A 4 size photopolymer processing machine
Designed and manufactured by our company, to produce photopolymer stamps from liquid resin or hard photopolymer plates to be pressed into a matrix board (mold)
The machine is made of 3 parts :
Exposure part (to expose photopolymer material to UV light)
Engraving part : (to develop (wash out) photopolymer material
Drying part (to harden photopolymer material)
« stamp » word can include inking pad, box containing ink pad, instrument used to transfer a print on a document and even final print. Stamp can be manual or automatic.
Our company offers products for the “seal” technical part of the stamp : part in rubber, photopolymer or pre inked material with characters, logo or drawing to print.
In case of rubber or photopolymer resin, stamp surface should be coated with ink from an ink pad. Then, stamp is placed above support and pressure is applied to transfer ink from stamp surface to the support. For another print, it is necessary to ink again stamp surface.
In case of pre-inked material, ink is directly contained in the microporous structure of the stamp (ink capsules).
Rubber stamps are mainly used for administrative applications, as a signature of a company, administration, commercial entity or individual. However other kind of stamps are available, such as daters specifically used to date documents or numberers to affix numbers on document series.
In France, company stamp is required to process most documents such as contracts, quotes or delivery notes. Signature is generally made next to or on the company stamp, with date.
Stamp is also widely used in scrapbooking applications, to customize creations : cards, announcements, albums, Christmas cards, birthdays… Multiple accessories are available for using rubber stamps in a different way : embossing powder, multi-color ink, metallic inks ...
Finally, stamps are also used in specific applications: outdoor use with UV inks, tracking information (for instance ampoules, with acid inks), textile marking for clothes…
Historically, texts were arranged and images were engraved by typographic workers then gathered together and tightened inside a forme. Then a matrix made of wax and other materials was placed on top and the whole was placed inside a heating press to imprim patterns inside softened wax.
After cooling, the wax mold was covered with rubber and parchment paper and placed again in the heating press so that rubber can flow inside mold depth and produce relief for stamps. The resulting rubber sheet was cut into stamps.
Development of computers allowed to give up cumbersome manufacturing tools (lead character fonts, presses..) and use computer-aided publication and photosensitive polymers
Now, stamp manufacturing process consists of several easy steps:
- patterns to be reproduced are drawn on a computer
- a film is printed to get a negative
- photopolymer liquid resin is exposed through the negative to get a photopolymer stamp, or hard photopolymer plate is exposed to produce a cliche
- photopolymer cliche is pressed into a matrix board to get a mold for rubber (rubber stamps) or premix gel (pre inked stamps) moulding
In case of rubber stamps, two manufacturing solutions are possible : laser engraved rubber or rubber molded in a matrix board. These two techniques are to be compared to photopolymer resin technique
Photopolymer liquid advantages
Photopolymer liquid drawbacks
Laser/conventional rubber advantages
Laser engraved rubber advantages
Conventional rubber advantages
Laser engraved rubber drawbacks
Conventional rubber drawbacks :
Production of photopolymer stamps is very easy and does not require important equipment.
Once a positive film is printed (laser or inkjet printer), all other operations are made in the same Thermogravor machine including 3 parts: exposure, engraving, drying.
Negative film is processed in the exposure part of the machine, then developed and fixed in trays
Liquid resin is
- exposed in the exposure part of the machine
- washed out in the engraving part of the machine
- post exposed in the exposure part of the machine
- dried in the drying part of the machine.
Space-saving, easy to use and designed by Thermoflan, Thermogravor machine allows the manufacture of photopolymer stamps up to A4 format.
Characteristics of 3 stamp types are summarized in the table below: