Carpet Tile and Method of Manufacturing Same

Abstract

The carpet tile system uses preferably Aluminum Hydroxide (Al(OH).sub.3) as a flame retardant in the secondary backing of the carpet tile or in the pre-coat adhesive on the primary backing, or alternatively uses Magnesium Hydroxide (Mg(OH).sub.2). The flame retardant has been optimized to interact with the other components of the system to produce a carpet tile that achieves flammability ratings that are comparable or superior to carpet tiles with more expensive pile fibers.

Claims

1. A carpet tile system comprising a pile fiber made of polypropylene, tufted into a primary backing that is combined with a secondary backing system, which includes a flame retardant in at least one of (a) the secondary backing system and (b) the pre-coat adhesive on the primary backing, the flame retardant provided in a sufficient concentration to achieve an ASTM E 648 Class I flammability rating.

2. The carpet tile system of claim 1 wherein the secondary backing system is a bitumen based secondary backing system.

3. The carpet tile system of claim 1 wherein the secondary backing system is a PVC-based secondary backing system.

4. The carpet tile system of claim 1 wherein the secondary backing system is a polyolefin-based secondary backing system.

5. The carpet tile system of claim 1 wherein the secondary backing system is a polyester-based secondary backing system.

6. The carpet tile system of claim 1 wherein the flame retardant is Magnesium Hydroxide Mg(OH).sub.2.

7. The carpet tile system of claim 1 where in the flame retardant is Aluminium Hydroxide Al(OH).sub.3.

8. A carpet tile system comprising a pile fiber made of polyester, tufted into a primary backing that is combined with a secondary backing system, which includes a flame retardant in at least one of (a) the secondary backing system and (b) the pre-coat adhesive on the primary backing, the flame retardant provided in a sufficient concentration to achieve an ASTM E 648 Class I flammability rating.

9. The carpet tile system of claim 8 wherein the secondary backing system is a bitumen based secondary backing system.

10. The carpet tile system of claim 8 wherein the secondary backing system is a PVC-based secondary backing system.

11. The carpet tile system of claim 8 wherein the secondary backing system is a polyolefin-based secondary backing system.

12. The carpet tile system of claim 8 wherein the secondary backing system is a polyester-based secondary backing system.

13. The carpet tile system of claim 8 wherein the flame retardant is Magnesium Hydroxide Mg(OH).sub.2.

14. The carpet tile system of claim 8 where in the flame retardant is Aluminium Hydroxide Al(OH).sub.3.

15. A carpet tile system comprising a pile fiber made of polypropylene or polyester, tufted into a primary backing that is combined with a secondary backing system, which includes a flame retardant in at least one of (a) the secondary backing system and (b) the pre-coat adhesive on the primary backing, the flame retardant provided in a sufficient concentration to achieve a superior rating to the rating normally achieved on a carpet tile with polyester or polypropylene pile fiber.

16. The carpet tile system of claim 15 wherein the secondary backing system is a bitumen based secondary backing system.

17. The carpet tile system of claim 15 wherein the secondary backing system is a PVC-based secondary backing system.

18. The carpet tile system of claim 15 wherein the secondary backing system is a polyolefin-based secondary backing system.

19. The carpet tile system of claim 15 wherein the secondary backing system is a polyester-based secondary backing system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Examples of the invention will now be described with reference to the accompanying drawing, in which:

[0035] FIG. 1 (Prior Art) is a cross-section of a typical prior art carpet.

DETAILED DESCRIPTION OF THE INVENTION

[0036] FIG. 1 (Prior Art) shows a typical prior art carpet, comprising a pile fiber 1, a secondary backing 2, and a primary backing 3 into which the pile fiber is tufted.

[0037] As stated above, the preferred embodiment of the invention uses Aluminum Hydroxide (Al(OH).sub.3) as a flame retardant in the secondary backing 2. However, other embodiments of this invention could use Magnesium Hydroxide (Mg(OH).sub.2) as the flame retardant and such other embodiments could also put the flame retardant into the pre-coat adhesive on the primary backing instead putting it in the secondary backing.

[0038] Due to the interactions with different parts of the carpet tile during combustion, the concentration of Aluminum Hydroxide which should be included in the carpet tile depends on the type of fiber, pile construction, the pile weight and the secondary backing system of the carpet tile. The appropriate concentration for any given carpet tile must be determined by routine experimentation, based on the following guidelines.

[0039] In general flammability performance is worse with higher pile weight as compared with lower pile weight. Also in general more, flammability performance is worse with higher and looser constructions (i.e. higher pile heights and lower gauge and stitch counts) as compared with lower denser constructions. Also flammability performance is worse with PVC secondary backing systems as compared to bitumen secondary backing systems. These different factors interact with each other such that some trial and error is needed to come up with an optimization of these different factors.

[0040] Specifically, it was determined that with a concentration of 7 oz of aluminum hydroxide per square yard of carpet tile in combination with a bitumen secondary backing system, a pile fiber made of two polypropylene yarns of approximately 1100 decitex twisted together at 1.5 to 2.5 turns per inch, tufted on a 1/10 inch gauge tufting machine with 10 stitches per inch and with uniform pile height of ⅛ inch, a critical radiant flux of greater than 0.45 W/cm.sup.2 could be reliably achieved when tested according the ASTM E 648 test method. The flame retardant was added to the secondary backing in powder form and mixed in evenly along with the bitumen and the calcium carbonate.

[0041] However, in order to achieve a critical radiant flux of greater than 0.45 W/cm.sup.2, for carpet tiles using a bitumen secondary backing system and pile fiber having two polypropylene yarns of approximately 1100 decitex twisted together at 1.5 to 2.5 turns per inch, tufted on 1/12 inch gauge tufting machine with 10 stitches per inch and with pile height varying throughout the carpet between 1/16 inch and ¼ inch, a concentration of 9 oz of aluminum hydroxide per square yard of carpet tile was needed.

[0042] For any given carpet tile construction, using the teachings of this invention, it is only necessary to conduct routine experimentation to determine the appropriate concentration of the chosen flame retardant and chosen location of application (i.e. secondary backing or pre-coat adhesive on the primary backing).

[0043] It will be evident to those knowledgeable in the field of the invention that many variations on the examples described above are conceivable within the scope of the invention. It should therefore be understood that the claims which define the invention are not restricted to the specific examples described above. Possible variations include, for example, the use of different flame retardants and in different concentrations optimized for used with different pile fibers, pile constructions and different secondary backing systems in order to achieve different flammability standards.

[0044] Further variations may be apparent or become apparent to those knowledgeable in the field of the invention, within the scope of the invention as defined by the claims which follow.