions may be formed as shown in FIG.
This can be achieved by forming the grooves on the surface of the roller in a knurled shape, and the pattern of the grooves may be appropriately set to a shape that can prevent the propagation of the tear as much as possible.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a laminating device suitable for manufacturing a laminated film according to the present invention, FIG. 2 is a perspective view showing a laminating roller of the laminating device, and FIG. 3 is a perspective view of a laminated film. FIG. 4 is a perspective view showing another embodiment of the laminate film. 1... Crystalline plastic film, 3... Reinforcing film, A... Welded area, B... Non-welded area.

Claims (1)

[Claims] 1. A reinforced horticultural laminate film made by welding a reinforcing film to a crystalline film with low tear strength in the stretching direction, characterized in that the laminate film has a discontinuous welding surface along the stretching direction. Laminated film for gardening.