TPE applications in the market for dental hygiene products
Over the past 25 years, dental hygiene habits have significantly improved in Germany. German consumers buy two toothbrushes and five tubes of toothpaste on average every year, according to a recent study by the market research institute Nielsen.
What initially sounds rather modest adds up to around EUR 1.66 billion a year for dental hygiene products, i.e. an average of EUR 20 per capita. Worldwide turnover with oral and dental hygiene products amounted to USD 36.2 billion in 2017.
In Germany, 168 million toothbrushes (6 billion toothbrushes are sold worldwide every year) and 413 million tubes of toothpaste were sold, whereby the market researchers established a growing trend toward gum protection and desensitizing toothpaste. There is also a growing demand for dental floss and interdental brushes for cleaning interdental spaces, recently rising by almost 10 %. Germans invested more than EUR 107 million in interdental products.
The study concluded that the market for dental and oral hygiene products is a billion-dollar business, whereby the limit has by no means been reached yet. After all, the recommended number of toothbrushes per capita and per annum is six to eight and the number of tubes of toothpaste should be twice as high, claims GABA within the framework of its prophylaxis concept. And the fact that toothbrushes should be replaced after a common cold as bacteria can collect over the time further underlines the growth potential.
Actega DS is offering its Provamed TPE range in hardnesses ranging from 40 – 80 Shore A, e.g., for the production of toothbrushes and interdental brushes. The products are supplied both natural-colored and in translucent material versions. According to the manufacturer, these TPE formulations were developed for the production of manual toothbrushes and interdental brushes in the private label segment which are distinguished by their particular softness, individual colouration properties, pleasant haptics, and shorter cycle times in the injection-moulding process.
Today, most manual toothbrushes are designed and manufactured to consist of up to four plastic components – this seems to be a must in the market for toothbrushes – and in general in a great variety of colours. Polypropylene (PP) or polyethylene terephthalate (PET) are used in the hard component, while thermoplastic elastomers are utilised as soft-touch elements for more grip. This translates into high demands on toothbrush production which also needs to be cost-efficient. Economical production of this mass-market item therefore involves the use of multi-component technology. The multi-component injection-moulding process offers the possibility to unite the properties of various plastics or colours in a single moulded part. In terms of tools, multi-component injection-moulding is realised using rotary tables or rotation cores, core-back or stack-turning techniques which means that the first component is injected similar to classic injection-moulding. The various processes or tools outlined above are available for injecting the other components. In the case of toothbrushes, i.e. the combination of parts with a hard substrate and soft surface, a turning or displacement technique is applied, i.e. the pre-moulded part stays in the cavity. By turning or displacing a section of the die, space is created for injecting the TPE.
Interdental brushes also usually comprise several components: brushes, wire and substrate. Interdental brushes with fixed or replaceable handles, handles of varying lengths or for plugging on are available for electric toothbrushes. And the shape of the brush is also variable, ranging from “fir tree” through “paintbrush” to “bottle” versions.
In terms of material, handles and protective casings are usually manufactured from PP while brush necks are made of a TPE and brushes are made of polyamide (PA). Wires are usually plastic-coated to facilitate cleaning of retainers, bridges, crowns or implants. In terms of tools and production technology, injection moulding methods are also used here, in which the (usually) three components are produced in independent processes. Fully-automated production was recently presented which entailed the shaping of up to 500 brushes directly in single-component injection-moulding together with the “soul” and grip area – for an interdental brush in a one-shot process.
According to Actega DS, the Provamed TPE can do much more, i.e. attributing toothbrushes a fresh and pleasant peppermint fragrance or a soothing chamomile or lavender aroma. There is no limit to the variety of scents and applications available. Additivation can be realised using highly-concentrated masterbatches of fragrances prior to processing in the extrusion or injection-moulding machine or in a separate dosing unit during processing. This applies for all formulae. These fragrance-compounded TPE now offer customers not only the possibility to attribute their products with individual fragrances, but also the opportunity to supplement their applications with an entirely new sales pitch, said the company.
Dog bones with BBQ aroma and much more
Actega DS with new TPE materials at Fakuma
Actega DS presented at Fakuma TPE especially for consumer goods applications which can be processed efficiently in an injection-moulding process. This new TPE portfolio offers an extensive range of functions (colours, fragrances, etc.) which gives products a significant and attractive appearance. The series targets applications from kitchen and household, bath and body care to sports and leisure.
Soft Est is the brand name for the latest portfolio addition of Actega DS. The new series has been developed especially for consumer goods applications and features a number of special benefits. Comprising 22 grades, the series offers ultra-transparent, translucent and natural-coloured versions in Shore hardnesses ranging from A-20 to A-85. All grades are food-safe in accordance with EU 10/2011 and FDA regulations and are suitable for applications which come into contact with aqueous, acidic, alcoholic, dry and fatty foods. These characteristics are decisive for application of the grades for household and kitchen products, baby items and toys, sports and leisure items or bathroom and personal care products, stationery and cosmetics packaging or garden and pet accessories, such as play and chew bones for dogs. Here comes another factor in: the aroma component. If so required, individual Soft Est materials can feature individual aromas. So what about bite-resistant dog bones with chicken or BBQ aroma? These fragrance-compounded TPEs are now offering customers not only the possibility to attribute their products with individual fragrances, but also the opportunity to supplement their applications with an entirely new sales pitch. Additivation can be realised by adding highly-concentrated fragrance master batches from a separate dosing unit during the injection moulding process.
Furthermore Actega DS presented transparent and natural-coloured variants of TPE compounds for pharmaceutical closures. Provamed 6145 TL, 6245 NC and 6345 NC passed all tests in accordance with USP 381 and show very good self-sealing properties for safe reclosure even after multiple piercing which not only extends the useful life and minimises the risk of contamination but also increases patient safety.
Actega DS completed its portfolio of PVCfree sealing solutions for the food and beverage industries with VinTellox compounds for wine and sparkling wine closures. The compounds are distinguished by a low level of migration, good closing and sensory characteristics as well as controlled oxygen input. The company said that pressure retention and side impact resistance tests have displayed significantly higher pressure retention values compared to conventional sealing discs as well as outstanding closure tightness. VinTellox is an alternative to natural and synthetic corks, aluminum closures with sealing discs or glass corks. In particular, with regard to improved closure properties, excellent pressure retention and the possibility of various controlled oxygen permeations. Unlike inserted sealing discs the VinTellox sealing compound is punched with an additional profile in the aluminum closure during the compression moulding process. This guarantees optimal sealing even where differing bottle mouth qualities prevail. Long-term tests have proven that even under very warm storage conditions, no leaks were reported. The opening values displayed lower and more constant values than when conventional sealing discs were used.
Investments in Bremen
Actega DS recently announced that it will invest around EUR 18 million in the expansion of its Bremen research and production site over the next two years. The production and storage area will be expanded by 8,000 m2, total production capacity will be increased by 50 % and the R+D area will be tripled. Start of construction is scheduled for spring of 2018.
Sterile from A to Z
Those responsible for packaging solutions for sterile medical products require a great deal of imagination and perception concerning the risks to which packaging is exposed from commencement of production through to the time of use. Packaging is exposed to an enormous level of stress en route to patients with numerous potential hazards lurking during the production process in the factory, the packaging process and transport. In the development of new products in medical technology, it is therefore necessary that right from the start the aspects of packaging, sterilization, transport and storage are complied with in order to eliminate any potential hazards endangering sterility.
Even the raw materials for manufacturing medical packaging and medical products must be sterilisable just as the same applies for thermoplastic elastomers as a group of materials.
Ulterior proceedings are the choices of sterilisation processes. Apart from electron and x-radiation, ethylene oxide (EtO), gamma irradiation or hot vapor in the autoclave are also used as sterilisation methods in medical technology. When applied as designated, each of these methods is regarded as both effective and safe.
Ethylene oxide sterilisation is a low-temperature method which kills microorganisms at 10 °C by forming a compound with the protein molecules and destroying them. As the sterilisation time depends on the temperature – the higher the temperature, the shorter the sterilisation time – a temperature range of 37 to 60°C is usually applied. Combined with a low process temperature, this method is suitable for many thermoplastic materials and is applied in particular for disposable items such as syringes, compresses, swabs and medical products which are sensitive to temperature.
Sterilization with hot vapor is at 121 or 134°C and overpressure of up to three bar in the autoclave. When the vapor condenses on the item to be sterilised, energy is released which damages the microorganisms. Hot vapor sterilisation at 134°C is the most popular method of sterilizing reusable medical products.
High-energy, ionizing gamma irradiation deactivates the microorganisms. When this low-temperature method is applied, the minimum radiation dose must be observed. But not all plastics are suitable for multiple sterilisation by gamma rays: this method is only applied industrially and almost exclusively for disposable items.
All of these methods can prevent biological contamination. But they each have advantages and disadvantages and above all significant effects on the material used. In order to prevent any negative impacts, the material formulae need to be compiled very carefully using stabilisers and other supporting ingredients – as is the case with the ProvaMed portfolio offered by Actega DS. Extensive tests of the various variants comparing gamma irradiation, autoclaving and gassing with ethylene oxide indicate the resistance displayed by these materials to signs of wear such as swift ageing, brittleness, discoloration or changes in mechanical properties possible in the case of highenergy gamma irradiation, for example, while hot-vapor sterilization can cause shrinkage, deformation or even melting of the plastic.
Tests on ProvaMed compounds indicate that tensile strength remains virtually unaffected even after irradiation with 50 kGy. The high temperatures in the autoclave can even have a positive effect on the relaxation and crystallisation processes of some polymers contained in the TPE recipe. This can increase tensile strength and elongation at break. Similar effects have been detected when gassing with ethylene oxide.