WO2015140558A1

WO2015140558A1 - Flooring

Info

Publication number: WO2015140558A1
Application number: PCT/GB2015/050806
Authority: WO
Inventors: Andrew Jones; Mark Dalziel
Original assignee: Dycem Limited
Priority date: 2014-03-20
Filing date: 2015-03-19
Publication date: 2015-09-24
Also published as: GB2524306B; GB201404988D0; GB2524306A

Abstract

A contamination control mat (10) comprising a core layer (16) which is a non-woven substrate, wherein the core layer (16) is coated on one surface with a contamination control polymeric top layer (12), and coated on the opposing surface with a polymeric backing layer (14) wherein the core layer (16) is printed, the top layer(12) is translucent or transparent, and the print on the core layer (16) is visible through the top layer (12). The contamination control mat (10) is, in particular, for use as flooring in contamination control situations.

Description

Flooring

Field of the Invention

This invention relates to the field of flooring. In particular, the invention relates to flooring for use in contamination control situations.

Background to the Invention

Maintaining a controlled environment is essential in many academic, industrial and medical settings, and controlling contamination entering that environment is very important. For example, many hospitals, factories, food preparation areas, spray-paint booths and laboratories utilise a controlled environment, which may be referred to as a cleanroom. Precautions are taken such as subjecting cleanroom staff to strict clothing regulations and using a gowning room where the staff can change clothes under "controlled" conditions so as to prevent any particulates from entering from the outside environment. Certain areas in a cleanroom may have more stringent measures than others, with packaging areas, corridors, gowning rooms and transfer hatches being incorporated to maintain strict contamination control measures.

In hospitals, cleanroom precautions can be used to try to reduce the incidence of infectious diseases spreading. In industry, particularly in the pharmaceutical, electronics, aerospace, catering, automotive, biomedical, IT, nuclear, optical and medical devices industries, it is often essential to ensure that the products are free from contamination. Contamination of a controlled environment poses a threat to product processes, the consequences of which are lower product yields, raised costs and decreased profits.

Contaminants are particles that enter an environment where they may potentially have a negative effect. There are many types of contaminants and they can have a wide variety of effects on different environments. Contaminants can be bacteria or other organisms that are potentially harmful to their surroundings. More familiar contaminants can be things such as dust and dirt. Contaminants can be carried on any surface entering a controlled environment, or in the air. Particles can be suspended in the air for hours where they undergo rapid proliferation, contaminating the surrounding environment. Once there is no movement and turbulence stops, airborne contaminants fall. If they fall onto an unprotected floor they may rise again and be redistributed into the air as a result of the vortices created by the movement of personnel and wheeled traffic.

Studies have shown that over 80% of contamination enters a controlled environment through entrances and exits, mostly at or near floor level. As a result of this, attempts have been made to reduce the contamination entering a controlled environment by using particular floor coverings.

It is known to use particular floor coverings in entry and exit areas to controlled environments to attract, collect and retain foot and wheel borne contaminants, thereby reducing the contamination entering the controlled environment.

One type of flooring, known as polymeric matting, is particularly effective in certain situations in controlling particulate contamination. It is semipermanently installed and can be cleaned as required. Dycem's Protectamat flooring system is an example of this. The polymeric matting comprises a single layer of polymer, usually a specially blended polymer formulation comprising polyester plasticisers. This is typically at least 7mm thick, making it heavy to manoeuvre. As noted above, this is a semi-permanent or permanent solution, in that the polymeric matting is particularly long-lasting and can be used for 3-5 years before replacement. This works very well when long term contamination control is required and the operator has sufficient resources to invest in such a system. However, it is less suitable for a situation where contamination control flooring is needed for a short period or at a low cost, for example, a testing laboratory, where testing is going on for a few days or for a few weeks.

"Peel off mats, also known as adhesive floor mats or tacky mats, are also used in contamination control situations particularly where the need for contamination control is short lived, or there is not enough resource to fund installation of permanent contamination control flooring. These mats comprise a laminate of thin (0.1 to 0.2 mm) synthetic material layers, typically thirty layers, which are stuck together by a pressure sensitive adhesive to form a mat which is several millimetres thick. The mat is then placed on a floor to capture contaminants, for example, from feet or the wheels of trolleys. In use, the upper layer of a mat is removed from the base on a regular basis, exposing a new clean layer.

These "peel off mats have several disadvantages. Firstly, and most importantly, the peel off mats do not work very well in comparison to polymeric matting. The surface tack is not as good as polymeric matting and does not retain nearly as many contaminants. Second, adhesive can be removed from the uppermost layer to adjacent floor surfaces by feet and wheels which can itself attract contaminants, meaning that peel off mats can be counterproductive by actually encouraging contaminants into the controlled area. Third, when an upper layer is removed from the mat it creates a considerable volume of waste which is difficult to recycle. Fourth, when removing an upper layer, contaminate particles can be released which may be hazardous to a user who may breath them in.

It is an object of the invention to overcome, or at least to mitigate, the disadvantages of prior art products.

Summary of the Invention

According to one aspect of the invention there is provided a contamination control mat comprising a core layer which is a non-woven substrate, wherein the core layer is coated on one surface with a contamination control polymeric top layer, and coated on the opposing surface with a polymeric backing layer. In use, the top layer is uppermost and attracts, and at least substantially retains, contaminants.

Contamination control mats in accordance with the invention, with a three-layer structure having a non-woven substrate as a core layer, a contamination control polymeric coating as the top layer, and a polymeric coating as the backing layer, have several advantages over known contamination control mats. Falling between polymeric matting and peel off mats they are, in particular, inexpensive and easy to fit, requiring low capital investment by the user. The contamination control mats may be easily movable, allowing maximum flexibility for users in contamination control situations.

The flexibility and light weight of the mats according to the present invention is achievable because of the new three-layered structure (Tri-Layer Technology), which is in contrast to the peel off mats, and to the traditional polymeric mats which contain a single polymer material all the way through. In particular, using a non-woven substrate core layer gives rigidity and cross dimensional stability to the mat which means that a much thinner product can be used than when using polymers alone.

A further advantage of using a non-woven substrate as the core layer, is that it can be printed as described below, to allow for a pattern to be visible to the user.

The contamination control mat may not need cleaning, before replacement, on a regular, say weekly, basis. Additionally, the contamination control mat is unlikely to be deployed in the wrong orientation because the two outer surfaces, i.e. the top layer, and the backing layer can be visibly different to a user.

Accordingly, the present invention provides a mat which is better suited to short term contamination control than existing polymeric products, and is much more effective in controlling contamination than peel off disposable mat products.

The top layer provides the contamination control properties to the mat. By contamination control polymeric top layer, we mean that this layer must be made from a material that attracts, and at least substantially retains, contaminants. The top layer is preferably formed from a blended polymer comprising polyester plasticisers. Suitable materials are known to those skilled in the art. Suitable materials are described in WO2006/1 14599, GB1399191 , GB1475366, GB2025319, and GB2144139. Permanent versions of the contamination control floor coverings are available from Dycem, under the "CleanZone" and "WorkZone" trade names. The same materials can be used in the polymeric layer of the present invention, but in a much thinner layer than in the permanent version, and in combination with the non-woven substrate.

The top layer may be dyed, and can be translucent, transparent, or solid in colour, but is preferably translucent or transparent. This is advantageous, as it allows any printing on the non-woven substrate to be visible from the surface.

The contamination control mat may have antimicrobial properties. For example, the top layer may include an antimicrobial ingredient. A preferred antimicrobial ingredient is silver ions which inhibit the growth of microorganisms, preferably derived from silver nitrate.

Similar to the top layer, the backing layer is a polymeric coating on the non- woven substrate. It can also be a blended polymeric formulation comprising polyester plasticisers. It may be the same as, or different from, the top layer in composition. In a preferred embodiment, the backing layer looks different from the top layer, so that consumers do not use the backing layer to try to provide contamination control. The backing layer preferably has non-slip properties, for example may be textured. The backing layer often has a black appearance, which can be through the polymer coating on the non-woven substrate being black in colour, or having an additional coating which is black.

The top layer and backing layer are added onto the core layers as coatings on opposing surfaces of the core layer. Where they are coated directly onto the core layer, they can impregnate the non-woven substrate and encapsulate the core layer. This is preferable. Alternatively, there may be one or more other layers between the core layer and the top and/or backing layers. In this case the top and/or backing layers are coated onto the core layer indirectly, on top of any other layers that are present.

As mentioned above, the core layer is advantageous in that it adds rigidity and cross-dimensional stability to the mat. The core layer is formed from a non- woven substrate such as a fabric, for example, non-woven spun bond polyester. This is typically the type of material that is used in cleaning products, where cross-dimensional strength is important. The non-woven substrate is typically 0.5 to 3mm, preferably 1 to 2mm thick.

The material of the core layer is preferably printed before the contamination control mat is formed. For example, the outer edges of the core layer can be printed with a set pattern. Usually the substrate is light in colour, often white, and the printed areas are darker. In this way, the printed area is relatively dark compared to the centre of the core layer, thus visually defining a border around the core layer. In a preferred embodiment, the print on the core layer is visible through the top layer. In contrast, the backing layer is usually solid in colour, so the print on the core layer is not visible through the backing layer. The backing layer is typically a darker colour than the core layer and/or the top layer. The backing layer is often black.

Further layers may be interposed between the top layer and core layer, and/or between the core layer and backing layer. For example, where the core layer is white, an additional white polymeric layer may be interposed between the core layer and the backing layer which can, for example, be black.

Typically, a contamination control mat in accordance with the invention will be relatively thin compared to conventional polymeric contamination control mats, preferably 0.5 to 3mm thick, more preferably 1 to 2 mm thick, most preferably, contamination control mats in accordance with the invention are about 1 .2 mm thick. This is substantially thinner than previous contamination control flooring. The use of the non-woven substrate core layer allows for the product to be this thin. The top and backing layers are very thin, with the core layer typically making up the majority (more than 50%) of the thickness of the mat.

In a preferred embodiment, the contamination control mat includes or is supplied with means for indicating the length of use of the mat. For example, the contamination control mat may include an area, preferably a strip, on which can be indicated the date of first deployment of the contamination control mat, or may include an indicator that changes with time and/or use. Alternatively, a separate indicator can be supplied, that can be displayed close to the mat, for example a chart on a piece of paper or card, which can be pinned to a wall adjacent the mat.

According to another aspect of the invention there is provided a method of contamination control, the method comprising deploying a contamination control mat in accordance with the first aspect of the invention in an environment where contamination is to be controlled, such that the top layer is uppermost.

The contamination control mat may have double sided adhesive applied to the perimeter of the backing layer to allow it to be adhered to surfaces such as vinyl or a smooth epoxy resin.

The top layer may be cleaned on an occasional basis, with water and a gentle surfactant product.

In contrast to the top layer, the backing layer is preferably solid in colour, meaning that it is not transparent or translucent. This means that any print on the core layer would not be visible through the backing layer. The backing layer is often black.

According to a third aspect of the invention, a contamination control mat is made by providing a) non-woven substrate as a core layer, b) coating one surface of the core layer with a contamination control polymeric material to provide a top layer, and c) coating the opposing surface of the core layer with a polymeric backing layer.

The top layer is translucent or transparent and the core layer is printed, so that the print on the core layer is visible to the user through the top layer, whereas the backing layer is preferably solid in colour, so that the print on the core layer is not visible through the backing layer. Brief Description of the Drawings

Contamination control mats in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawing, Figure 1 , which is a cross-section through a mat in accordance with the invention.

Description

The mat 10 comprises a top layer 12, a backing layer 14 and a core layer 16 which is coated on opposing surfaces by the top layer 12 and the backing layer 14.

The top layer 12 is formed from a blend of polymers comprising polyester plasticisers. The top layer is tinted blue, and is substantially translucent so that the core layer 16 is visible to a user. An area 13 is provided on the upper surface of the top layer 12 for a user to mark the date of first deployment of the contamination control mat. Alternatively, an indicator can be a separate item, which can be mounted on an adjacent wall, such as a sheet of paper specifically designed to allow use of the mat to be monitored.

The backing layer 14 is formed from black polymeric material and has surface adhesive qualities to allow a temporary bond to the subfloor.

The core layer 16 is formed from a nonwoven substrate which is a spun bond polyester of the type used in cleaning products where cross-dimensional strength is important. In this embodiment the core layer is white. A black awareness border 17 is printed around the perimeter of the core layer 16 and is visible to a user through the top layer 12. The awareness border 17 visually defines the periphery of the mat to a user.

The top layer 12, the backing layer 14 and the core layer 16 are thermally bonded together. In use, the contamination control mat 10 is deployed in an environment where contamination is to be controlled. The contamination control mat 10, is deployed with the backing layer 14 lowermost and the top layer 12 uppermost. Typically, the contamination control mat may be changed on a regular basis. For example weekly. The contamination control mat may be cleaned, for example with water and a cleaning product.

Claims

1 . A contamination control mat comprising a core layer which is a non-woven substrate, wherein the core layer is coated on one surface with a contamination control polymeric top layer, and coated on the opposing surface with a polymeric backing layer.

2. A contamination control mat according to claim 1 , which is 0.5 to 3mm thick.

3. A contamination control mat according to claim 2, which is 1 to 2mm thick, preferably about 1 .2mm thick.

4. A contamination control mat according to any preceding claim, in which the top layer is formed from a blended polymer comprising polyester plasticisers.

5. A contamination control mat according to any preceding claim, in which the top layer is translucent or transparent in colour.

6. A contamination control mat according to any preceding claim, which has antimicrobial properties.

7. A contamination control mat according to claim 6, in which the top layer includes at least one antimicrobial ingredient.

8. A contamination control mat according to claim 7, in which the antimicrobial ingredient is silver nitrate.

9. A contamination control mat according to any preceding claim, in which the backing layer has nonslip properties.

10. A contamination control mat according to any preceding claim, in which the backing layer is solid in colour, preferably wherein the backing layer is black.

1 1 . A contamination control mat according to any preceding claim, in which the core layer is printed, preferably wherein the core layer is printed with a border around the edges.

12. A contamination control mat according to any preceding claim, in which the core layer is visible to a user through the top layer.

13. A contamination control mat according to any preceding claim, including at least one further layer interposed between the top layer and core layer.

14. A contamination control mat according to any preceding claim, including at least one further layer interposed between the core layer and backing layer.

15. A method of contamination control, the method comprising deploying a contamination control mat in accordance with any of claims 1 to 14 in an environment where contamination is to be controlled, such that the top layer is uppermost.

16. A method of contamination control according to claim 16, in which the contamination control mat is stuck down using a double sided adhesive.

17. A method of making a contamination control mat according to any of claim 1 to 14, the method comprising the steps of providing a) non-woven substrate as a core layer, b) coating one surface of the core layer with a contamination control polymeric material to provide a top layer, and c) coating the opposing surface of the core layer with a polymeric backing layer.