Heat curing system for silk screen printing press

In an automatically indexing silk screen printing machine having a plurality of ink layers printed successively on a plurality of textile items, a method of the printing plurality of ink layers and curing ink printed on the textile items comprising the steps of:

• a) screen printing an underprinted base layer of ink on one of the textile items at a first print processing station;
• b) moving the textile item to a second print processing station and placing an electrical resistance heater at a distance between two to four inches away from the first ink printed image on the textile item while the textile item is stationary at the second print processing station;
• c) supplying power to the electrical resistance heater to heat the ink of the underprinted base layer of ink on the textile item for curing;
• d) sensing the temperature of the ink of the underprinted base layer of ink on the textile item with an infrared sensor as the heater heats the ink and generating an ink temperature signal in response thereto;
• c) comparing the value of the ink temperature signal to a preselected maximum temperature value and interrupting power to the heater when the value of the ink temperature signal exceeds the preselected maximum temperature value, whereby the preselected maximum temperature value for the underprinted base layer of ink on the textile item is sufficient to cure the underprinted base layer of ink and facilitate effective printing of subsequent images on the underprinted base layer of ink without allowing heat from the electrical resistance heater to damage the underprinted base layer of ink or damage the underlying textile;
• f) moving the textile item to a third print processing station and screen printing a second image on the textile item which covers the heat-cured underprinted base layer of ink at least in part while the textile item is located at the third print processing station;
• and
• g) repeating steps a-e for each of the textile items.

In an automatically indexing silk screen printing machine having a series of pallets that are sequentially moved among a plurality of print processing stations including a plurality of silk screen printing stations and at least one heat curing station, an improved heat curing station comprising:

• a frame;
• a flash unit housing having a top hood and an open bottom, the housing being mounted to the frame;
• a heat retaining heater support board mounted inside of the housing and spanning completely across the housing;
• a bank of electric resistance heaters mounted to the support board so that the heaters are exposed through the bottom of the housing;
• a control box for the heat curing station mounted to the hood of the housing;
• and
• a fan for blowing cooling air in a space between the heater support board and the top hood of the housing in a direction substantially parallel to the heater support board.

In an automatically indexing silk screen printing machine having a series of pallets that are sequentially moved among a plurality of print processing stations including a plurality of silk screen printing stations and at least one heat curing station, an improved heat curing station comprising:

• a frame;
• a bank of electrical resistance heaters for heat curing an underprinted layer of ink printed on a fabric at one of the silk screen printing stations of the automatically indexing silk screen printing machine;
• and
• a control system for regulating the operation of the electrical resistance heaters, the control system having an infrared sensor that senses the temperature of the ink printed on the fabric and outputs an ink temperature signal in response thereto, a temperature controller that receives the ink temperature signal from the infrared sensor and interrupts power to the bank of electric resistance heaters if the value of the ink temperature signal exceeds a preselected maximum temperature value set in the controller;
• whereby the preselected maximum temperature value set in the controller for the underprinted layer of ink on the fabric is sufficient to cure the underprinted layer of ink and facilitate effective printing of subsequent images on the underprinted layer of ink at another silk screen printing station on the automatically indexing silk screen printing machine without allowing heat from the heat curing station to damage the underprinted layer of ink or damage the fabric.

In a multi-colored silk screen printing press having a series of pallets that are moved among a sequence of print processing stations including a plurality of silk screen printing stations and at least one heat curing station, an improved heat curing station comprising:

• a bank of quartz flash lamps for heat curing ink printed on a printing substrate mounted on a pallet of the screen printing machine;
• means for supplying electric power to the bank of quartz flash lamps when a pallet is located in the heat curing station, said means comprising a proximity switch that detects when a pallet is located at the heat curing station and wherein electric power cannot automatically be provided to the bank of quartz flash lamps when a pallet is not located at the heat curing station;
• means for interrupting electrical power to the bank of quartz flash lamps when the temperature of the ink on the substrate at the heat curing station exceeds a preselected maximum temperature
• means for interrupting electrical power to the bank of quartz flash lamps when the period of time that power has been supplied to the bank of quartz flash lamps exceeds a preselected maximum time period;
• and
• time-delayed means comprising a time-delayed relay switch in parallel with a temperature control switch to allow electric power to be supplied to the quartz flash lamps after the proximity switch senses the presence of a pallet in the heat curing station and before the temperature control switch is reset.