NNPB and wide mouth plungers for glass container manufacturers.
VIDREMOT manufactures NNPB and wide mouth plungers with a wide range of coatings suited to our customer’s needs. All coatings are applied using the HVOF process.
We have a complete laboratory where we analyze all the materials used in the manufacturing of the plungers:
• Each lot of steel is certified not only by our suppliers but also by our lab so we can assure it fulfills the strict specifications of our materials.
• We know our powder suppliers check the composition and hardness after welding a sample, however their welding process has nothing to do with the actual processes used in manufacturing plungers. We check each lot of powder after spraying a sample plunger with our HVOF equipments so we know exactly how that powder will behave when we spray our plungers.
• We blend our own powders. Again we adjust our blends after spraying a sample plunger so we can assure that our blends have the exact specifications of our standards. We are able also to blend powders with specific requirements from our customers.
We use the best spraying systems available. In 1995 we installed our first HVOF equipment, and since 1998 all our plungers are sprayed with hybrid HVOF equipments. The low temperature of the flame (2600 ºC) together with the high kinetic energy (particles travel at a speed of 400-1000 m/s) gives us the following benefits:
• High carbide integrity although we are using very fine carbides (1-3 microns).
• Low oxidation.
• Dense and well bonded coatings.
After spraying the coating has to be fused. The fusing can be done by induction heating or by an oxy-acetilene flame.
Although it is a more expensive process we have choosen the second as it gives a better quality of the coating (no carbide degradation specially on the tip, no contamination from the base material, better control of the fusing temperature).
With fusing you obtain:
• Adhesive strength (> 80 MPa), we change from a mechanical bond to a metallurgical bond (interdiffusion).
• Cohesive strength: nearly 0% porosity, B and Si dissolve oxide to form borosilicates, uniform distribution of phases.
• Stress relieving.
After 30 years manufacturing plungers we have developed strict machining processes to achieve the high precision that is required by our customers. Only giving high attention to the small details we can offer our customers the best plunger in the market.
With our processes we can assure:
• Perfect concentricity of the wall thickness in all the length of the plunger.
• Uniform coating thickness. This uniformity is very important to obtain a perfect temperature distribution in the plunger while in production.
• Very good perpendicularity.
• Achieve the strict tolerances required by our customers.
Plungers are high precision parts and as such we treat them:
• 100% of our plungers are dimensionally checked.
• 100% of our plungers are visually checked to assure they have a perfect polish and no surface defects.
• Every plunger is individually packed and protected. We have the best plunger packaging in the market to assure that no damage is done in transportation.
So, why use second-class plungers when you can afford the best?