Systems And Methods For Thermoplastic Pultrusion Dies

The thermoplastic pultrusion die system involves a first and a second die. The thermoplastic composite will be pultruded. There is a gap between the first and second pultrusion die members in the die cavity. In addition, an adjustment mechanism for adjusting the die cavity gap within a very tight tolerance is incorporated into a first and a second pultrusion die.

Brief Introduction

Historically, thermoplastic tapes have been pultruded as a layering process. Tapes are made up of a coordinated combination of fibers (such as fiber glass, carbon, aramid, etc.) and fiber bundles that are heavily impregnated with thermoplastic resin and fully coated. Polypropylene, polyethylene, and polyetheretherketone are some examples of resins used.

Despite the fact that the panel referenced above has been pultruded successfully, the fabrication of other types of composites presents different challenges. Typical thin sections of composite materials are composed of 2, 3, or 4 layers of thermoplastic tape, all of which can be at 0 degrees of orientation, 45 degrees of orientation, 90 degrees of orientation, or any other orientation relative to the 0 degree direction of pultrusion. The die thickness must be placed just at the right gap (called the cavity gap) for perfect pultrusion results. When pultrusion is performed on a 32-layer composite material at 0.303 inches, there is much greater forgiveness in the die cavity gap than when it is performed on a 4-layer composite material at 0.040 inches, for example.

The Invention In Short

A feature of the invention includes a unique and new method and system for pultruding thermoplastic tape in order to create thermoplastic composites of high efficiency.

In accordance with another aspect of the invention, a thermoplastic composite is pultruded by a thermoplastic pultrusion die system. First, there is a thermoplastic pultrusion die; second, there is a thermoplastic pultrusion die. Between the first and second pultrusion die members, there is a die cavity gap; and an adjustment mechanism that allows at least one of the first and second pultrusion die members to move so that the die cavity gap can be varied within a tolerance of less than one thousandth inch.

Additionally, a function of the present invention that incorporates computer numerical controls (CNC) is that the die can be adjusted to achieve maximum performance based on die pressure.

A Summary Of The Drawings

This specification is accompanied by drawings in which embodiments of the invention are illustrated and a description is given to help explain its principles based on those drawings.

Diagram 1A illustrates an embodiment of a pultrusion process for thermoplastic composite tapes in which the thermoplastic pultrusion die system and method of the present invention have been incorporated into one embodiment.

A side elevation of FIG 1B shows the exit of a die and die cavity gap of an embodiment of the thermoplastic pultrusion die system and method (the die exit is defined as being at the pultrusion grippers as viewed from the pultrusion grippers) in an embodiment.

The figure above shows an embodiment of the thermoplastic pultrusion die system and process shown in FIG. 2. As the die cavity gap opens, the 1B can be controlled and synchronized with the pultrusion speed in steady state, which is a closed loop control.

Implementation Of Invention: Description

Using FIGS as examples. In Figures 1-8, a thermoplastic pultrusion die system (“system”) and way of processing thermoplastic materials using the same will be described.

Before describing the system, the thermoplastic pultrusion die system will first be described with reference to FIG 1A, which illustrates an exemplary thermoplastic composite tape pultrusion processing assembly and method.

Pultrusion takes place from left to right in the thermoplastic composite tape processing assembly. A thermoplastic pultrusion die system, a tunnel oven, and one or more grippers are shown from left to right in the assembly. According to FIG 1A, a fairly short thermoplastic pultrusion die system is illustrated. However, the thermoplastic pultrusion die system may extend for up to twenty feet in a manufacturing process in order to help achieve faster line speeds by heating multiple tapes or plies of thermoplastic tape.