Plastic costs more than glass, but it is just as malleable and has superior quality features. According to Carlo Candiani, president of the G. Candiani, an Italian company, «Plastic gives us caps, jars and bottles processed in ways that would otherwise be impossible». Furthermore, it does not reduce the appeal of products destined to appear on the shelves of prestigious perfumeries. «Demand now is mainly for clear materials, like Surlyn by DuPont and co-polyester – even though these are not easily moulded – because they offer considerable advantages over the use of glass» Mr Candiani tells to Plastix World.
So glass is destined to be replaced by plastic?
Absolutely not! Glass has certain incomparable inherent characteristics; but it has to be considered that a glass jar designed to hold 200 ml of cream weighs like a little brick.
From a technical point of view, the flatness of closures for glass containers is inversely proportional to the width of its mouth: to obtain good results it would be necessary to produce them on a large scale and then carry out frosting or coating processes on all the pieces: these treatments are necessary in order to disguise the imperfections that result from semi-automatic processing. Then it is necessary to consider the question of colour: glass manufacturers only occasionally produce coloured containers, and they are not at all flexible on this issue. Hence the main advantages offered by plastic are its lower weight, remarkable flexibility, the possibility of producing coloured items according to specifications, continuous availability and the possibility of ordering even small quantities.
But what are the reasons why plastic is increasingly considered preferable?
Processing transparent materials is difficult because there are few resins that are not subject to warping once they come into contact with perfume. Surlyn works well with snap top closures but not with friction ones, which are subject to deterioration after a few uses. We can obtain high thicknesses with the single-piece moulding technique, which, together with overmoulding, is one of the technologies requested by the most demanding customers. In particular, the use of overmoulding has led us to develop a post-conditioning system. Conditioning is critical if the part includes a galvanised component because overmoulding can ruin the substrate component. For this reason, in the production of plastic parts with metallic components, we opt for a galvanic treatment when the part is made of ABS, whereas parts in polypropylene are metallised with a UV or traditional finish.
What will become of glass containers?
First of all, glass containers will undoubtedly continue to exist. As far as closures are concerned, making them in glass is a complex undertaking, both in cost and in production capacity terms, as it is necessary to calibrate both the neck of the container and the stem of the cap. For these reasons, I am convinced that these products will increasingly be destined for niche products: perfume extracts, for example.
Other than plastic, are there any other materials that are used as alternatives to glass?
One of our main competitors manufactures products in zamak, which does not have a high purchase price but requires expensive manual processing, which unsurprisingly is often carried out in China. This is a situation that does not really concern us, as we have never considered outsourcing anything. Rather, as an alternative, we have developed a material with a density of 4.8 g/cm3, filled with metal. We also use highly filled polypropylene, which, even in the presence of large volumes and thicknesses, offers good results in weight terms.
Can you suggest a low-cost solution?
After ruling out the possibility of creating a transparent cap in polystyrene, one might opt for polyethylene and polypropylene, starting with the production of samples to put through various tests. In the Far East they make jars in acrylic, which costs less and does not require sliding core moulds, but acrylic carries a high risk of breaking. It is not easy explaining to customers the problems linked with the various materials, nevertheless, nine times out of ten, it is left to us to choose the material and other production techniques.
Do the clients give you projects to be freely developed or do they impose rigid specifications?
First of all it is necessary to point out that some manufacturers look after the production process of the perfume themselves, while others license their brand to third parties. We, in any case, always interface with the customer, who provides us with a virtual image or a mock-up, which is the starting point for our technical feasibility check. Within a short space of time, it is possible to start preparing the moulds and thus to arrive at the finished product. One important advantage that we have is the possibility to carry out stereo-prototyping; this helps us enormously in developing prototypes of the items we are about to produce, and the size, shape and mechanical features of these prototypes comply fully with the customer’s requirements.
What is the average life of a mould in this market sector?
As things currently stand, the average life of a perfume, with a few exceptions, is around three-five years. However, this does not alter the fact that all the moulds we produce are well maintained and kept in a good state of repair. Packagings often undergo aesthetic adjustments, which however do not necessitate modification of the moulds.
Was it difficult to “colonise” this French-driven market?
The link between fashion and perfumes is a strong tradition in France, whereas in Italy it is something that only began to catch on in the 1980s. Some of the top Italian fashion designers were pioneers in this sense. Operators in this sector needed technical support, particularly with regard to the knowledge of materials. We spotted an opportunity to carve out a niche for ourselves and reorienting our production was a logical consequence of this.
Did this have repercussions on your technical organisation?
Not excessively. We have always managed to look after the entire production process ourselves: in addition to injection moulding we can also perform extrusion blow molding and injection blow molding. A huge advantage for us is that we have an internal mould manufacturing department, which currently delivers 20 per cent of the moulds we need for our products and does a lot of the regular and extraordinary maintenance, whereas galvanic treatments, metallisations and painting jobs are outsourced to subcontractors not far from our headquarters. All our products can therefore be considered “zero kilometre” products.
Do these short distances translate into a faster time to market?
The perfume industry is constantly reinventing itself and this means that times have to be cut to a minimum. If we were to relocate our production, this would mean much longer times that could leave us cut off from the market.
As regards the machines, on the other hand, do you consider it better to work with a single supplier or to rely on different brands?
On the basis of our experience, the first option is preferable and this is the direction we shall continue to follow in the future too. We have just taken delivery of a 240-ton electric moulding machine from our regular supplier and we are thinking of purchasing others in order to renew our machine fleet. We believe that the future of injection moulding lies with electric machines, for reasons linked to market trends, but also because of the practical advantages they offer, such as their cleanliness and low noise.