GB2323711A - Flexible magnetic articles - Google Patents

Abstract

A flexible magnetic article 1 comprises a flexible magnetic sheet 2 with one face, for attachment to another body, which has a smooth surface and the other face is coated with a material 3 on to which further material 4 is printed. The coating material 3 may be light-reflective or non-light-reflective. The magnetic article may comprise a vinyl binder which is soft and pliable such that the article will readily conform to the shape of the surface on to which it is attached. A high number of magnetic poles per unit length may be formed in a matrix to provide a good magnetic attachment. The magnetic material 2 may be non-toxic and weather resistant. The article may be used for high visibility warning signs, advertising or decretive motives on various vehicles or metal structures.

Description

FLEXIBLE MAGNETIC ARTICLES The present invention relates to flexible magnetic articles.

In conditions of reduced visibility, e.g. fog, precipitation and hours of darkness, the position, dimensions, location and perception of vehicles and structures become less clearly defined. A significant safety hazard may arise as a result of these conditions.

Although it is clearly recognised that some vehicles and structures have design features which indicate their position, dimensions, location and perception, a flexible magnetic article according to the present invention may add to and enhance those features by increasing overall visibility.

Currently, commercially available reflective devices comply with minimum safety standards applicable to the country of destination, which under normal circumstances are adequate for the purpose for which they were provided, in addition to which such devices are designed to be a permanent fixture.

WO 93/22137 describes a particular process for printing an image on to a plastic lamina body which may be backed by a magnetic sheet.

US-A-4 310 978 describes a plasticised wallet, with an outer layer being of transparent plastic that has been heat sealed with one edge left open so that paper materials containing advertisements or information may be inserted and changed at will.

GB-A-2 273 386 describes a magnetic tile which must be affixed to a secondary magnetic backing board to form a sign board that allows proportional spacing of letters and numbers.

US-A-4 663 874 describes a flexible magnetic sign whose rear surface is formed with trough-indentations or scoring.

According to the present invention, there is provided a flexible magnetic article comprising: a laminar formation of a flexible sheet comprising magnetic material having a smooth face for attachment to another body; a lightreflective or non light-reflective coating adhered to the other face of said sheet; and printed material on said coating.

A flexible magnetic article according to the present invention may be a non-permanent fixture, which may be mounted and de-mounted swiftly and easily. This makes such an article reusable, available for display when increased visibility is required, easily removed and stowed under normal circumstances.

A flexible magnetic article according to the present invention may complement existing fitted equipment, and also provide increased visibility and definition of a vehicle or structure. Where existing luminary devices are not in evidence, the article may be sited to enhance the vehicle's or structure's position, dimensions, location and perception.

The present invention will now be described, by way of example, with reference to the accompanying drawing, in which: - Fig. 1 is a section through an example of a flexible magnetic article according to the present invention; and Fig. 2 is a perspective view of the flexible magnetic article.

In Figs. 1 and 2, a flexible magnetic article 1 comprises a flexible sheet 2 comprising magnetic material having a smooth rear face, reference numeral 3 designating a coating of light-reflective or non-light-reflective material adhered to the other face of sheet 2 and reference numeral 4 designating printed material on the coating 3.

The sheet 2 may be in the form of a flexible magnet manufactured by Magnet Sales & Manufacturing Inc., 11248 Playa Court, Culver City, California 90230, United States of America. Such a magnet is made by bonding a magnetic powder in a totally smooth, flexible vinyl binder. The vinyl binder is so soft and pliable, that it conforms totally to the shape of the surface it is affixed to without the need for unnecessary scoring or texturing of the magnetised surface. The polarity of the magnet is created and increased using a matrix formation rather than common plurality of poles. The magnetic force exerted is provided by a matrix of magnetic poles which generally run parallel to the length of the strip or sheet. The greater number of poles per unit length, reducing magnetic reach, the stronger the magnetic hold.

The matrix formation with the increased number of poles per unit length is designed to provide maximum magnetic hold. This matrix structure counters commonly encountered "air-gaps", caused by paints, rust, or other non-magnetic gaps between the magnet and the surface to which the magnet is attached, to ensure the eradication of air bubbles or lift caused by partial non-magnetic surfaces etc. As a result of the composition of the matrix, it is not necessary to increase the thickness of the magnetic material to increase strength of magnetic force exerted. Rather, the number of poles per unit length within the matrix is increased, thereby increasing the magnetic force exerted, i.e. the shorter the reach of the magnetic field the greater the magnetic holding force exerted.

The formation of the matrix means that greater control may be exerted over the magnetic properties demonstrated by the magnet. For example, the flexible magnet may be magnetised on either or both surfaces.

The magnetic material is non-toxic, being made using a lead free construction and the magnetic powder being derived from strontium rather than barium or bromine ferrite and being W resistant for outdoor weatherability.

Where the coating 3 is a light-reflective coating, it may be provided by a suitable paint or an adhesive sheet, such as, but not restricted to, those manufactured by 3M, Commercial Graphics Group, 3M United Kingdom PLC.

The reflectivity of '3M Scotchlite' Diamond Grade self adhesive sheeting is up to nine times greater than that of traditional 'engineering grade' reflective films. It also offers greater angularity (up to and well beyond 45" from perpendicular), so that reflected light can be seen from a wider range of viewing positions to ensure a vehicle can be seen at all times, at greater distances right up to 500 metres and beyond.

The typical coefficient of retroreflection values of these sheetings when new are given below in terms of candlepower per foot-candle per square foot (candelas per lux per square metre).

Scotchilte w 980-10 0.2e Observation Angle and 980-72 films Typical Coefficient of Retrorenection

Entrance Angle A 4 45 White 900 250 Red 170 45 Observation Angle: The angle formed by the light beam striking the reflective surface and the light beam returning to the observer (from 245 metres, a motorist normally views a marking at approximately a 0.2 observation angle).

Entrance Angle: The angle formed by a light beam striking a surface at point and a line perpendicular to the surface at the same point.

Where the coating 3 is a non-light-reflective coating, it may be provided by a suitable paint or an adhesive sheet, such as, but not restricted to, Scotchcalw 100F/220 (Opaque Film), Controlacw 160/180 (Opaque Film) Series, manufactured by 3M, Commercial Graphics Group, 3M United Kingdom PLC.

One method of manufacturing the flexible magnet 2 is as follows. A single layer of lamina, for example 3M Scotchcalw or 3M Scotchlitem, is overprinted with, for example, 3M Scotchcalm screen printing ink to provide printed material 4. Either screen-printing, ink-jet, bubble-jet or spray-jet printing technology is used for example. The lamina is attached to the sheet 1 utilising either " Contact" or "Intelligent" adhesives such as, those produced by 3M > .

The flexible magnetic article 1 may be used as a safety or conspicuity marker and then would be manufactured in a wide range of sizes and colour combinations to meet with all aspects of safety specifications, road traffic legislation and functional requirements, in addition to the cosmetic requirements predominant in the private vehicle marketplace. In order for the article 1 to be utilised, it is secured by means of its sheet 2 being placed in contact with a vehicle, vessel, craft, offshore installation, moveable or fixed structure which itself must have magnetic properties. The flexible nature of the flexible magnetic article allows it to adapt its shape to that of the surface it is in contact with.

Each flexible magnetic article remains in situation until it is no longer required when it may be removed by peeling away from the body of the vehicle, vessel, craft, off-shore installation, moveable or fixed structure and retained for future usage.

To reapply the flexible reflective magnet the steps described above are carried out again.

By way of example, the minimum surface area of the flexible reflective magnet is no less than 1mum2, its maximum surface area no greater than 500m2 and its thickness no less than 1 micron and no greater than 1 metre.

Claims (2)

1. A flexible magnetic article comprising a laminar formation of: a flexible sheet comprising magnetic material having a smooth face for attachment to another body; a light-reflective or non-light reflective coating adhered to the other face of the sheet; and printed material on said coating.

2. A flexible magnetic article, substantially as herein described with reference to the accompanying drawing.