NL2007709C2

NL2007709C2 - Carpet with a high light reflectance value and method of producing such carpet.

Info

Publication number: NL2007709C2
Application number: NL2007709A
Authority: NL
Inventors: Ludwig Maria Gerardus Irma Cammaert; Antonius Hendricus Johannes Negro
Original assignee: Desso B V
Priority date: 2011-11-03
Filing date: 2011-11-03
Publication date: 2013-05-07
Also published as: CN104040069B; AU2012331708A1; US20140272259A1; EP2758587A1; CA2853055A1; EP2758587B1; WO2013066185A1; AU2012331708B2; CN104040069A

Description

Carpet with a high light reflectance value and method of producing such carpet

The present invention relates a carpet with a high light reflectance value, and a method for producing such carpet.

5

It is known that people and their behaviour and/or well-being depends on the amount of light in their environment. Architects, designers and the construction industry use this knowledge to either improve visual ergonomics in designing buildings / interiors or support in creating lighting plans.

10

The amount of light in a room evidently depends on the illumination, either by sun or artificial light, but also by the way the light is absorbed or reflected by the room and the objects placed therein.

15 The 2008 report BS8493 from the British Standards Institution, provides a method for quantifying the amount of reflection of light by a certain object, with its so called light reflectance value (LRV), which is defined as the total quantity of visible light reflected by a surface (e.g. floorings, ceilings, walls and furniture), at all wavelengths and directions when illuminated by a light source, which may be sunlight or artificial light.

20

The LRV scale runs from 0, which is a perfectly absorbing surface (assumed to be totally black), up to 100, which is a fully reflective surface (considered to be perfectly white). Because of practical influences in any application, black is always greater than 0 and white never equals 100. Additional to colour, the structure and luster (gloss) of the 25 product or surface can influence the LRV. LRV measurements are best performed using a spectrophotometer. This equipment accurately and directly measures the LRV of flat and curved items, matt and lustered (including carpet).

Another method is developed by the Commission Internationale de 1'Eclairage 30 (CIELAB) and uses three coordinates to locate a colour in a colour space and is used to describe colours that are visible to the human eye. This colour system quotes values for L*, a* and b*, wherein these three parameters of the colour model represent the lightness of the colour ranging from white to black, L*, its position between red and green, a*, and its position between yellow and blue, b*.

2

The L* value (colour depth) can be used to calculate the LRV of a surface (also referred to as the ‘p-value’ (rho)), as a close approximation of the directly measured LRV according BS8493, by the following formula: LRV = rho (p) = 100 x ((L*+16) /116)3 5

In order to assist people, especially those with a visual impairment, to find their way around, it is a requirement that there is a visual contrast between the floor and the walls and between different levels of the floor or on stairs. The greater the difference in LRV between two surfaces, the more likely the difference is identified. According to the 10 British Standards Institution, whilst there is a considerable confidence in recommending a difference of LRV of 30 points or more (the good zone), there is also much anecdotal evidence to suggest that a difference of around 20 points may still be acceptable.

Furthermore, products with higher LRV values help to reflect incoming light, either 15 daylight or artificial, to reinforce its effect. This offers the possibility to reduce the need of artificial light in a room or building and therefore saves on energy (up to 30%) use and costs (related to lighting). Due to its large surface, carpet can play a significant role in contributing to a higher light reflectance value.

20 There are two important factors that influence the LRV of a carpet, being the yam from which the loop piles are made, and the fabric or web from which the tuft substrate is made. For broadloom carpet, that is, carpet which is laid in one piece in room, the influence of the backing material on the light reflectance value is relatively small.

25 In the case the carpet is cut and laid as multiple separate tiles, the tangent interfaces of the separate tiles may become visible, and therefore impose more stringent requirement. Furthermore, for practical reasons, there is a minimal weight for loose laid carpet tiles, which is a mass that is higher than 3500 g/m2.

30 So, although broadloom carpet with higher LRVs may be offered, loose laid carpet tiles with a high LRV, i.e. a value above 30, and preferably more than 35, is seen as impossible for especially loop pile and fibre bonded substrates with the current build up of the product, since visibility of carpet tile edges is common practice when installed monolithically, ashlar or brickwise.

3

Typically, the method for manufacturing a carpet tile comprises the steps of tufting onto a tuft substrate, either loop pile / cut pile or combination of those or the technique of fibre bonding, subsequently applying a primary coating (e.g. SBR / polyacrylates / 5 polyolifen) to the top-cloth substrate in order to fix the pile yam, and then applying a secondary coating (polyolifen / bitumen / EVA / PVC etc..) to the primary coating. For carpet tiles it may be finished with a glass scrim and/or protection fleece.

The reason for visibility of the carpet tile edges with high LRV colours needs to be 10 found in the area of the used colour of the different layers in the product build-up. By die cutting (or alternatives as ultrasonic/knife/water cutting) carpet tiles (e.g. from roll goods / platines) some piles at the cutting edges are damaged or half lost, since only part of the tuffs are “locked in” the primary backing. When then, installing these carpet tiles, (half) tuff holes of imperfections are present. Depending on the tuft machine gauge this 15 may range between 2.5mm (1/10”) to 3.2mm(l/8”) to 4.0mm (5/32”). When the colour contrast then, between pile yam and backing is too high, or by light shadow effect, this will be visible as imperfect carpet tile edge covering. The darker backing colour becomes visible in between the tiles, at the edges of the carpet tiles. Next to that, also some layers as e.g. bitumen compound can contaminate the die cutting equipment or 20 cutting knife, basically accentuating the edges of the next die cut.

It is a goal of the present invention to take away the above disadvantages of the prior art, and to propose a carpet that contributes to visual ergonomics and lighting plans.

25 The invention thereto proposes a method for manufacturing a carpet, comprising tuffing yams onto a substrate and then precoating the substrate, wherein the combination of the yams and the substrate has a light reflectance value above 30, and more in particular above 35. Herein, the substrate may be manufactured by needling fibres to become a substrate, and the yams may be tufted onto the substrate into loop pile or cut-loop pile. 30

The yams may for example be made of one ore more materials from the group of PP, PA (e.g. PA6, PA66, PA6.10, PA10, PA11), PET and/or PTT, and may be based on white (overdyable) yams or solution dyed yams.

4

The substrate or backing may be a woven or non-woven backing. In order to fix the yams to the substrate, the substrate may be pre-coated with a polyolifen such as HYPOD or SBR, whitened with a filler, such as MgCC>3, TiC>2, ATH and/or CaCC>3 or others. Such precoat may be applied either via dispersion or hotmelt, or any other 5 known method., and the MgCC>3, TiC>2, ATH, CaCCb may have a chemical purity higher than 90%, in particular more than 95%, and preferably even more than 99%.

In particular for loose laid carpet, or carpet tiles, the method according to the invention may comprise applying a secondary heavy coating consisting of a light coloured 10 polymer, which can for example be a specific polyolifen, PVC, EVA or a synthetic bitumen.

For this, it was proven that polyolifen polymers based on either PE and/or PP did not fulfill the carpet tile performance based on dimensional stability and lay flat 15 performance under all practical in-situ circumstances as a temperature range between 5 and 40 degrees Celsius and a percentage of relative humidity between 20 % and 80%.

Herein, the viscosity behaviour (process) on one hand as well as temperature resistance, flexibility, mechanical strength and dimensional stability of the product are key polymer 20 blend characteristics.

Suitable recipes for the heavy coating layer are a specific polymer blend based on polyolifen co-polymers, tackifiers and wax/oil which may be filled with CaCC>3 and/or ATH and/or other salts, e.g. NaCl or MgCC>3 may be used. The filler preferably has a 25 high purity (>90%), high whiteness (>90%), and particle size ranging from ca. 15 pm -300 pm.

Besides a method for manufacturing a carpet, the invention further relates to a carpet with a LRV bigger than 30. In particular such carpet comprises yams are made of PP / 30 PA6 / PA66 / PET and or PTT, which are either white based or solution dyed based, and tufted on a white or very light woven or web substrate, pre-coated with a polyolifen such as HYPOD or SBR which is whitened with a filler, such as MgC03, Ti02, ATH, CaC03, and which may comprise, in particular in the case of loose laid tiles, a secondary heavy coating consisting of a light coloured polymer such as a specific 5 polyolifen, PVC, EVA or a (synthetic) bitumen, loaded with a filler pre-selected on lightness and purity as CaC03 and/or ATH and/or specific salts, e.g. NaCl or Ti02.

The following colours with their Natural Color System values (NCS) and LRV have 5 proven to be very useful for manufacturing carpet according to the present invention.

Desso SAP: LRV_NCS:

1107 43.65 S1502-B50G

1908 35.54 S2020-Y20R

10 2917 43.97 S2010-Y10R

9037 35.32 S3005-B20G

1610 51.09 S1010-Y20R

1321 42.22 S2005-Y30R

1660 34.81 S2010-Y20R

15 9507 32.89 S2502-B

9508 36.08 S1502-B

9517 31.00 S2502-G

1364 34.52

9518 55.67 S1502-G

20 1254 60.21 S1005-B

9516 39.82 S3502-G

2927 36.65 2010-Y30R

A recipe that appeared to be very suitable for a carpet that can be recycled comprises a 25 mixture of about 50% tackifier, about 30% Co-polymer and about 20% Oil-wax. The filler level may vary between 20 to 80%, and more in particular 60 - 75%.

Claims

A method for manufacturing a carpet tile, comprising: tufting yarn on a substrate in intermediate peg carpet or cut intermediate peg carpet; pre-coating the substrate; wherein the combination of the yarn and the substrate has a light reflection above 30, and in particular above 35. 10

Method according to claim 1, wherein the yarns are made from PP / PA / PET and / or PTT.

3. Method as claimed in any of the foregoing claims, wherein the yarn is based on white yarn or yarn dyed by means of a solution.

The method according to any of the preceding claims, wherein the substrate is pre-coated with a polyolifen such as HYPOD or SBR, whitened with a filler such as MgCO3, TiO2, ATH, CaCO3. 20

A method according to claim 4, wherein the filler has a chemical purity higher than 90%, and in particular higher than 95%.

6. Method according to any of the preceding claims, comprising applying a second heavy coating consisting of a light-colored polymer such as a specific polyolefin / PVC / EVA or a (synthetic) bitumen.

7. A method according to claim 6, wherein the second heavy coating is provided with a filler selected on the basis of lightness and purity as CaCO 3 and / or ATH and / or specific salts.

A method according to any of the preceding claims, comprising adding TiO 2 to the pre-coating and / or heavier heavy coating layers.

Method according to any of the preceding claims, comprising applying a specific polymer mixture based on polyolefin copolymers, adhesives and wax / oil filled with (or without) CaCC> 3 and / or ATH and / or other salts (e.g. NaCl / MgCCf ) for the heavy coating layer. 5

The method of claim 9, wherein the filler has high purity (> 90%), and / or high whiteness (> 90%), and / or has a particle size in the interval between about 15 µm and 300 µm.

Carpet made according to a method according to one of the preceding claims.