SE463371B - TRAEL-LIKE PLASTIC LOW AND WERE MADE TO MANUFACTURE IT - Google Patents

Description

465 571 _2- BRIEF DESCRIPTION OF DRAWINGS Figure 1 shows a standard milled batten in cross section. The shape shown is not typical of the invention, but is an example. Figure 2 shows a common profile from, for example, window manufacturers. Figure 3 shows a cross section of a profile made of solid PVC.

The figure also shows the cavity in an extruder's mold tool, which could give rise to the invented batten. Figure 4 shows an example of the invented hollow batten. Figures 5 and 6 show details of the shape and the resulting narrow profile. An example of a design with a thick profile is shown in Figures 7 and 8.

AN EXAMPLE OF THE INVENTED PLASTIC BATH In many applications for wood, the batten shape required is shown in Figure 1.

Characteristic here is that it has a thick part 1 and a thin part, fl änsen 2. If this batten form is made of wood, you must ensure that the wood is twig-free and that the batten is straight after a long drying time.

You can easily make a plastic profile by extruding PVC into a profile as shown in Figure 2. The same external boundary lines are obtained. By calibration during manufacture, you get a smooth surface and straight profiles, as every professional knows.

The profile in the mold has not been machined because it also indicates the shape of the cavity in the mold tool from which the profile is extruded. If the profile is made of PVC, high values of flexural strength are obtained. The profile will be insensitive to moisture and rot. But unfortunately you can not arrange nail joints in the profile, which the professional would like.

Nail joints require that the nail be able to penetrate the material without it cracking or splitting. Furthermore, it is required that the material to which the nail is to attach provides a sufficiently long distance for contact with the nail.

The feature of the long nail length is shown in Figure 3, where a pin 3 is drawn in the axis 2. Compared with Figure 2, a 50% increase in the nail bracket in Figure 3 is obtained if the nail is driven through the pin 3.

Pin 3 is a special novelty of the invention. It can be varied in length so that sufficient strength is obtained, while the requirements for the correct placement of nails are reduced. If the profile is made of solid pure PVC, however, there is still the risk that the pin will break off when a nail is driven through the end and pin.

If, on the other hand, an expanded plastic is selected, as the present invention specifically states, a nail can penetrate into the pin without it being split or otherwise deformed. By choosing the pin width so, in relation to the surrounding free space, that this is partly filled with expanded plastic, a support is obtained for the plastic pin and a longer nail contact.

The invented batten therefore has a cavity, for example in the end 2, which contains a pin 3, which due to expansion after the mold has varying density and in favorable cases fills the cavity with a denser part surrounded on one or both sides by an expanded plastic material. , which bubbled out of the pin. Figure 4 shows this with the irregular bulges on the pin. A favorable feature of this is that the swollen parts 4 of the pin 3 touch the walls of the profile, which means that the pin does not bend as easily when a nail is to penetrate the pin. Since the cooling of the profile is different for the pin and the profile outer walls, there is usually no swelling of the outer wall and expanded plastic from the pin. Although the technology for extrusion of plastic has been based on PVC, other materials can also be included within the scope of the claims. Expanded PVC should, however, have significant advantages and has given excellent results. The shown mold shape is not characteristic of the invented batten and the person skilled in the art can produce other embodiments within the scope of the claims. Another embodiment of pin 3 is shown in Figure 8.

It is a characteristic feature of the invented method that the pin 3, which in the mold tool corresponds to a cavity, does not have a smooth surface. Instead, the pin has received grooves on the sides, which face the outer profile walls. Any professional can do this forrn.

It is known to those skilled in the art that if the hot soft profile after the mold comes into contact with a cooled calibrator, the extruded expanding profile obtains a skin. Its thickness can be varied by varying the cooling of the profile surface.

Inside the profile, where pin 3 is located, cooling cannot be performed. Little skin is formed. Instead, the plastic expands and shows a tendency to fill the space between the profile's outer walls. The density of this filling becomes low. Contact with the outer walls is also obtained in the invented profile. However, when the outer calibration mold is cooled down, no aggregation takes place between expanded plastic from the pin and already solidified plastic from the outer walls.

Figure 5 shows an example of a cavity 5 in a part of a forming tool 6. In the center is the cavity of a pin 7. Unlike the pin 3 in Figure 3, this shows 463 57 _4_ extensions of the cavity in two places 8 and 9. With pure plastic, these extensions would essentially correspond to a pin with elevations. Since the invented method specifically states that expanded thermoplastic is to be used, these elevations give fracture indication in the skin surrounding the pin. Plastic bubbles out and can, depending on the shape of the extruder, fill the cavity of the profile with a denser core 10 in the pin 3 surrounded by lower density plastic at 11 on each side of the pin in Figure 6.

The contact between expanded plastic in the pin and the surrounding wall provides support for the pin when a nail is to be pierced through the profile wall and pin but not penetrate the other profile wall.

The method can also be used for larger cavities, which is exemplified in Figure 7 with the cavity in the mold and the resulting profile in Figure 8. A "T", 12, has been formed in the center of the profile. Special fracture instructions for the plastic skin are indicated by the tips 13. Around these tips, the plastic expands and ruptures the skin, forming suitable nail supports in the interior of the profile.

The cavity shapes shown in Figures 5 and 6 have given good resulting nail supports of expanded plastic, which rest against the outer walls of the profile usually without collapsing with them. "Other forms of fracture instructions for skin can also be chosen by the person skilled in the art. for cooling and calibration, which are well known methods.

Expanded thermoplastic has the advantage of being malleable in heat, which means an additional advantage. The profile produced can be heated and bent. INDUSTRIAL APPLICABILITY The present invention provides a method of producing a profile which has the same properties as wood in terms of nail and screw joints. In relation to wood, formability, insensitivity to moisture and low values of heat conduction are obtained. In all, a simple product with many uses is obtained.

Claims (6)

"S" 465 371 PATENT CLAIMS Wood-like batten made of plastic, extruded from thermoplastic material to a profile with air-filled cavities, and after the extrusion in terms of external shape calibrated, characterized in that blowing agent was dosed to the thermoplastic, which means that the finished profile contains small bubbles, ie is an expanded thermoplastic, and that protruding outer profile parts enclose cavities with one or more complementary pins (3), which after the expansion of the plastic partially fill the cavities and can form nail or screw supports. Wood-like lath made of plastic according to claim 1, characterized in that the expanded plastic originating from some filling pin (3) is anchored to the pin but not coiled together with the enclosing outer wall or walls. Wood-like lath made of plastic according to claim 1, characterized in that the thermoplastic consists essentially of PVC. Method of making a wood-like batten of thermoplastic according to Claim 1, characterized in that the test tool also forms space for a central pin (3) when forming enclosing narrow cavities, which pin has one or two narrow grooves on its side facing the cavity. where expansion of the thermoplastic can be initiated, and that enclosing parts are cooled so that swelling of expanded plastic in the pin and enclosing profile does not take place. 5. The method is characterized in that it is formed by widenings (8 and 9) of the pin (3) in the cavity of the mold (6) for the same (7). A method of manufacturing wood-like battens according to claim 1, characterized in that the expanding thermoplastic consists of PVC.