Shellac based blocking pitches

Our program comprises types C and Punktkitt. They mainly consist of natural resins like rosin and shellac as well as rosin pitches and natural softening agents. As these types are particularly elastic and stable they are suitable for gluing optic parts at reduced tension.

Bonding large round-optic and plano-optic parts to proper and temporary substrates at surface and center cementing. These types are capable to compensate high stress and high temperatures, particularly when processing precise plain surfaces. Type C of hardness 36 is especially designed to cementing parts for contact centering. Furthermore it can be used for bonding parts before the cutting process. Shellac compounds must not be heated up for more than 20 minutes when exceeding temperatures of 180°C as, afterwards, shellac tends to cross-link (rubberise), and, hence, the solubility of the cements will deteriorate.

Technical Data

Type Hardness Softening Point in °C Solubility Specification
C 36 ± 1 68 A, A/S partly resistant
39 ± 1 70 A, A/S to oil-containing coolants
Punktkitt 30 ± 1 62 BDG, NMP and petroleum

Please Note

Shellac compounds must be kept from open fire as they are extremely inflammable.

Delivery Units

· Bars 25 x 25 x 160 mm
· Bars 85 x 25 x 160 mm
· Alu- trays 128 x 33 x 220 mm