Multicomponent aliphatic polyester blend fibers

Abstract

The present invention provides multicomponent thermoplastic fibers that are biodegradable and that are capable of forming strong bonds in air bonding processes. In various embodiments, the multicomponent fibers can include a first polymer component that includes a first aliphatic polyester, and a second polymer component also including an aliphatic polyester, wherein the first polymer component comprises at least a portion of an exposed surface of the multicomponent fiber. The first polymer component can be a fully amorphous polylactic acid and the second polymer component can be a semicrystalline polylactic acid. The multicomponent fiber can have cross-sectional area comprising the first polymer component and the second polymer component in about a 1:1 ratio, wherein the first polymer component and the second polymer component are configured in a sheath / core arrangement.

Description

FIELD OF INVENTION[0001]The present disclosure relates to a multicomponent thermoplastic fiber. In particular, the fiber can exhibit useful thermal-bonding characteristics, such as during thermal-bonding processes, including thermal bonding processes that do not require application of pressure.BACKGROUND[0002]Synthetic fibers are widely used in a number of diverse applications to provide stronger, thinner, and lighter weight products. Synthetic thermoplastic fibers are typically heat adhesive (thermobondable) and thus are particularly attractive for the manufacture of nonwoven fabrics, either alone or in combination with other fibers (such as cotton, wool, and wood pulp). Nonwoven fabrics, in turn, are widely used as components of a variety of articles, including without limitation absorbent personal care products, such as diapers, incontinence pads, feminine hygiene products, and the like; medical products, such as surgical drapes, sterile wraps, and the like; filtration devices; i...

AI Technical Summary

Benefits of technology

[0009]In various embodiments, the first polymer component is polylactic acid. In some embodiments, the first polymer component comprises a fully amorphous polylactic acid, wherein the D-isomer content of the amorphous polylactic acid is about 5% or greater, or about 8% or greater. In addition, in various embodiments, the first polymer component can have a melt flow index of about 30 or greater when evaluated according to melt flow test ASTM D1238 at a temperature of 210° C. and using a 2160 g basis weight. In various embodiments, the melt flow index of the first polymer component is about 45 or greater, or about 60 or greater. In some embodiments, the first polymer component can further comprise an additive adapted to one or both of increase the melt flow rate of the first polymer component and reduce the viscosity of the first polymer component at a target bonding temperature. Thereby, the additive may reduce the temperature at which satisfactory bonding can occur. The bonding temperature can be defined as the temperature at which the first polymer component softens or flows sufficiently to enable bonding between adjacent fibers, and wherein the second polymer component does not soften, flow or melt, such that the fibrous shape of the multicomponent fiber is maintained. The additive can be present in an amount sufficient to reduce the bonding temperature of multicomponent fiber at which satisfactory bonding occurs by about 10° C. or more. This can be advantageous because with conventional air bonding, the temperature required for satisfactory bonding of the sheath component can be above the temperature at which the core component either softens or melts or shrinks to an unacceptable degree. Therefore, reducing the bonding temperature can provide energy savings, increased line speed, and make air bonding a practical option for binder fibers disclosed herein, whereas conventional fibers are limited to use in a pressure bonding process such as calendar bonding or point bonding, for example.

Problems solved by technology

Thereby, the additive may reduce the temperature at which satisfactory bonding can occur.

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