Showing posts with label dibattito. Show all posts
Showing posts with label dibattito. Show all posts

Thursday, 29 September 2016

Where are water-based coatings gone?



A good question, which is difficult to answer in a comprehensive way.

On one hand, we could say that the industrial world and the new global economic conception is going in the direction of reducing costs (and pollution is a cost, indeed), improving the workers’ living conditions (even if in current water-based coatings there is a certain amount of solvent, it is undeniable that they are less toxic) and consumers’ living condition (the "indoor" emissions are virtually nil), improving material performance (almost 100% of water-based paints are used for frames painting and, consequently, they have excellent resistance "even" outside where the stresses are definitely superior to internal ones), in our “explorations” looking for virtuous companies we often stumble in organizations resigned in using traditional solvent-based paints.

The most common answer that is given by those working in this field is always the same: “I would like to use them, but they dry with more difficulty, and it is necessary to pay more attention in the preparation of the substrate, and furthermore they are more expensive”.

Is it true that water-based coating’s technology – which has been produced since the late sixties of the last century… - has not solved those problems? I don’t think so. After all there are companies that produce wood paintings – practically – only water-based, and with a recognized high quality. Unfortunately, not the Italian ones: some of them which started “in the right way”, but then they backtracked, except a couple of exemplary companies, which truly believe in a future of low environmental impact paints, starting from their sellers (at least those who we know) first ones to promote these products to users.

DRYING: Everyone assume that water-based coatings dry very slowly, slower than the solvent-based ones, without knowing that the water, with the help of some co-solvents in small quantities, forms "azeotropic" solutions that evaporate at water’s temperature (100° C), faster than toluolo (111° C), so that “hydro” paints dry out faster: seeing is believing.

SUBSTRATE PREPARATION: We talk a lot about quality, but we haven’t yet taken for granted that quality starts from smoothing, pre-treatment, in conclusion from substrate preparation?
COSTS: It is trivially a matter of market functioning, considering that if there was a greater demand, raw materials would reduce their cost and, consequently, also paints. Anyway, not to pollute is already a way to reduce costs (health care, waste, diluents, and so on).

Finally, without giving due consideration to other “defects” reported by detractors as, for example, the need to have a heated warehouse. Progress needs a healthy “natural selection”; having adequate production systems – not only plants, but also business organisation and work-condition’s respect – are essential conditions for companies’ survival.

Monday, 11 April 2016

3D PRINTING BETWEEN MYTH AND REALITY: how are the implications for finishing?


3D printing is one of the fashio­nable “technologies” and accor­ding to many it will fundamen­tally change the way we produce.
The futurologists speculate a scena­rio where traditional factories will di­sappear, swept by a wave of a wide­spread” electronically craft”, able to manufacture small batches (ideally 1 item) of customized products accor­ding to customer requirements.
Someone will remind when in 2000, with the internet spread, we said that traditional stores would disappear.... It did not happen, but the world of bu­siness is still fundamentally changed.
In this article we will try to under­stand the possible implications for manufacturing, and then for fini­shing, starting with the understan­ding of the technology and clarifying some of the words that are beco­ming fashionable.

3D PRINTING
3D printing, refers to various pro­cesses used to create an object by adding successive layers of material
We can see two kind of printing:
  • Extrusion or material deposition: various layers are created and depo­sited one after the other to “create” the object.
  • For sintering or hardening of mate­rial: in this case, usually with a laser, the object is drawn within paints or powder coating which are hardened by the laser.

In both cases the object is created through layers, as if we would build a mountain adding one section above the other corresponding to the con­tour lines.

The printer receives as input a 3D model of the object to create, re­presented according to a standard language - there are more than one - and it is able to decode the informa­tion into movement instructions for its moving parts, exactly like a paper printer is able to move its head to print a file from a computer.
Let’s see the benefits - typical of the digital transformation of any process – compared to the “traditional” pro­duction:
  • Flexibility and cost-effectiveness in particular for small batches: tools and moulds are not required.
  • Despecialization: the 3D printer replaces several equipment and traditional processes. For example in a single operation we can create complex shapes which would requi­re material removal after casting or moulding, or even the production of many parts to be assembled.
  • Zero or minimum setup time or however minimal: just load the 3D model of the object, and you can start.
  • Scalability: with less than 1000 Euros now it is possi­ble to buy home printers for plastic, to create industrial models
  • Possibility to create complex objects larger than the printer, dividing them into many parts to be produced on the same printer. Usually the design software supports the division in parts from the finished product

As regards the materials, the most use one is plastic and to follow metal. Then there are applications still on test for wood, food (for example printing of chocolate pra­lines), the electronic circuits, and even the molecules, with achievements in biotechnology or nanotechnology sectors.
The fields of application are extremely various: some are very specialized, such as the prosthetics sectors, with already a good spread in the dental industry, but also in cardiology or artificial limbs sector. Jewellery, and in particular furniture and home accessories industry.
We can even mention buildings created with printers for concrete (opening picture). And of course the industry at large, which we will talk about later.
I would like to end this brief overview on the technology with some considerations.
The first is that it is a rapidly evolving technology. I do not exclude that in a few months there will be innova­tions that overcome the considerations reported in this article. It is hard to draw conclusions, because we are “photographing” an evolving situation.
The second is that technology, even we can imagine ex­tremely interesting application areas, and it is still rather “primitive.”
Chris Anderson, in the book “Makers” to which I refer those who want to know more about this topic, draws a parallel with the traditional desktop printing: today we have at home, for a few hundred Euros, laser printers with photo-quality level; but do you remember the mid- 80’s dot matrix printers?
So we can think that riding on what we call the ‘long wa­ves of innovation, in thirty years or maybe earlier some of the applications, that today are only feasible, will be­come possible. Therefore it is important to distinguish the myths from reality.