3M Innovative Properties Company

Minnesota Mining and Manufacturing Company

Imation Corporation

Donald L Pochardt

Satinder K Nayar

Dennis Earl Ferguson

John W Louks

Stanley Rendon

Peter T Benson

James N Dobbs

Paul M Fettig

Donald S Oblak

Charles R Kleissler

Elizabeth M Schornak

Desmond T Curran

Christopher P Henderson

Daniel H Carlson

G Phillip Rambosek

Robert B Secor

Karl J Warren

William Joseph Vanderheyden

Leif O Erickson

John Russell Mlinar

Robert C Martin

Daniel Charles Egan

Timothy J Rowell

Richard L Sheehan, Jr

Randy S Bay

Joseph S Warner

Wayne K Morris

John R Mlinar

Dennis E Erguson

Injection molding parts onto a carrier web located between mold halves, each mold half having a cavity, resulting in molded articles having parts on both sides of the carrier web. Polymer flow into the cavities is assisted by application of ultrasonic energy to the mold. After the molding operation, mold halves are separated, and the carrier web is advanced, or indexed, to a next position for another molding sequence. Articles produced include lenses with part of the carrier web between lens halves, and a carrier web bearing an array of molded parts.

Web with molded articles on both sides

An ultrasonic-assisted injection molding system and method for making precisely-shaped articles. A source of ultrasonic energy is positioned to apply vibrational energy to a mold cavity connected to at least one gate in flow communication with a source of molten (co)polymer. The mold is heated to a temperature of 104-116&#xb0; C., and the molten (co)polymer is injected into the mold cavity. After cooling the mold until the molten (co)polymer within the gate has solidified, ultrasonic energy is applied to the mold without remelting the solidified (co)polymer within the gate until the temperature increases to 116-122&#xb0; C., thereby substantially relieving flow induced stresses. The mold is then cooled until the temperature decreases to 101-107&#xb0; C., and is thereafter heated until the temperature increases to 116-122&#xb0; C., thereby substantially relieving any thermally induced stresses. The mold is cooled until the molten (co)polymer has solidified, thereby forming a precision molded plastic optical element.

Ultrasonic-assisted molding of precisely-shaped articles and methods

A method of molding a microneedle including providing a mold apparatus having a mold insert having the negative image of at least one microneedle, a compression core, a mold housing configured to allow a reciprocal motion between the mold insert and the compression core. The method includes placing the mold apparatus in a closed position, injecting polymeric material into the closed mold apparatus, compressing the injected polymeric material between the mold insert and the compression core by a reciprocal motion between the compression core and the mold insert, opening the mold, and removing a molded microneedle from the mold. The mold insert has a mold insert height and the molded microneedle has a height that is from about 90% of the mold insert height to about 115% of the mold insert height.

Method of molding a microneedle

Articles enabled by an injection molding process that molds parts on a carrier web located between mold halves and uses ultrasonic energy to assist flow of polymer melt into the mold cavity. One such article is a carrier web having a high density of molded parts, i.e., bearing an array of molded articles adhered to the web in rows and columns, the articles being spaced closer (center-to-center or edge-to-edge) than the diagonal spacing between articles in the next adjacent row and next adjacent column. Another such article is a microneedle array on a land no more than 250 &#x3bc;m thick on which at least 60% of the microneedles across the array are filled (i.e., completely formed).

Articles injection molded on a web

Ultrasonic injection molding on both sides of a web

A method of molding a microneedle using a mold apparatus that includes the use of high frequency acoustic energy, such as ultrasonic energy.

Injection molding, parts onto a carrier web () located between mold halves (). Flow of polymer melt into the mold is assisted by application of ultrasonic energy to the mold cavity. After the molding operation, mold halves are separated, and the carrier web is advanced, or indexed, to a next position for another molding sequence. Molding apparatus comprises a moving mold face (), that can move toward and away from a first mold member () (which can be stationary) in which the mold cavity is located, a means () for moving and/or indexing carrier web between the first mold member and the moving mold face, means () to inject polymer melt into the mold cavity, and an ultrasonic system () providing ultrasonic energy to the mold cavity. The carrier web can transport molded parts to subsequent process steps, such as coating, drying, inspection, curing, assembly or packaging.

Ultrasonic injection molding on a web

A method of molding a microneedle using a mold apparatus that comprises a mold insert ()having the negative image of at least one microneedle (), a compression core (), and a mold housing configured to allow a reciprocal motion between the mold insert and the compression core. The mold apparatus has an open position and a closed position. The mold apparatus is placed in the closed position and polymeric material is injected into the closed mold apparatus. The injected polymeric material is compressed between the mold insert and the compression core by a reciprocal motion between the compression core and the mold insert. Also, molding methods wherein the mold apparatus has sidewalls having an injection gate (). Also, molding methods comprising a heated mold insert. Also, molding methods comprising the application of high frequency acoustic energy, such as ultrasonic energy, to the mold apparatus.

A system for applying ultrasonic energy to a workpiece, the system including a horn stack; a mounting system upon which the horn stack is mounted; a source of energy coupled to the horn stack; an anvil having a surface for supporting the workpiece; and a controller configured to receive a resonant frequency of the horn stack, and to determine a quantity standing in known relation to a change in gap between the horn stack and the anvil.

Method and system for determining a gap between a vibrational body and fixed point

A system and method for maintaining a substantially constant gap between a horn and an anvil includes the act of positioning a horn proximal an anvil, so that a gap is established between the horn and the anvil. An alternating current (AC) signal is applied to a converter coupled to the horn. The AC signal exhibits an amplitude. The amplitude of the AC signal is adjusted during operation of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

Amplitude adjustment of an ultrasonic horn

A system and method for adjusting the gap between a horn and an anvil in an ultrasonic welding system includes the act of positioning a horn proximal to an anvil, so that a gap is established between the horn and the anvil. A force is applied to the horn, so as to urge the horn toward the anvil. A deformable stop is positioned at a location, such that application of the urging force causes a member operatively connected to the horn to abut the deformable stop, and to deform the stop. The urging force is iteratively adjusted during operation of the horn, so as to adjust the extent of the deformation of the deformable stop, and to maintain the gap between the horn and the anvil substantially constant.

Cantilevered bar gap adjustment for an ultrasonic welding system

A system and method for monitoring a gap between a vibrational body and a reference is achieved by monitoring the resonant frequency of the vibrational body. A portion of the vibrational body is fixed a given distance from the reference by a rigid mounting system. A resonant frequency of the vibrational body is received. Then, a quantity standing in known relation to an approximate change in the length of the gap is determined, based upon the resonant frequency.

Growing community of inventors

Hastings, MN, United States of America

Donald L Pochardt