Stock material or miscellaneous articles – Composite – Of bituminous or tarry residue
Patent
1997-08-05
1999-04-06
Beck, Shrive
Stock material or miscellaneous articles
Composite
Of bituminous or tarry residue
4285371, 428489, 427393, 427397, 427441, 156337, B32B 1100, B05D 302
Patent
active
058915834
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to a method of protecting wooden objects, particularly elongate ground contact objects such as fence posts and telephone and electricity poles, from decay.
Preservative treated fence posts despite advances in preservative technology are still prone to ground level decay. Typically, after 20 years service, 5%-30% of posts will be showing signs of decay at or below ground level, although this is to some extent dependent on ground conditions and standards of preservative treatment.
This is unfortunate as the other parts of the posts, i.e. those deep below ground and those well above ground, would give a typical life of 40-50 years or more.
The top portion of a fence post, i.e. that from approximately 50-75 mm above ground level, is exposed to natural air flow and sunlight which will ensure a typical moisture content of 15%-70%, dependent on weather conditions. These factors combined with preservative treatment should mean that decay is very rare.
The bottom portion of the post, i.e. that from approximately 300 mm below ground level, does not decay because of the very high moisture content (typically 30%-90%) and the compacted wet soil conditions will ensure minimum levels of oxygen which is vital for the growth of rotting organisms.
This leaves the middle portion from about 300 mm below ground level to about 75 mm above ground level where conditions are ideal for decay.
The fence post acts as a wick drawing up water and solids to a band at ground level where the water evaporates. This portion of the post is very damp, typically 30%-90% moisture content, and is exposed to ground and airborne micro-organisms which come into contact with the post and form primary moulds which are then followed by soft rots and Basidiomycetes.
Although preservatives greatly extend the life of fence posts (untreated posts typically last only 3-4 years), it is difficult to measure the standard of preservative treatment. Consequently, poor treatment can pass unnoticed.
Preservative belts, sleeves and wraps are also known. These relatively expensive products are predominantly used for the treatment of posts and poles in service, where their main purpose is to provide preservative material to replace that which may have been lost due to, inter alia, leaching. The sleeve wrap or belt provides additional preservative material at the outer face of the pole or post which is then absorbed, the objective being to totally penetrate the pole or post with preservative, hence eliminating decay.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of protecting wooden objects from decay, the method comprising the step of applying a flexible outer barrier layer to at least that part of the object most vulnerable to decay, providing a bituminous substance between the barrier layer and the object and heating the barrier layer so as to melt the bituminous substance sufficiently for it to bond intimately to the wooden object.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the avoidance of doubt, the term "bituminous substance" used herein includes, for example, bitumen, tar, pitch, coal tar, asphalt, gilsonite, or any combination thereof in straight or modified form.
Preferably, the outer barrier layer is in the form of a plastics film or a metal foil or a combination thereof. Where a plastics film is used, it may be made from recycled plastics material.
Preferably, the barrier layer is coated with said bituminous substance prior to application to the object.
Preferably, where the barrier layer is in the form of a plastics film, it is applied to the object at an elevated temperature.
In this latter case, the plastics film is, preferably, of heat shrinkable plastics material and is formed into, or is in the form of, a sleeve which is heat shrunk onto the object.
Alternatively, the plastics film may be in the form of an elongate strip which is wound about the object while applying heat and tension to the strip, or may be in the form of a sheet which is wrapped aro
REFERENCES:
patent: 893391 (1908-07-01), Sinclair
patent: 2109508 (1938-03-01), Schmittutz
patent: 2875020 (1959-02-01), Ring
patent: 3448585 (1969-06-01), Vogelsang
patent: 3467490 (1969-09-01), Sommer
patent: 3638790 (1972-02-01), Schmid et al.
patent: 4708527 (1987-11-01), Inhofe, Jr. et al.
patent: 4779735 (1988-10-01), Kelso, Jr.
patent: 4908085 (1990-03-01), Makus et al.
patent: 5138806 (1992-08-01), Marx et al.
Barr Michael
Beck Shrive
Fenson & Company Limited
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