JPH0321957Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a tape made of a multilayer polyethylene film stretched in the longitudinal direction.

(Prior art) A single-layer film of high-density polyethylene (HDPE) or medium-density polyethylene (MDPE) is stretched in the longitudinal direction, and the film obtained is cut into strips of the desired width in the longitudinal direction and then made into tape. It is well known that tapes are used for packing, packaging, and various other purposes, and are made of a film made of vertically stretched high-medium density polyethylene, or can be folded into multiple sheets to make a tape, or lightly bundled to make a string. It is being

(Problems to be Solved by the Invention) However, these high-density polyethylenes and medium-density polyethylenes stretched in the longitudinal direction have great strength in the longitudinal direction and are strong, making them extremely desirable for tapes, strings, etc. It has the disadvantage of being easily torn in the vertical direction.

(Means for solving the problem) For this reason, we have conducted extensive studies to obtain a tape that does not have the disadvantage of being easily torn in the vertical direction without sacrificing its desirable properties of high strength and stiffness in the vertical direction. , high-density polyethylene or medium-density polyethylene and linear low-density polyethylene (LLDPE) are co-extruded to form a multi-layer film, and this is stretched in the longitudinal direction to create a tape consisting of a multi-layer stretched film. As a result, it was possible to obtain an almost ideal tape free of the above-mentioned drawbacks.

(Example) An example of this invention will be explained with reference to the accompanying drawings. Reference numeral 1 indicates a tape according to this invention. This tape 1 consists of multiple layers of polyethylene, one of which is high-density or medium-density polyethylene 2, and the other layer is linear low-density polyethylene 3.
It is. This tape 1 is obtained from a multilayer film obtained by longitudinally stretching a high-density or medium-density polyethylene 2 and a linear low-density polyethylene 3 fused together by co-extrusion. That is, the tape 1 of this invention is composed of multiple layers, with one layer of high-density or medium-density polyethylene 2 and the other layer of linear low-density polyethylene 3, and these are fused and integrated by coextrusion. It was further stretched in the longitudinal direction. The stretching ratio in this case is usually preferably about 4 to 5 times, but is not limited to this. In order to integrate high-density or medium-density polyethylene and linear-low-density polyethylene into a multilayer film, there are methods such as creating separate films for each film and bonding them with adhesive or laminating them. When using co-extrusion, there is a risk of peeling, but when using co-extrusion, the product is fused and integrated, and there is no need to worry about peeling. In this invention, the tape 1 is obtained from a multilayer film in which high-density or medium-density polyethylene and linear low-density polyethylene are co-extruded and further stretched in the longitudinal direction, as described above.
This multi-layer film is made with a wide width, so
Tape is obtained by cutting this into pieces of desired width. However, the tape is not limited to this,
For example, it may be cut into pieces several times the width of the desired width and folded to make a tape, or it may be cut into pieces of an appropriate width and twisted or bundled by other means.
It can also be used as a so-called string. Alternatively, without cutting a film formed into a wide width, it may be extruded during coextrusion to a width that does not require cutting, and then stretched to form a tape. In this invention, tape is not limited to flat or film-like materials, such as tapes used for packaging or adhesive tapes, but is also a collection of film-like or flat materials, represented by a string. It also refers to non-flat shapes such as

The ratio of high-density polyethylene or medium-density polyethylene and linear-low-density polyethylene constituting the tape is arbitrary, but linear-low-density polyethylene accounts for about 50% to 20%, so high-density or medium-density polyethylene accounts for about 50% to 20%. A range of about 50% to 80% seems appropriate.

The use of this tape is arbitrary, but
For example, there are various uses for tapes, strings, etc., such as tapes and strings for packaging, and adhesive tapes coated with adhesives.

(Effects of the invention) As explained in detail above, this invention is made by fusing high-density polyethylene or medium-density polyethylene and linear low-density polyethylene into one by co-extrusion, and stretching this in the longitudinal direction. However, tape made only of high-density polyethylene or medium-density polyethylene has stiffness and
Although it has excellent properties as a tape in that it is strong in the longitudinal direction, it has the disadvantage of easily tearing longitudinally, and since linear low-density polyethylene film has a low molecular density, It was thought that it could not be used as a tape because the molecules were not aligned neatly, but it was difficult to tear vertically. By combining these two, the properties of stiffness and strength in the longitudinal direction as high-density or medium-density polyethylene are not impaired in any way, and the property of being resistant to vertical tearing as linear-low-density polyethylene is maintained. , high-density or medium-density polyethylene is covered, making the tape as a whole difficult to tear vertically, and linear
It was thought that low-density polyethylene could not be used as a tape, but it was covered by high-density or medium-density polyethylene, and now it can be used as a tape.In helping each other, the two are considered to be the same polyethylene comrades. By fusing and integrating the polyethylenes through co-extrusion, results were obtained that could not be obtained by integrating them by means such as adhesives, and the excellent properties of both polyethylenes were not compromised. This was an extremely excellent invention, as linear low-density polyethylene, which had been thought to be unable to be used alone as a tape, was successfully made into a tape. It is.

[Brief explanation of drawings]

The accompanying drawing is a perspective view showing an example of the implementation of this invention. 1: Tape, 2: High density or medium density polyethylene, 3: Linear-low density polyethylene.

Claims (1)

[Scope of utility model registration request] A multilayer polyethylene stretched tape comprising a multilayer film obtained by coextruding high-density polyethylene or medium-density polyethylene and linear low-density polyethylene and stretching the film in the longitudinal direction.