JPH042386Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an open-type refrigerating case, in which the viewing window opening of the case can be opened and closed with a transparent plastic film that has good anti-fog and heat insulation properties, especially for the purpose of reducing the power consumption for refrigeration. This invention relates to a case that can be freely covered.

In the present invention, freezing means cooling, and specifically means refrigeration and/or freezing.

The shift from the traditional face-to-face sales system to the self-service supermarket system for fresh foods is progressing, and open refrigerated cases that are open to the outside air are widely used so that customers can freely check and select products. I reached it.

However, the open type refrigeration case consumes a large amount of electricity for refrigeration, which puts pressure on market management.

As a measure to solve this problem, the openings are covered with plastic films or sheets, at least when the store is closed, but in the latter case, it is not only inconvenient to handle and takes up space, but also prevents repeated use. It is not hygienic.

In the former case, a transparent film is used because it allows the product inside to be checked and is convenient because it can be opened and closed at will.

However, even in this case, due to the sharp temperature difference between the inside and outside of the film, dew condensation occurs on the outside of the film, and the inside of the show case cannot be seen because the film becomes cloudy. Furthermore, water droplets adhering to the film make it difficult to handle and unsanitary when the film is rolled or folded.

In order to avoid this drawback, a film in which a large number of holes are mechanically punched is used, but cold air escapes through the holes, resulting in a reduction in the refrigeration effect.

SUMMARY OF THE INVENTION An object of the present invention is to provide a refrigeration case suitable for reducing heat loss, ie, loss of refrigeration power, caused by the viewing window opening of a conventional open-type refrigeration case.

Based on the knowledge that anti-fogging properties and infrared reflective abilities can be imparted to a film by subjecting it to a specific treatment, the purpose of the present invention can be achieved by using a film obtained by such specific treatment. was confirmed, and the present invention was completed.

The plastic film used in this invention is a film formed by extrusion molding, calendar molding, etc. and uniaxially or biaxially stretched.
Resin films such as PMMA, polyethylene terephthalate, polyvinyl alcohol, polyamide, polysulfone, and polyacetal are commonly used. Note that transparency, cold resistance, and toughness are preferred, and from the viewpoint of handling and workability, rigidity is preferred.

As a method for imparting antifogging properties, approximately 0.1 to 5% by weight of commonly known surfactants such as nonionic, anionic, or cationic surfactants are kneaded into the plastic and allowed to ooze out onto the surface of the plastic film, thereby reducing the surface tension of water droplets. There is also a method of lowering the surfactant, or a method of coating and fixing the surfactant on the surface of a plastic film, but any of these methods may be used.

As a method for imparting infrared reflective ability, it is preferable to impart a property that has some degree of transparency in visible wavelengths and high reflectivity in infrared wavelengths. The above performance is imparted by forming a thin film of metal or its compound on the surface of the plastic film.
For example, Al, Au, Ag, Cu, Ni, In ₂ O ₂ , TiO ₂ ,
Examples include thin films of 20 to 500 Å such as SnO ₂ and BiO ₂ . A light transmittance of 40% or more is necessary to impart transparency, and from the viewpoint of heat insulation, infrared,
It is desirable to have an infrared reflectance of 30% or more in the far infrared region.

As the thin film forming method, vacuum evaporation method, cathode sputtering method, plasma spraying method, vapor phase plating method, electroplating method, etc. are preferable, but solution coating method may also be used.

The film that has anti-fog properties and infrared reflective properties used in the present invention may be a film that has anti-fog properties and has infrared reflective properties, or vice versa. The antifogging film may be laminated at least in its periphery.

When an anti-fog film and an infrared reflective film are bonded together at their periphery, an air layer is formed between the two films, resulting in improved heat insulation.

The means for covering the opening of the case so that it can be opened and closed should be a known means that can be rolled up or rolled up, or should be in the form of a strip, taking into account whether the opening is on the side or upwards. Any known means can be selected as appropriate.

In order to clarify the structure and effects of this invention,
A test example is shown.

A: A film having infrared reflective ability was prepared by using polyethylene terephthalate (PET) with a thickness of 100 μm as a base film and providing a gold (Au) layer with a thickness of 200 μm using a cathode sputtering method.

B: A film having anti-fogging properties and infrared reflective properties used in the present invention is coated with 30μ of a solution containing 5% by weight of a sorbitan nonionic surfactant on the surface of the film A on the side opposite to the gold layer. It was dried and prepared.

The above A and B films were used in the show case shown in FIG. 1, and the differences in their effects were compared.

The temperature inside the case was maintained at -20°C, and after 3 hours, the visibility of the frozen food inside the case was judged visually from the outside at an outside temperature of 25°C and a humidity of 90%.

In the frozen food case using the film A, water droplets were generated on the surface of the film, causing it to become cloudy and making it difficult to distinguish the frozen food display inside the case.

In the case of the frozen food case of the present invention using film B, the film did not fog up and the display of the frozen food inside the case was clearly visible, without damaging the image of the product.

Next, we will discuss the effects of this invention.

By using a film with special properties to cover the viewing window opening of the show case so that it can be opened and closed, we were able to significantly reduce the electricity used for refrigeration without losing much of the open-type effect. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory perspective view illustrating the refrigerating case of the present invention. 1...Show case, 2...Peep window opening, 3
...Transparent plastic film with anti-fog properties, 4...Film winding device.

Claims (1)

[Claims for Utility Model Registration] 1. A refrigerated show case in which a viewing window opening 2 of a show case 1 is covered with a transparent plastic film 3 having antifogging properties and infrared reflective ability so as to be openable and closable. 2. The plastic film 3 is an anti-fog film whose surface has been treated with transparent infrared reflective properties, or a film with anti-fog properties and a transparent film with infrared reflective properties, and at least the surrounding area thereof. 1. A refrigerated case according to claim 1 of the utility model registration claim, which is laminated together.