CZ20002154A3 - Method of bonding plastic articles - Google Patents

Abstract

In the method of bonding plastic objects using hot melt adhesive, in addition to heating and adding a plasticizer-resistant hot melt adhesive, one of the objects to be bonded, in particular a multilayer pipe (1, 2), is heated in its end region (6) intended for bonding above the melting temperature of the materials of the object.

Description

Method of gluing plastic objects

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The invention relates to a method for gluing plastic articles by means of a hot-melt adhesive.

Current_stay_technics

Hot melt adhesives are used for joining objects of various materials, which are used in the form of bars, powder or boards. A variety of plastics, such as polyamide, polypropylene and the like, serve as the basis for these hot-melt adhesives. As a rule, gluing of the objects is effected by applying a hot-melt adhesive in a heated, i.e. liquid, state to one glued surface having a room temperature, and then pressing the two glued surfaces together. After a short cooling, both objects are firmly connected to each other.

It is also known to first apply the hot melt adhesive to the article, then heat the hot melt adhesive above its melting temperature and compress the two objects together. This has been proposed, for example, in the gluing of floor coverings, wherein the heating adhesive is heated through the floor covering. However, the floor covering itself is not heated above its melting temperature.

According to another known design, the installation boxes are glued with masonry, whereby the masonry is first heated and then the boxes are glued by means of hot-melt adhesive. Here, too, the masonry melting temperature is not exceeded.

However, all of these methods are not suitable for some mate. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Or the final strength is not sufficient.

The essence of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for bonding objects by means of a hot-melt adhesive, which is also applicable to materials in which hot-melt gluing has not been possible.

According to the invention, this object is achieved in that, in addition to or during the heating and addition of the plasticizer-resistant hot-melt adhesive, one of the objects to be bonded, in particular multi-layer pipes, is heated above its melting point.

As the experiments have shown, the components of the materials to be bonded and the hot-melt adhesive are mixed using the method according to the invention so as to form an internal and therefore also a firm connection. Also, optionally used plasticizers which otherwise impair the bonding ability do not cause any undesirable effect when using the process according to the invention. Materials such as polyethylene PE can also be bonded to each other by the process of the invention.

In the context of the invention, it is possible first of all to heat at least one of the glued objects in its glued region above the melting point of the materials of the object and subsequently to apply the hot melt adhesive.

When using materials with different melting points that are joined and where a material with a lower melting point could be disrupted when a higher melting point is reached, it is possible first to heat one of the glued objects in its glued area above the melting point of its material and mix it with

The hot melt adhesive is then cooled and mixed with the material of one object in the second process.

However, an embodiment of the process according to the invention is also possible by heating the hot melt adhesive so high and until the materials to be melted and flowed into the hot melt adhesive.

EĚšl ·! in the drawing

The invention will now be described in more detail by way of example with reference to the drawing, without the use of the method of the invention being limited to this embodiment.

The drawing is a schematic sectional view of a joint of two pipes.

The invention

As shown in the drawing, two pipes 1 and 2 are connected to each other. These pipes J and 2 have a multilayer construction and have a helical portion 3 of rigid PVC PVC along their length for mechanical reinforcement. Between these helical parts made of hard PVC PVC there are provided soft PVC PVC parts 4 which allow the deformation of tubes 1 and 2. Inside the tubes 1 and 2 have an inner tube 5 of FU polyurethane.

Both tubes 1 and 2 were heated in their end regions 6 above the melting temperature of at least the materials of parts 3 and 4 and a hot-melt adhesive was applied. In the end region 6, the molten materials are thereby mixed to form an internal connection of the tubes 1 and 2.

Claims (4)

PATENT CLAIMS Method for gluing plastic articles by means of a hot-melt adhesive, characterized in that, in addition to or during heating and addition of a plasticizer-resistant hot-melt adhesive, one of the glued objects, in particular multilayer tubes, is heated above its melting temperature. Method according to claim 1, characterized in that at least one of the glued objects in its glued region is first heated above the cooling temperature of the materials of the object and subsequently a hot-melt adhesive is applied. Method according to claim 2, characterized in that first one of the glued articles in its glued area is heated above the melting point of its material and mixed with the incoming hot melt adhesive, and then in the second process the hot melt adhesive is already cooled and heats up and joins the material of the second article. Method according to claim 1 or 3, characterized in that the hot melt adhesive is heated as high and as long as the glued materials are melted and flowed into the hot melt adhesive.