What is Additive Manufacturing (AM)?
A technical committee under ASTM international finally defined these processes appropriately as Additive Manufacturing (AM), as the technology builds 3D parts by adding material, as compared to subtractive manufacturing.
According to ISO/ASTM 52900-2015, Additive manufacturing is commonly given to the technologies that use successive layers of material to create a three-dimensional object. By using various techniques the printer builds the 3D geometry by constructing a thin 2D plane layer by layer.
There are seven main categories of AM technologies viz Vat photopolymerisation, Material Extrusion, Material Jetting, Binder Jetting, Powder bed fusion, Direct energy deposition and Sheet lamination.
Additive manufacturing technology types
Many companies have invented and introduced new techniques and Because the technology is fairly new, the companies who develop and introduce different techniques come up with their own marketing terms for the process, even though the core technique might be the same.
As per ISO/ASTM standards AM can be divided into the following seven process categories or types according to the techniques used to create those layers. Though companies who have developed some of the AM technologies have their own names.
Vat Photo Polymerization
In this process, a liquid photopolymer is selectively cured by light-activated polymerization to create a 3D part. It is based on the curing and hardening of photopolymers on exposure to ultraviolet radiation. The main types of this technology are Stereolithography (SLA), Digital Light Processing (DLP) and Continuous Digital Light Processing. Only Plastic can be printed using these technologies.
Binder jetting process
As the name implies this technique selectively deposits the bonding agent a binding liquid to join the powder material together to form a 3D part. This process is different to any other AM technology as it does not employ heat during the process like others to fuse the material.
Directed energy deposition
Direct energy deposition uses focused thermal energy such as a laser, electron beam, or plasma arc to fuse materials by melting as they are being deposited. Types include LENS, EBAM.
Benefits of cosmetics
While some people believe that cosmetic and personal care products are a recent invention, discoveries of their use and widespread benefits go back thousands of years. Today, Europe’s 500 million consumers use them to protect their health, enhance wellbeing and boost their self-esteem.
Cosmetics contribute to wellbeing and healthy lifestyles. Our hands carry pathogens from contaminated sources; so simple tasks such as washing hands with soap can help prevent serious illness. Indeed, multiple studies have shown that the leading causes of child mortality in developing countries, diarrhoea and respiratory infections, can be prevented by hand washing with soap. The use of toothpaste, particularly when containing fluoride, reduces the prevalence of dental caries. Toothpaste reduces plaque and tartar, which can lead to tooth damage and gum disease. Beyond health, there are economic advantages to dental care: there is strong evidence that the benefits of preventing tooth decay far exceed the costs of treatment. Indeed, if we assume that, without toothpaste, total expenditure on oral health would be 5% higher, the total benefits of using toothpaste (in terms of avoided costs) would be approximately �26.5 billion by 2020.
Exposure to ultraviolet radiation is the only established exogenous causal factor for melanoma, a type of skin cancer that can spread to other organs of the body. Consistent and optimal use of sunscreen may prevent the incidence of melanoma. A study carried out between 1992 and 2006 and reported in ‘Reduced melanoma after regular sunscreen use: randomised trial follow up’ in the Journal of Clinical Oncology (2011) examined the cancer rates of two groups of adults aged between 25 and 75 years old. One used sunscreen daily and the other did so at their discretional frequency. It was found that invasive melanoma was reduced by 75% for approximately 15 years after trial cessation in the group that applied sunscreen daily.
Beyond physical health, cosmetics can help to improve our mood, enhance our appearance and boost our self-esteem. They can also help to exhibit personal style and, as such, are an important means of social expression. In a study by FEBEA, over 60% of respondents claimed that cosmetics have a positive impact on well-being, image, self-confidence and mood, with a large proportion (+40%) also identifying benefits in terms of social life, love life, family life, professional life and health.
A study published by IKW, the German Cosmetic, Toiletry, Perfumery and Detergent Association, assessing the self-perception of adolescents and young adults, found that 73% believe body and beauty care is very important in their lives. Moreover, 85% feel safer when they use cosmetics products, and 63% feel more attractive when they do so.
Synthetic chemicals are usually applied as additives in everyday products, which can help to improve the flexibility and versatility of these materials. For instance, plasticizers and flame retardants are commonly used in plastic products and electronic products respectively. However, many of the chemicals used in these products will inevitably enter the environment. Some synthetic chemicals can exhibit environmental persistence and possess characteristics of bioaccumulation, which can induce acute or chronic toxicity for organisms and further influence both ecological and human health. Therefore, despite the fact that the chemicals in these products play an important role for promoting the development of human society, the risks they pose to the environmental health of our planet must not be neglected.