Reference - Manufacturing of Polymer Composites
Type | Book |
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Title | Manufacturing of Polymer Composites |
Abstract | Cosmetic products are generally formulated as emulsions, ointments, solutions or powders containing active ingredients. According to EU legislation, a cosmetic product is "any substance or preparation intended to be placed in contact with the various external parts of the human body with a view exclusively or mainly to cleaning, perfuming them, changing their appearance, and/or correcting body odors and/or protecting them or keeping them in good conditions". However, science advancement in both active carriers and ingredients has streamlined the process through which many cosmetic products by their delivery systems can induce modifications on the skin physiology. This is the reason why Reed and Kligman redefined these products as "cosmeceuticals", which refers to the combination of cosmetics and pharmaceuticals. Until recently, the term of cosmeceuticals has not had legal significance. The so-called cosmeceuticals, in fact, may induce modifications on the skin physiology, modifying, for example, transepidermal water loss, keratinocytes cohesion and turnover, modulating the inflammatory cascade, and/or altering the surface microbiota by the activity of the preservatives content. For these reasons, they are claimed to have medical or drug-like benefits. Naturally, their effectiveness on minor skin disorders or mild skin abnormalities has to be shown by in vitro and in vivo studies. On the other hand, their formulations contain emulsifiers, preservatives, and other chemicals which, by their cumulative use, may provoke side effects, such as allergic and/or sensitization phenomena. Moreover, many ingredients and packaging for such products are not biodegradable. In this study, we would like to introduce an innovative category of cosmeceuticals made by biodegradable nonwoven tissues. These cosmeceutical tissues, produced through the use of natural fibers, may bind different active ingredients and therefore become effective as antibacterial, anti-inflammatory, sun-protective, whitening, or anti-aging products, depending on the ingredient(s) used. Differently from the usual cosmetics, they do not contain preservatives, emulsifiers, colors, and other chemicals. They can be applied as dried tissue on wet skin, remaining in loco for around 30 min, slowly releasing the active ingredients entrapped into the fibers. It is interesting to underline that the tissue, acting as a carrier, has its own effectiveness via chitin and lignin polymers with an antibacterial and anti-inflammatory activity. When hydrolyzed by the human microbiota enzymes, they give rise to ingredients used as cell nourishment or energy. This paper will review part of the scientific research results, supporting this new category of biodegradable cosmetic products known as facial mask sheets. |
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ISBN | 9780748770762 |
Welcome
Welcome to the CKN Knowledge in Practice Centre (KPC). The KPC is a resource for learning and applying scientific knowledge to the practice of composites manufacturing. As you navigate around the KPC, refer back to the information on this right-hand pane as a resource for understanding the intricacies of composites processing and why the KPC is laid out in the way that it is. The following video explains the KPC approach:
Understanding Composites Processing
The Knowledge in Practice Centre (KPC) is centered around a structured method of thinking about composite material manufacturing. From the top down, the heirarchy consists of:
- The factory
- Factory cells and/or the factory layout
- Process steps (embodied in the factory process flow) consisting of:
The way that the material, shape, tooling & consumables and equipment (abbreviated as MSTE) interact with each other during a process step is critical to the outcome of the manufacturing step, and ultimately critical to the quality of the finished part. The interactions between MSTE during a process step can be numerous and complex, but the Knowledge in Practice Centre aims to make you aware of these interactions, understand how one parameter affects another, and understand how to analyze the problem using a systems based approach. Using this approach, the factory can then be developed with a complete understanding and control of all interactions.
Interrelationship of Function, Shape, Material & Process
Design for manufacturing is critical to ensuring the producibility of a part. Trouble arises when it is considered too late or not at all in the design process. Conversely, process design (controlling the interactions between shape, material, tooling & consumables and equipment to achieve a desired outcome) must always consider the shape and material of the part. Ashby has developed and popularized the approach linking design (function) to the choice of material and shape, which influence the process selected and vice versa, as shown below:
Within the Knowledge in Practice Centre the same methodology is applied but the process is more fully defined by also explicitly calling out the equipment and tooling & consumables. Note that in common usage, a process which consists of many steps can be arbitrarily defined by just one step, e.g. "spray-up". Though convenient, this can be misleading.
Workflows
The KPC's Practice and Case Study volumes consist of three types of workflows:
- Development - Analyzing the interactions between MSTE in the process steps to make decisions on processing parameters and understanding how the process steps and factory cells fit within the factory.
- Troubleshooting - Guiding you to possible causes of processing issues affecting either cost, rate or quality and directing you to the most appropriate development workflow to improve the process
- Optimization - An expansion on the development workflows where a larger number of options are considered to achieve the best mixture of cost, rate & quality for your application.