DD148797A1 - SURFACE-MODIFIED PLASTIC SEALING FOIL FOR PRESSURE WATER-RESISTANT SEALS - Google Patents

Abstract

Surface-modified plastic sealing film for pressure-water-retaining seals for sealing of structures, especially in water and transport construction against seepage and pressurized water, consisting of surface-modified structural film of copolymer, wherein the surface is structured and / or laminated with woven or nonwoven fabrics. As a result, better friction values between the sealing film and the adjacent natural materials are achieved. On the other hand, a Veerklebung with solid components is possible by the erfindungsgemäaesze sealing film. The copolymer used is ethylene-vinyl acetate copolymers having a vinyl acetate content of 2 to 30%.

Description

218 454 - / -

VEB Leuna-Werke Merseburg, 7.1.80

»Walter Ulbricht" DC.Hi / Mö

LP 79 106 Title of the invention

Surface-modified plastic sealing foil for pressurized water-retaining seals

Field of application of the invention

The invention relates to a plastic sealing film for sealing of structures, especially in water and transport, against seepage and pressurized water.

Characteristic of the known technical solutions

Known is the use of thermoplastic films for sealing purposes against seeping or oppressive liquids, especially water. The known and technically introduced materials for these sealing foils are PVC-soft and polyethylene. The seal is achieved by welding the single sheets. Difficulties in the application of sealing films arise from the structure of the overall seal. The actual sealing element, the sealing film, is embedded in the majority of applications in protective and outer layers of natural or artificial materials. Since the surfaces of plastic films are very smooth, due to the production of polished calender rolls, these sealing films tend on all slopes, so slopes,

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Dikes or earth walls for slipping on the lower protective layer, or slip lying protective and cover layers on the sealing film.

This forces the use of sealing foils to keep the slope of slopes very flat, which means a considerable amount of earthworks.

Solutions to the problem are known in that one changes the surface of the sealing film by gluing or flocking with foreign substances or by the introduction of ribs (DE-OS 2054029), nubs or roughening, so that increased friction between film surface and resting, mostly fine-grained materials achieved become. These measures are intended to obtain steeper slopes in use.

The same purpose is also a step-shaped installation of the sealing film, as described in DD-Y / P 77 166.

These known solutions have disadvantages in that they are carried out to a large extent only on one side (gluing, flocking, pimples) that they require additional operations in the production of the sealing film that they are installation direction dependent, as the longitudinally ribbed PVC sealing foils, or a require considerable installation effort in step-like installation.

On vertical structures, sealing foils must be glued in order to establish a connection with the building surface.

This results in the use of polyethylene sealing foils considerable difficulties, since polyolefins can hardly stick due to their chemical structure.

Object of the invention

The aim of the invention is a sealing film which makes it possible to

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when sealing buildings, especially in hydraulic engineering to realize steeper embankment slopes, or perform on vertical components bonding the sealing film.

Explanation of the essence of the invention

The invention has for its object to develop a plastic material from a suitable plastic material with improved properties.

The object is achieved by a surface-modified plastic sealing film for pressurized water-retaining seals of ethylene-vinyl acetate copolymers, the surfaces of which are structured according to the invention in the preparation of both sides or modified and has a smooth, unmodified edge strip for welding.

Advantageously, ethylene-vinyl acetate copolymer having a vinyl acetate content of from 2 to 30% by weight is used as the starting material for realizing the requirements of a synthetic rubber sealing film.

This material fulfills the requirements of the user better than the previously used PVC soft and polyethylene sealing foils. In contrast to the PVC-soft and the polyethylene, ethylene-vinyl acetate copolymer remains extremely elastic and flexible up to temperatures below freezing and shows no susceptibility to cold breakage. This significantly limits the dependence of the laying of plastic sealing foils on construction sites on the outside temperature. This extensive temperature independence of the laying leads to a rapid construction process also in the cold season and thus ensures a rapid construction progress.

In contrast to the PVC-soft ethylene-vinyl acetate copolymer does not emigrate, which leads to embrittlement and thus endangers the sealing function.

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218 454

The modification of the sealing foil surfaces takes place on a plate extrusion line with smoothing calender. The melt film emerging from a slot die is guided into the nip of a smoothing calender. In the rollers of the calender, a structure is incorporated. It is a waffle-like structure, wherein the groove depth, groove width and grid width can be varied by the use of different pairs of rollers. Groove depths of 0.2 to 1.5 mm with a groove width of 1 to 1.5 mm and a grid width of 5 to 10 mm have proven successful. During calendering, the melt fills the grooves of the roll surface, so that the given structure is formed as a protrusion on the sealing film.

The processing of the calender rolls is done so that offset to the top and bottom rollers each a structureless, smooth polished edge zone remains. This gives the calendered sealing film, offset on both sides, a defined, smooth edge strip for welding the individual webs. In the welded state, however, a continuous surface structure is ensured. ·

Particularly advantageous for the user has the effect that the surface-modified sealing film with its executed on both sides, waffle-like surface structure contrary to known solutions during installation can be installed independently of direction.

To enable bonding of the sealing film, e.g. On vertical components, a fabric or nonwoven fabric is laminated on one side of the molten ethylene-vinyl acetate copolymer film in the nip of the calender. The bond between the woven or nonwoven fabric and the ethylene-vinyl acetate copolymer sealing film is so strong that it forms a permanent bond after cooling. Via this, with fabric or nonwoven fabric modified sealing film surface can now be adhesions to solid components with suitable, commercial adhesives, e.g. Two-component adhesives based on PUR, perform in accordance with quality.

LP 79 106

embodiments

example 1 Example 2

Extrusion through a slot die gives a plastic melt film. The material used is ethylene-vinyl acetate copolymer having a vinyl acetate content of 8 to 14 wt .-%. In the rollers of the smoothing calender a lattice structure is incorporated. The groove width is 1.2 mm, the groove depth 1.0 mm and the grid width 10 mm. The upper and middle rollers of the smoothing calender each have a smooth, polished edge strip. The structure-free basic thickness is 1.5 mm.

The EVA melt film is driven through the nip with a slight bead. The surfaces receive the structure of the rolls as elevations. The thus surface-structured sealing film is fixed by cooling. Subsequently, the edge trimming takes place on both sides, so that offset at the top and bottom of a non-structured, smooth edge strip for welding stops.

Extrusion as in Example 1, wherein the ethylene-vinyl acetate copolymer used has a vinyl acetate content of 2 to 8 wt .-%.

The top roller of the smoothing calender is polished smooth. In the center roller a grid structure is incorporated. The groove width is 1.0 mm, the groove depth 0.8 mm and the grid width 6 mm. The structure-free basic thickness is 1.2 mm. Over the top roller of the smoothing calender, an endless fabric web is fed.

The EVA melt film is driven through the nip with a slight bead. The fabric is firmly laminated to the top and on the bottom you get the structure of the roller as

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Survey. The thus modified DichtuDgsfolie is fixed by cooling. Subsequently, the

defined edge trim. By prior trimming of the fabric web, it is possible to have one

non-laminated edge strips for overlap welds. '

Claims (4)

Invention claim. 1. Surface-modified plastic sealing film for pressurized water-retaining seals based on ethylene-vinyl acetate copolymers, characterized in that the surfaces of the film on both sides have a lattice-like structure as survey or have a one-sided fabric or nonwoven lamination, wherein the other side is structured like a grid, and a smooth, unmodified edge strip for welding is present. 2. Surface-modified plastic sealing film according to item 1, characterized in that the structure of the surfaces is formed like a lattice survey as having the following dimensions: Bridge height from 0.2 to 1.5 mm
Bridge width of 1.0 to 1.5 mm and
Grid width of 5 to 10 mm. 3. Surface-modified plastic sealing film according to item 1, characterized in that the sealing film consists of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 2 to 30 wt .-%. 4. Surface-modified plastic sealing film according to items 1 to 3, characterized in that the structure-free basic thickness of the sealing film is 0.8 to 4.0 mm.