Stock material or miscellaneous articles – Pile or nap type surface or component – Composition of pile or adhesive
Reexamination Certificate
2000-11-13
2001-11-06
Edwards, N. (Department: 1774)
Stock material or miscellaneous articles
Pile or nap type surface or component
Composition of pile or adhesive
C428S364000, C428S373000, C008S483000, C264S210800, C264S078000, C264S210600
Reexamination Certificate
active
06312783
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the manufacture of colored polymeric filaments that are especially useful in the construction of carpeting. The polymeric filaments of the present invention are blends of polypropylene with nylon or polyester. Solid or multi-color filaments (nylon or polyester is compounded with polypropylene) by using MB; alternatively, dyeable filaments (nylon or polyester is compounded with polypropylene) to produce solid colors or space dyes.
BACKGROUND OF THE INVENTION
In the field of carpets, nylon filament is generally preferred for the pile because of its look (luster), feel (silky), and dryability. In some applications, the look and soft feel of polyester filament is desirable. However, nylon and polyester are relatively expensive.
An object of the present invention is to provide blends of nylon or polyester that will be significantly less expensive than pure nylon or polyester yet will retain, in large part, desirable attributes attributable to the nylon and polyester resins.
SUMMARY OF THE INVENTION
The present invention bonds two dissimilar materials together that otherwise would have poor adhesion to each other. These two materials are polypropylene on the one hand and nylon or polyester on the other hand. In accordance with the present invention, they are bonded together with maleated polypropylene.
The process of the present invention involves compounding and extruding a composition, comprising 60-95 weight-% polypropylene, 0.1-10 weight-% maleated polypropylene, and 5-40 weight-% nylon or polyester, through a spinneret at a temperature in the range of 235-285° C., and drawing the resulting filament. Drawing is carried out at a draw ratio substantially lower than the draw ratio that would be necessary to obtain the same elongation with 100% polypropylene. The terminology “substantially lower” in this case means at least 10% lower. Drawing in the present invention is carried out in order to obtain filaments having a denier in the range 2-35/filament.
In accordance with the present invention, color pigments may be included in the composition which is compounded and extruded. For instance, nylon or polyester may be compounded in a masterbatch with polypropylene, maleated polypropylene, and pigment in a conventional extruder through different feeding hoppers, or two or more of these materials may be compounded or mixed together in a first step and added to the remaining components in a second step to provide the same final product. The masterbatch may also contain such conventional additives as TiO
2
, UV stabilizers, and/or antioxidants. These additives can be added direct to the extruder. If more than one extruder is used, multicolor yarn can be obtained. Using this approach, high proportions of polypropylene may be blended with nylon or polyester without detracting substantially from the good touch and luster attributable to the latter polymers.
Alternatively, the process of the present invention may make use of the additional step of acid or dispersion dying to provide space dyed yarn. Even with this approach, some pigment may be added to the masterbatch in order to provide a dyeable filament having a color closer to the desired final color than the resins themselves would have. As in the case described above, nylon may be compounded in a masterbatch with polypropylene, maleated polypropylene, and pigment in a conventional extruder through different feeding hoppers, or two or more of these materials may be compounded or mixed together in a first step and added to the remaining components in a second step to provide the same final product. The masterbatch here too may also contain such conventional additives as Tio
2
, UV stabilizers, and/or antioxidants. However, with this approach, a preferred additive is a liquid dye enhancer. This increases the dyeing sites in the nylon by about 0.5%, thus permitting the use of less nylon in the blend. The liquid dye enhancer is not washed out of the filament during processing. The product can be dyed with disperse dye or with acid dye, depending on the relative amount of nylon in the blend, the darkness of the target color, and the intended application. This approach can be accomplished in conventional extruders, without the necessity for side extruders or special spinnerets such as those used in the manufacture of sheath-core type bicomponent filament yarns.
The present invention also contemplates carpeting and rugs in which the pile is made up of filaments produced by any process of this invention. In the manufacture of such carpeting or rugs, individual filaments can be dyed and then assembled into a rug, or the composite material can be manufactured and then the composite material piece can be dyed. In accordance with the latter technique, piece dyeing occurs when the composite material is contacted as a unit with the dyeing medium. An example of piece dyeing is the immersion of carpeting (backing and pile) in a bath of dye.
REFERENCES:
patent: 3182105 (1965-05-01), Bonvicini et al.
patent: 3651028 (1972-03-01), Maemoto et al.
patent: 3659009 (1972-04-01), Fuest et al.
patent: 3820949 (1974-06-01), Johnson
patent: 3926553 (1975-12-01), Fuest
patent: 5186879 (1993-02-01), Simons et al.
patent: 5576366 (1996-11-01), Sheth
patent: 5985999 (1999-11-01), Dominguez et al.
patent: 6046279 (2000-04-01), Roberts et al.
patent: 6132839 (2000-10-01), Reader
Edwards N.
Oriental Weavers of America
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