Comparison and Selection of Raw Materials in Lost Foam---White Area!

Jun. 03, 2019

Comparison and Selection of Raw Materials in Lost Foam---White Area!

Comparison of EPS-FD Series and EPS-H Series

STMMA-FD: bead spec., particle size, foaming odds
bead spec.	particle size	foaming odds
1	0.6-0.9mm	45
2	0.45-0.6mm	35-45
3	0.35-0.45mm	30-45
4	0.25-0.35mm	20-30
STMMA-H: bead size, particle size, foaming odds
bead spec.	particle size	foaming odds
H-MS	1.2-1.8mm	70-85
H-SA	0.9-1.4mm	60-70
H-SB	0.7-1.1mm	50-65
H-S	0.5-0.9mm	35-50
H-4S	0.3-0.6mm	20-35

Comprehensive properties comparison of STMMA, EPS and STMMA-FD

Item	Unit	STMMA	EPS	STMMA-FD
composition		[(H802)*(C8H8)y]m	[C8H8]n
carbon content	%	62	92	82
Tf	℃	85-95	80-85	83
decomposition heat	℃	-863	-912	-900
gas evolution(900)	ml/g	800	600	650
casting temperature(gray iron housing)	℃	1450-1420	1500-1460	1480-1450
pattern decomposition residuum		few	a lot	a few
pattern quality		bead: uniform in size pattern: good consistency	bead diameter: wide range	bead: uniform in size pattern: good consistency
pattern contraction	%	0.1-0.3	0.3-0.5-0.8	0.2-0.4
castings yield(housing, motor casing)	%	medium and high-end product≧93%	<80%-92%	≧93%

Comparison of the pattern residuum by combustion decomposition

Bead Name	Weight of the Pattern(g)	Weight of the Residuum(g)	Residuum Percent (%)	Pattern Density(g/l)
ordinary EPS	3.37	2.22	65.9	21
STMMA-FD	3.37	1.03	30.6	19
STMMA	3.37	0.15	4.45	20

STMMA-FD bead (LFC special material) is a new material modified based on EPS according to the property of copolymers. Its carbon content?is 82%. Compared with EPS, the carbon content decreased to a certain extent. Due to the superior properties of the material, the decomposed residues during pouring and casting are about 20% lower than ordinary EPS.

It is widely used in the mid-low-end castings production, like aluminium?alloy and gray iron motor casing, housing, pipes, pumps, valves, etc.

STMMA-FD (LFC special material) Advantages

1. Using FD beads, the castings have few carbon defects (the original beads contain less carbon).

2. Using FD beads, pattern decomposition gasification residue is little during pouring and casting.

3. Using FD beads, the pattern dimension stability is good (The molecular weight of the original beads is slightly higher and the size shrinkage is smaller).

4. Using FD beads, the quality of original beads is guaranteed(we specialize in the production of beads for lost foam casting models and have a complete set of inspection, testing equipment and quality management system from original beads to pattern molding).

5. Using FD beads, making patterns is energy-saving, high-efficient and low reject rate.

6. Using FD beads, the rate of finished products is high, the comprehensive production cost is low(the superiority of the raw material, excellent after-sales service and complete technology concept make the rate of finished products improve above 5% and the comprehensive cost drop by more than 200 yuan/T, compared with using ordinary EPS beads).

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