AUTOMOTIVE | INTERIORS AND EXTERIORS
Right: Grivory G7V grades are designed to make technical components more economi- cal. From pearl white through neon colours to glossy black: Grivory G7V grades offer a high degree of creative freedom
which until recently could only be achieved with metallic materials. The improved creep resistance of both products allows lower wall thickness- es to be used, allowing cost and weight savings to be achieved, even compared to other metal replacement solutions. The company adds that Grivory G5V has been developed for applications at temperatures of up to 100°C. The stiffness of the material (measured as modulus of elasticity) in a conditioned state at 80°C is 45% higher than that of Grivory GV. This is due, among other things, to reduced moisture absorption, which also ensures improved dimen- sional stability. The improved stiffness at higher temperatures makes component designs with lower wall strengths possible, which is further facilitated by a 35% improvement in creep resist- ance compared to Grivory GV. This allows cost and weight savings to be achieved. As is usual for Grivory GV components, the mechanical properties of the product remain practically unchanged, even after conditioning (moisture absorption) and Grivory G5V is also easy to process using injection moulding methods. Grivory G5V has been de- signed for use in structural components in automo- bile interiors, such as instrument panel supports, air vents and seat shells, as well as functional components in mechanical engineering, furniture fittings and fastening elements, where the mate- rial’s stiffness at temperatures of up to 100°C and low tracking index are important. The company has also introduced Grivory G7V for high gloss metal replacement and a good surface finish. The new high-performance polyam- ide gives visible components a decorative and stylish finish that is also resistant to scratching and chemicals. In addition, Grivory G7V makes high- gloss surfaces possible for glass fibre-reinforced compounds. Glass fibre-reinforced Grivory G7V combines properties such as increased stiffness and strength, even after moisture absorption, with the chemical resistance of a Grivory GV and the high-quality finish of a low or non-reinforced polyamide. In addition, the new Grivory G7V products exhibit better UV stability than other semi-aromatic polyamides. The material is a new aliphatic high-performance polyamide with well-balanced properties, which enable cost-effi- cient production of lightweight components without any additional painting. The surface sheen of glass fibre-reinforced polyamides often misses the mark when it comes to visible parts because the surface is too rough or too uneven, adds EMS-Grivory. Partially crystalline
36 INJECTION WORLD | November/December 2021
polyamides contract during cooling, leaving sink marks on the surface and rough areas due to exposed glass fibres. Complex injection moulded parts therefore often have to be painted in a separate production step to cover critical areas. Grivory G7V has a melting point of 215°C and offers all the advantages of a semi-crystalline aliphatic polyamide, such as PA6 or PA66. Lower shrinkage and a reduced crystallisation
rate compared to PA66, make for a shinier, smooth- er, more uniform, and easier-to-clean surface, says the company. This makes it possible to produce a perfect surface finish using glass-fibre-reinforced material. In addition, the smooth surface also minimises friction noise and wear. The company says G7V also benefits from being a ‘genuine Grivory GV’ with reduced moisture absorption and comparable stiffness and strength in a dry and conditioned state. The new polymer glass-fibre system Grivory G7V significantly improves the finish of the surface while maintaining a high glass fibre content. Due to its delayed freezing behav- iour, it reproduces the mould surface perfectly without extending the length of the cycle. Another advantage of the aliphatic polyamide is its minimal shrinkage. This allows for the precise production of components, while the risk of ending up with a wavy surface (known as ‘orange peel’) is significant- ly reduced. Even the basic grade, Grivory G7V-5H (GF 50), low-distortion parts with a high-quality surface and an average roughness depth (Rz) of less than 1µm can be produced. Special X-types reduce distortion even further. Gloss and rigidity combined A high-gloss and uniform surface sheen defines the value and brilliance of a surface. Another required property is increased hardness of the surface to ensure the surface is scratch resist- ant. Grivory G7V combines these properties in one product. If a surface achieves a gloss value of greater than 70 at an angle of incidence of 60°, it is considered a high gloss surface. All new versions of Grivory G7V easily meet these requirements with a
www.injectionworld.com
IMAGE: EMS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
