Corks molds

Bottle caps made from different plastics are extensively used. Some closures are of the simple cork snap type design, but most are of the screw type. Strong, accurate threads can be molded, which represent undercuts. Simple designs should be used when permitted, such as wide-pitch threads. The thread should be designed to start about 1 /32 in. (0.08 cm) from the end of the face perpendicular to the axis of the thread. It is usually practical to mold up to 32 threads per in. more than this number can give certain molders trouble. 

After a final rinse with clean water in tumbler washers, the cork moisture levels arc adjusted to 5.5 to 8% in continuous tunnel dryers to avoid growth of microorganisms on the washed corks. An ideal moisture level achieves a water activity unsuitable for mold growth, yet high enough to maintain the flexibility of the cork necessary for bottling. 

Cork boards should not be stored in the forest close to the soil with its high numbers of mold spores, and soil should not splash onto the boards during rain. 

Corks must be shipped and stored in moisture-controlled air-tight containers, not in open bags, in order to avoid recontamination with mold, excessive moisture levels, and absorption of ubiquitous TCPs or TCA from the storage environment. 

The Penicillium mold has another important use, namely the production of antibiotics. Two species have been used for the production of penicillin, the first antibiotic to be discovered Penicillium notatum and Penicillium chrysogenum. The Penicillium species can grow on different substrates, such as plants, cloth, leather, paper, wood, tree bark, cork, animal dung, carcasses, ink, syrup, seeds, and virtually any other item that is organic. 

Use Fungistats for the control of certain molds and yeast in foods humectant for baked goods, and plasticizer for cork seals and crowns. 

Vc table oork R Molded pipe insulation, Compre ible under light Good Pair Granulated vegetable cork High vibration rtsisUnee, fair -300 200 0.285 0.300 11... 

Moldy off-flavors are attributed to the effects of many types of mold. Contamination may start on the tree and continue during storage and treatment of the cork sheets and cork manufacture, as well as in the bottles of wine as they age in the cellar. The microbial flora at each of these stages are not necessarily the same. 

Recently, Mazzoleni et al. (1994) used gas-phase chromatography coupled with mass spectrometry (GCMS) to identify 107 volatile compounds in powdered new and used corks. These findings are not qualitative, but they certainly confirm the complexity of the cork taint issue. Cork is a biological medium, and therefore necessarily complex. Even after boiling and chloride treatment, it retains a nutritional value that mold, bacteria and even yeasts are capable of... 

Chloroanisoles are produced when mold acts on chlorinated derivatives used to treat trees and prepare corks, as well as in cork manufacture. Chlorophenols are considered to be the main precursors of chloroanisoles (Figure 8.15). They are believed to be methoxylated by fungi without tetrahydrofolic acid (FH4) deficiency. This acid is a growth factor known as a unit transporter and has a single carbon atom. 

The same types of mold (particularly Penicil-lium) may find a similar environment (humidity, temperature, presence of chlorinated derivatives, etc.) in cork as well as wooden containers and structures in the winery. This explains the possible confusion between authentic cork taint and moldy off-flavors , which have similar smells, but different origins. When cork is responsible, only a few bottles are affected, whereas all the bottles may be spoiled if the defect is of external origin. 

Products and Uses The outer bark of the cork oak tree. A renewable natural resource as the bark can be harvested every eight to ten years without harming the tree. Used as insulation for heat as well as noise resistant to rot and mold. Also used for wall tiles. A component in linoleum floor tiles. 

Gaskets NBR is used either in sheet form, molded or as a binder for cork granules in a wide range of oil resistant gasketing materials. 

Geosmin is a sensory-active metabolite of Streptomyces, Cyanobacteria, as well as molds (Simpson and Lee, 1990) growing on or in the immediate proximity of cork. Geosmin, detected as the odor of cooked beet and/or freshly tilled soil, has a sensory threshold of 25 ng/L (ppt) (Amon et al., 1989). Although relatively stable in cork, geosmin decomposes in wine (Amon et al., 1989) to yield products which, reportedly, lack sensory properties (Gerber, 1979). Thus, contaminated cork may serve as a reservoir for transitory but potentially continuing extraction into wine. 

Gas-injection molding n. A specialized technique for molding low-density structures in which a mixture containing cork particles, or glass or phenolic microspheres, glass fibers, and a thermosetting resin is injected into a mold by fluidizing it in a gas stream. 

Specimen Molding compound Powders, granules, pellets or molded part cut with a microtome, razor blade, hypodermic pimch, paper punch or cork borer slivers cut from films and sheets. 

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