Effective production of large, extremely stressed plastic parts with the possibility of very different wall thicknesses
What is NYRIM ?
NYRIM® is a polyamide-type polymer system characterized by extraordinary toughness, stiffness, high abrasion resistance, low coefficient of friction, excellent resistance to breakage and very good chemical resistance.
Chemically, NYRIM is a block copolymer of type A-B-A based on polyamide-6 and polyether. The individual segments are chemically bonded, which contributes to the optimal combination of copolymer properties.
Nylon-6 ———-> elastomer phase ———-> Nylon-6
NYRIM is not a single polymer designation. By varying the ratio of the inlet components of the formula, the amount of elastomeric phase in the final product can be varied from 10% to 40%, thereby fundamentally changing the material properties.
The properties of the product can be further modified by various additives such as fillers, lubricants, flame retardants, atmospheric protection systems and the like.
The recipe composition variability described makes it possible to adapt the properties of the polymeric material to a large extent to a particular application and customer requirements.
An example of NYRIM properties at standard temperatures is given in the following table:
|notched toughness Izod||kJ/M2||35|
(*) N 1000 is the designation for the NYRIM non-filled material containing 10 wt.% of the elastomeric phase. Conditioned at 23 ° C-50% RH.
All types of NYRIM can be recycled by grinding and granulation. The granulate thus obtained can be processed on conventional injection molding machines suitable for injection of polyamide. With proper recycling, the properties of the recycled and original material are very close.
How is NYRIM processed?
NYRIM material can be processed by all common reactive technologies. Promens uses RIM (Reactive Injection Systems), RRIM (reactive injection molding systems, SRIM – Structural Reactive Injection (injection of mass into reinforcement molds – eg glass fabric) and reactive casting technology.
The essence of reactive injection is spraying the monomer mixture (final formulations) directly into the mold, where the polymer blends under specific conditions. Upon completion of the polymerization, the finished product is removed from the mold. For the NYRIM system, the accompanying conditions of this process are very low viscosity of the sprayed material at a temperature below the mold temperature. Unlike conventional injection molding where the viscous polymer melt is injected with high pressure into a mold much colder than the melt temperature, NYRIM technology uses only low pressure to transport and mix the reactive components, making it possible to produce large parts (tens of kilograms) on a relatively small device, and use light molds. Since a monomer (not a polymer) is injected into the mold, there is practically no internal tension in the products or so-called “cold bonds”
Material properties of the NYRIM system in terms of application options
The most valued feature of the NYRIM range is the extraordinary toughness that can, in addition, be controlled to a wide extent by the elastomeric content – in practice only by changing the ratio of the ingredients of the recipe. Furthermore, NYRIM has a high abrasion resistance, low friction coefficient, excellent resistance to breakage, and very good chemical resistance. Because of its water absorption, NYRIM has a limitation for very precise products.
Thanks to the ability to accept large filling contents, the properties can be further modified. Examples are non-flammable formulations, materials with high resistance to weather, materials with reduced friction coefficient, etc. Due to the possibility of dosing large quantities of fiber fillers, NYRIM can produce parts with controlled anisotropy properties.
Within RIM systems, NYRIM is unique in its ability to be dyed in the mass without the need for additional painting. If necessary, however, it is easy to paint.
Significant is its use in products with strict recycling requirements – NYRIM is easily recyclable.
Specifics of RIM in terms of NYRIM application options
NYRIM’s reactive injection system enables large, non-residual products to be manufactured, products with large and / or different wall thicknesses and various filler contents. Since the liquid reactive components are impregnated at low pressure, much cheaper forms can be used for production than are necessary for conventional systems. The low viscosity of reactive components allows excellent mold surface reproduction. The total investment costs for a technology unit are significantly lower than for conventional systems, with the possibility of producing larger and more complex products. The production of large parts can be economical already in small series of about 1000 pieces / year. For medium production series, ie tens of thousands of products per year, the competitiveness of this technology is the highest. For smaller products, it is common practice to place multiple products in one mold.
Summarized from the point of view of technology, NYRIM is best suited for large, thick-walled mid-range products.