NL8103141A - METHOD OF REINFORCING PLASTIC ARTICLES WITH METAL REINFORCEMENT AND A CHARGING BOARD WITH A REINFORCED TOP AND / OR BASE PLATE. - Google Patents

Description

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Inventor: Hendrik VAN DALEN at Geleen 1 3296

METHOD OF REINFORCING PLASTIC ARTICLES WITH METAL ΕΝ A LOADING BOARD WITH A BQVEN- / OR BASE COVERED THEREFORE

The invention relates to a method for metal reinforcing objects made of plastic, in which the raw metal reinforcement is heated and then, while softening or melting the plastic coming into contact with the reinforcement, pressed into the surface of the object .

Plastics are widely used because of their special properties. In those cases where the construction parts must not have too great a material thickness and yet must have sufficient rigidity or tensile strength, the plastic parts of a construction which is for instance loaded on bulging or tension are provided with a reinforcement. Different materials can be used for this, depending on the intended strength. Metal is often used for this. In, for example, an injection mold, a metal reinforcement can be applied, which is then injection molded with plastic, so that the reinforcement is embedded in the plastic. Another plastic reinforcement is obtained by inserting wood or metal cores after the manufacture of extruded or injection-molded tubular profiles. This is a technique often used in the manufacture of plastic frames.

20 Due to the scarcity of raw materials and energy, the use of plastic is increasingly shifting. Reinforced plastics must therefore be separated from their reinforcement. Plastics reinforced according to the methods outlined above have the drawback that the separation of the reinforcement from the surrounding plastic can only be carried out with great effort and cost. French patent specification 2,097,399 discloses a method of reinforcement for plastic plates, in which the heated reinforcement is pressed into the surface of a finished plate. The reinforcement remains easily accessible from the outside so that it can be removed afterwards. However, this method has the drawback that the entire volume of plastic occupied by the reinforcement must be melted and displaced. This method is therefore less suitable from an energetic point of view, especially for free 8103141 2 * · s substantial reinforcement parts. In addition, the melting process takes too long to guarantee responsible business operations. Attempts to accelerate the melting process by raising the temperature of the reinforcement to be applied are faced with the drawback that this increases the chance of the plastic degradation, which entails additional complications during reprocessing. Incidentally, in this method the direction of displacement of the molten plastic cannot be properly controlled, as a result of which the surface of the object becomes irregular and thereby obtains an unattractive appearance.

The object of the invention is to provide a method for reinforcing plastics with metal, which method does not have the above-mentioned drawbacks and wherein the plastic objects reinforced by means of this method are more suitable for re-use of the plastic.

This is achieved in that a part of the plastic material is omitted by providing a recess before the reinforcement is fitted at its location.

Preferably, a recess 20 is provided in the surface, the shape of which is substantially similar to and smaller than the shape of the part of the reinforcement to be fitted in the plastic.

By applying the reinforcement according to this method, only a fraction of the volume of the reinforcement needs to be melted on plastic. In the manufacture of the article, less plastic has to be used and much less molten plastic has to be displaced, which gives the appearance of the I.

object benefits.

To completely prevent molten plastic from entering the surface of the object to be reinforced, the recess can have a widening along its top side with dimensions such that the plastic material displaced by the reinforcement can be accommodated in the widening.

The surface of the part of the reinforcement to be applied in the plastic is increased by advantages with respect to the adhesion of the reinforcement in the plastic as well as to the prevention of the molten plastic material coming to the surface. % 3 were provided, the shape of the recess being similar to and so much smaller than the shape of the reinforcement determined by the tips of the elevations that the plastic material displaced by the elevations can be wholly or partly taken up by the space 5 between the increases. Preferably, the shape of the recess is chosen such that the volume of plastic material displaced by the elevations is exactly absorbed by the space between the elevations.

The invention also relates to a plastic board with metal reinforcement, wherein the board comprises a top plate and a bottom plate separated by spacers therefrom.

This type of Xaadbord is widely used in the storage and transport of goods. A metal board reinforced with metalX of this type is known, for example, from the Belgian patent no.

15 854.656. This pallet is not suitable for reusing the plastic for the reasons already explained above. Such a pallet reinforced according to the method of the French patent 2097.399 will exhibit irregularities on its surface which promote the occurrence of skew and irregular load transfer in a stack.

By now providing a pallet of this type with its base plate and / or its top plate with a reinforcement by means of the method according to the invention, these irregularities are prevented, which benefits the technical usefulness of the pallet. Because the method according to the invention also allows substantial reinforcement parts, in the form of solid or tubular profiles, to be applied without thereby making the surface less flat, the pallet can already be given sufficient strength by only SSn plate to arm. The pallet is also suitable for reusing the plastic because the reinforcement accessible from the surface can easily be pulled out of the plate after heating. This heating can suitably be effected by means of resistance heating. Two electrodes serving as grippers are excellent for this purpose.

Being able to apply the reinforcement in SSn plate of the pallet offers advantages both in the manufacture of the pallet and in the subsequent removal of the reinforcement because the 8103141; ** 4 stretching operations need only be performed on the side of the pallet.

It is advantageous to install the reinforcement only in the bottom plate, because the reinforcement then also has to prevent wear of the pallet when it is dragged over the ground, in addition to a reinforcing function.

The method according to the invention will be explained in more detail below with reference to an application example in the form of an embodiment of the pallet 10 according to the invention shown in the drawing.

In the drawing is:

Fig. 1 is a side view of a metal pallet, to be reinforced with metal, according to the invention;

Fig. 2 is a bottom view of the pallet of FIG. 1; FIG. 3 is a section on line III-III in FIG. 2;

Fig. 4 is a section on line IV-IV in FIG. 2;

Fig. 5 shows an enlarged detail according to the dotted section V in FIG. 3 and a cross-section of a reinforcement profile to be applied.

FIG. 6 is a variant of FIG. 5, with a widening along the top edge of the recess;

Fig. 7 is a variant of FIG. 5, with a recess congruent with the cross section of the reinforcement profile; FIG. 8 is a variant of fig. 5 with a cross-section of a cross section which is provided with elevations in the form of toothed ribs and

Fig. 9 is a variant of FIG. 5, with barb-shaped elevations in cross section.

In Figs. 1 and 2, a side view is shown respectively. a bottom view of a metal-reinforced pallet that is injection molded from plastic. See also fig. 3 and 4. The pallet has a top plate 1, a bottom plate 2, with spacers 3 to 11 arranged between them. In the bottom plate there are openings 12, 13, 14 and 15. 35 16, 17, 18 and 19 indicate the corners of the loading deck.

In the bottom plate according to fig. 2 on the side of the bottom plate remote from the spacers and in the surface thereof there are 8103141 5 recesses 20 Cot and with 26 of which the recesses 20, 21 and 22 are parallel to a long side 27, and the recesses 23 through 26 are parallel to a short side 28 of the rectangular pallet. The recesses always extend from within an area where a spacer is located to within another area where a spacer is located. Thus, the recess 20 extends from within the region of spacer 3 through region 4 of spacer 4 into the region of spacer 5. In FIG.

2, the dotted lines indicating the location of the spacer 10 also indicate the areas referred to above. The reinforcement is placed in the recesses of the pallet described above. These can be solid metal bars, but hollow hollow profiles are preferably used. Suitable material can be aluminum.

Fig. 5 shows an enlarged detail of the dotted portion of Fig. 3 indicated by V, comprising a part of the bottom plate 2 with the recess 20 therein. In the elongated recess 20 an aluminum tubular profile is 20 'is provided as a reinforcement, the cross section of which is also shown in Fig. 5. The shape of the recess 20 is similar to, but smaller than, the shape of the reinforcement profile 20 * to be fitted. This means, among other things, that the with resp. A and C indicated sizes are smaller than those with resp. B and D are indicated. Hereby it is achieved that when the profile 20 brought to a sufficiently high temperature is pressed into the recess 20, this profile comes into contact with the plastic material of the walls 29, 30 and the bottom 31 of the recess and these over a small depth. to melt. When the profile 20 'is completely pressed into the recess 20, only a small part of the molten plastic will have come out, depending on the dimensional difference between A and B and between C and D.

In order to completely avoid the displacement of displaced plastic material, the recess, as indicated in Fig. 6, can be provided with a widening 32 in which possibly displaced plastic can be accommodated. The dimensions are preferably chosen such that the displaced plastic precisely fills the widening.

8103141 • ψ '0 6

Fig. 7 shows a variant of Fig. 5. The shape of the cross-section of the profile 20 * is the same as that of the recess 20. During pressing, the sections 33 and 34 of the profile melt the parts 35 and 36 of the walls 29 and 30 from top to bottom. , the molten material moves into the narrowed part of the reinforcement profile. If the profile is completely pressed in, no plastic material will have come out.

Another variant which guarantees a good anchoring of the reinforcement in the plastic is shown in Fig. 8. The profile 20 '10 here is provided with elevations 37 in the form of tooth-shaped ribs arranged in the longitudinal direction of the profile. Between the tooth-shaped ribs are the intermediate spaces 38. The shape of the recess 20 is similar to and smaller than the shape of the profile determined by the tops 39 of the elevations. The dimension A in Fig. 8 is smaller than the dimension B and preferably so much smaller that the volume of plastic material displaced by the elevations is exactly absorbed by the space between the elevations. In this way no displaced plastic material will surface.

The variant according to Fig. 9 has a reinforcement with barb-shaped elevations 40 in cross section, which provide an even better anchoring in the plastic and moreover facilitate the insertion of the reinforcement.

The pallet can be injection molded from 66n piece of plastic. It is also possible, for example, to spray the top plate and the spacers from βέη 25 piece and to spray the bottom plate from the same or another plastic, and to attach them to the spacers, for example by gluing or mirror welding.

The top and / or bottom plate can be formed by a grid of ribs to be provided in the recesses. Suitable plastics for the use of the process are the thermoplastics such as polymers of ethylene and propylene, as copolymers of ethylene and propylene, as well as mixtures of such polymers and / or copolymers.

The reinforcement profiles can also have a shape that they continue to protrude partly above the surface of the plastic object. The part protruding outside the plastic can hereby cover the recess. A T-profile, the vertical leg of which is made 8103141 * 7, is a suitable reinforcement element for this.

Instead of one profile, more than one profile can be applied per construction part.

Pre-treated iron or steel (galvanizing, hot-dip galvanizing) can also be used as reinforcement.

8103141

Claims (12)

1. A method for metal reinforcing objects made of plastic, wherein the metal reinforcement is heated and then, while softening or melting the plastic coming into contact with the reinforcement, pressed into the surface of the object 5, characterized in that a part of the plastic material is omitted by providing a recess before the reinforcement is provided at the location thereof. 2. A method according to claim 1, characterized in that before the reinforcement is applied there is already a recess in the surface 10 of the object, the shape of which is substantially similar to and smaller than the shape of the material to be applied in the plastic. part of the reinforcement. Method according to claim 1 or 2, characterized in that the recess has a widening along its top edge with dimensions such that the plastic material displaced by the reinforcement can be accommodated in that widening. Method according to any one of claims 1 to 3, characterized in that the surface of the part of the reinforcement to be applied in the plastic carries elevations, that the shape of the recess is uniform and so much smaller than the shape of the reinforcement determined by the tips of the elevations that the plastic material displaced by the elevations can be wholly or partly absorbed by the space between the elevations. Method according to claim 4, characterized in that the volume of plastic material displaced by the elevations is exactly absorbed by the space between the elevations. 6. Plastic pallet with metal reinforcement applied by means of the method according to any one of claims 1 to 5, wherein the pallet comprises a top plate and a bottom plate separated by spacers thereof, characterized in that at least one of the plates has a metal reinforcement. Plastic loading pallet according to claim 6, characterized in that only the bottom plate has a metal reinforcement. 8103141 9 Plastic loading pallet according to claim 6 or 7, characterized in that the metal reinforcement is located on a side of a plate remote from the spacers. 9. Plastic pallet according to any one of claims 6 to 8, characterized in that the metal reinforcement extends from within an area of the plate where a spacer is located to within another area where a spacer is located. Plastic pallet according to any one of claims 6 to 9, characterized in that the reinforcement consists of straight tube profiles, which tube profiles run parallel to the sides of the pallet. Plastic pallet according to any one of claims 6 to 10, characterized in that the plastic part of the pallet is manufactured by injection molding. 15 12. Method for reinforcing plastic objects with metal and a plastic pallet thus reinforced as described and / or explained with reference to the drawing. JJS / WCH 8103141