BMC safest bet for engine components
In the Plastics News story titled ``Valve covers latest push from industry'' (March 29, Page 1), reporter Rhoda Miel states: ``The plastics industry is ... trying convince North American automakers to use thermoplastics in valve covers in place of the existing metal components.''
In a virtual sales pitch for engineered nylon, PN goes on to substantiate its headline with quotes from both producers and consumers of nylon materials. While mentioning the use of nylon in applications such as intake manifolds, PN fails to illustrate the environmental differences between applications (manifolds vs. valve covers). Nor does PN touch upon the complications forecasted with thermoplastics and the impending move to hotter-running, 42-volt engines. Most absent from PN's effort, however, was input from those that have supplied the valve cover industry for years: the manufacturers and processors of fiber-reinforced thermosets.
Bulk molding compound is the only composite material that has met the automotive industry's performance/durability benchmark for valve covers (10 years/150,000 miles). BMC has been molded into more than 60 million valve covers without one material-related failure. Everyone knows that manufacturers and processors of nylon maintain a tremendous marketing presence in Detroit. These people have certainly presented their offerings to engineers responsible for valve cover design and material specification. So I would like to ask: Why are fewer than 1 percent of the valve covers made in the United States nylon and 37 percent thermoset? The answer: properties and price!
In metal-replacement applications such as valve covers, the rigidity or modulus of the material used is critical. Valve cover test protocol often requires durability testing at 150° C (302° F). BMC maintains flexural modulus properties greater than three times those displayed by nylon when tested at these temperatures. Nylon covers often require more mounting bolts to offset this modulus loss. These bolts are relatively expensive and increase general assembly costs when compared to BMC.
Material shrink is another important factor when considering a sealed engine system. Nylon shrinks several times more than BMC. Nylon also displays variation in shrink transverse to flow. The manufacture of long, flat parts (such as valve covers) is difficult when materials behave in this manner. Adjusting for these shrink idiosyncrasies contributes to the expense of tooling revisions and overall project start-up. BMC eliminates these shrink issues.
Nylon displays hydroscopic tendencies and will absorb water and engine fluids more than BMC. The physical properties of nylon are affected by this moisture absorption. Additionally, post-consumer recycling of nylon becomes less likely if engine fluids have been absorbed by the substrate. Recyclability has been touted as a major selling feature for nylon over thermoset. BMC 685 (used in GM's 3800 valve cover) contains up to 9 percent reground BMC product. Thermosets are being recycled - don't be misled.
The reason less than 1 percent of the valve covers produced in the United States are nylon is not because automotive engineers have refused to study the option. Rather, U.S. automotive engineers refuse to compromise the integrity of their sealing systems because they understand the limitations that accompany nylon materials. Engine designers will not compensate for a material's shortcomings (especially when the more advanced polyamides cost three times their BMC equivalent). The 42-volt engine is on its way and with it even greater operating temperatures. For price and performance, BMC will continue to be the answer.
Bulk Molding Compounds Inc.
West Chicago, Ill.
To regain U.S. jobs, cut corporate taxes
On the surface it would stand to reason to buy American. However, when buying an ``expensive, quality product'' such as an automobile or machine tool, what do you look for? Quality! What are the most reliable long-term cars on the market? Who makes the best machine tools? I am sorry but American companies do not come to the front of the line here.
The problem with American companies is that they put profit before quality. This is not true with every American manufacturer. But take the average American car and go head-to-head with a comparable Japanese or German car. Let's compare them at 100,000 miles.
The commodity items being imported and sold by the big-box stores are where American jobs are going and have been going for 25 years now.
This is because people want to pay less, not more. The large corporations have a better bottom line importing also. Why pay an American seamstress $10 an hour or even minimum wage, when in South American countries companies can pay them $5 per day! With the same productivity! Lax labor laws, lax environmental laws, and the big one - very low taxes! Stop shopping at the stores that sell imported merchandise. You can buy American-made mercandise, but it will cost more.
Want to get American jobs back? Eliminate corporate taxes altogether. Gut and streamline the government programs. I am sorry if government jobs are lost. This happens to many people in the private sector every day. This is called reality.
Our government is here to take care of things the everyday citizen cannot do. It does a great job of protecting us from invasion and attack. Everything else is so-so at best.
Need funding for the military? A federal sales tax would more than make up any loss in corporate tax income.
Enact federal tort reform now. Stop the silly lawsuits and make people responsible for their own actions.
This is just the tip of the iceberg of things that can be done to fix America.
Three R Plastics Inc.
Round Lake, Ill.