CN1962372A - Packing material and manufacture method thereof - Google Patents

Abstract

The invention relates to a package material, formed by 3-5 layers of materials, which comprises a support layer (12) strengthen the package, a most inner layer (16) for keeping the quality of liquid and thermoplastic sealing, and an insulated layer (14) between the support layer and the most inner layer, to insulate oxygen and sunlight, as well as high-frequency induction conductive layer. One side of longitudinal area of package material is up-to-down symmetry, semi-sealed, while it comprises most inner layer (16) and insulated layer (14) from outer to inner. The invention also provides relative production.

Description

A kind of packaging material and its manufacturing method

technical field

The invention relates to a packaging material for making packaging containers, especially a composite packaging material used in the field of aseptic filling, and also relates to a manufacturing method of the packaging material.

Background technique

In the beverage filling equipment, the roll packaging material is stretched into a strip shape, the strip packaging material is formed into an ellipse in the forward direction, and the elliptical packaging material is further formed into a cylindrical packaging material, and the two sides are overlapped longitudinally Seal (longitudinal seal) to form a tube. The tube is transversely sealed (transversely sealed) at one end to form the top (or bottom) of the packaging container. Fill the desired content, and seal the remaining end of the tube correspondingly (horizontally) to form the bottom (or top) of the packaging container. The transverse sealing area is then cut by a cutter to form individual packaging containers, optionally, the packaging container is further folded along the creases to form the final shape, i.e. brick or other shape, by means of corresponding folding and forming devices packaging container.

At present, the roll-type packaging materials used for packaging containers are mostly composite materials, which are laminated and compounded by 3-5 layers of materials as a whole, and are not easy to separate. At least including: the supporting layer that stabilizes and strengthens the packaging container, maintains liquid quality and The innermost layer for thermoplastic sealing, there is an insulating layer between the support layer and the innermost innermost layer to isolate oxygen and sunlight and prevent the loss of product taste, and it is also a conductive layer for high-frequency induction.

The longitudinal sides of the roll packaging material are formed by cutting, and when they are directly overlapped to form a longitudinal seal, they will be exposed to the contents of the finished package. At this time, the packaging material contains absorbent materials, such as paper or cardboard, and the contents will be sucked into the packaging material, so that the packaging material will be corroded and softened, and there may even be dangers such as leakage. On the other hand, in aseptic packaging, if the barrier layer contains metal, such as aluminum foil, this unprotected cut edge cannot come into contact with the contents and must be protected in some way, since metal has a negative effect on food.

A known method of preventing the cut edge from coming into direct contact with the contents of the packaging container is to cover the cut edge with a longitudinal plastic strip, such as a PP (polyethylene) strip, which moves forward while forming the tube , over the cut edge and welded to the plastic covering inside the packaging material. One edge of the packaging material overlaps the opposite edge so that the longitudinal joint of the packaging material tube is strong and durable. But the disadvantage is that the thickness of the packaging container in the longitudinal junction area will be twice that of the rest of the packaging container, making the transition of the longitudinal sealing area not smooth enough, which affects the appearance and is not conducive to automatic packing and handling on the production line.

Chinese patent ZL97193921.7 (invention name: strip-shaped laminated packaging material, its manufacturing method and packaging container made of the packaging material) adopts the method of obliquely cutting the edge of the material strip, and wraps the edge through a separate laying stage up, while completely covering the cut edges with a layer of heat-sealable material.

However, in a diagonal cut, the cut is made at an angle to the horizontal plane of the strip that is small enough to allow good bonding of the outer covering along the beveled edge, but at the same time Sufficiently large so that the edge is durable for handling within machinery and in storage. Therefore, it is difficult to control the beveling process to ensure that the angle of beveling is appropriate.

Contents of the invention

The purpose of the present invention is to provide a packaging material, in which no cutting edge is exposed to the contents of the finished package during longitudinal sealing, and the thickness of the overlapping joint is less than twice the thickness of the packaging material itself.

The technical solution adopted in the present invention is: the longitudinal side area of the packaging material is up-and-down symmetrical and semi-closed structure, at least from the outside to the inside: the innermost layer and the insulating layer.

The method for producing the above-mentioned packaging material is: cutting, indentation, coating of viscous agent, folding, and compaction.

The packaging material is composed of three to seven layers of film composite structure. It at least includes: a supporting layer, an insulating layer, an innermost layer, and may also have an outer layer and an adhesive layer.

The outer layer refers to the liquid-tight covering layer of the outer plastic, which can provide effective protection for the contents of the packaging container and prevent moisture and liquid from intruding into the packaging material. It is composed of thermoplastic materials such as polyethylene.

The support layer, that is, the core layer, has high mechanical strength and is used to maintain and support the shape of the packaging container. The core layer can give good mechanical stability to the shape of the packaging container, so that the packaging container can be distributed in a simple manner and can be handled conveniently. Food-specific cardboard can be used as the base material.

The insulating layer is used to isolate oxygen and sunlight and prevent the loss of product taste, and also serves as a conductive layer for high-frequency induction heating. Metal conductive materials containing metal foil, such as aluminum foil and steel foil filler, can be used, as well as conductive layer films formed by steps such as vapor deposition, electroplating, and printing. Due to the conductivity of the conductive layer, when a high-frequency current is applied to the external coil, an induced current will be generated in the conductive layer due to high-frequency induction, and the induced current will generate heat, which will be transferred to the innermost layer through the conductive layer. The layers are heated, softened and melted by this heat, thereby forming the sealed area.

The innermost layer is the innermost layer of the container wall, which is in direct contact with liquid food, can maintain the quality of the content, prevent the liquid from penetrating and wetting relative to the container support layer, and is softened and melted by heat during heat sealing, so as to To form the sealing area, thermoplastic materials such as polyethylene can be used.

Adhesive layer: In order to strengthen the stability between the outer layer and the support layer, and between the insulating layer and the innermost layer, an adhesive agent can be added in the middle. If the viscous agent is made of thermoplastic materials such as polyethylene, so that the material of the viscous layer is similar to that of the outer layer and the innermost layer, this layer may not be listed separately.

One longitudinal edge of the packaging material is cut away to form a protruding bridging tab. Indentation is made on the bridging sheet, adhesive is coated, and the part outside the indentation of the bridging sheet is folded around the indentation and sealed on the part inside the indentation of the bridging sheet.

The packaging material thus formed has no cut edge exposed to the content when the packaging container is sealed longitudinally because the bridging sheet is protected by a surrounding plastic layer (innermost layer).

It is also possible to suitably creasing the above-mentioned board, that is, by using a creasing tool, so that the board has creasing lines so that in the subsequent process, the board can be easily folded into a final packaging container.

The shape of the packaging container made of the packaging material of the present invention can be brick-shaped (parallelepiped), and shapes such as hexagonal column, tetrahedron, and triangular top.

Description of drawings

Figure 1 is a schematic diagram of the structure of composite packaging materials currently used for aseptic packaging;

Fig. 2 is for manufacturing the packaging material of the present invention, the outline schematic diagram after the first process (cutting) of the existing packaging material;

Fig. 3 is for manufacturing packaging material of the present invention, the structural representation of existing packaging material after the first process (cutting);

Fig. 4 is for manufacturing the packaging material of the present invention, the outline schematic diagram after the existing packaging material carries out the second process (indentation);

Fig. 5 is for making the packaging material of the present invention, the outline schematic diagram after the existing packaging material carries out the 3rd process (coating adhesive);

Fig. 6 is for manufacturing the packaging material of the present invention, the outline schematic diagram after the existing packaging material carries out the 4th process (folding);

Fig. 7 is for manufacturing the packaging material of the present invention, the outline schematic diagram of existing packaging material after the fifth process (compacting);

Fig. 8 is to manufacture the packaging material of the present invention, the structural representation of the existing packaging material after the fifth process (compacting);

Fig. 9 is a schematic diagram of longitudinal sealing using the packaging material of the present invention.

Detailed ways

The production of the following packaging materials can be carried out on the packaging material production line or the finished beverage filling production line.

Packaging material 1 is a six-layer composite packaging material, from outside to inside (from top to bottom): outer layer 11, support layer 12, first adhesive layer 13, insulating layer 14, second adhesive layer 15, innermost layer 16. They become an inseparable overall packaging material through compounding, and the structures of the left and right longitudinal ends are completely symmetrical.

Cutting is performed on the packaging material, that is, a part of a longitudinal side region of the board-shaped packaging material is milled from the outside to the inside, so that the thinned part of the remaining board-shaped packaging material can be folded to form a protective edge.

The packaging material 1 has a thickness of H. After cutting the packaging material 2, the cut part becomes a bridging piece 21, and the cutting thickness is h. The preferred solution is: h is 1/2 of H. The optimal solution of cutting width B is: 6? mm. But the bridging sheet 21 of packaging material 2 has insulation layer 14 at least, the second adhesive layer 15, innermost layer 16, or in other words, the cutting edge 22 place of packaging material 2 has at most complete outer layer 11, support layer 12, the second An adhesive layer 13 .

The packaging material 2 is indented by the extrusion roller device to form the packaging material 3, and the indentation position b is preferably 1/3 to 1/2 of the cutting width, that is, the width B of the bridging piece 21 . The bridging piece 21 is divided into two parts, the outer part 51 and the inner part 52, from the indentation 31 .

At least 1/2 surface of the bridging sheet 21 of the packaging material 3 is coated with an adhesive 41 to become the packaging material 4 .

Then, the outer part 51 is turned upwards along the indentation 31, and pasted on the inner part 52 through the adhesive 41, and becomes the packaging material 5 during the forming process.

The outer 51 and the inner 52 of the packaging material 5 are compressed to make the final packaging material 6 and become a composite whole that is difficult to separate.

In the packaging material 6 of the present invention, the left end is different from the right end, as shown in Fig. 7 and Fig. 8 . The left end is up-and-down symmetrical and semi-closed structure. From the outside to the inside, the innermost layer 16, the second viscous layer 15, and the insulating layer 14 are arranged. And the right end still belongs to the laminar structure that can be regarded as parallel up and down, and from outside to inside (from top to bottom) is successively: outer layer 11, support layer 12, first viscous layer 13, insulating layer 14, second viscous layer 15 , the innermost layer 16.

In this embodiment, the packaging material is longitudinally sealed during the process of making the tube of the packaging container, as shown in FIG. 9 . The two longitudinal sides 2-1 and 2-2 of the packaging material overlap together. The above-mentioned processed side 2-1 is in the inner layer of the packaging container, which is structurally symmetrical and semi-closed (as shown in Figure 8). From the outside to the inside, the innermost layer 16, the second viscous layer 15, Insulation layer 14. However, the outer packaging material at the lap joint of the packaging container is still approximately parallel six-layer packaging material, which are as follows from the outside to the inside: the outer layer 11, the supporting layer 12, the first adhesive layer 13, the insulating layer 14, and the second adhesive layer. 15, the innermost layer 16. Therefore, the overlap is where the two innermost layers 16 are in contact.

Since the insulating layer 14 is a conductive layer with conductivity, when a high-frequency current is applied to the external coil, an induced current will be generated in the conductive layer due to high-frequency induction, and the heat caused by the impedance will be transferred to the two most On the inner layer 16, the two innermost layers 16 are heated, softened, melted, and sealed together by this heat.

In addition, the semi-closed structure of the inner layer at the overlap makes the innermost layer 16 in contact with the content, and no cutting edge can contact the content.

A heat-sealing area is formed by high-frequency induction heating at each predetermined interval in the transverse direction of the above-mentioned longitudinally-sealed tube, which is preferably below the liquid surface, and transversely sealed. The package is given the desired final geometry, such as a shaped brick pack, by additional forming and heat sealing operations.

The packaging container formed above has high air-tightness and liquid-tightness at the longitudinal joints, and at the same time can protect the packaged product from direct contact with the metal layer.

When the above-mentioned packaging material is made into a packaging container, the lap joint on the longitudinal seam is thinner than twice the thickness of the packaging material, and the transition zone from the longitudinal connection to the surrounding packaging material is almost flat, so that it can be seen from the outside of the packaging container. It looks smoother vertically.

Claims (6)

1. A packaging material, which is formed by laminating 3-5 layers of materials and is not easy to separate. It has at least a support layer (12) that stabilizes and strengthens the packaging container, and an innermost layer that maintains liquid quality and performs thermoplastic sealing. (16), there is an insulating layer (14) between the support layer and the innermost layer, which isolates oxygen and sunlight and prevents the loss of product taste, and is also a conductive layer during high-frequency induction. It is characterized in that: packaging material The side area in the longitudinal direction is symmetrical up and down and has a semi-closed structure, at least from the outside to the inside: the innermost layer (16) and the insulating layer (14). 2. A method for manufacturing a packaging container as claimed in claim 1, the method can manufacture a whole by laminating and compounding 3-5 layers of materials, a kind of packaging material that is not easy to separate, with at least a supporting layer (12), Innermost layer (16), insulating layer (14), is characterized in that: The first step is to perform cutting processing, that is, to mill a part of a longitudinal side area of the plate-shaped packaging material from the outside to the inside to form a bridging piece (21); In step 2, the packaging material (2) is creased (31) to form a new packaging material (3); In the 3rd step, the adhesive agent (41) is coated on the bridging sheet 21 of the packaging material (3); Step 4, turn the outside of the indentation (51) upward along the indentation (31), and make it stick to the inside of the indentation (52) through the adhesive (41); In step 5, compress the outside (51) and inside (52) of the indentation of the above-mentioned packaging material to make the final packaging material (6). 3. A method of manufacturing a packaging container as claimed in claim 2, characterized in that: the packaging material (1) has a thickness of H, and the cut thickness is h, and h is 1/2 of H, but the packaging material ( 2) The bridging sheet (21) has at least an insulating layer (14) and an innermost layer (16). 4. A method for manufacturing packaging containers as claimed in claim 3, characterized in that: the cutting width B is between 6-9mm. 5. A method of manufacturing a packaging container as claimed in claim 3, characterized in that: The packaging material (2) is indented by the extrusion roller device, and the indentation position (b) is 1/3 to 1/2 of the cutting width, that is, the width (B) of the bridging sheet (21), thereby forming the packaging material (5) Indentation outer (51) and indentation inner (52) two parts. 6. A method of manufacturing a packaging container as claimed in claim 3, characterized in that: At least 1/2 width of the bridging sheet (21) of the packaging material (3) is coated with an adhesive (41) to become the packaging material (4)

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