Flexible letterpress plate making method

1, rubber version

The rubber plate is made of natural rubber or synthetic rubber and is hand-carved or molded.

1. Hand carving

This plate making method is similar to engraving a rubber stamp. First, the painted pattern and text are inversely attached to the surface of the rubber plate, which is then carefully carved into a relief plate. The sculpted rubber is then affixed to the plate cylinder of the rotary printing press and printed. Hand-sculpting is slow and the accuracy is poor. Only some low-quality packaging materials with simple patterns can be printed, such as corrugated cardboard boxes, packaging kraft paper, and plastic woven bags. However, although this law is old, it is still widely used. Paste can use 501 or 502 adhesive or double-sided tape.

2, molding method

Molding method is divided into three steps:

1 Preparation of metal letterpress (original). Photographic platemaking method is used to photograph the manuscript of the manuscript as a negative film negative, and a photosensitive adhesive is coated on the surface of the metal plate (copper and zinc), and the metal plate is developed, etched and corroded by printing.

2 Pressing stencils: The metal stencil is used as the original, and a thermosetting resin (phenolic resin) is used as a material on the press machine to press the concave stencil by heating.

3 Pressed Rubber Relief: A rubber sheet (natural rubber or synthetic rubber) is placed on a concave stencil and vulcanized, molded, and cured to make a rubber plate. According to the thickness required for printing, the back of the printing plate can be ground and printed.

The graphic precision of the embossed rubber plate is better than that of the hand-engraved rubber plate. A block plate can repeatedly compress a plurality of rubber plates, but the process is complicated, the cost is high, and the efficiency is low.