JPH06270902A - Method for wrapping hot-melt - Google Patents

Abstract

PURPOSE:To efficiently wrap an adhesive hot-melt block with a wrapping material which may not degrade hot-melt performance when it is melted. CONSTITUTION:A double-layered plastic sheet comprising a first layer 2 made of polyolefin and a second layer 3 made of low melting point plastic having good compatibility with hot-melt wherein the two layers are overlaid is used to form a container with the first layer 2 outside and the second layer 3 inside. Melted hot-melt is put into this container and cooled to solid, whereby obtaining a method for wrapping the hot-melt into a block-like package without surface adhesiveness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot melt packaging method having tackiness.

[0002]

2. Description of the Related Art Sticky hot melts are widely used as adhesives and the like, but in order to prevent self-bonding during transportation, storage, etc., block-shaped hot melts are wrapped with a material having releasability. ing. As a packaging method using such a packaging material, a PET film or paper treated with silicon is folded and molded into a box shape, and then directly or by inserting it into a metal tray and melting hot melt. How to pour in, or silicon treatment on the inner surface of the step ball box,
A method of directly pouring the molten hot melt into this, a method of molding a sheet of thick polypropylene or the like into a tray, and pouring the molten hot melt directly into it have been adopted.

However, in the above conventional packaging method,
When using the packaged hot melt, it is necessary to peel off the packaging material and dispose of it, which requires complicated labor and may cause environmental pollution due to waste. Therefore, from the viewpoint of resource saving and environmental protection, without using these containers, the adhesive hot melt is wrapped with a thin polyolefin film or powder that does not affect the performance of the hot melt, and the polyolefin film or the like is peeled off at the time of use. It is considered that it melts as it is.

As described above, a method which does not use a packaging container is a method in which a wax or the like is sprayed inside a metal container in advance and molten hot melt is poured into the container to eliminate surface tackiness. Extruding adhesive hot melt and polyolefin into water into a double cylinder,
For example, a method of cutting it to an appropriate length to eliminate surface tackiness, etc. However, the wax spray method has a problem in that the surface becomes tacky within a few days during storage and the blocks are re-fused to each other. Further, the method of extruding into water into the double cylindrical shape, because the proportion of polyolefin increases,
There has been a problem that the performance of the hot melt is deteriorated and the thermal stability in the hot melt tank is deteriorated due to the incompatibility of the compatibility of each.

In order to solve these problems, it is necessary to pack as large a hot melt block as possible by using a polyolefin film as thin as possible, but since the melting point of the polyolefin film is lower than the temperature of the molten hot melt, It is necessary to cool the polyolefin film so that it will not melt during packaging. As such a method, for example, a method has been developed in which a polyolefin film is placed along a tray of various shapes such as a rectangular parallelepiped and a cylinder, and a hot melt is poured while cooling the outside of the tray. A part that does not adhere to the tray is generated, and this part is not cooled, so that it is often melted by the heat of the hot melt.

In order to bring the polyolefin film into close contact with the tray, a method has been studied in which the film is formed into a shape that fits the tray in advance and the films are fitted into the tray one by one, but the actual process becomes complicated. Besides,
There was a problem that the film was deformed when the hot melt was poured and slipped into the tray.

[0007]

Therefore, the present invention solves the problems of the conventional packaging method described above, using a thin polyolefin film without melting the film,
The challenge is to be able to successfully package sticky hot melt blocks.

[0008]

In order to solve the above problems, the present invention employs the following configurations. That is, the hot-melt packaging method according to the present invention comprises a two-layer plastic sheet in which a first layer made of a polyolefin and a second layer made of a low melting point plastic having a good compatibility with the hot melt are superposed. -A block having no surface tackiness by molding a container having the first layer on the outer surface side and the second layer on the inner surface side by pouring the molten hot melt into the container to cool and solidify It is characterized in that it is a package.

The polyolefin as the first layer prevents the tackiness of hot melt from appearing on the outer surface, and it is generally preferable to use polyethylene having a melting point close to that of hot melt. The thickness of the polyolefin layer is preferably 20 to 50 μm. If the thickness is too thin, the temperature at the time of pouring hot melt (12
It is about 0 to 180 ° C. If it is too thick, the concentration as a different polymer mixed with the hot melt when melted together with the hot melt becomes high, and the performance of the hot melt may be deteriorated. As this olefin, low density polyethylene, linear low density polyethylene,
Medium / high density polyethylene, ethylene / propylene mixture,
There are copolymers, ethylene / acrylic acid esters, methacrylic acid / ester copolymers, and ethylene-vinyl acetate copolymers.

The second layer is preferably made of a component similar to the component of the hot melt to be packaged, for example, ethylene vinyl acetate copolymer, ethylene / acrylic acid alkyl ester copolymer, amorphous α-olefin, SBS. , SI
Various tackifiers, plasticizers, base polymers such as ABA type block copolymers such as S, SEBS, SEPS, etc.
There are those in which other additives are mixed, and further, there may be only the base polymer or two components thereof. These may be selectively used depending on the type of hot melt to be packaged. The thickness of the second layer is 150-40
It is preferably 0 micron. This second layer is to prevent the heat of the molten hot melt from being directly applied to the first layer, and if it is too thin, the heat of the hot melt when poured may damage the outer first layer. If it is too thick, the performance of hot melt may be deteriorated.

A plastic sheet container is molded by stacking the first and second layers of polymer and extruding two layers. At this time, the non-sticky first layer is on the outside and the second layer is on the inside. The shape of the container is preferably such that hot melt can be easily poured and is convenient for transportation, storage, etc. In general, a rectangular box shape or a cylindrical shape is preferable. The thickness of each layer of the two-layer plastic sheet constituting this container is as described above.

Next, hot melted hot melt is poured into the container made of the obtained two-layer plastic sheet. Since the second layer having a component similar to that of the hot melt is interposed between the hot melt and the first layer, the heat of the hot melt is not directly applied to the first layer, and the first layer is not melted. In this state, the hot melt is cooled and solidified to form a block. At this time, it is preferable to cool the outer surface of the first layer with water or air.

In this way, the hot melt block having tackiness can be packaged so that the tackiness does not appear on the surface. The obtained package can be melted together with the container and used as a hot melt. Since the container is formed of a thin polyolefin layer and a low melting point plastic having good compatibility with the hot melt, the performance of the hot melt is not significantly impaired even when it is melted together with the hot melt.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show an example of a container (tray) used in this packaging method.
It is formed of a plastic sheet in which a first layer 2 made of polyethylene and a second layer 3 made of SBS are superposed. This molding is a two-layer extrusion molding using polyethylene and SBS polymer as raw materials. The thickness of the first layer is about 30 μm and the thickness of the second layer is about 3 μm.
It was 00 microns.

Molten hot melt (SBS type) was poured into the obtained container 1 to be cooled and solidified. At this time, the outer surface of the container was forcedly cooled with a shower. As a result, a hot-melt block package having no surface stickiness was obtained. When this package was directly melted by heat and used as a hot melt, the same performance as a normal hot melt was obtained.

[0016]

As described above, according to the present invention, sticky hot melt can be efficiently packaged in a non-sticky thin plastic sheet.
Even if a non-sticky polyolefin thin film is used for packaging, a layer of low melting point plastic similar in composition to hot melt is provided in advance on the inner surface, so that the layer of polyolefin is heated by the heat of the hot melt during pouring. Not damaged. Moreover, since the thickness of the polyolefin layer can be reduced, the performance of the hot melt does not deteriorate even if the packaging material is melted and used as a hot melt, and the labor of peeling or discarding the packaging material is unnecessary. It was

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a container.

FIG. 2 is a sectional view thereof.

[Explanation of symbols]

 1 container 2 first layer 3 second layer

Claims (1)

[Claims] 1. A two-layer plastic sheet comprising a first layer made of polyolefin and a second layer made of a low-melting point plastic having good compatibility with hot melt, and the first layer is used. Is formed into a container having a layer of which is the outer surface side and the second layer of which is the inner surface side, and the molten hot melt is poured into the container to be cooled and solidified to form a block-shaped package having no surface tackiness. Characteristic hot melt packaging method.