Process for preparing engineered fiber blend
AssigneeHoechst Celanese Corporation
InventorRichard C. Holliday
Life of this patent
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Abstract
The invention is directed to a process for preparing a blended tow of thermoplastic and reinforcing fibers. The process of the invention includes the steps of forming a substantially planar spaced array of thermoplastic multifilament yarns and superimposing the spaced array of separate yarns onto a spread tow of reinforcing fibers. The resulting planar mixed yarn is then gathered into a tow having a nonuniform distribution of thermoplastic fibers throughout the tow. The tow is useful in forming fiber-reinforced composite articles by shaping the tow into a desired form and then heating the shaped tow to melt the thermoplastic fibers which, in turn, form a plastic matrix which is reinforced by the reinforcing fibers.
Claims25
A process for preparing a non-uniformly blended tow of thermoplastic and reinforcing fibers comprising:
- forming a substantially planar, spaced array of substantially parallel, continuous thermoplastic multifilament yarns wherein each of the multifilament yarns is substantially discrete and is spaced from adjacent yarns in the array by an amount substantially greater than the width of the individual, discrete multifilament yarns;
- spreading a tow of reinforcing fibers to provide a substantially planar spread tow of said reinforcing fibers wherein said array of multifilament yarns has a width of at least about 50% of the width of said spread tow of reinforcing fibers;
- continuously superimposing said substantially planar spaced array of thermoplastic fibers onto said substantially planar spread tow of reinforcing fibers to thereby continuously combine said superimposed array and said spread tow into a substantially planar non-uniformly mixed yarn;
- and
- gathering said substantially planar non-uniformly mixed yarn into a tow of non-uniformly blended reinforcing fibers and thermoplastic yarns.
A process for preparing a non-uniformly blended tow of reinforcing fibers and thermoplastic yarns comprising the steps:
- forming a substantially planar spaced array of substantially parallel discrete continuous thermoplastic multifilament yarns separated from each other by an amount substantially greater than the individual widths of said discrete yarns in said array by directing each of a plurality of thermoplastic yarns into contact with a separate circumferential groove on a rotating drum comprising a plurality of spaced circumferential grooves;
- spreading a tow of reinforcing fibers to provide a substantially planar spread tow of said reinforcing fibers;
- superimposing said spaced array of thermoplastic fibers onto one side of said spread tow of reinforcing fibers to thereby continuously combine said superimposed array with said spread tow to form a substantially planar non-uniformly mixed yarn;
- and
- non-uniformly gathering said substantially planar non-uniformly mixed yarn into a non-uniformly blended tow of thermoplastic yarns and reinforcing fibers.
Dependencies are inferred from the claim text.