JPS5919812B2 - Sheet of extruded foamed thermoplastic heat shrinkable material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to sheets of extruded foamed thermoplastic heat shrinkable material for container covering protection.

In particular, the present invention selects plastic as a covering material for glass as a container material, and it is exceptional in terms of strength, glass protection, appearance, ease of manufacture, labeling, decorative printing, etc. Aiming to provide sheets with advantages o In the field of glass containers, several attempts have already been made to protect the glass outer surface of containers.

For example, it has been proposed to spray coat a metal oxide such as a compound of titanium, tin, etc. onto a glass surface and form a thin invisible coating layer through thermal decomposition to prevent wear on the glass surface. Several other transparent organic coatings have also been provided to similarly avoid external abrasion and abrasions to which the container may be subjected due to handling after container manufacture. These protective coatings are intended in part to provide lubricity to the glass, thereby reducing adhesion and friction between the glasses.

This certainly reduces wear when the containers come into contact with each other. However, there are additional problems associated with applying such coatings to newly manufactured containers. In particular, two problems arise: the difficulty of applying labels, e.g. paper or foil strip labels coated with adhesive 5, and the difficulty of discerning whether a suitable coating has already been applied. arise. One of the inventions recently proposed to solve this problem is the invention of US Pat. No. 3,482,724.

The present invention relates to a composite container characterized in that a paste material is affixed to the glass to provide a protective coating to the lower part of the glass container, thereby preventing glass-to-glass contact from occurring at the largest diameter. the pre-labeled add-on material is attached to the container;
and the base material provides a stable and undamaged bottom container bearing surface suitable for packaging. In contrast to the conventional containers described above, the sheet of the present invention provides a special sleeve covering to the container;
According to the invention, the sleeve can be pre-decorated or labeled by high-speed, high-quality printing in flat sheet form, without requiring high costs for manufacture and application, and without damaging the container from abrasion or surface abrasions. Provides reliable protection from water and a convenient bottom container bearing surface.

The sheet sleep of the present invention, in its final form, tightly engages the glass container to prevent surface abrasion and scratches that would weaken the container.

According to a preferred embodiment of the sheet of the invention, the sleeve is made from a pre-foamed, collapsible material to provide the container with a lightweight, cellular, but relatively thick protective cushion. Further in accordance with a preferred embodiment of the sheet of the invention, the sleeve is a plastic sleeve, preferably of foamed shrinkable thermoplastic material 9, and the rectangular sheet material is wound around a cylindrical mandrel such that the opposite sides of the sheet It is made by overlapping the edges and sealing them.

That is, heat and pressure are applied to the overlapped bonded areas to heat seal and press the materials so that the thickness of the overlapped portion is substantially the same as that of the other layer to form a cylindrical shape. sleeves are made.

This creates a strong edge bond and provides an excellent protective covering for the container when the sleeve is contracted over the container until it conforms to the shape of the container. According to another embodiment of the invention, the plastic sleeve of shrinkable thermoplastic material is a seamless tubular body, the tubular body being strongly oriented laterally (circumferentially) and preferably have a thin film wall that may be colored, translucent, or transparent.

One of the features of a container protected using the sheet of the present invention is that it provides wall-to-wall contact protection for the glass container during transportation or shipping in a box.

Conventionally, glass containers, particularly glass bottles, have typically been packed individually into separate compartments within a box. The partitions are made of corrugated paper, and when bottles are packed in boxes, fine paper waste or paper dust called 6-box-9'' is generated. Empty bottles are placed in boxes and shipped from bottle manufacturers to bottle users. Box dust accumulates in the bottles during transportation to and from the bottle, thus requiring the user to take additional expense and effort to remove this foreign material prior to filling the bottle.
The use of containers protected using the sheet of the present invention eliminates the need for box dividers, which not only saves material for shipping boxes, but also eliminates the box dust described above. Problems are eliminated.

Additionally, containers protected using the sheets of the present invention avoid the problems of food contamination due to insect infestation that occur with some food containers.

For example, heavy hoods are usually capped with ear-shaped threaded caps and stored in glass shears. In this type of heavy food shear, insect eggs and hatched larvae tend to accumulate in the area between the cap and the glass slot end of the shear while the shear is on the shelf. The food in the shell is sealed under vacuum, so when the cap is loosened, air is suddenly blown through this area and into the shell, causing small invisible insects to enter the food. They will enter together. Containers protected using the sheets of the present invention eliminate this problem. That is, a plastic sleeve is mounted over a food container, such as a heavy food shear, with the upper end of the sleeve in intimate contact with the skirt portion of the threaded cap. Since the sleeve and the cap overlap, there is no void area in which insect eggs such as those mentioned above can be laid. Alternatively, after the container is capped, a sleeve can be placed over the end of the skirt portion of the cap, and the sleeve can be contracted to cover the end of the skirt portion of the cap. This ensures that the gap between the cap and the glass slot is completely sealed and has the added benefit of preventing unauthorized access to the container while it is being placed on the shelf. The present invention allows various embodiments and has a wide range of application.

If the smallest area of the container body is covered by the sleeve, the sleeve extends from the largest diameter part of the container body to the bottom container bearing surface.

In the case of widest coverage, the sleeve extends almost over the entire body of the container, from the area directly at the mouth end of the container top (with or without including the cap) to the bottom surface.
It is best to cover almost the entire container from the standpoint of appearance, safety, and reinforcement, but this should be selected by taking into account the shape of the container and the type of article to be stored in the container. . A suitable coverage ranges from the area of maximum circumferential dimension (which usually lies at the shoulder where the neck transitions into the cylindrical body) to the heel of the container.

In practicing the invention, it is suitable to use a plastic sheet in which the thermoplastic material is oriented as follows when it is formed into a sheet.

That is, with a dominant (primary) orientation M in the direction of the machine and a slight (secondary) orientation T in the transverse direction, M/
The ratio of T is substantially greater than 1, preferably M/T-2
or larger plastic sheet. When a thermoplastic material is formed into a seamless tubular body, its main orientation is along the circumference of the tubular body. ``Slight orientation 1'' refers to a range in which the shrinkage rate during heating is greater than 0 and smaller than the shrinkage rate of the main orientation. Furthermore, plastic sheets suitable for the sleeve are those whose coating thickness is defined as follows:

In other words, when a sleeve is made and coated on a container, the thickness of the film on the surface that directly contacts the container (back surface) is 1.2 times larger than the thickness of the film on the surface exposed to the outside (front surface).
The sheet is twice as large.

Additionally, an antistatic agent can be applied to the side of the sheet opposite the printing side (usually the outer surface) to facilitate printing when the sleeve is preprinted. Additional benefits are obtained by applying this antistatic layer. That is, the adhesion of the plastic material to the container is enhanced after the plastic sleeve is compressed onto the container and tightly attached to the container. In this specification, "glass container 1, 6 bottles 1,
6 Shears 1 each refer to a container that has an article storage chamber defined by a glass wall and has an opening to the storage chamber. Of course, said opening is closed by a suitable lid to enclose the article within the container.
The sheet of the present invention can be used in any round, oval or square container, as well as in various types of containers such as lipped, wide-mouthed, narrow-necked, crown-shaped ends, helical threaded or ear threaded ends. It can also be applied to shaped glass containers.

Next, the present invention will be explained in more detail with reference to the drawings.

As can be clearly seen in FIG. 3, the glass container 10 has a neck 1
3 is inwardly recessed and has an opening 11 defined by a mouth rim 12.

The neck 13 transitions downwardly into an outwardly flared shoulder 14 which continues into a cylindrical body 15 . The cylindrical body 15 is the largest diameter part (the largest circumference is 15a) of this type of container 10. The cylindrical body 15 is curved at its lower end into a heel portion 16 , which leads to the bottom 17 of the container 10 . Preferably, the heel portion 16 transitions to the sole with a relatively large radius of curvature. The container 10, which has a conventional design, has a slightly concave bottom 17, so that the container 10 is supported on a flat horizontal surface by an annular portion of the bottom 17 called a bearing ring surface. Ru. The portion corresponding to this bearing ring (hereinafter referred to as the bearing portion) is shown by dotted portions in FIG.
A plastic sleeve 19 is assembled to the container 10 in a manner detailed below.

In one embodiment, the sleeve 19 is made from a rectangular sheet of heat-shrinkable plastic material (see FIG. 4).

The edges 20 and 21 of the rectangular sheet are overlapped and joined. In the case of the illustrated embodiment, the dimensions of the end edges 2Q, 21 are slightly longer than the distance from slightly above the cylindrical body portion 15, around the heel portion 16, to the inner diameter side of the bottom support portion 18. selected (see 19 in Figure 2). The sleeve 19 has end edges 20 and 21 overlapped and heat sealed to form a substantially hollow cylinder. The thus produced hollow cylindrical sleeve is fitted into the container from the bottom side of the container so that the upper end side 22 of the sleeve is aligned with the cylindrical body portion 1.
It is moved until it reaches a point slightly above the upper limit of 5.
With the sleeves thus fitted together, the container 10 and its sleeve 19 are placed in a heated atmosphere sufficient to cause the plastic material of the sleeve to shrink and the cylindrical shape of the sleeve to extend from its lower edge 23 to its upper edge 22. (See FIG. 2) It is held in the heated atmosphere until it shrinks to a τ shape that matches the shape of the crack 9 and the container. Sleeve 19 can be prepared by cutting a rectangular blank, as shown in FIG.
A decorative image 24 of a preselected design can be printed on one side between 0, 21 and 0. This printing can be carried out in any suitable manner and can be provided in any suitable color and design. The image 24 can be printed on the web 5 before the sleeve material is cut, or it can be printed on each individual sleeve material sequentially. Of course, there may be cases where it is not necessary to add a design to the sleeve 19. However, the advantages of the present invention are particularly apparent when a decorative image is applied to the container. In other words, since the printing is done separately, it is possible to print decorative images of a higher quality at a lower cost, and furthermore, the complicated handling of the container for simply applying decorations can be avoided, which is a double advantage. It is. FIG. 5 shows another example of sleep.

In this case, a cylindrical sleeve 25 of the desired length is produced from a long seamless plastic tube by cutting at 25a and 25b. The cylindrical sleeve 25
A seamless, suitably diameter plastic tube formed prior to cutting is highly oriented in the circumferential or transverse direction by being diametrically stretched immediately after extrusion. If the tube is slightly elongated in the axial direction of the tube, the tube has a high degree of orientation in the circumferential direction and a biaxial orientation with a slight orientation in the axial direction of the tube. The tube thus obtained can be folded flat and the desired image can be printed on it. Thereafter, each cylindrical sleeve 25 is cut and placed over the container 10. The sleeve is shrunk over the container 10, covering it below the bottom in a manner similar to that shown in FIG. Although not shown, in accordance with the present invention, a container may be provided, for example, with a dark opaque image pattern previously provided on the surface of the cylindrical body 15 and then coated with a shrinkable sleeve 19 or 25 of transparent or translucent material. It is also possible to attach the sleeve to the container as described above so that the image on the surface of the container can be seen through the sleeve.

In this case, the sleeve serves as a protective covering layer for the decorative image on the body 15 of the container and also serves to protect the container 10 itself from external wear and damage. In the embodiment of FIG. 10, the material of the sleeve 19 is a sheet of transparent or translucent shrinkable plastic material, and the desired decorative image 24 is
' is printed on the back side of the sleeve, that is, the side that contacts the container.

In this case, the decorative image 24' can be seen through the sleeve, and the sleeve also serves to protect the decorative image. The two embodiments for protecting decorative images described above are suitable if the container is used repeatedly as a so-called recycled container, such as beer bottles or soft drink bottles.

The decorative image provided by the sleeve and the protection of the container itself extend the life of the container during portability, filling, sealing and
Despite having to go through multiple stages of processing, shipping to the market, consumer handling, recovery, and even cleaning, they are significantly longer than traditional American containers.

FIG. 6 illustrates the importance of selecting the height of the sleeve over the container 10 in accordance with the present invention. That is, by applying sleep to just the upper limit of the body portion 15, which is the maximum diameter portion of the container, when the container falls over as shown in FIG. There is no direct collision contact with the horizontal surface 26, that is, the floor surface or the table base surface. Then, the sleeve 19 and the cap 27 placed over the neck opening come into contact with the floor 26, and the cap 27 absorbs the impact. It is therefore important for the protection of the container that at least the bulging region of the container and the surface of the bottom support region be covered with a sleeve.

The drawings clearly show this sleeve coverage area for containers of various shapes.

In the case of the container of FIG. 3, the area where the container body bulges out the most is the area where the shoulder 14 transitions into the cylindrical body 15, and another important area of protection is the heel area 16 and the bottom bearing area 18. is the surface of

In the case of the container 26 constructed as a shear shown in FIG. 7, the important areas of protection are the shoulder 37, the heel 43 and the bottom bearing surface 44. Container 4 having the shape shown in Figure 8
In case 5, the important areas of protection are the shoulder extension 47, the lower side wall extension 48, the heel part 49 and the bottom edge 53. In the container 50 having the shape shown in FIG.
Protection is required for the top part of 2 and the bottom support surface. 1st
In the case of the container 60 shown in FIG. 9, it is important to protect the shoulder bulge 61, the heel bulge 62, and the bottom end surface. The lid 27 of the container shown in FIGS. 2 and 6
consists of a crown-shaped cap 28 made of aluminum, fitted with a tension ring 29 to facilitate the removal of the cap by pulling on it.

On the back side of the cap 28 is placed a gasket 30 of a resilient material, such as polystyrene. The gasket 30 is sized to annularly surround the mouth end 12 of the container 10 and preferably seal the entire surface of the opening 11. The shape of the mouth end 12 may be any shape of a known container mouth end. The crown cap 28 is clipped to the mouth end 12 of the container in a tight engagement manner and is capped along the sloping neck 13. The gasket 30 provides a gap between the container mouth end and the lid and cushions the impact on the container when the container is tipped over as described in connection with FIG. 7th~
The embodiment shown in FIG. 9 includes another important feature of the invention.

A container 26 in FIG. 7 shows a glass shear for heavy food, and is made as a wide-mouthed container.

The shear has a mouth end 34 with ear-shaped threads 35. Beneath the mouth end 34 is a cylindrical neck 36. The glass wall of the shear 26 is curved and radially expanded at the shoulder 37 and then transitions into a cylindrical side wall of approximately the same diameter as the shoulder. On the bottom side, there is a heel portion 43 curved with a relatively large radius of curvature, and a bottom bearing surface 44 connected thereto. For example, a plastic sleeve 25 is applied to the shear. The sleeve 25
The axial dimension of is selected such that in the raw state (see FIG. 5) its upper edge 25a reaches slightly above the shoulder 37 and its lower edge 25b reaches below the bottom bearing surface 44. When the material of the sleeve 25 is fitted onto the shear 26 and contracted, the sleeve tightly covers the glass wall region from the neck 36 to the bottom bearing surface 44.
When a screw cap (not shown) is placed over this shear, the lower edge of the skirt portion that hangs below the lid tightly engages the upper edge of the sleeve and the neck 3 of the wall of the shear.
6 and the lid are completely sealed to prevent foreign objects or insects from entering between them. Of course, as mentioned above,
Protection against contact abrasion, abrasion, etc. of the large diameter body and bottom bearing surfaces is achieved by the sleeve.

The sleeve applied to the shear may be a seamless sleeve 25 or a heat-sealed sleeve 19. In the example of FIG. 9, all side walls and the bottom bearing surface of the container 10 are covered by a plastic sleeve 19b.

This exemplifies a sleeve that extends almost the entire length of the container, with the sleeve 19b being collapsed into the neck 13 after it has been deflated.
The dimensions are selected so that the sleeve covers from the heel area to the bottom surface. The method of shrinking and sealing the sleeve to the container is as described herein.
The narrow-necked container 45 of FIG. 8 has a mouth end 46 suitable for a conventional crown cap, and the elongated neck transitions into a bulbous shoulder 47. Below the shoulder 47 is an intermediate cylindrical body;
The torso continues with an outwardly bulging heel portion 48 having a curved portion 49. The curved portion 49 is connected to the bottom bearing surface 53. For example, the seamless sleeve 25 is placed over the glass container 45 from just above the shoulder 47 to the bottom annular bearing surface 53 and contracted. As mentioned above, the sleeve 25 on the body can be provided with a label or decorative surface image 24. In the embodiment of FIGS. 7 and 9, in which the sleeve is applied to cover substantially the entire glass wall of the shear 26 and container 10, up to 85% of the fragments will be within the sleeve in the event of a rupture of the container. will be put on hold.

In the embodiment of FIG. 8, up to 70% of the debris can be retained within the sleeve. The container is therefore further characterized by a high degree of safety. Examples of materials suitable for use in the coated container will now be described in relation to each of the above embodiments.

Containers such as those illustrated in the drawings by reference numerals 10, 50, 60, 45 or 26 are manufactured by conventional molding techniques from soda lime silicon glass compositions well known in the container making art.

The plastic material of sleeve 19 or 25 is molded with the primary and secondary biaxial orientation described above. When the thermoplastic material that is the raw material for the sleeve is first extruded, it is stretched by a desired amount in a direction transverse to the axis of the sleeve to be produced, that is, in a direction corresponding to the circumferential direction of the sleeve. When extruded and cooled, the plastic is given a slight secondary orientation transverse to the machine direction. The direction of this secondary orientation is the so-called lateral direction. As mentioned above, if the degree of orientation of the primary orientation is represented by M and the degree of orientation of the secondary orientation is represented by T, a plastic tube suitable for use as a sleeve material has an orientation ratio M/T. 2 or more. This tube can be cut into sheets or webs by cutting along its length. The web has the orientation characteristics described above and, if desired, is preprinted as described above. The web is then longitudinally cut into individual blanks as shown in FIG.

During cutting, the height of the material 20, 21 is of course matched to the width of the particular sleeve desired and the circumferential dimension (5th
Figure) Cut to desired dimensions. When printing on the web, multicolored decorative images can be printed at high speeds on a printing press.

It has been found that it is more efficient to apply an antistatic layer to the surface of the web opposite to the printing surface before printing.
An example of a suitable antistatic agent to be applied is a water-alcoholic solution of lauryltrimethylammonium chloride. This compound was manufactured by Arnlour Inc., Chicago, USA.
d) produced in the chemical sector and 1 Alquad 12
It is commercially available under the trade name ``Arq Dl2''''. Surface treatment with a solution of this compound has the additional benefit of increasing the adhesion of the plastic sleeve to the glass container when the sleeve is shrunk over the container. You also get benefits.
It is important that the primary orientation of the web and the ultimate shrinkage response be along the long side of the material of the sleeve 19 (2223 in FIG. 4) or, in the case of seamless sleeve 25, circumferentially thereof.

After cutting the web into desired width (height) dimensions in the longitudinal direction, it can be wound into rolls and stored.
The preprinted roll is then fed to a cutter where it is further shredded into pieces for each sleeve 19 and fed to a mandrel 31 as shown in FIG.
The density and wall thickness of the sleeve material can be controlled and adjusted during the initial sheet or film forming stage.

This can also be controlled using post-homing technology. For example, polystyrene sheets can be made to have a density range up to 65 pounds/cubic foot (approximately 30 kg/30 Cr!I3) depending on the desired end use. The final density of the sleeve material on the container will thereby be reduced somewhat further, since the subsequently heated expanded plastic may expand further as it shrinks on the container. Example 1 A sleep material is made from a sheet of foamed plastic material having the orientation described above.

Examples of the types of plastics used are as follows: A copolymer of a carboxylic acid-containing monomer and ethylene. It is commercially available under the trade name "Surlyn". Medium to low density polyethylene, polypropylene, polystyrene, cellulose propionate and cellulose butyrate. The preferred sheet thickness is 0.01 to 0.03 inches (0.01 to 0.03 inches). approximately 0.25 to 0.75 mm).

In actual use, 10 to 12 fluid ounces (0.
The most suitable sleep material for coating beer bottles or alcoholic beverage bottles having a capacity of 3 to 0.351 is approximately 0.02 inches thick, oriented as desired, and has a density of approximately 15 pounds. /cubic foot/(approximately 7.
It has been found that it was made from expanded polystyrene sheet of 8k9/30cm3). The coating on one side of this polystyrene sheet is about 1 to 2 times thicker than the thickness on the opposite side, and when the mandrel 31 (see Figure 12) is used, the side with the thicker coating becomes the inner surface of the sleeve. It is made into a cylindrical sleeve.

When this polystyrene sheet is immersed in an oil bath at 100°C, it expands slightly immediately after immersion, and then begins to shrink.

In the present invention, the shrinkage rate for 1 minute after immersion was used as a measure of orientation. In this case, the shrinkage rate is 30% in the sleeve circumferential direction M.
The value was 5% in the sleep axis direction T. Furthermore, when this polystyrene sheet is immersed in the oil bath, it curls like a clockwork so that the side with the thicker film is on the inside9, and the thicker the film, the stronger the shrinkage force. By attaching the sleep material having the above performance to a container and keeping it in a heated atmosphere, the material shrinks and tightly covers the container. When a cylindrical sleeve is made using the above polystyrene sheet and the thicker side of the film becomes the outer surface of the sleeve, which is the exact opposite of the sleeve making method mentioned above, and when it is attached to a container and contracted, it is possible to Shrinkage on the contact surface side of the sleeve is insufficient, causing wrinkles and poor adhesion between the container and the sleeve.

In particular, if the upper edge 22 of the sleeve located at the shoulder 14 of the container is not sufficiently contracted, it will curl in a direction away from the outer wall of the container, resulting in the upper edge not coming into close contact with the container. If the degree of adhesion deteriorates, during the washing process when filling the container with contents, when washing water is sprayed with high pressure, the washing water will be forced into the gap between the upper edge 22 and the container and the sleeve will peel off. This results in a serious drawback.

Therefore, it is important that the sleeve tightly adheres to the container, and even if the sleeve is not oriented in the axial direction T, the contracted shape of the upper edge 22 of the sleeve is unstable, and it is difficult to contract the sleeve when attached to the container. In some cases, the container becomes wavy and the adhesion of the container is poor.

Example 2 The sleeve material is made from a sheet of non-foamed plastic material having the orientation and shrink properties described above.

A similar type of plastic material as exemplified in Example 1 is used. The preferred thickness of the sheet is 0.0025 to 0.007 inches (about 0.06 to 0.17 mm), with the thickness selected taking into account the desired functionality of the sleeve covering and the economics of the final container. In practice, the use of a sheet of clear polystyrene shrink film about 0.005 inch (about 0.12 mm) thick for coating the beer bottles and alcoholic beverage bottles illustrated in Example 1 is particularly useful. has been found to be appropriate. 11 to 17 show an example of the manufacture of a container covered with a joined sleeve. A sheet of material as exemplified above is cut into the shape of the sleeve 19 material (rectangular in the illustrated example) as shown in FIG.

Decorative image 2 printed on the material before or after cutting
4 is attached. The material is fed to a rotating mandrel 31. The mandrel 31 is mounted on a shaft 32 and held there by a collar 33 and a set screw 34. The shaft 32 is rotated with suitable power. The material is held on the mandrel by suction by a vertical row of vacuum holes 35. The suction hole 35 is connected to a vertical passage 36 and communicates with the internal passage of the hollow shaft 32 through a radial opening 37. The mandrel 31
is placed concentrically with the strip-off sleeve 38 carried on the bracket of the vertical spindle 39 (FIG. 12). The material is attached to the mandrel 3 by suction at its leading edge 21.
1 and is wound around the outer surface of the mandrel 31 as the mandrel rotates. At this time, the stripping sleeve 38 is in its lowest position and does not interfere with the material. The mandrel is a container 1 into which the finished sleeve is fitted.
It has a desired diameter dimension adjusted to 0. When the mandrel rotates once, the trailing edge 20 of the workpiece meets the leading edge 2.
Form a seam area for overlap welding and overlap welding.

Welding in the seam area is done with heat and some pressure;
In the illustrated example, a heater 40 is used. The heater 40 has a Teflon surface layer 40a to prevent this protrusion from adhering to the sleep material. When the heater 40 is pressed against the seam area, heat sealing and ironing are performed by the heat and pressure of the heater 40, and the thickness of the overlapping seam area is reduced to approximately the same thickness as the other parts. In this way, an endless sleeve is created.

5 heater 40 is carried on a suitable carriage and brought into contact with and away from the material at the appropriate times. In addition to the above example, the overlap bonding can also be performed using a hot-melt adhesive.

That is, as shown in FIG. 411, if adhesive is applied between the inner edge 20 of the material and the imaginary line A, and the adhesive is activated by the heater 40, it can be easily bonded on the mandrel 31. will be done. In this case too, the joining area is ironed by the heater 40. As seen in FIG. 13, the container 10 is placed over and in axial alignment with a sleeve 19 made on the mandrel 31. The container is at an elevated temperature, i.e. 175°F.
1' (approximately 80°C). When the peel-off sleeve 38 is raised, it engages the lower edge of the formed sleeve 19 and lifts the sleeve upwardly and off the mandrel 31. When the sleeve 19 leaves the mandrel 31, the cylindrical shape is deformed into a somewhat oval shape due to the lap joint. Since the sleeve has a diameter slightly larger than the maximum diameter of the container as described above, it would be expected that there would be loose fit when the sleeve is fitted onto the container. However, as described above, since it is deformed into an oval shape by stacking, it has enough contact to be held on the container at the desired height and will not fall off. This contact state is shown in FIG. Good results are obtained when using a heated container when contracting the sleep on the container.

In other words, the container is heated to 175 to 300 points (approx. 80 to 149 degrees Celsius).
) It is best to preheat it to a temperature in the range of . When using the polyethylene materials illustrated in Examples 1 and 2,
Preferably, the container is preheated to about 220 EP (about 104° C.). After being pretreated in this way, the shape of the shrunk film of the sleeve will easily match the container. Note that this preheating temperature can be appropriately selected in consideration of the plastic material used and the thickness of the sleeve. On the other hand, the thickness of the sleeve is also appropriately selected in consideration of the shape of the container to which it is applied, the functions that the sleeve should have, manufacturing costs, etc. Figure 15 shows sleep 19
is shown initially fitted into the container, the lower end of the sleeve being spaced downwardly from the bottom 17 of the container by a distance indicated by the reference numeral 0.

Generally, this spacing 0 is approximately x inches (approximately 1.3Cf11)
This is sufficient to form a ring-shaped bearing surface 18 (see FIG. 3) of the bottom 17 of the container. In the position shown in FIG. 15, the peeling sleeve 38 is pulled away and the container 10 fitted with the sleeve 19 is held in suspension by the conveyor gripper 19 shown in FIG. 16 and transported to the oven 42 shown in FIG. It will be done.

Open 42 is constructed of long tunnels, and heated air is circulated vertically through the tunnels.9
, the container is moved through this hot air tunnel.
The temperature of the heated air inside the open is approximately 400 degrees F' (approximately 20
4°C) is preferred. Under these conditions, the sleeve is contracted in a period of 4 to 15 seconds until it fits snugly and conforms to the shape of the container. Then, a container with a protective coating and an annular bearing surface on the bottom as shown in FIG. 1 is completed. Increasing the temperature of the circulating heated air reduces the time required for contraction. Of course, this temperature can be determined depending on the desired production rate and the type of material of the sleeve being shrunk. The required shrinkage time will be slightly longer if heated air is not circulated and is kept in a tunnel or stationary. However, if the container is preheated as described above, it will hold about 4000P (approx.
Even when using still air (4°C), the required time is 6 to 15 seconds. When a sleeve made of polyethylene film as exemplified in Example 2 is used,
30 minutes in an oven at 600'P (approximately 316℃) in still air.
Second heat treatment is required. Most shrinkable thermoplastic materials can be shrunk at temperatures of 175 to 8000F (about 80 to 427C) without requiring a significant amount of time. Preheat the container to 175 to 300 F depending on the type of container sleeve
Better results are obtained by varying the temperature within the range (approximately 80 to 149°C). Once the sleeve 19 has been crimped and shrunk against the container 10, the composite container is removed from the oven. Due to the presence of an overlapping seam line in the axial direction of the sleeve, the thickness and/or density of this seam line area differs somewhat from the remaining single layer portion. This may result in slight protrusions or bumps in the area of the bottom bearing surface 18 when the sleeve is retracted. These small bumps are smoothed out by pressing the bearing surface area against a flat hard surface, such as a flat iron plate. The bearing surface of the annular flat container is then formed. The container thus completed is then filled with the article and covered with a lid (FIG. 2). The working method for attaching the seamless sleeve 25 to the container is exactly the same as that for the joined sleeve 19 except for the joining work.

The results of a comparative test between a container protected using the sheet of the present invention and a conventional container are described below.

10 fluid ounces (approximately 0.31) in the shape illustrated in Figure 1.
A capacity container was filled with carbonated beverage and sealed under pressure equal to 4.5 gas volumes.

This was tested for drop strength in comparison with a control container not according to the invention, ie, without the protective covering of sleeve 19. The number of test containers was 24 each, and the container main body was 10 (
Figure 1) were all identical in terms of capacitance shape. Just for comparison, the control sample containers were provided with a conventional metal oxide outer coating. On the other hand, containers protected using the sheet of the present invention were not subjected to such coating treatment, and only the sleeve was covered with the sheet of the present invention. Of the 24 test samples, 12 in each half were dropped with the side facing a 3/4 inch (approximately 1.9 cm) thick steel plate, and the remaining 12 in each half were dropped with the bottom facing the steel plate. I let it happen. Each sample container is dropped by gradually increasing the drop height until it is broken by impact, and the average height limit that can withstand the impact without breaking (this is set as 0 average remaining height 1 and below) ).

The test results were as follows. In addition, in this test, when a container was broken, the containers protected using the sheet of the present invention had 34 to 37% more reduced scattering of fragments than the control container.

This shows that the safety of containers protected using the sheet of the invention is increased by the cover of SLEEP 19. Furthermore, containers protected using the sheets of the present invention were tested in a standard CONBURIMPA test (CONBURIMPA).
CTTEST) was conducted.

This test method is based on AS Part 5 (April 1970).
D-1880-68. 4th filled with water
/5 quarts = approximately 0.761) were placed side by side in rows in a regular box with the partitions removed.
The test container was covered with a sleeve 25 as shown in FIG. The sleeve is approximately 0.075 inch (approx.
．． It was made from expanded polystyrene with a thickness of 2 mm. The results of this test confirmed that the strength of containers protected using the sheet of the present invention was increased compared to when packed in boxes with partitions v. Other examples protected using container sheets of the present invention are Nos. 18 and 19.
As shown in the figure. The glass container 50 shown in FIG. 18 is characterized by having a raised lip 52 on its body 51. The glass container 50 shown in FIG. The sleeve 19 is made of the rectangular material described above. Sleeve 19' is contracted over the container in the manner described above, conforming to the contours of the ridges and valleys of the container and snugly covering container body 51. In the case of a container of this shape, the initial diameter when made with the mandrel 31 is 5.
The sleeve 19' undergoes a relatively strong contraction since the final diameters of the neck, the ribbed body 52, the heel and the bottom are reduced to considerably different degrees.
This strong contraction causes the sleep to adhere snugly to the irregular surfaces of the glass container. Moreover, at this time, no contraction occurs in the height dimension of the sleeve (corresponding to the side edges 20, 21 of the material in FIG. 4). This is due to the aforementioned preferred orientation in the film from which the sleeve was made. Another irregularly shaped container 60 shown in FIG. 19 has a shoulder portion 61 on its body.

This shoulder portion 61 is the large diameter portion of the container. A large diameter portion 62 that bulges out in the same way near the bottom
There is. Between the two large diameter parts 61 and 62 is a small diameter recessed part 63. The shape of this container is roughly similar to what is called an "hourglass" shape. In this case too, the sleeve 19a is made from a rectangular piece of foam shrinkable plastic material. The sleeve 19a is suitable for glass containers shaped like container 60, or square or panel-shaped containers used for special purposes. The example of FIG.
This shows an example in which an adhesive is applied to the inner surface of the holder.
When the material for the sleeve 19b is made, a hot melt adhesive is applied to the side that will later become the inner surface of the sleeve. This helps achieve a reliable layering when making sleeps. The temperature of the glass container is approximately 220 degrees F (approximately 104 degrees Celsius)
), the hot-melt adhesive in the overlapped seam area is activated by the heat and can be applied without the use of heater 40, e.g. It will easily seal with some pressure. This sleeve is attached to the container 10.
After mating as shown in the figure, put it in the oven.
Residual heat in the container and heat in the oven (4000F - approx. 204℃)
) both cause the sleeve to contract and activate the adhesive to securely bond it to the container. In this case, 60-70% of the glass fragments remain within the sleeve covering upon container rupture. Therefore, safety is increased compared to the example shown in FIG. Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to the above embodiments.

[Brief explanation of the drawing]

Figure 1 shows one of the containers protected using the sheet of the present invention.
It is a perspective view showing an example. FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. FIG. 3 shows a perspective view of the glass container portion of the container of FIG. FIG. 4 is a perspective view showing an example of a material for a covering sleeve made of the sheet of the present invention. FIG. 5 shows another example of sleeve material. FIG. 6 is a perspective view of the container shown in FIG. 1 when it falls down on a horizontal surface. FIG. 7 is a partially cutaway front elevational view of another example of a container protected using the sheet of the present invention. FIG. 8 is a front elevational view of yet another example of a container protected using the sheet of the present invention. FIG. 9 is an elevational view of an example of a container protected using a sheet of the invention that is sleep coated over substantially its entire length. FIG. 10 is a drawing similar to FIG. 1, but with a portion of the sleeve cut open and turned inside out to show the decorative printing on the inner surface of the transparent sleeve. 11 to 17 are perspective views for sequentially explaining the manufacturing process of a container protected using the sheet of the present invention, and only FIG. 14 is a plane view taken along line 14-14 in FIG. 13. It is a diagram. 1st
8 and 19 each show in perspective view an example of a container protected using a sheet of the invention having an irregular surface shape. 19... Covering sleeve or covering sleeve material 24... Decorative image or label, 25... Seamless covering sleeve, 31... Mandrel, 35
...Vacuum suction hole, 38...Peeling sleeve, 40.
··heater.

Claims (1)

[Scope of Claims] 1. A sheet of extruded foamed thermoplastic heat-shrinkable material for protecting container coverings, which when formed into a foamed sheet has a predominant orientation M in the direction of the molding machine and a minor orientation in the transverse direction. It is molded as a biaxially oriented product with an orientation T, and M/T
1. The sheet of foamed thermoplastic shrinkable material, characterized in that the ratio of . 2. A sheet of extruded foamed thermoplastic heat-shrinkable material for protecting container coverings, the sheet having a thickness of 0.01 to 0.
．． 03 inches, the thickness of the coating on the surface of the sheet directly in contact with the container is 1.2 times greater than the thickness of the coating on the surface exposed to the outside, and the sheet is molded as biaxially oriented with a predominant orientation M in the direction of and a slight orientation T in the transverse direction, and
1. A sheet of foamed thermoplastic heat-shrinkable material, characterized in that the ratio of /T is substantially greater than 1. 3. A sheet of extruded foamed thermoplastic heat-shrinkable material for protecting container coverings, the sheet having a thickness of 0.01 to 0.
．． 03 inches, an antistatic layer is applied to the surface of the sheet that is in direct contact with the container, and when the sheet is formed into a foam sheet, it has a main orientation M in the direction of the molding machine and a slight orientation in the lateral direction. 1. A sheet of foamed thermoplastic heat-shrinkable material, characterized in that it is formed as biaxially oriented with orientation T and has an M/T ratio substantially greater than 1. 4. A sheet of extruded foamed thermoplastic heat-shrinkable material for protecting container coverings, the sheet having a thickness of 0.01 to 0.
．． 03 inches, and an antistatic layer is applied to the surface of the sheet that directly contacts the container, and the thickness of the film on the surface of the sheet that directly contacts the container is greater than the thickness of the film on the surface exposed to the outside. M/T 1. A sheet of foamed thermoplastic heat-shrinkable material, characterized in that the ratio of