EP2327844A2

EP2327844A2 - End clip

Info

Publication number: EP2327844A2
Application number: EP10013695A
Authority: EP
Inventors: Harry Georges Rhodes; Michael David Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-10-15
Filing date: 2010-10-15
Publication date: 2011-06-01
Also published as: GB2474756A; GB0918075D0; EP2327844A3; GB201017168D0; GB2474756B

Abstract

A folding closure member for closing the end of multi-wall hollow sheeting which may be supplied on a roll and is fixed by means of a liquid or semi liquid adhesive which flows into the previously created cavities and troughs of the surfaces of the closure members and exterior surfaces of the outer walls of the sheeting. Once folded and squeezed together it forms substantially a 'U' shape and provides a secure water impermeable bond and seal between the UPVC and sheeting surfaces which are extremely difficult to bond to for prolonged periods. There is also attached a filter tape which lifts as the wings are folded into and glued into position position.

Description

Polycarbonate sheeting as commonly used for conservatory roofs and similar constructions suffers from the problem of algae growth within the flutes of the extruded sheeting.
The only protection is to seal the cut ends of the sheeting with suitable means as to prevent the ingress of dust and moisture which is the root cause of the growth of algae, the spores of which are essentially always present in the air.
The system currently employed is to provide a form of filter at the cut ends of the sheeting which will allow the movement of air in and out of the flutes. The filter is then protected by a plastic end cover generally in the form of a square 'U' shape which clips on to the end of the sheeting covering the filter and maintaining it's position on the sheeting by the action of the 'legs' of the 'U' shape which are designed grip the top and bottom surfaces of the sheeting.
The problem arises from the fact that it has proved very difficult to extrude the polycarbonate sheeting without causing small channels on the surface of the sheeting and all such sheets have these small channels.
It has also proved very difficult to design a form of plastic end closure which by its grip alone can effectively squeeze in to the small channels and seal them against the ingress of water. Consequently all such enclosures do allow water to pass. This water then gets on to the filter and the then combination of water sunlight and filter with the slightest component of dust will permit the growth of algae.
The difficulty is further enhanced by the requirement of the purchasers of these structures that the roof will remain clear for at least ten years.
The only way to ensure that the end closures are completely sealed to the roofing sheets is to fasten them to the sheeting with a suitable adhesive which is firmly bonded to the sheeting providing an effective seal against the ingress of water for the required time in the challenging conditions found in these situations.
Due to the nature of plastic extrusions the surface of such extrusions can be particularly resistant to normal adhesives; the invention describes a method which effectively achieves a solution to this problem.

Technical Description

The invention concerns a method for the attachment of a Folding End Clip or Closure Member (Which relates to our previously granted Patent No GB 2412928 ) to the cut ends of hollow sheeting.
The above patent GB 2412928 describes the attachment as being strips of compressible material which can substantially adapt to the surface profile of the sheet sides.
It was found in later trials that the this method was not satisfactory as the surface profile of the polycarbonate sheeting and in particular the grooves running down the sheeting could not be sealed sufficiently using the compressible strips. These grooves are sometimes a deep triangular shape which end in a narrow point and require a liquefied adhesive to flow deep within the narrow trough and so therefore will secure a good seal.
Additionally, the adhesive would lift away from the PVC due to a critical breakdown of the adhesive bond upon the surface of the PVC. This technique of the patent above failed on two counts. The grooves of the surface, and, the unstable surface of the PVC. This will be later explained.
Previously, using the technique of the patent above the seal was only temporarily held as the 'memory' within the compressed strips over time gradually contracts itself from within the grooves it was originally designed to seal. It will only seal correctly if constant downward pressure is maintained and it is not.
This then allows surface water to pass into the area enclosed by the closure member and consequently on the filter component which eventually becomes contaminated with algae. Once this occurs, the algae can spread into the inner compartments or flutes of the sheeting and effectively destroys the look and transparency of the roofing sheets.
The entrance of water and suspended particles onto the air filter permanently compromises it's performance. The suspended dust particles build up to such a degree that, the airways within the closure profile fill with this sludge and as a consequence it again virtually destroys the essential ventilation and filtration of the flutes within the multi-wall sheeting.
The only way to completely seal the surface grooves is to use an adhesive which is sufficiently liquid that it will consistently flow into the depth of the grooves to both seal and bond the surfaces for a very long time. These grooves being on the multiwall sheeting and the contacting surfaces of the closure profile. The added problem is that the setting time for this adhesive must be short enough such as to meet manufacturing requirements of time and profitability.
Also the extrusion material for the end closure is composed of PVC and has a surface which does not provide good adhesion. It is well known that these types of plastics contain 'oily' plasticizers which migrate to the surface. Consequently, this results in a catastrophic failure of the adhesive bond. This requires that the extrusion is provided with a keyed surface to allow the liquid adhesive to flow into the keyed area and on setting be locked firmly to it
By 'keying' grooves, troughs or protrusions into and onto these surfaces the negative effect of these plasticizers on the adhesive bond is virtually eliminated.
An adhesive may be provided on either of the surfaces of the hollow sheeting or the keyed surfaces of the U channel sealing folding member prior to the respective surfaces being married and joint together. The adhesive is desirably a polyurethane hot-melt. The adhesive is desirably a flowing liquid such that it may be urged and pressed into an over the surfaces to be joined together.
The surface of the polycarbonate is such as will give good adhesion and the grooves themselves will also aid adhesion. The adhesive is desirably a PUR adhesive which has a Hot Melt addition to provide fast setting while the PUR will give long term structural bonding.
The combination of surface treatment and liquid adhesive provides for the required essential long-term adhesion of the Closure Member and effectively controls any ingress of water.
In one embodiment, a filter member may be provided extending over the vent holes, on the side of the member in use towards the sheeting. The filter member may be in the form of a strip of filter material extending along the length of the body. The filter material may be bonded at side edges thereof respectively to the base of the U, and the side limb of the U in which the vent holes are provided, beyond the vent holes relative to the base. The filter member may be arranged such that when the body is unfolded the filter member extends substantially parallel thereto, when the body is folded the filter member tends to bow away from the vent holes.
The accuracy of the placement of the Closure Member on the sheeting and the added requirement for the folding of the member (see Patent GB 2412928 ) can be achieved with the use of a machine specifically designed for the purpose.
An end clip may be provided for closing the gap at the edges or the sheets between the base of the U and the body and the end of the sheet. The end clip may comprise a projection locatable in said gap. The projection may include vent means, and may also include filter means. A filter tape may be provided on the ends of the hollow sheet within the closure member.

Drawings

1. Shows section of closure member extrusion
2. Shows sectional view of enclosure folded over sheeting
3. Shows adhesion areas of closure member
4. Shows enlarged view of adhesion area of closure member
5. Shows examples of keyed surfaces
6. Shows end view enclosure member, sheeting and filter
7. Shows adhesive encapsulated within feyed surface
8. Shows detail of down turned edge of extrusion member

A. Extrusion Member

B. Area of encapsulation of adhesive

C. Enlarged view of Keyed Surfaces

E. Breather slots in extrusion member

F. Filter

G. Adhesive

H. Down turned edge of extrusion to contain adhesive spread

J LIVING HINGES.

I Hollow sheet surface channels or grooves.

There will follow a detailed explanation for each diagram to clearly explain the core features and novelty of this invention. Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:-
Fig 1 Shows a cross section of the closure member 'K' in its open position. There is present the anti-dust tape 'F' in position ready to lift as the adjacent joint below 'J' is folded into position fig 6 'J'.
The grooves and troughs are shown as 'B' positioned on the upper surfaces. This is where the flowing adhesive would be applied prior to positioning and folding onto the outer walls of the polycarbonate. As shown in fig 2.
Fig 2 Is a diagrammatic cross sectional view of the closure member of fig 6 and shows the completed fold 'J' onto the outer walls of the polycarbonate sheeting. The tape 'F' has lifted into its correct position. The air can now ventilate through the punched out aperture holes 'E'. It can then freely flow along the cavity created under the lifted anti-dust tape 'F' and through this tape as it filters out the foreign dust and pollen particles prior to entering the flutes inside the polycarbonate 'D'. A plurality of holes 'E' are provided in one of the side limbs of 'K' towards the centre section of 'K'.
In use, the body 'K' is folded to a U shape as shown for instance fig. 2 and can be mounted on the end of sheeting 'D' with the side limbs of 'K' securely attached to the sides of the sheeting 'D' by means of the adhesive flowing into the keyed surfaces and troughs or grooves and thereby spaced parallel with the sheet 'D' being trapped and sandwiched between the limbs of 'K'.
Figs 6 & 7 Most importantly, the flowing adhesive has filled the cavities and troughs and additionally encapsulated the protrusions of the pvc profile 'G' It has additionally flowed into and filled the grooves and troughs within the surface of the polycarbonate sheeting 'I' in fig 6. This is a critical feature of the patent as the integrity of the sheet and the tape is ensured. Neither water nor dust can pass there-through whilst clean air can.
Fig 3 shows the position of the 'grooved' or 'keyed' surfaces 'B'. This is the opened position of the closure profile 'A' and shows the folding crease lines 'J'.
Fig 4 Shows an enlarged view of the adhesion area 'B' of closure member surface. This is the desired area for the initial application of the flowing adhesive.
Fig 5 is a further enlarged example of the 'keyed' pvc surface 'B' 'C' of the contact area applied to the sheet surface 'I'. The feature of these surfaces is that, not only does it increase the surface area substantially for the adhesive to bond to, but it also physically entraps the set adhesive so that it is locked within the cavities 'B' & 'C'.
Fig 8 Shows the position of the surface of the polycarbonate and the surface of the PVC 'keyed' surface but without any adhesive present
Therefore, even though as mentioned previously, pvcs contain oily plasticizers which can break the adhesive bond, both the seal and the physically locked adhesive fig 7 'G' remain intact.
The form of the closure members readily permits them to be supplied as a roll, thereby providing for convenient storage, packaging and dispensing into required lengths. As the current method is to supply from 10 metre solid fixed lengths, the wastage is considerable. 25% wastage is common. The wastage from a roll supplied cut to length is expected to be less than 2%. The closure members can readily be applied immediately after the sheets are cut to size at the factory and not on site. This allows the sheet roof fitters more time on site, but more importantly minimal future call outs to failed and faulty roofs due to a failure of the end closure and filter from water ingress and contamination.
Normally this process would be too difficult to apply and assemble by hand. It is also critical the members are married together accurately to work successfully especially if the roofing sheet is to fit properly.
Therefore, a second patent is required and being applied for which involves the use of mechanical means and automation.

Claims

According to the present invention there is provided a folding
closure member for attachment to multiwall sheeting characterised as having provided along the closure member at least one channel
and protrusion capable of being wholly or partially encapsulated by adhesive means to form a strong bond to the sheet being
substantially impermeable to water and air, such closure member having openings or apertures to allow the passage of air and condensation and may have attached to it at least one ventilating filter
to retain dust particles but allow passage of air.
Claim according to claim 1 that such encapsulation may be achieved by means of a hot melt adhesive which may be a flowing
polyurethane hot melt adhesive.
Claim according to claims 1 and 2 that such encapsulation may be achieved by means of a semi flexible free standing pressure sensitive tack adhesive.
Claim according to claims 1.2 and 3 that, such closure may be fabricated of synthetic materials as plastic or rubber.
Claim according to claims 1.2.3. and 4 that, the filter may be made of spun bond fibres.
Claim according to claims 1.2.3.4. and 5 that such encapsulation may be achieved by means of a epoxy adhesive.
Claim according to claims 1.2.3.4.5. and 6 that such a filter may run the length of the closure.
Claim according to claims 1.2.3.4.5.6. and 7 that such a filter may be mounted at the ends of the closure member.
Claim according to claims 1.2.3.4.5.6.7 and 8 that such assembly may have applied a sealing supporting block or guide.
Claim according to claims 1.2.3.4.5.6.7.8. and 9 that, such filter may fold and lift upward away from the closure member to substantially form an airway.