Low expansion super white fritware body

*This is not a vitreous porcelain at low fire, but it is strong and very white burning, the whitest we have ever seen. We are using it across a wide temperature range to discover possible uses.

To achieve low thermal expansion, Ferro Frit 3249 was used (Fusion Frit F-69 is an equivalent). A mix of alumina and wollastonite instead of silica. This sacrifices maturity compared to Zero4 porcelain. Glazes will craze on this, so it must be used in applications that do not require glazing.

Casting pieces were fairly stable at cone 6 with good translucency. Cone 7 and 8 did not improve translucency but are warping progressively more

This has remarkably low fired shrinkage (e.g. 3.5% vs 10% for the Zero4 body). This fact, combined with its lesser degree of vitrification means that fired warpage should be less of a problem.

This is not quite plastic enough, 4% Veegum is likely needed. Extreme high-speed propeller mixing is needed to break up agglomerates and wet all particle surfaces.

Joe: May 24/22 measured bar specimen #4 which already has values.
Current values Joe recorded were:
Fired length was 91.15 mm.
Fired weight was 40.91 grams
S.S. cone 4 down and touching shelf but not badly deformed so entered value of cone 4.0+ for other bars fired at the same time.

L4498 3249 porcelain vs Polar Ice fired bars

This fires much whiter than Polar Ice, the whitest porcelain we can make using silica and feldspar.

L4498 with Spectrum 700 glaze at cone 06

Crazing badly so this is definitely a very low expansion body. Spectrum 700 is the lowest expansion common glaze we have found, if it does not fit nothing will.

L4498 Low Expansion Porcelain fired bars

This has a very stable fired shrinkage across the entire range of testing. Total shrinkage is amazingly low given the strength.

L4498 cone 6 vs L3924J cone 02

The Zero4 at cone 02 is much more translucent but not nearly as white.

L4498 Low Expansion Fritware fired bars

Testdata

SHAB - Shrinkage/Absorption

	DLEN	FLEN	FWT	BWT	CONE	DSHR	FSHR	ABS
6	94.26	91.69	37.82	Bloating	6.0	5.7%	2.7%
55	94.25	91.33	39.59	40.19	5.0	5.8%	3.1%	1.5%
44	94.35	91.15	40.91	42.59	4.0	5.7%	3.4%	4.1%
4	94.35	91.03	40.95	42.17	3.0	5.7%	3.5%	3.0%
2	94.7	91.26	40.99	41.5	2.2	5.3%	3.6%	1.2%
1	94.71	91.55	38.85	40.61	1.0	5.3%	3.3%	4.5%
3	94.4	91.16	41.58	42.21	-1.0	5.6%	3.4%	1.5%
5	94.25	90.83	39.69	40.43	-3.0	5.8%	3.6%	1.9%
7	94.34	90.98	37.81	39.17	-5.0	5.7%	3.6%	3.6%
8	94	90.34	37.58	39.82	-6.0	6.0%	3.9%	6.0%

APD - Apparent Density

	LEN	WID	HT	WT	CONE	DENS
1	99.61	22.55	9.7	41.58	-1.0	1.91

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Low Expansion Super White Cone 6 Fritware" id="213309" key="psfwdjsb" date="2022-09-15" codenum="L4498"> <recipelines> <recipeline material="New Zealand Kaolin" amount="40.000" tolerance=""/> <recipeline material="Fusion Frit F-69" amount="20.000" tolerance=""/> <recipeline material="Calcined Alumina" amount="20.000" tolerance=""/> <recipeline material="Wollastonite" amount="20.000" tolerance=""/> <recipeline material="Veegum" amount="3.000" added="true"/> </recipelines> </recipe> </recipes>

Born: 2022-02-28, Modified: 2022-09-15 22:56:48