Sanjan’s Cold Transfer Holo Packaging Machine (September 2010)
Sanjan was established in 2001 as a hologram producer by Wu Xiao Hua, a mechanical engineer who had previously worked with Foshan Sun Packaging, an embossed hologram producer (now closed). Wu built the hologram embossing equipment, and according to Thomas Chen, Sales Director, hologram sales were slow in the first few years, but they did get interest in their embossing machine. So they started building machines for sale, at the rate of 2-3 a year at first. Sales of machines grew as the Chinese market for embossed holograms grew and as the company’s reputation spread. It also has the benefit of being based in Foshan, within the Guangzhou conurbation and close to around 60% of China’s hologram producers.
In 2006 Wu re-designed the embossing machine and the company moved to larger premises, from where machine sales took off. Sanjan has sold over 400 wide-web hologram embossing machines since moving to its new premises to become one of the largest suppliers in the world (see HN Vol 23 No 10). On a recent visit there were 17 machines being built, tested or readied for shipping, and the company aims to build each machine within two months.
Its newest offering is the wide-web UV cold transfer packaging machine which uses a an embossed holographic film as ‘master’ to transfers a holographic pattern onto coated packaging paper or board. The receiving substrate is coated with a UV lacquer or varnish which is then partially hardened under UV radiation; this is brought in to contact with a reel of surface-relief OPP holographic film, so that the relief pattern is cast in to the coating on the substrate. The two are separated and the film re-wound for re-use, while the coating on the packaging substrate is further cured. The whole process takes place at room temperature.
The machine as currently configured will run packaging substrate from 200-450 gsm in sheets 920 x 650 mm or 920 x 1300 mm, at 5000 per hour for the smaller size, 3000 for the larger size. The OPP film can be 20-75 µm thick and is re-usable, for at least 10 cycles, Sanjan states.
Unless there is further coating to protect the hologram layer, this is obviously not suitable for any kind of security hologram, but the UV varnish, once cured, is hard enough that it withstands the treatment of a package through the distribution chain. Sanjan’s specification states that the process produces very bright and sharp holographic effects because the grooves are very deeply cast in to the UV layer, and that the whole process is low-cost because of the re-use of the master hologram film.
UV Embossing Under DevelopmentSanjan is also developing a UV embossing process, suitable for PET film 20-200 µm and OPP 20-100 µm, in 800 and 1300 mm widths at up to 40-50 metres/minute.
As reported in Holography News last year, Shantou Yiming Holotech Co asserts that Sanjan’s seamless embossing equipment copies its process which is patented in China, but it withdrew a patent infringement claim that it had filed in the courts.
Thomas Chen will be presenting details of the UV Cold Transfer process at the Holo-pack•Holo-print conference in Kuala Lumpur in November.
Contact: www. sanjan.com.cn