JPS59204728A - Time-temperature display device - Google Patents

Abstract

PURPOSE:To judge whether the time and temperature when the temperature becomes high are allowable values for sales of food as commercial products or not, by observing the amount of a liquid with viscosity, which is infiltrated in a fiber part. CONSTITUTION:A container part 1 is filled with a liquid such as glycerol. A cavity is provided at a tip part 6 of a thin pipe 5, which is communicated to the container part 1. A hard ball 7 is arranged on the opposite surface through a bottom plate 3 comprising an aluminum foil. A filter paper 9 is covered by a transparent plastic outer wall 10 on the back side of the bottom plate 3. Approximately concentric circles are drawn on the filter paper 9. When food is taken out of a warehouse, in which the temperature is controlled, the hard ball 7 is strongly pushed by a finger, and a separating film 8 is broken. When the food is temporarily exposed to a high temperature, the viscosity of the liquid in the container part 1 is decreased. The liquid flows out through the thin pipe part 5 and infiltrates into the filter paper 9. The longer the time and the higher the temperature, the larger the amount of the infiltration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a time-temperature indicator that is useful for controlling the quality of stored foods.

[Description of prior art]

The storage temperature of foods is very important to prevent bacterial contamination and to keep flavor changes due to chemical alterations within acceptable limits. Temperature control of frozen or refrigerated foods is extremely important at any stage of production, distribution, and consumption, but the difficulty of implementing strict control increases the closer you get to the end of distribution.

Traditionally, small product units are stored and transported with food, their temperature is recorded, and the food is monitored to see if it has been exposed to inappropriate conditions during storage or transportation to prevent poisoning accidents. There is an idea to try. Various ideas have been published regarding temperature recording instruments for this purpose, but
The ``many'' uses a single point of liquid.

For example, a method that utilizes the fact that a colored liquid is stored in a capsule, the capsule and the liquid are placed in the same container, frozen, the capsule is destroyed, and the color changes when the liquid re-melts (particularly 1982-35751), a method that utilizes the fact that a colored flake and a substance with a constant melting point are sealed in contact with each other and the colored flake changes color due to melting (Utility Model Application 175735-1983), a method in which a liquid is frozen into a specific shape. Leave it for a change in shape or luster due to melting (
There are some that refer to JP-A No. 48-81149.

On the other hand, if the target of temperature recording and management is food,
Physical rigor is not necessarily required, and it is sufficient if a certain degree of quantitativeness can be obtained. For example, it is desirable to be able to distinguish between cases where a product has been left at a temperature above a specified temperature for 2 hours and cases where it has been left for 3 hours, or whether it has been maintained at a temperature 10°C higher than the specified temperature and a case where it has been maintained at a temperature 15°C higher than the specified temperature. Since the above known examples utilize the freezing point of the liquid, it is sometimes difficult to obtain a recorder with quantitative performance as described above. In addition, most of the known examples require storage at low temperatures from the time the recorder itself is manufactured until it is used, and the disadvantage is that the recorder cannot be transported or stored in a box at room temperature. be.

[Purpose of the invention]

The present invention covers whether the food was stored or transported together with a food that was kept at a low temperature and reached a high temperature, and whether the time and temperature were at an acceptable level for selling the food as a product. The purpose is to provide a time-temperature indicator that can identify whether

Further, it is an object of the present invention to provide a time and temperature indicator which is small and simple, and which can be manufactured at room temperature and stored at room temperature before starting food monitoring.

[Features of the invention]

In the present invention, a viscous liquid is stored in a container part, and the liquid is guided from the container part to a fiber part through a thin tube, and is allowed to soak into the fiber part. At low temperatures, the viscosity of the liquid is high, or at even lower temperatures, the liquid is frozen and hardly flows through the tubes. As the temperature rises, the liquid slowly travels through the tubes and soaks into the fibers. As the temperature rises further, the viscosity of the liquid decreases, and it flows through the thin tubes at a relatively high speed and soaks into the fibers. Therefore, the higher the temperature and the longer the time, the greater the amount of liquid that has soaked into the fibers. In the structure of the present invention, a partition wall is provided between the container part and the tip of the thin tube, and this partition wall is destroyed with a finger or the like when starting to use this indicator to establish continuity from the container part to the fiber part. . With this structure, the display device can be manufactured at room temperature 2 or stored or transported at room temperature for a long period of time until the partition wall is destroyed.

Note that the definition of "liquid" herein includes substances that are solid at low or normal temperatures and liquefy or fluidize at the temperature to be monitored.

[Explanation based on examples]

FIG. 1 is a top view of a display device according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view thereof. FIG. 3 is a cross-sectional view thereof.

The container part 1 is filled with liquid. Here, the liquid is glycerin, for example. The outer wall 2 of this container part 1 is made of transparent plastic. The bottom plate 3 of this container portion 1 is made of aluminum foil. The liquid in the container section 1 communicates with the thin tube section 5 via the passage 4. In this example, the thin tube portion 5 has an inner diameter of 0.2
A 111rrl iron tube (tubing material for a syringe needle) was used.

A small cavity is provided in the tip 6 of this thin tube part 5, and a hard ball 7 is placed on the opposite side of this cavity with a bottom plate 3 made of aluminum foil interposed therebetween. This hard ball 7 has a diameter of approximately 1.6 mm.
In this example, it is a grain of legend.

The bottom plate 3 at the tip portion 60 is a partition wall 8, and when the hard ball 7 is strongly pressed from the outside with a finger, the partition wall 8 portion is pierced and destroyed.

On the back side of the bottom plate 3, there is a transparent plastic outer wall 10 with filter paper 9.
covered and expanded by. As shown in FIG. 4, lines are drawn on the filter paper 9 in advance in substantially concentric circles from the position 11 of the hard sphere 7.

To explain how to use a display device configured in this way,
The food to be monitored is manufactured, transported to a cold warehouse, and stored frozen. Nowadays, the indicators are frozen and stored in appropriate numbers, for example together with the food.

When this food is stored frozen in a warehouse, its temperature is controlled by relatively highly accurate and expensive equipment, such as an automatic temperature controller and a self-recording temperature recorder installed in the warehouse. However, when this food is taken out of a temperature-controlled warehouse and shipped, it is packaged in small portions, for example, in cardboard boxes, and then transported in refrigerated trunks. At this time, one display device of the present invention is placed in each cardboard box in which the food is packaged and transported together with the food.

From this point on, the food is exposed to conditions where proper temperature control is not necessarily carried out, so from this point on, monitoring is performed using the display of the present invention.

When starting this monitoring, press hard on the hard ball 7 with your finger,
It breaks through the partition wall 8 made of aluminum foil. As a result, the liquid begins to flow out into the filter paper 9 little by little through the thin tube portion 5. However, if the cardboard box filled with food is at a low temperature, the viscosity of the liquid in the container section 1 is high and does not pass through the thin tube section 5. When the food is loaded onto a refrigerated truck and delivered to the store at the point of consumption, if the temperature has been maintained at a low level over the intervening period, little liquid will seep into the filter paper. However, when loading and unloading luggage,
Alternatively, if the food is temporarily exposed to high temperatures due to malfunction in the temperature control of the refrigerated transport vehicle, the viscosity of the liquid in the container section 1 decreases, and the liquid flows out through the thin tube section 5 and flows into the filter paper 9.
seeps out. The longer this time and the higher the temperature, the greater the amount that oozes out.

As shown in Figure 4, concentric circles are drawn on the filter papers 9 & 4. For example, if the liquid seeps out up to A, it is OK, if it reaches B, caution is required, and if it exceeds C, it is judged as dangerous. do. Judgment criteria vary depending on the type of food being monitored. That is, the size of the concentric circles, the thickness and properties of the filter paper, the thickness of the thin tube portion 5, the type of liquid, etc. are selected and set depending on the type of food.

When the liquid in the container part 1 flows out, the pressure inside the container part 1 is reduced, but the air around the filter paper 9 intermittently flows back through the thin tube part 5, and air accumulates in the space of the container part 1.

When the thin tube 5 has a double structure in which two thin tubes are parallel to each other, one of the two thin tubes becomes a liquid outflow passage, and the other becomes an air backflow passage, so that the liquid flows continuously and conveniently. Met.

The outer wall 2 of the container part 1 is formed of soft plastic,
It may also have a structure that deforms as liquid flows out. In this case as well, the flow of the liquid in the thin tube portion 5 is continuous, so that the observation is accurate.

However, it is necessary to provide the outer wall 2 of the container part 1 with an even harder outer wall so that the outer wall 2 is not compressed and excess liquid does not flow out. Furthermore, it is necessary to provide a small hole in this hard outer wall to communicate its interior with the filter paper portion.

FIG. 5 is a top view showing another embodiment of the structure of the present invention.

In this example, four thin tube portions 5 are provided. In this shape, the liquid flows out from the thin tube section 5 which happens to be located at the lower side depending on the position of the indicator at that time, and the thin tube section 5 which is located at the upper side serves as an inlet for air.

It is preferable to color the liquid in advance so that when it soaks into the filter paper, the soaked area can be easily identified.

Even if the liquid is colorless, the filter paper can be impregnated in advance with a coloring agent (for example, lidmus solution) that develops color when it comes into contact with the liquid. A coloring agent can be applied so that letters such as "Rejected" will stand out when it comes into contact with a liquid.

Although the present invention is not limited by the type of liquid, it is preferable to select the type of liquid that is suitable for the temperature to be monitored, depending on the temperature characteristics of viscosity, surface tension, and the like. In addition, the type of liquid should preferably not be harmful to food, in case the display is accidentally damaged.

Desirable liquids include glycerin, glycols, ethyl alcohol, water, and mixtures of the above, aqueous solutions of sorbitol, mannitol, crucose, sucrose, etc., mixtures of these aqueous solutions with glycerin, glycols, ethyl alcohol, etc., liquid paraffin, These include refined salad oil, edible soy sauce, and Hobu.

Further, for displaying temperatures above room temperature, there are glycerides, saturated alcohols having 8 or more carbon atoms, refined paraffins, aliphatic ketones, animal and vegetable waxes, and edible butter.

Next, the experimental test results will be shown. This test was conducted using the structure shown in Fig. 1, and the length of the thin tube section 5 was 20 mm.
, the inner diameter of the thin tube portion 5 is 0.2 mm. The filter paper used was Toyo Roshi 5A.

After the partition wall 8 was destroyed, the thin tube part 5 was placed directly under the container part 1, and each was left at a constant temperature. For each temperature at this time, the time and area of seepage onto the filter paper are shown.

○ Test results 1 When using the reagent glycerin as a liquid: [+20°C] [+3℃] [-5℃] (No leakage 2 (as it was soaked in at the beginning) FIG. 6 shows the above results graphically.

○ Test result 2 When a mixture of 0% sorbitol and 30% water was used as the liquid: [+20°C] [+3°C] [-5°C] The above results are shown graphically in FIG.

○ Test results 3 When using edible butter as liquid: [+20℃] No leakage.

[+60° C.] (At 60° C., the flow rate increases rapidly after about 20 minutes and foaming begins.) The above results are shown graphically in FIG.

〔Effect of the invention〕

As explained above, the display device of the present invention (1) has a simple and inexpensive structure, (2) can be manufactured and stored at room temperature, and (3)
It has an excellent feature that allows you to easily identify whether the results are good or bad.

Although the measurement results of the device of the present invention are not necessarily exact,
This level of accuracy is sufficient to identify whether a food product is acceptable for sale as a commercial product. On the other hand, by using this display, the transportation of products is managed to prevent them from being rejected, which has the effect of making it possible to safely deliver individual foods to consumers.

[Brief explanation of drawings]

FIG. 1 is a top view of a structure according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the same mm. Figure 3 is a cross-sectional view of the same mm. FIG. 4 is a diagram showing filter paper. FIG. 5 is a top view of another embodiment structure of the present invention. FIG. 6 is a diagram showing the test results when glycerin was used as the liquid. FIG. 7 is a diagram showing test results when a mixture of 70% crane beer and 30% water was used as the liquid. FIG. 8 is a diagram showing the test results when edible butter was used as the liquid. 1... Container part, 2... Outer wall, 3... Bottom plate, 4...
・Communication part, 5... Thin tube part, 6... Thin tube part tip, 7.
... Hard sphere, 8 ... Partition wall, 9 ... Filter paper (fiber part),
10...Outer wall, 11...Center of concentric circles. Figure 4\ Figure 5

Claims (5)

[Claims] (1) A container section for storing a liquid, a capillary section connected to the container section and configured to guide the liquid, and a fiber provided in contact with the tip of the capillary section and impregnated with the liquid flowing inside the capillary tube. and a partition that is provided between the container part and the tip of the thin tube part and prevents the flow of the liquid are packaged together, and the partition wall is destroyed by an external operation to transfer the liquid to the container. A time-temperature indicator, characterized in that the time-temperature indicator is configured to allow conduction from the part to the thin tube part, and is configured so that the amount of the liquid that has soaked into the fiber part after the partition wall is destroyed can be observed. . (2) The fiber part is a flat filter paper, and a circle is drawn in advance on the filter paper centered on the point of contact with the thin tube part, so that the amount of liquid that has soaked into the filter paper can be visually identified. The time-temperature indicator according to claim (1), characterized in that the time-temperature indicator is configured as follows. (3) The liquid is a colored liquid.
The time-temperature indicator described in item 2). (4) The liquid is colorless, and the filter paper is impregnated with a coloring agent that develops color when it comes into contact with the liquid.
) Time-temperature display device as described in section 2. (5) Claim No. 1 (1) in which a plurality of thin tube portions are provided.
) to (4).