Plungers, stems, plunger supports
 
Injection plungers

PLUNGERS MADE WITH COPPER-BERYLLIUM-COBALT ALLOY
Omnia Press produces plungers for die casting with Copper-Beryllium-Cobalt alloy (CuCo2Be) Werk 2-1285 according to the ISO 9002 and DIN 17666 standards. It is obtained via the MHD patented process, which foresees a homogeneous Beryllium spreading in Copper alloy. After hardening, the Brinnel hardness is the same throughout the whole piece. Forged bars, quenched and tempered to a hardness range between 235 and 250 Hb are used .

 
Chemical composition %
BE
Co
Cu
0.40 - 0.70
1.50 - 2.70
resto
 
Mechanical properties
Tensile strength
N/mm²
Yield strength
R. 0,2% N/mm²
Elongation %
HB hardness
5/250/30
680 - 830
550 - 670
10 - 25
230 - 250
 
Physical and electrical properties
Density
g/cm³
Coef. thermal exp.
Thermal conductivity
20-200°C cal/cm/cm²/s/°C
Conductivity %
IACS
Young modulus
N/mm²
8.9
17
0.47
>45
130.000
 
The plungers are mainly produced on client design and they are supplied, if required, with a testing and composition certificate.
Omnia Press develops its own plungers with a particular shape and with reduced thickness head placed on the plunger support.
Thanks to a special cooling circuit developed on the piston head, the plunger temperature is always low and it creates an aluminium neck which, being the first to become cool, makes a natural seal during the injection phase and cools the riser, thus allowing a faster press opening.
STEEL PLUNGERS
These plungers are produced with quenched and tempered steels:
  • Mechanical machining on numeric-controlled lathes;
  • Milling, if required;
  • Hardening and tempering in order to obtain a hardness value included between 44 and 48 HRC according to the user's needs;
  • Grinding on automated machines;
  • Surface coating with the formation of anti-seizure and anti-plating nitrides;
  • Dimension control;

If required, it is possible to obtain certification of steel, head treatment and dimension.

INJECTION STEMS AND PLUNGER SUPPORTS

Omnia Press produces the stems with high machinability steels, with good hardenabily, high ductility together with a high strength.
Together with the usual UNI C45 steel (DIN CK45, W NR. 1.1191, AFNOR XC48H1, AISI 1045) Omnia Press uses the construction alloy steel UNI 39NiCrMo3.

 
Name
UNI
DIN
AISI
Wnr.
AFNOR
39NiCrMo3
36NiCrMo4
9.840
1.6511
40NCD3
 
Chemical composition
UNI
C
Si
Mn.
Cr.
 Mo V
39NiCrMo3
0.32-0.40
max 0.40
0.50-0.80
0.90-1.20
0.15-0.30
0.90-1.20
 
Mechanical properties
Rm ( N/mm²)
Re ( N/mm²)
A %
Z %
936
814
16.5
56.7
 
Quenched and tempered steel bars are used and certificate by EN-10204 testing certificate (3.1B). The machining is performed with numeric-controlled machines in order to grant the required tolerance values. With particularly stressed stems induction hardening is performed in order to obtain a higher hardness level with anti- smashing functions in the area of contact with the machine injection jack head.
Omnia Press produces a plunger support with a cooling labyrinth in the plunger supporting area, a cooling chamber for the plunger skirt and a Viton OR which does not allow the water to reach the plunger fixing area on the plunger support.
In this way no limestone deposition is present on the screw threads and no problem arises during the replacement. As final heat treatment the surface is coated with a saturated oxide layer does not allow the limestone to obstruct the flow of the cooling water.
The whole injection system (plunger- spigot - stem) is supplied with water connections and special mastics suitable to avoid water leakages and unscrewing problems.
Omnia Press S.r.l.
 Via Olona, 116 - 21013 Gallarate (VA) - Italy
Tel. e Fax +39 0331 770503 e-mail:info@omniapress.it
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