Apr 02, 2014
Rubber or silicone? Do you know the true value and cost of your milking liners?
By Nathan Brown, Solution Manager, Liners and Tubes, DeLaval North America
With countless liner options on the market – each one making unique performance and length-of-life claims – it’s important that producers understand the true value and cost of the liners they choose.
Outside of the liner performance discussion, a common misperception in the market is that most liners have similar lengths of life. This, however, is not true. When comparing costs per milking on liners of varying life, the shorter-life liner will sometimes actually be more expensive than a longer-life liner. The longer-life liner might appear more expensive from a billing perspective because you’re paying more when you buy, but remember, you’re paying less often. With this in mind, it is important for producers to calculate the costs per milking on inflations and compare the options. Use this formula to help determine the liner cost per milking:
When I visit dairies, producers often ask me about liner life and material compounds. Many have commented: "Aren’t all compounds the same?" or "I buy (brand X) because they use natural rubber or silicone, and that is best, right?"
Let’s consider some facts and historical data on liner compounds, which are constant no matter who manufacturers them. A variety of compounds are blended to become what you see as a finished product on your farms. Making a rubber compound is very similar to baking a cake. Add too much or too little of one ingredient and your liner might be too stiff or soft, or not able to withstand chemicals.
For decades, natural rubber was the most popular liner material since the invention of the "modern" milking machine in the early 1900s. As dairy herd sizes grew, producers demanded longer-life products. This shift ushered in a host of new liner options to help producers reduce liner changes – which, according to most, are about as fun as getting a tooth pulled! As a result, synthetic rubbers are now the main components in many liners known to be "rubber." In fact, it is virtually impossible to go beyond 800-1,000 milkings per liner when using 100% natural rubber.
Synthetic rubbers have become the new age material most commonly found in liners. This material offers longer service intervals as well as other benefits to dairy producers. Many manufacturers offer "extended-life rubber" products, which traditionally milk slower as compared to their "standard-life" counterparts. However, there are liners on the market today which claim to show no difference in milking performance between standard life and extended life inflations, including silicone. Although silicone offers an extended life, producers often experience cutting and butterfat migrations issues, which can actually shorten liner life and affect performance.
Commonly used compounds used to make synthetic rubber.
Other components sometimes used in liners are FDA-approved phthalate plasticizers, which are used to "soften" the rubber compound. However, be aware that phthalates are suspected to be a carcinogen. They are linked with some instances of breast cancer and may affect hormone levels in young children. As a result, some manufacturers have decided to eliminate phthalates from their rubber compounds in an effort to be more socially responsible. If this is concerning, ask your route driver if the liners you are using contain phthalates, and if they do, perhaps your specialist can recommend a phthalate-free liner.
In conclusion, knowing your true costs per milking and understanding the value in the rubber formulations of the liners used on your dairy can play a vital role in your profitability as well as the social responsibility of the products you produce.
You can reach Nathan Brown at firstname.lastname@example.org or visit www.delaval-us.com for more information.