The Dow Chemical Company

Other

Gkn Westland Aerospace, Inc.

Warren D White

William Davis

Martin Wai

Phil H Cook

Johnny P Gendreau

Henry G Heck

Paul M Puckett

L James Lee

Mary N White

Muhammad A Shafi

James H Barron

Brenda Thies Colegrove

Curt Goodwyn Wilkinson

Alton E Martin

Larry T Blankenship

Larry N Varholak

Kerang Han

Muhammed A Shafi

Samuel L Smolik

A preform suitable for use in a resin transfer molding process comprising (1) one or more layers of a non-woven random mat and (2) one or more layers of a series of tows of unidirectional fibers held together by a polymeric curable resin film grid. The polymeric resin film is in the form of a grid, such that only a fraction of the surface area of the fibers contacts the resin film.

Unidirectional fiber-random mat preform

A system and method for simulating LCM mold filling utilizes at least one processor, suitable RAM and storage memory, a data input, a display, and logic for simulating the injection of resin into a mold cavity containing a preform based upon mold cavity design parameters, mold filling processing parameters, physical property parameters, and system processing parameters, and identifying the current state of selected mold filling conditions at selected points in time during the simulated mold filling process. The system logic includes an error estimator for periodically estimating the error in the flux computations, preferably during each iteration in the solution of the governing equations. The system also preferably includes predictor/corrector logic which modifies a variable relaxation parameter and a variable convergence tolerance, based upon the estimated error and other predefined computational thresholds to urge rapid convergence to a correct solution of the governing equations in an efficient manner. The system also preferably includes logic for allowing the operator to modify one or more process parameters while the simulation is in process, so that the simulation may continue utilizing the modified process parameters thereby obviating the need to repeatedly re-run the simulation with changed process variables.

System and method for modeling plastic molding and molding parts

A process for preparing a matrix resin composite contains the steps of: (1) preparing a preform containing multiple layer of reinforcing material and a crosslinkable tackifier by (a) applying the tackifier onto the reinforcing material, (b) compressing the layers of reinforcing material and partially crosslinking the tackifier under a pressure sufficient to compact the tackified, reinforcing layers to a volume which is less than their volume in the finished composite part and in a manner such that at least one surface of each of the reinforcing layers is or will be, during partially crosslinking, in direct contact with the tackifier, and (2) contacting the preform with a matrix resin.

Process for preparing a resin matrix composite using a preform

An improved process to make composites contains the steps of: (1) partially curing a tackifier resin in contact with a substrate to form a shapeable preform; (2) adding a matrix resin and co-curing the tackifier and matrix resin to form a composite. The resulting composites are useful in structural applications.

Process for resin transfer molding

A system and method for simulating LCM mold filling utilizes at least one processor, suitable RAM and storage memory, input means, display means, and logic for simulating the injection of resin into a mold cavity containing a preform based upon mold cavity design parameters, mold filling processing parameters, physical property parameters, and system processing parameters, and identifying the current state of selected mold filling conditions at selected points in time during the simulated mold filling process. The system includes logic for identifying incipient dry spots, and also preferably includes means for interrupting the operation of the program at selected points to vary selected parameters to eliminate incipient dry spots and otherwise maximize the mold filling process. The system may additionally include logic for determining whether the output from a mold filling simulation satisfies a set of predefined criteria to determine whether a particular mold design and/or filling process is acceptable for use in production and, if so, record the approved mold filling process parameters for transfer and input to an RTM mold control. Alternatively, the system may be incorporated into a conventional mold control for direct input of developed mold filling process parameters into the control for use in operating the mold to produce liquid composite plastic parts.

Process for resin transfer molding and preform used in the process

An improved process to make composites contains the steps of: (1) contacting a substrate with a thermoplastic partially-cured curable resin at above the glass-transition temperature to form a preform; (2) adding a matrix resin that can dissolve the tackifier and co-curing the tackifier and matrix resin to form a composite. The resulting composites are useful in structural applications.

Process for resin transfer molding using a partially cured tackifier

Preforms for molding processes such as resin transfer molding processes are prepared by melting a solid, non-sintering, thermoplastic-like resinous compound on the surface of a substrate material. After cooling, assembling one or more plies of the coated substrate material into the desired shape; heating the shaped substrate material to a temperature above the melting temperature of the resinous compound and subsequently cooling to a temperature below the melting point of the resinous compound.

Preforms for molding processes

Preforms for molding processes such as resin transfer molding processes are prepared by melting a solid, non-sintering, thermoplastic-like resinous compound on the surface of a substrate material; after cooling, assembling one or more plies of the coated substrate material into the desired shape; heating the thus shaped substrate material to a temperature above the melting temperature of resinous compound and subsequently cooling to a temperature below the melting point of the resinous compound.

Method for preparing preforms for molding processes

Damaged composites are repaired by use of a rubber modified vinyl ester resin composition as either an adhesive for bonding metal or cured composite to the area surrounding the damaged area or by placing an uncured reinforcing material saturated with a rubber modified vinyl ester resin composition over the prepared damaged zone and curing in place.

Method for repairing damaged composite articles

A process for producing polyamines such as methylene dianiline wherein an aromatic amine such as aniline is reacted with formaldehyde in the presence of an acid catalyst sufficient water is employed to cause a separation into an aqueous phase and an organic phase and the methylene dianiline is extracted with a solvent said process is improved by employing as the solvent a mixture of aniline and either a water immiscible organic solvent such as orthodichlorobenzene or conducting the extraction in the presence of a water soluble inorganic salt such as zinc nitrate or a combination thereof.

Growing community of inventors

Lake Jackson, TX, United States of America

Warren D White