Dollfus & Muller manufactures for years endless ironing felts with special anti static fibers in order to prevent static electricy problems.
Ironing tannery machines often have static electricity problems, specialy during winter time. Dollfus & Muller developped in 2005 special ironing felts with exlusive fibers in order to reduce considerably static electricity problems on tannery ironing machines.
Yes, it does ! The woollen fibres help the felt to absorb better the fats from the hides and the water, this is why mixed felts have always been very popular as sammying felts.
Nevertheless, todays synthetic felts have improved their capacity of absorbing or their drainage, and even if their absorption is still a little less, as their longevity is much higher, synthetic felts are today recommended felts for sammying machines. Wool fibres are very sensitive fibres. The major sammying machine maker Bauce (1500 machines manufactured as of today) uses only synthetic felts originaly on its machines.
No, synthetic felts absorb a little less the fats and the water in the sammying machines than mixed felts, but the synthetic fibres are longer lasting than mixed ones. As a consequence, synthetic felts are the best value for money to recommend for sammying machines.
The most important when you need to decide which sammying felt to use is to know how many pressure cylinders has your sammying machine. Sammying machines are built with 2, 3, 5 or 6 pressure cylinders and the consecutive stress for the felt is very different from one to the others.
Type of hides, type of felts used up to now, type of tanning, or any problem which occured can help in the sammying felt recommendation.
The most important when you need to decide which ironing / embossing felt to use is to know the maximum pressure you will apply on your ironing and embossing machine. Through feed embossing machines are built to work with pressures as high as 240 Kg/cm² and the consecutive stress for the felt is very different from an ironing at 30 kg/cm².
Type of hides, type of felts used up to now, required embossing, or any problem which occured can help in the ironing / embossing felt recommendation.