JPS62270313A - Manufacture of band for packaging - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention & Detailed Description of the Invention (Field of Application in the FFL Industry) The present invention relates to a thermoplastic, PP, suitable for winding machines, the ends of which can be welded, for example by frictional heat.
A method of manufacturing a packaging strip that can withstand wrapping tension using PETP, R'8, etc. is inspired by a method of extruding the base layer, stretching the base layer, and winding it.

Base layer is defined within the scope of the invention as a strip of material when this type of material is extruded, or as a strip or a wide film when a board or a wide film is extruded, stretched and, after stretching, divided into strips by cutting. Rent materials. Represents a wrapping band that withstands the winding tension when it is regulated and does not disintegrate at all or to a significant extent due to the sacrifice.

BACKGROUND OF THE INVENTION Within the framework of similar known measures, single-layer base layers of PP or PETP or PA are extruded. This thing is not without its drawbacks. Packaging bands made of PP tend to crack or tear and are highly rosaceous and cannot withstand the wrapping tensions of the packaged products at elevated temperatures during transportation.

High strength bands cannot be made from PP. Certainly PI
' is a relatively inexpensive material and has good weldability (although it must be accepted that this is also the case when welding is carried out by frictional heat. PETP packaging strips certainly do not have the above-mentioned tendency to split). High-strength strips can also be produced from PETP, which do not have any adverse effects even at high transport temperatures.However, PETP is an extremely expensive material.In addition, packaging made from this material Another hindrance is that the strips are not easy to weld. All this also applies to packaging strips made of PA.

On the other hand, thermoplastic plastics for different uses are known which have good extrudability and are inexpensive, but which are not or only poorly suited for the production of packaging strips. These are in particular PE and II O-PE. These cannot be used because their Sake Sen behavior is too high. This is because they cannot withstand higher transport temperatures and have poor weldability.

(Object of the invention) The present invention certainly includes the material ['P, I'ETP1 or P
The object of the present invention is to show a method of making a packaging strip which is constructed using one of A, has the advantageous properties thereof, is free from the above-mentioned defects, and can be produced at low cost. This is the basis.

(Structure of the Invention) To solve this problem, the present invention provides that the base layer is produced by a common extrusion method from at least two layers, one of which is made of a plastic of the first group, I'l"1r'ETI.
', I', also in the form of filled or granules, others of the second group, IIE,
It teaches that it is composed of different plastics belonging to pH. The filler 11 may consist of particulate mineral matter, wood flour or the like. The granules are recovered from corresponding waste material. According to a preferred embodiment of the invention, the base layer is extruded in three layers, the intermediate layer a of a first group of plastics and its outer layer of a second group of plastics. The intermediate layer can then be extruded in such a way that it is completely surrounded by the outer layer. However, if a temporary or wide film is first extruded and then cut into strips after stretching, the edges remain uncircumscribed by the material of the outer layer. According to the invention, it is possible, if this is necessary, for the layers to be joined together during common extrusion with the intervention of an adhesion medium. This is because these materials do not have sufficient adhesion directly. The base layer is advantageously extruded with a layer thickness of O0↓ to 41111 (before stretching), which is sufficient for the production of packaging sheets i7 with the demands customary today.

The present invention combines the above-mentioned materials by a common extrusion process, optionally with the interposition of an adhering medium, into a composite material which is distinguished by unexpected elastic properties when used as a stretched packaging strip. It is based on the knowledge that it can be done. In this way, the technical and economic disadvantages mentioned at the outset can be avoided.

Common extrusion can be performed in a variety of ways.

In particular, a wide variety of material combinations are possible when producing the packaging strip according to the invention. One is characterized in that the middle layer consists of PP and the outer layer of II D-PE, but it is also possible for the middle layer to consist of PETP, in which case the outer layer is extruded from PI' or from PE. be done. Another direction is that the middle layer is composed of PA and the outer layer is extruded from PP or from PE.

The attached Table 1 reveals the special properties of the above material combinations for use as packaging strips.

Table 2 explains the abbreviations used above.

Table 1 Outer layer Middle layer Outer layer Various properties PP
PETA'r'P High strength, good weldability, cheaper than plain PETP, PE without liquorice PETP PE High strength, good weldability, cheaper than plain I'ETI', PP without liquorice PAPP High strength, good weldability, r'
Cheaper than ETP alone, no sakeen 1"E PA PE High strength, good weldability, cheaper than I'ETP alone, no sakeen Table 2 PP Polypropylene PETr' Polyethylene terephthalate, i.e. polyester PA Polyamide

Claims (10)

[Claims] (1) Thermoplastics suitable for winding machines and whose ends are weldable, for example by frictional heat;
In a method for manufacturing a packaging strip that can withstand the winding tension of extruding a base layer using PP, PETP, PA, etc., and winding the base layer after stretching, the base layer is made of at least two layers by a common extrusion method, and one of them is one is made of one of the first group of plastics, PP, PETP, PA;
A method characterized in that it is in the form of a filled or granule, the other being composed of another plastic belonging to the second group PE, PP. (2) The base layer is extruded into three layers, the middle layer of which is composed of a first group of plastics and the outer layer of a second group of plastics. the method of. (3) A method according to claim 2, characterized in that the intermediate layer is completely surrounded by the outer layer. (4) Claims 1 to 3, characterized in that each layer is bonded by an adhesive medium during extrusion.
The method described in any one of paragraphs. (5) A method according to any one of claims 1 to 4, characterized in that the base layer is extruded with a layer thickness (before stretching) in the range from 0.4 to 4 mm. (6) The method according to any one of claims 2 to 5, characterized in that the middle layer is made of PP and the outer layer is made of HD-PE. (7) The method according to any one of claims 2 to 5, characterized in that the middle layer is made of PETP and the outer layer is made of PP. (8) The method according to any one of claims 2 to 5, characterized in that the middle layer is made of PETP and the outer layer is made of PE. (9) The method according to any one of claims 1 to 5, characterized in that the middle layer is made of PA and the outer layer is made of PP. (10) The method according to any one of claims 2 to 5, characterized in that the middle layer is made of PA and the outer layer is made of PE.