Franking Machine

Overview

A franking machine prints prepaid postage directly onto envelopes, replacing stamps with a printed indicia that encodes the value, date, and a cryptographic mark proving the postage was paid. It is a metered device: funds are loaded from a postal account into a secured module inside the machine, and each frank debits that balance. The combination of weighing, rating, sealing, and printing in one pass lets a mailroom process outgoing post far faster than hand-stamping.

The machine is a small transport deck topped by covers. The Housing & Chassis is the sheet-metal chassis and moulded top cover. The Feed & Transport Deck deck pulls envelopes in and drives them under the printhead, while the Moistener & Sealer wets and closes the flap on the way through. The Print Head Assembly lays down the indicia, and the Integrated Weigh Platform scale sets the correct rate. Everything is run by the secure Main Controller Board, operated through the Touchscreen UI Panel, and franked mail collects in the Output Stacker Tray.

How it works

An envelope placed on the feed deck is detected and pulled in by the rollers of the Feed & Transport Deck against a separator that admits one piece at a time. If sealing is enabled, the flap passes the Moistener & Sealer, where a wick or roller wets the gummed edge and a pressure roller closes it.

Meanwhile the operator weighs the piece on the Integrated Weigh Platform and the Main Controller Board looks up the postal rate from its downloaded rate tables. The board's postal security device authorises the value and decrements the stored funds; this tamper-resistant module is what postal authorities certify. As the envelope passes the Print Head Assembly, a thermal-inkjet array fires the fluorescent-red indicia, value, date, meter number, and a 2D barcode, at 300 dpi. The franked envelope drops into the Output Stacker Tray, and the Power Supply feeds the deck, heaters, and electronics throughout.