EP1024235A1 - Preparation of a dilatation joint material for floating floors - Google Patents

Abstract

An expansion joint for placing between screed sections has a plastic foam inner (4) bonded on each side to plastic film outer layers (2,3). The bottom ends of the plastic film layers extend past the bottom edge of the foam strip and are bent into L-shapes w.r.t. the joint. The expansion joint is secured onto the base layer by self adhesive tape under the L-shaped profiles. Holes can be cut through the joint to fit over pipes and cables.

Description

The invention relates to the production of expansion joint material for screed. Like other parts of the building, the screed is subject to expansion when heated or to contraction when it cools down. The total extent of the expansion or contraction depends on the screed dimensions, whereby the length is included in the calculation as a factor for the expansion coefficient and the temperature.
It is known that stretching can result in extreme wall loads and contraction can lead to cracking. With larger screed areas, efforts are therefore made to install expansion joints. The expansion joints are installed in such a way that the screed surfaces enclosed by the expansion joints and possibly adjacent walls / edges are not damaged or destroyed by expansion and contraction.

The expansion joints must be kept open after they have been created. It is therefore not sufficient to create a joint with formwork boards. After removing the formwork boards, there is a risk that the expansion joint will become clogged with dirt during further construction work. Initially, when pouring liquid screed, this led to the use of joint tapes, which are known from the outside. More recently, plastic foam strips have been used for the expansion joints in the screed. These are plastic foam strips that are laminated on both sides with non-foamed plastic. The laminated unfoamed plastic, for example PET, has a relatively high strength compared to the plastic foam and is smooth, so that the screed does not cling to the material and an undisturbed relative movement in the longitudinal direction of the joint is possible.
The foam strips are set up before the screed pouring or pressed into the still liquid screed after the screed pouring.

The plastic foam has so much rigidity that it is under the pressure of the liquid Screed does not give way significantly, but yields slightly with thermal expansion. At Subsequent contraction of the screed follows the plastic strip Contraction movement. This ensures that no dirt fills the joint and prevents stretching.

It is known to set up the plastic foam strips on an L-shaped Angle profile made of non-foamed plastic. The angle profile has a double-sided adhesive tape on the inside. One side of the self-adhesive tape is glued to the angle profile, the other has a cover. After subtracting the Cover can be glued to the angle profile.

It is also known to prepare the plastic foam strips and the angle profile for possible heating cables for underfloor heating. In the case of the angle profile, semicircular recesses are incorporated in the upstanding leg. The plastic foam strip has punched holes in the edge that protrudes downwards. This involves a bilateral severing of the laminated unfoamed film and a partial severing of the intermediate plastic foam, so that the punched part can be removed by hand without the help of tools.
After gluing, the plastic foam strip with the angle profile is placed at the desired location before the screed is poured.

The previously used plastic angles with the self-adhesive tape form a right complex component. Efforts have therefore been made to assemble the To enable plastic foam strips with less effort.

According to an older proposal, the effort for the plastic foam strips is reduced by the bottom end of the foam strip formed a plastic foot in another way which is self-adhesive on the underside and therefore when pressed optimal detention conditions unfolded on the substructure. This will cause it to slip away of the foam strip when screed pouring is not to be feared. The pressures that occur should go to zero because the foam strip does not function as a formwork has and should only cause a gap formation alone. The screed should, if possible be poured evenly on both sides of the foam strip. An overly raw job can nevertheless cause pushing forces.

To form the plastic foot on the plastic foam strip, a lower part of the foam strip is permanently bent and reinforced with another plastic strip at the bottom of the foot.
When kinking, the laminated unfoamed plastic film provides considerable help by heating the kink and cooling it again when it is kinked. The unfoamed plastic gives the kink in the plastic foam strip so much strength that undesired regression is avoided. This applies particularly to rigid plastic films.
The plastic foam strip bends to both sides, so that any restoring forces that may occur counteract each other and already largely or even cancel each other out.

For the laying of cables on the substructure of the screed are on the older one Plastic foam strips provided openings at the bottom. Nevertheless, the older solution still needs improvement.

According to the invention an improvement is achieved with the features of the subclaims. For the cables, openings are cut into the plastic strips on the spot using scissors or pliers. Advantageously, the unnecessary preparation of openings / breakthroughs can be dispensed with when manufacturing the openings on site. The production can be limited to the openings / openings actually required.
In addition, a very simple manufacture of the openings / openings opens up in that plastic foam strips with a pair of scissors or pliers are used, the angled base of which can be bent or bent back to cut out the openings / openings. The scissors and pliers offer a very convenient way of making the openings / openings.
The material properties according to the invention allow bending and cutting out by hand with scissors or pliers. The bending or back-bending is particularly dependent on the thickness of the non-foamed foils provided on both sides of the foam layer. Their thickness is preferably less than or equal to 1 mm per film, the total
Plastic foam strips preferably have a thickness of 6 to 12 mm. The question of when the limits of cutting ability have been reached can be clarified with just a few attempts at cutting with scissors and pliers. In the context of this application, what is referred to as scissor thickness is what can be cut by hand with scissors. Accordingly, what is called pliers thickness is what can be cut by hand with pliers.

According to the older proposal, the foam strip is to be used on both sides Split the L-shaped bend in the lower edge of the plastic foam strip. Arise at the bottom two free legs. The fission can be thermal with a heating wire or a heated knife or mechanically with a rotating knife. The plastic foam of the core is preferably completely or partially removed again. Optionally, the unfoamed foils can also protrude downwards own the plastic foam core and exactly at the lower end of the plastic foam core are bent so that the splitting of the plastic foam core and, if necessary, the removal become wholly or partially dispensable.

It is favorable to grasp the split lower edge when splitting or after splitting and to bring the unfoamed film into the intended angular position while at the same time heating the kink. The targeted heating is preferably carried out with a heating wedge or heating knife. The cooling that follows the kinking can be carried out with the aid of a blower.
The stiffer the lamination, the more precise the kink remains. The stiffness largely depends on the thickness. Therefore, the thickness of the laminating film is preferably 0.2 mm. Particularly favorable conditions arise at 0.3 to 0.4 mm. Larger thicknesses are not excluded.

The plastic films are preferably laminated onto the plastic foam strips. During lamination, the lamination surfaces are warmed up to lamination temperature and pressed against each other. Regularly it is not necessary to apply the surfaces to melt fluid bring to. The heating can e.g. with a hot air blower.

The lamination processes require a lamination ability.
If the materials to be laminated are related to each other, laminating is particularly easy. A relationship is given in this sense if there is a significant component of the material from which the plastic strip was made in the lamination material. With the same material, there are optimal conditions.

In the case of a lack of kinship, a desired liability can nevertheless be generated in part by heating and pressure.
In some cases, liability is only achieved with the help of adhesion promoters.

Under the foot is an adhesive layer / tape for placing on the Substructure provided.

When gluing, depending on the glue, there are hardly any essential requirements for each other connecting materials. It has been found that a butyl adhesive has special advantages unfolded. Such an adhesive adapts to the harsh conditions, especially in a larger thickness on the building and the dirt found there. Dirt is pressed into the Glue and is trapped there. Adhesive layers up to 3 mm are without with butyl adhesive further economically feasible. If necessary, the butyl adhesive is also available in a foamed form used in the form of narrow strips.

The thickness of the foot is at least equal to the thickness of a film provided on the plastic foam strip plus the adhesive. The thickness is largely freely selectable / expandable upwards.
The width of the foot is also freely selectable on a larger scale. Of course, a larger contact area has its advantages. However, the stackability and transport and storage capacity must also be taken into account. This is called stack size / stack width. You can also deviate from the stack size / stack width by choosing larger widths. A width of up to 100 mm is preferably provided.

The strips according to the invention not only open up a very advantageous production but also an extremely advantageous application, by the cover / protective film from the adhesive strip deducted and the strip is placed at the predetermined location.

As already stated, all lines laid on the substructure can be taken into account in a very economical manner. The lines of floor heating or heating lines, electrical lines, water lines, telephone lines, empty pipes, etc. come into consideration.
While the two-part strip construction explained at the outset presupposes that the lower part of the strip construction is already being installed when the lines are laid and that this leads to considerable complications, the use of the strip according to the invention is considerably simplified. Advantageously, the "line laying" and "laying the strip construction" trades no longer have to be carried out overlapping. The appointment coordination and the arrival and departure alone cause considerable costs in the overlapping implementation, which are unnecessary in the procedure according to the invention. According to the invention, further savings result from the one-piece construction. The advantages include one-piece production, as well as less work for laying the plastic foam strips.

The pliers provided for cutting can be provided with interchangeable matrices and patrices. Advantageously, matrices and patrices can be used specifically for all common line types and line diameters. As a result, the openings / openings can be made with low tolerance. This leads to small gap widths between lines and plastic foam strips and already to an extensive seal. Further sealing can be achieved with sealing compounds. Textiles that are wrapped around the lines in the area of the plastic foam strips and close the gap mentioned are also suitable as sealing compounds. Depending on the nature, the textiles are also suitable for sealing imprecise openings / openings.
Suitable textiles can be fabric scraps / pieces and / or fleece scraps / pieces or tangled fibers such as wool balls.

When cutting out it is regularly not necessary to use the ones provided under the foot Adhesive tape to be considerate. As long as the adhesive strips with the protective film / release film are covered, no connection of the free edges with each other is to be feared.

After cutting, the elasticity of the plastic causes it to regress into the original L shape. Then the remaining protective strips are removed and the plastic foam strips placed on the substructure.

An exemplary embodiment of the invention is shown in the drawing:

In Fig. 1, 1 denotes a plastic strip which consists of a plastic foam core 4 and non-foamed foils 2 and 3 laminated on both sides. PE is provided for the plastic foam core and PET for the foils 2 and 3. The plastic foam core 4 has a density of 30 kg per cubic meter. The films each have a thickness of 0.35 mm, the entire plastic strip 1 has a thickness of 10 mm.
The plastic strip is available in different heights. In the exemplary embodiment heights of 40, 60, 80, 100 or 140 mm are provided. In other exemplary embodiments heights of 20 to 300 mm are provided. The heights correspond to the desired screed thickness.

A foot 5 is provided at the bottom of the plastic strip 1. The foot 5 has a stack width of 30 mm. In the exemplary embodiment, the stack width means that the protruding edges of the foot 1 do not protrude any further than the thickness of the plastic strip 1. This enables space-saving stacking by stacking on top of one another. This is essential for economical storage and transportation.
When stacking, the subsequent strip 1 is placed so that its foot lies in the opposite direction to the strip 1 previously placed.

The foot 5 is created in the embodiment that as a starting material for the Plastic strip 1 is used a material that is wider than that by a riot later planned height. The riot measure is equal to the measure by which the edges protrude.

The lower edge of the strip is centered and in with the help of a rotating knife Slotted lengthways. The slot depth is slightly larger than the contact size. in the In the exemplary embodiment, the rotating knife is arranged stationary and becomes the strip held between two circumferential conveyor belts, which the strip in the longitudinal direction move. When moving, the conveyor belts leave the edge of the slit to be slit Streak free.

After slitting, the slotted edge is gripped by a guide which is wedge-shaped in grips the slot and, after the kink has warmed up, unfolds through the Slit caused free leg. This is done by widening the wedge causes.

The heating at the kink occurs through contact with a heating plate. The Heating plate touches the plastic material in a line with a width of im Embodiment 2 mm. The contact length of the heating plate is chosen so that the necessary heat penetrates into the foils during the contact time to the foils for the To make kinks permanently compliant.

Copper is provided as the material for heating the heating plate and an electrically operated and temperature-controlled heating cartridge is mounted on the plate. The maximum temperature of the heating plate is in the embodiment just below
Melting temperature of the foils to avoid burning.

The bending of the free legs provided after sufficient heating Cooling ensures that the resulting kink is preserved. The one for the sufficient Heating the decisive length of the sheet can be extended with a few attempts or shortening can be determined.

The intended wedge engages directly in the direction of movement of the slit strip behind the slitting tool in the strips, where by the slitting process or by the Slot tool a distance between the free created by the slot Thighs.

Fan air is provided for cooling.

After kinking, a plastic foam strip is placed on the resulting edges 6 and 7 laminated below, so that under the edges 6 and 7 further edges 8 and 9 are formed together form the width of 30 mm of the foot 5 indicated above.

For lamination, a strip of the same material as the core 4 and with one chosen such a thickness that after lamination there is a thickness of the foot 5 of 5 mm.

During lamination, the lamination surfaces are heated to the lamination temperature with hot air brought. It is a temperature at which the material is below the provided pressure in the embodiment without further auxiliary substances to the bent edges 6 and 7 sticks.

Before lamination, the plastic foam strip provided for the foot 5 underside with two spaced apart in the longitudinal direction Butyl adhesive strips have been prepared. Both adhesive strips, not shown, have one Thickness of 1 mm with a width of 5 mm and are covered with an oil paper. The Butyl tape is available in roll form. The cover strip can be in the roll at the same time form a separating layer so that the strip is easily pulled off and onto the Plastic foam strips can be pressed. This is preferably done between one Pair of rolls, the plastic foam strip from a supply roll and the butyl strip is pulled from another roll and with both strips positioned laterally for positioning be performed.

The list of the construction created according to the invention is shown in FIG. 1. she takes place after pulling off the oil paper at the desired location on the broom-clean Screed substructure, in the exemplary embodiment the concrete. After positioning the Construction, the screed is poured on both sides. The plastic strip forms one Expansion joint with the advantages described at the beginning.

2 shows the cutting out of a previously marked recess 11. The edges 6 and 7 are pressed together with thumb 10 and fingers in order to bring a pair of scissors (not shown) into engagement.
The associated expansion joint is located in the exemplary embodiment in the door area between two rooms. The plastic foam strip has been cut to the width of the door opening. The recess 11 was marked after stopping the plastic foam strip in the door opening.

Claims (10)

Process for forming an expansion joint in the screed, using a plastic foam strip, onto which non-foamed plastic foils (2,3) that are rigid against the screed load are glued or laminated, whereby the foils (2,3) are thermoformed with an L-shaped foot is given and the L-shaped base is provided with a self-adhesive strip on the underside and is placed with the adhesive strip on the substructure for the screed and a) with a pair of scissors or pliers and b) with plastic foils (2, 3), the L-shaped base of which can be bent by hand or with the aid of a device for cutting out passage openings. A method according to claim 1, characterized by the molding of the Through openings in situ. A method according to claim 1 or 2, characterized by the use of foils (2,3) with a thickness of up to 0.4 mm and / or slits in the plastic core on the Bottom and angling the edges (6,7). Method according to one of claims 1 to 3, characterized by the use of Butyl adhesive strips and / or the production of a foot with a width of up to 100 mm and / or the use of a strip of material with a height of 20 to 300 mm. Method according to one of claims 1 to 4, characterized by cooling the Kinks after thermoforming and / or linear heating of the Foils (2,3) at the kinks and a guide for kinking the free legs. A method according to claim 5, characterized by the use of a heating plate and / or the widening or deformation of the guide to kink the free Leg and / or by regulating the heating temperature and / or by adjusting the Contact length of the heating plate and / or setting of the contact time and / or through the use of copper for the heating plate and / or an electrically operated one Heating cartridge for the heating plate. Method according to one of claims 1 to 6, characterized in that the individual used foamed and / or non-foamed plastic strips and / or the Adhesive strips are pulled off a roll and / or brackets and guides and / or through the use of thermal or mechanical Cutting / slitting devices A method according to claim 6 or 7, characterized by the use of Pairs of rollers and / or circulating belts and / or sheets for guiding and Bracket and / or kink. A method according to claim 8, characterized in that the buckling tools according to the Slit and heat under and between the edges (6,7). Method according to one of claims 1 to 9, characterized in that the Plastic foam strips are cut to length and stacked after kinking, whereby when stacking the one with the following strips in the middle of his foot so on the previously placed strip is placed that his foot in the opposite Direction to the foot of the previously placed strip.

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