Browse Prior Art Database

METHOD OF MANUFACTURING RAPID TURN FLEXIBLE TOOLING

IP.com Disclosure Number: IPCOM000007302D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2002-Mar-13
Document File: 2 page(s) / 116K

Publishing Venue

Motorola

Related People

Steve D. Pratt: AUTHOR [+3]

Abstract

Standard silicone rubber tool manufacturing prac- tices typically require two days for the construction of a flexible tool. A master which is an exact replica of the part to be produced by the tooling is supplied to the tool builder. The tool is then constructed 'around' the master, one mold halfper day, such that it can be assured that the parting line of the two halves of the mold meets exactly. The master is setup in a specially constructed box to form the tool halves. The silicone rubber material is poured around the master to form the first half of the tool. The tool builder adds other devices to the tool half for the purpose of mold alignment, gating and venting. This first half of the tool then requires one full day to cure before the second half of the tool can be poured. Aher the second half of the tool is poured, another full day is required for curing before the tool can be used.

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MO-LA Technical Developments Volume 23 October 1994

METHOD OF MANUFACTURING RAPID TURN FLEXIBLE TOOLING

by Steve D. Pratt, Stephen D. Hunt and Frank Garcia

  Standard silicone rubber tool manufacturing prac- tices typically require two days for the construction of a flexible tool. A master which is an exact replica of the part to be produced by the tooling is supplied to the tool builder. The tool is then constructed 'around' the master, one mold halfper day, such that it can be assured that the parting line of the two halves of the mold meets exactly. The master is setup in a specially constructed box to form the tool halves. The silicone rubber material is poured around the master to form the first half of the tool. The tool builder adds other devices to the tool half for the purpose of mold alignment, gating and venting. This first half of the tool then requires one full day to cure before the second half of the tool can be poured. Aher the second half of the tool is poured, another full day is required for curing before the tool can be used.

  The typical two-day tooling cycle can be cut to one day by using the herein described invention. The invention consists of a set of two plates, built via Stereolithography, with each plate incorporating the detail to be reproduced in one of two halves of a silicone rubber tool (see figure). The surface ofeach plate represents the flexible tool's parting line, thus the plates can include features such as the feed sys- tem (runners, gates) for delivery of material to the tool cavity, cavity venting, and mold half alignment features. Inclusion of such features eliminates the need for them to be constructed by the tool builder. Once the plates are delivered to the tool builder, standard silicone rubber tool manufacturing prac- tices are employed to produce the tool.

  Utilization of two masters to produce the two halves of a tool simultaneously has previously proven ineffective (typically the parting line mates poorly). This invention works in that the flatness of the SLA material results in an even, smooth mating surface for the two mold halves. Also, since no supports are needed near the part surfaces, smooth accurate sur- faces are created requiring a minimum of post

0 Motorola. 1°C. ,994

finishing operations. Incorporation of alignment fea- tures in the SLA master plates ensures that there...