JPH0360614A - Material and container for keeping freshness - Google Patents

Abstract

PURPOSE:To keep food fresh for a long period of time and prevent adverse effect on food by using a material made of a flexible base material on which an inorganic substance is applied. CONSTITUTION:This freshness keeping material is obtained by applying an inorganic substance on a flexible base material. The main ingredient of the inorganic substance is diatomaceous earth having respiratory function when applied to a container and adsorbs moisture coming out of food and prevents sweating in the container. The substance also has a pumping effect similar to that of the base material and therefore is capable of maintaining the temperature and humidity in the container constant. The baked powder content in the diatomaceous earth is 5-95% by weight. If the content is below 5%, property of preventing sweating on the container becomes weaker, while if more than 95%, mechanical strength becomes weak, although the property of preventing sweating is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of Industrial Soil] The present invention relates to a freshness-preserving material and a freshness-preserving container using the same. More specifically, the present invention relates to a freshness-preserving material that can maintain the freshness of foods such as perishable fresh agricultural products throughout Nagasaki, and a freshness-preserving container using the same.

[Conventional technology]

In recent years, it has become a problem that fresh agricultural products harvested by farmers lose their freshness during the distribution process before being sent to the market.

Conventional methods for preserving the freshness of fresh produce include (a) wrapping fresh produce in newspapers soaked in water to replenish moisture; and (b) wrapping fresh produce in plastic bags to prevent moisture from escaping. In order to adsorb and remove ethylene, which is generated from fresh produce and is the cause of deterioration of freshness, methods such as placing ethylene adsorbent in a plastic bag and sealing it are used.

However, in the method (a) above, spoilage may occur at the contact area between wet newspaper and fresh produce, and newspaper dries in a relatively short period of time, so it is not an effective method. The disadvantage is that the agricultural products must be wrapped in newspaper, which is time-consuming. In addition, in the method (b) above, the ethylene adsorbent is expensive, it cannot be used to recycle deer, and its safety has not been established. It has drawbacks such as complicated work.

In addition, when distributors and others transport food products to markets or households, the freshness of the food products has deteriorated significantly, especially during hot and humid periods such as summer or when transportation takes a long time. Although methods for maintaining the freshness of foods such as foodstuffs have been studied, at present no means for maintaining the freshness of such foods has yet been found.

[Problem to be solved by the invention]

In view of the above-mentioned prior art, the present inventors have conducted extensive research to develop means for safely preserving and hanging fresh agricultural products and foodstuffs for long periods of time. in a shipping container such as
When a freshness-preserving material is provided, which is made by adhering an inorganic substance to a flexible base material, surprisingly, the freshness of food is maintained for a long time, and there is no adverse effect on the food. Furthermore, he discovered for the first time a completely new method that eliminates the need for complicated operations such as packaging food in plastic bags, leading to the completion of the present invention.

[Means to solve the problem]

That is, the present invention provides (1) a freshness-preserving material formed by adhering an inorganic substance to a flexible base material, and (2) placing the freshness-preserving material in a container so that the freshness-preserving material shakes when the container is subjected to vibrations. The present invention relates to a freshness preservation container provided in a.

[Function and Examples]

The freshness preserving material of the present invention is obtained by attaching an inorganic substance to a flexible base material.

Since the base material can be attached with an inorganic substance, there is no particular limitation on the base material as long as it bends and sways due to vibrations during transportation of the container when fixed to a part of the container, and various materials may be used. Can be used. Examples of the material for such a base material include synthetic resin foams such as flexible polyurethane foam, polypropylene foam, polyethylene foam, and polyvinyl chloride foam, sponge, nonwoven fabric, and paperboard. Open-cell synthetic resin foams are preferred because they are porous bodies that are easily adhered to the inside, and among such open-cell synthetic resin foams, open-cell flexible polyurethane foams are particularly preferred.

The size of the base material used in the present invention cannot be determined in part because it varies depending on its material, etc., but it is usually adjusted as appropriate depending on the size of the container and the amount of foodstuffs etc. to be placed in the container. It is preferable that

In addition, the shape of the base material is such that when it is provided in a part of the container, it bends and shakes due to the vibrations of the container during transportation, etc., and has the effect of agitating the air inside the container (hereinafter referred to as a "bumping effect"). There is no particular limitation as long as the shape is such that it exhibits the following characteristics.

Specific examples of such shapes include a polygonal columnar shape as shown in FIGS. 1 and 2, a cylindrical shape as shown in FIG. 3, a rod shape such as an inverted conical shape as shown in FIG. In addition to the plate shape as shown in Figure 5, the step shape as shown in Figure 6, the spiral shape as shown in Figure 7, and the rod shape as shown in Figure 8. Examples include those that are hollow inside,
The base material used in the present invention is not limited to these shapes,
It may have any shape as long as it exhibits a bombing effect.

In addition, as shown in Figure 9, by attaching a plate ('2J, etc.) made of a material with a high specific gravity such as iron to the top of the base material (1), it is possible to further increase the shaking due to vibration during transportation. You can.

Since the inorganic substance attached to the freshness-preserving material is mainly composed of diatomaceous earth, which is a porous material, when it is installed in a container, it does not breathe in the same way as an earthen wall. Because it exhibits a wicking effect, it absorbs the water vapor evaporated from the food and prevents condensation from forming inside the container.It also has the same pumping effect as the base material, which keeps the temperature and humidity inside the container constant. Furthermore, when fresh produce is stored in a container, it has the effect of adsorbing gases that inhibit freshness, such as ethylene, released from fresh produce.

The inorganic substance mainly contains fired powder of diatomaceous earth as described above, but may also contain other components such as gypsum, sand, and a hardening agent.

The calcined powder of diatomaceous earth has a diatomaceous earth content of about 8
After firing and drying in an air atmosphere at 00°C,
A fine powder of about 0 mesh is used.

The purity and porosity of the diatomaceous earth are not particularly limited in the present invention, but the purity and porosity of the diatomaceous earth are as high as possible,
Moreover, it is preferable that the porosity is large. The content of calcined diatomaceous earth powder in inorganic substances is 5-95% (wt%
, hereinafter the same), preferably 10 to 70%, particularly preferably 15 to 30%. If the content of the calcined powder of diatomaceous earth is less than 5%, the resulting freshness-preserving material tends to have low dew-proofing properties, and if it exceeds 95%, the dew-proofing property of the resulting freshness-preserving material tends to decrease. Although the properties are improved, the mechanical strength tends to decrease.

The above-mentioned gypsum has the function of hardening the diatomaceous surface and improving mechanical strength, and such gypsum includes:
Calcined gypsum, dead calcined gypsum, or the like is pulverized into a powder of about 150 mesh. The content of gypsum in the inorganic material is less than 90%, preferably 15-30%, particularly preferably 20-25%. If the content of the gypsum exceeds 90%, the dew-proofing properties of the resulting freshness-preserving material tend to decrease.

The sand has the function of improving mechanical strength, and as such sand, silica sand or the like adjusted to a particle size of about No. 5 is used. The content of sand in the inorganic material is below 8096%, preferably from 20 to 70%, particularly preferably from 45 to 65%. The content of this strange substance is 8
If it exceeds 0%, the dew-proofing properties of the obtained freshness-preserving material tend to decrease.

The hardening agent has the function of imparting mechanical strength, and examples include Fujibeton (trade name, manufactured by Fujimasu General Chemical Research Institute), Toughlock (trade name, manufactured by Sumitomo Cement),
Examples include products such as (trade name) used as soil stabilizers to increase the bearing capacity of soft soils such as loamy soils and clayey soils, and cements. The content of the curing agent in the inorganic substance is 50% or less, particularly preferably 1 to 5%. If the content of the curing agent exceeds 50%, the dew-proofing properties of the resulting freshness-preserving material decrease, and cracks tend to occur in the inorganic material.

For example, SR Coat (trade name, manufactured by Ishiura Co., Ltd.) is easily available as a compound containing the above-mentioned inorganic substance components, and this can be used very suitably as an inorganic substance in the present invention. be.

In addition, in order to prevent cracks from occurring in the inorganic substance even when the freshness-preserving material of the present invention is used repeatedly, and to improve the adhesive strength between the inorganic substance and the base material ε, the inorganic substance is added to the inorganic substance. Furthermore, it is preferable to add vinyl acetate resin, ethylene-vinyl acetate copolymer, acrylic resin, polyester, polyurethane, polymethyl methacrylate, silicone resin, butyl rubber, modified epoxy resin, etc. as a binder in the form of an emulsion.

Among these, ethylene-vinyl acetate copolymer acts as a particularly excellent binder for inorganic materials, and when this ethylene-vinyl acetate copolymer is added, the crack resistance of inorganic materials is dramatically improved. This is preferable because it has the effect of improving. The ratio of such binder to the total amount of the inorganic substance and binder is 5 to 30%, preferably 10 to 25%. If the ratio is less than 5%, the effect of improving crack resistance is small; If it exceeds %, the porosity of the diatomaceous earth tends to decrease, and therefore the dew-proofing properties of the obtained freshness-preserving material tend to decrease.

The inorganic substance usually exhibits a white to brass color, but if necessary, pigments, dyes, etc. may be added to adjust the color to a desired color.

The inorganic substance may be provided on the entire surface of the base material or partially, and the ratio of the area where the inorganic substance is provided on the base material to the total area of the base material depends on the shape and size of the base material, It is preferable to adjust the number of freshness-preserving materials provided in the container as appropriate.

The method of attaching the inorganic substance to the base material is, for example, by adjusting and mixing the above-mentioned components, adding water and kneading to an appropriate viscosity, and applying methods such as brushing, troweling, and spraying. It may be applied by any conventionally employed means, and if the substrate is particularly porous, it may be impregnated into the substrate.

Furthermore, an inorganic substance is placed in a bag made of an air-permeable material such as paper, woven fabric, non-woven fabric, or a perforated resin film such as polyethylene, polypropylene, polyvinyl chloride, or nylon. As shown in FIG. 1O, a freshness-preserving material (1) in which a bag (3) is attached to a base material with an adhesive or the like may be used. In addition,
When using a resin film with holes on its surface as the material for the bag (3), the size of the holes should be such that the inorganic substance packed in the bag (3) does not pass through the holes. Preferably, the size is adjusted. The bag (3) may contain the inorganic substance itself, but instead, the inorganic substance may be attached to a carrier made of the same material as the base material in the same manner as when it is attached to the base material. You may also include

The size of the carrier is preferably adjusted as appropriate depending on the base material used, the size of the bag, etc. Further, the shape of the carrier is not particularly limited as long as it is a shape to which an inorganic substance can be attached, such as a spherical shape or a dice shape. Among the freshness-preserving materials that use bags, there are freshness-preserving materials that are made by placing a predetermined amount of small spherical carriers with inorganic substances attached to the bag and attaching the bag to a base material. By changing the number of carriers added to the container, it is possible to obtain an appropriate level of freshness retention as required.

The amount of inorganic substances attached to the base material depends on the number of freshness-preserving materials provided in the container, the type and content of the container in which the freshness-preserving materials are provided, as well as the type of food contained in the container and the amount of cucumber. It cannot be determined in part because it depends on the environment in which the container is placed, the period of time the food is kept in the container, etc., so it is desirable to adjust it appropriately according to these conditions. For example, if broccoli or the like is placed in a container made of expanded polystyrene with an internal capacity of 1011, it is sufficient to use an amount of about 10 to 50 g.

Since the freshness-preserving material thus obtained has excellent flexibility and flexibility, it can be easily subjected to post-processing or cutting as long as cracks do not occur, if necessary.

The freshness-keeping container of the present invention has the freshness-keeping material provided in the container so that the freshness-keeping material swings when the container is subjected to vibrations. In other words, if one end of the freshness-preserving material is fixed to a part of the container, when the container is subjected to vibration, the freshness-preserving material will flex, and the other end that is not fixed to the container will shake. . In the freshness-preserving container of the present invention, even when the freshness-preserving container is shaken in this way, the other end of the freshness-preserving material that is not fixed is connected to the inner surface of the container, other freshness-preserving materials provided in the container, and partitions. , which is installed inside the container so that it does not come into contact with the contents.

Note that it is desirable that the number of freshness-preserving materials provided be appropriately adjusted depending on the size and shape of the container, the shape of the freshness-preserving material, the size and amount of the contents, and the like.

Examples of methods for providing the freshness-preserving material in the container include a method of fixing the freshness-preserving material to the bottom of the container using an adhesive, and a method of providing a hole for assembling in the bottom of the container and adding the freshness-preserving material to the bottom of the container. The present invention is not limited to only these methods, but any method can be used as long as the effect of maintaining freshness by providing the freshness-preserving material is exhibited. Containers used in the present invention include containers used for transporting food, such as wooden boxes, cardboard boxes, plastic containers, and containers made of synthetic resin foam. However, the present invention is not limited by the type of container. Among these containers, containers made of synthetic resin foam are particularly preferred because they are lightweight and have heat insulating and cushioning properties. Examples of such synthetic resin foams include synthetic resin foams made of foamed polystyrene, foamed polypropylene, foamed polyethylene, foamed polyurethane, foamed polyvinyl chloride, and the like.

There are no particular limitations on the size and shape of the container, and it is usually preferable to adjust the size and shape as appropriate depending on the shape and amount of the contents.

As a specific example of the freshness preserving container, as shown in FIG. A freshness-preserving container (with a partition (6) having a ventilation hole (5) separating the freshness-preserving material (4) from the foodstuffs to prevent food items from directly touching the freshness-preserving material (4)). 7) As shown in FIG. 12, spaces (8) are provided at the corners of the container in which freshness-preserving materials can be placed, and flexible prismatic freshness-preserving materials ( 4), and as shown in Figure 13, powdered inorganic substance (9) is packed into the cavity □□□ of the step-shaped freshness preservation material (4), and the freshness preservation material is As shown in FIG. ) attached to the freshness preservation material (4) 4
As shown in Figure 15, inorganic substances (9) have the effect of preserving freshness by fixing them to the freshness preservation container M02) and closing the freshness preservation container lid 02J.
Two freshness preservation +47 materials (4) each attached with a freshness preservation material (4) are provided on the upper part of the opposing inner wall surface in the container.
For example, the steaming method (7) may be mentioned, but the present invention is not limited only to these examples.

In the freshness-preserving container of the present invention, the freshness-preserving material provided in the container has the above-mentioned bombing effect, that is, the action in which the freshness-preserving material is shaken by vibrations during transportation, etc., and the air in the container is agitated. This has the advantage that the temperature and humidity inside the container can be kept constant when transporting foodstuffs or the like inside the container. Therefore, the freshness preserving container of the present invention exhibits an extremely large freshness preserving effect.

Next, the freshness-keeping material and the freshness-keeping container of the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

Example 1 A rectangular parallelepiped (length 10 cm, width 2 CIn1, thickness 2 am) made of open-cell flexible polyurethane foam was used as a base material.

As inorganic substances, a mixture of 22.5% calcined diatomaceous earth powder (particle size: 150 mesh), 22.5% gypsum (particle size: 150 mesh), 50% silica sand (particle size: No. 5), and 5% cement was used. vinyl acetate resin emulsion (resin solids content: 2
0%) 20%) and 60% water are mixed thoroughly to form a mixture, and the mixture is sprayed onto the side surface of the substrate to deposit about 10% of the mixture on each substrate, thereby applying the freshness-preserving material. I got it.

The dew resistance of the obtained freshness-keeping material was evaluated based on the method shown below. The results are shown in Table 2.

(Dew resistance) A sample was prepared by cutting the part of the obtained freshness-preserving material provided with the inorganic substance so that the length of each side was 10cm111, and the sample was placed in a humidity tester (temperature: approximately 35°C). The sample was attached to a ceiling at a relative humidity of 98%, and the surface of the sample after 1 hour was evaluated based on the following criteria.

(Judgment criteria) ○: No dew condensation was observed on the surface of the sample.

×: Condensation was observed on the surface of the sample.

Next, heat-resistant expanded polystyrene resin (Kanebuchi Chemical Industry ■
Manufactured by, Product name: Heatmax, Grade: IN-M,
As shown in Figure 11, each of the four freshness-preserving materials is fixed to a portion near the bottom corner of a container (length: 28 cm x width: 39 cm x height: 18 cm) consisting of a foaming ratio of 40 times, and a lid is placed on the container. As a result, we were able to create a freshness-preserving container. The total weight of inorganic substances in the obtained freshness-preserving container was 40 g.Next, the physical properties of the obtained freshness-preserving container were evaluated for vibration resistance and freshness-preserving ability of fresh agricultural products, respectively, based on the following methods. . The results are shown in Table 2.

(Vibration resistance) Using a vibration tester, the obtained freshness preservation container 4 was tested with an amplitude of 101
A vibration test was conducted at a 111% vibration frequency of 5 Hz, and the freshness preservation containers after 20 minutes were evaluated based on the following criteria.

(Judgment criteria) ○: No inorganic substances were removed from the freshness-preserving material.

Δ: Inorganic substances were slightly separated from the freshness-preserving material.

×: A considerable amount of inorganic substances were removed from the freshness-preserving material.

(Freshness retention of fresh agricultural products) Fill the obtained freshness preservation container with 12 freshly collected broccoli, put a lid on it, and place it in a constant temperature and humidity room (room temperature 35℃,
(relative humidity 98%), and use a vibration tester to test the amplitude to 1.
Vibration was applied at a frequency of 511z at a speed of 0. After 24 hours, the broccoli was taken out and compared with the target sample to visually examine the difference, and also to examine the presence or absence of a foreign odor using the sense of smell, and also to examine the presence or absence of dew condensation. The judgment criteria are shown below.

(b) Visual test ○: No difference from the target sample was observed.

Δ: Slightly less fresh than the target sample.

×: The freshness is clearly lower than that of the target sample, and the yellowing is noticeable.

(b) Smell test ○: Almost the same as harvested broccoli.

△: A slightly strange odor is felt.

×: It emits a rotten odor and is not in a state that can be eaten.

(/9 Presence of condensation ○: No condensation.

×: There is dew condensation.

In addition, as a target sample, the same freshly harvested broccoli used in the above test was stored in the refrigerator (at room temperature 5℃).
, relative humidity 98%) for 24 hours.

Comparative Example 1 The container made of heat-resistant foamed polystyrene resin used in Example 1 was used as a freshness-keeping container without any freshness-keeping material, and its physical properties were measured in the same manner as in Example 1. The results are also shown in Table 2. Example 2 In Example 1, the content of calcined diatomaceous earth powder as inorganic substances was 27%, the content of gypsum was 18%, the content of silica sand was 50%, The content of cement was 5%, and vinyl acetate resin emulsion (resin solid content 20%) was added to it.
20% of the total amount of the inorganic substance was added, water was added to this, and the mixture was thoroughly stirred and applied to the same base material used in Example 1 in the same manner as in Example 1. I got freshness preservation material. The physical properties of the obtained freshness-preserving material were investigated using the same t and 1 as in Example 1. The results are shown in Table 2.

Next, using this freshness-keeping material, a freshness-keeping material was provided on the bottom surface of the container in the same manner as in Example 1, and a lid was put on to obtain a freshness-keeping container. The total amount of inorganic substances in the freshness preservation container was 40g.

Next, the physical properties of the obtained freshness-preserving container were examined in the same manner as in Example 1. The results are shown in Table 2.

Examples 3 to 5 Using the inorganic substances and binders shown in Table 1, the freshness was improved by brushing the inorganic substance on the side surface of the same substrate used in Example 1 in the same manner as in Example 1. I got the retaining material. The physical properties of the obtained freshness-preserving material were investigated in the same manner as in Example 1. The results are shown in Table 2.

Next, a freshness preservation container was made in the same manner as in Example 1.

The physical properties of the obtained freshness-keeping container were examined in the same manner as in Example 1. The results are shown in Table 2.

Example 6 Foamed polypropylene was used as the base material. In the same manner as in Example 1, 10 g of the inorganic substances and binders shown in Table 1 were attached to each substrate to obtain a freshness-preserving material. The physical properties of the obtained freshness-preserving material were investigated in the same manner as in Example 1.

The results are shown in Table 2.

Next, a freshness-keeping container was obtained in the same manner as in Example 1 using the same container and lid as those used in Example 1.

Next, the physical properties of the obtained freshness-preserving container were examined in the same manner as in Example 1. The results are also shown in Table 2.

Example 7 A nonwoven fabric was used as the base material. The inorganic substances and binders shown in Table 1 were attached to the nonwoven fabric in an amount of 10g per nonwoven fabric in the same manner as in Example 1 to obtain a freshness preserving material. The physical properties of the obtained freshness-preserving material were investigated in the same manner as in Example 1. The results are shown in Table 2.

Next, using the same container and lid as those used in Example 1, as shown in FIG. 14, four freshness preservation materials (4) are fixed to the freshness preservation container lid (+2) using adhesive. A freshness preservation container (7) was obtained by closing the MO2i.

Next, the physical properties of the obtained freshness-preserving container were examined in the same manner as in Example 1. The results are also shown in Table 2.

Example 8 Corrugated cardboard (B liner, tsubom 125g/c) as a base material
J, length 10 cm, width 3 cm) was used. A freshness-preserving material was obtained by attaching 10 g of the inorganic substances and binders shown in Table 1 to each cardboard in the same manner as in Example 1. The physical properties of the obtained freshness-preserving material were investigated in the same manner as in Example 1. The results are shown in Table 2.

Next, a freshness-keeping container was obtained in the same manner as in Example 7.

Next, the physical properties of the obtained freshness-preserving container were examined in the same manner as in Example 1. The results are shown in Table 2.

Example 9 and IO Instead of the container used in Example 1, containers of the types shown in Table 1 (however, the contents are the same as the containers used in Example 1)
A freshness-preserving container was prepared in the same manner as in Example 1 except that a lid was used, and the same freshness-preserving material as that used in Example 1 was provided on the bottom surface of the container. The physical properties of the obtained freshness-preserving container were examined in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2 A freshness-keeping material was obtained in the same manner as in Example 1 using the same base material, inorganic substance, and binder as in Example 1.

Next, as shown in Figure 16, the upper part of the freshness-preserving material (4) is fixed using the fixing part (2) and adhesive, so that the freshness-preserving material (1) will not shake even if the container vibrates. A freshness-keeping container was prepared in the same manner as in Example 1, except for the following changes, and the physical properties of the freshness-keeping container were investigated. The results are shown in Table 2.

Table 2 From the results shown in Table 2, it can be seen that the freshness-preserving material of the present invention has excellent dew resistance. In addition, the freshness-preserving container of the present invention is capable of retaining the freshness of fresh produce for a long time even under high temperature and humidity, with almost no inorganic substances being released from the freshness-preserving material even when subjected to vibrations during transportation. This shows that the pumping action of the freshness-preserving material provides even greater freshness-preserving performance.

[Effects of the Invention] The freshness-preserving material of the present invention is inexpensive, lightweight, and flexible, and can be easily installed in various containers.

Even when the freshness-preserving container of the present invention is subjected to vibrations during transportation, almost no inorganic substances are released from the freshness-preserving material provided in the container, and the freshness-preserving material has excellent dew-proofing properties. In addition, it adsorbs gases that promote spoilage, such as ethylene, generated from agricultural products, so it can suppress the spoilage of food stored in containers and maintain the freshness of such food for long periods of time, even during hot and humid periods such as summer. This effect is achieved.

Furthermore, the freshness-preserving container of the present invention can exhibit a greater freshness-preserving effect through the pumping action of the freshness-preserving material, so it can be suitably used as a container for transporting fresh agricultural products, foodstuffs, and the like.

[Brief explanation of drawings]

1 to 9 are perspective views showing an example of the base material used in the freshness-preserving material of the present invention, FIG. 10 is a perspective view showing an example of the freshness-preserving material of the present invention, and FIGS. 11 and 12 are FIG. 13 is a plan view showing an example of the freshness-keeping container of the present invention, and FIG. 14 and FIG. 15 are longitudinal cross-sectional views of the cavity of the freshness-keeping material, respectively. Fig. 16 shows an example of a freshness-preserving container according to the present invention, and is a vertical cross-sectional view of the central part of the freshness-preserving material. FIG. 3 is a cross-sectional view of a ventilation hole provided in a partition inside the container. (Main symbols in the drawing) (1) Two base materials (4): Freshness preservation material (7): Freshness preservation container (9): Inorganic substance

Claims (1)

[Claims] 1. A freshness-preserving material comprising an inorganic substance attached to a flexible base material. 2 The inorganic substance is 5 to 95% by weight of calcined diatomaceous earth powder.
The freshness-preserving material according to claim 1, which contains a freshness-preserving material. 3. A freshness-preserving container comprising the freshness-preserving material according to claim 1 provided in the container so that the freshness-preserving material sways when the container is subjected to vibrations.