Agglomerate Corks with
Starch-Polycaprolactone Composite Corks
Executive Summary Starch and polycaprolactone (SPCL)-based composite cork is a high quality replacement for natural and agglomerate cork. Synthetic corks have been developed in response to the rising costs of natural cork, though they are generally not well accepted by consumers. Agglomerate corks are more likely to break during removal from wine bottles, a major source of customer complaints, due to reduced tensile strength compared to natural cork; SPCL material can provide better tensile strength that will prevent this problem. SPCL is biodegradable, unlike plastic-based composites, which is an important feature for some consumers. The manufacturing process is similar to agglomerate cork, so there is no need for further investment in machinery. The main disadvantage is the higher cost of polycaprolactone, but this can be expected to fall in the future. This project consists of two phases of testing before full-scale production, and the initial budget is $30,000 and $100,000 for each phase of testing.
Introduction
The packaging of wine is an important contributing factor to the quality of the wine not only for its aesthetic value, but also because it affects how well the wine can be stored. Wine bottles are tightly-sealed to prevent exposure to oxygen, which, in turn, prevents aerobic fermentation of the wine. The second fermentation converts ethanol to acetic acid and produces other off-flavors, therefore spoiling the wine. For wines that can be aged for decades, it is vital that the bottles are completely sealed off during storage. (Robinson, 2006)
Cork has been used to seal wine bottles since the 7th century. Natural cork is highly valued for this task because it is almost impermeable to gases and liquids, highly compressible and flexible (Silva et al., 2005). Once the cork has been inserted into the neck of the bottle, it
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