What is tissue creping?
Tissue creping is an operation near the end of the tissue manufacturing process where bulk, stretch, absorbency, and softness are created in the tissue. Tissue creping is vitally important when these characteristics are key attributes of the final product. Technically, everything can be a factor which affects the tissue creping process. The process is simple in many respects, but to get high quality tissue and meet market expectations, good creping is essential. Doctoring systems are crucial to producing a high quality product and not damaging the Yankee shell in today’s high-speed process. The variables involved in the creping process are numerous, but with poor doctoring the ability to create a soft and absorbent tissue is limited.
What makes proper tissue creping so important?
Imagine two metal parts: one is stationary and the other is running; both rubbing against each other. That is doctor creping. As Yankee speeds increase, vibrations between the rolls, Yankee, and creping blade will become a more significant factor. If vibration is not controlled, the Yankee surface can be damaged and will need to be refinished typically by grinding, which involves downtime of three to five days. As the Yankee ages and is repeatedly ground, the steam pressure rating can be reduced resulting in lower operating steam pressure, reduced speed, and less production. If the process is not stable, the Yankee can wear out in 15 to 20 years. When maintained and managed properly, the Yankee could be expected to operate for more than 30 years.
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