On 04/01/18 09:50, Chris Hogg wrote:
On Wed, 3 Jan 2018 21:53:33 +0000, Tim Watts
wrote:

I'm in the market for a new set of china plates etc.

However, what happens is one of many parts will get broken or at least
chipped badly in just a few years.

Does anyone sell long life designs - nothing fancy, plain is good
(thinking hotels and restaurants must demand sets that they can get new
parts for?)

It's either that or buy a backup set and keep that in the loft!

Two principal factors affect the durability of tableware. The basic
strength of the stuff (as measured in fundamental units, kgf/cm² or
whatever), and the design (thin, thick, rolled edge etc). Basic
strength is controlled by composition and by porosity, which in turn
is usually related to firing temperature.

The strongest is bone china, often simply called porcelain in this
country by the retail trade (but true porcelain is something else).
Because it is strong, it can be made thin, so is light in weight,
translucent and elegant, if that's your thing. But the raw materials
are expensive, especially as it contains half it's weight of cattle
bone, hence the name (and no, you can't get BSE from it, as was once
asked!). There is a classic Wedgwood publicity photograph of a
double-decker bus supported by six bone china teacups!
http://bit.ly/2lSeqUI

Next strongest is what I call true porcelain, mostly made on the
Continent, especially Germany. Both bone china and porcelain are
non-porous because of their compositions and high firing temperatures,
a fact that contributes greatly to their strength and chip-resistance
(German porcelain is fired at typically 1400°C, bone china and other
types of 'soft' porcelain at about 1280°C). Bone china is whiter than
German porcelain, which tends to have a very slight grey tinge, almost
imperceptible except when they're compared side-by-side, due to their
respective compositions.

Then you have the huge range of earthenware tableware, known as
pottery by the retail trade. Probably the most common and the
cheapest, as it uses cheaper raw materials than the previous two, and
is fired to a lower temperature, usually no more than 1100°C, and is
porous and less strong as a result. But so-called 'stoneware' is a
variety of pottery fired to a higher temperature, and is less porous
and stronger as a consequence.

Design also plays a part. What is known as hotelware is generally
thicker, heavier and stronger than domestic ware, because it gets
rather rougher treatment in use. One of the commonest modes of failure
is rim chipping, where the edges come into contact with other things,
are subject to very high impact stresses, and chip or break. This is
combatted by making the rims a bit thicker than the rest of the piece,
known as a 'rolled edge'. I can't believe that much earthenware is
made without rolled edges these days.

We have used Denby tableware for many years, and bone china for posh
occasions (increasingly rarely these days!), but I do recommend Denby
(I have no connection; I've not even visited the factory, and AFAIK
they don't use any materials from my former employer! They have their
own unique deposit of clay close to the factory, I believe). It's a
bit heavier than ordinary earthenware and is properly described as
stoneware. It's remarkably tough and chip-resistant (although like
most tableware, it will break if you drop it; DAMHIKT!) and comes in a
range of designs. https://en.wikipedia.org/wiki/Denby_Pottery_Company
and https://www.denbypottery.com/tableware


Wow...