Doc's Corner

Doc's Corner

Be aware of poor quality silicone tubing.

Blooming is a symptom of poor quality silicone tubing. Blooming appears as a powdery white exudate on silicone tubing surfaces and can look like "snowflakes" forming. The cause is insufficient and/or incomplete processing of the silicone raw materials, most commonly, 'post curing' of material not done for long enough or at the wrong temperature.

If silicone components have not been sufficiently post-cured, over a period the catalyst remaining in the silicone component will make its way to the surface and cause Blooming. When used as a food contact material this exudates contaminates the food that passes through it with the catalyst chemicals, and so any such silicone item cannot be classified as Food Grade.

Also, if processing is not thorough, the cross bonding of the silicone molecules in the material may be incomplete, this will lead to premature break-down in use, and a degree of instability in the finished article, especially in the tough, aggressive environment of the dairy milking parlor.

dated: April 26, 2004

Doc's Corner is a contribution of Lionel H. Brazil, DVM (1928-2007). Dr. Brazil offered dairy consultation services worldwide for many years. His services covered the following areas: milking management, vacuum system evaluation; and all management procedures relating to mastitis control and SCC reduction.