New directions in multi-component injection moulding

THE growing popularity of multi-component injection moulding has been encouraged by the increasing demand for technologies capable of handling multi-colour and multi-materials processing.  Direct beneficiaries of this are the consumer, automotive, packaging, and other markets where sophisticated processes require machines that can handle a combination of functions effectively and cost-efficiently. 

The Texen Group, one of the largest global manufacturers of plastic packaging for cosmetic and perfume products, recently commissioned a KraussMaffei injection moulding machine for a wide range of technologies. With sales of nearly 170 million euros in the last fiscal year and almost 1,000 employees, Groupe Texen is one of the major companies in this market segment. The company manufactures injection-moulded plastic packaging and screw-cap closures at eight locations in Europe, North America and Latin America.

The multi-component machine from KraussMaffei’s CX series is equipped with many refined procedural and mechanical features that Texen finds useful in increasing its flexibility in the development of injection moulded packaging. Texen started producing innovative plastic packaging for premium quality cosmetics and perfume using a CXZ 160 – 380/180 hybrid, with a LRX 100 side-entry robot. It has a 1,600 kN of clamping force featuring an extensive equipment package.

 

Effective system operations

The CX hybrid series combines the benefits of a fully hydraulic clamping unit with those of electrically driven injection units. This series is characterised by low energy consumption and high power density. Each shaft of the injection unit is electrically driven separately so that the mould can be opened and the ejector activated, even during the plasticising phase. Shot weights up to about 140 g of polystyrene can be produced with the large injection unit.

The CX Hybrid from KraussMaffei

The machine is also designed for the injection of multi-component parts using a sandwiching technique and is equipped for moulds in index implementation. Furthermore, physical foaming (MuCell) is possible with all components. It also comes equipped with control system interfaces for essential processes for achieving high-end surfaces, such as in-mould decoration,

SkinForm/ColorForm, DecoForm or Coverform.

The Dynamic Mold Heating (DMH) system from KraussMaffei is an integral part of these technologies. It separates the temperature control circuits in moulds and creates a dynamic temperature profile in the mould. This innovation minimises the masses in need of heat-balancing in the mould-halves and does not allow the mixing of the heating fluid with the coolant, which ensures effective operation of the system. Furthermore, the machine is equipped with interfaces for gas injection technology and the processing of liquid silicone (LSR).

Electrically driven index drive behind the ejector plate saves space

Adding functionality and design quality

The combination of several plastic materials with different attributes and/or different colours into one component in a single cycle with integrated downstream steps, such as bonding, assembly and screwing, opens up new dimensions in product properties with simultaneous cost-efficiency.

Wittmann Battenfeld know-how includes all process variants such as multi-colour, composite, assembly, multi-component and sandwich injection moulding. The company’s multi-component COMBIMOULD series offers packages for all types of multi-component technology with an extensive range of optional extras and a great variety of combinations. This allows optimal adaptation of the machine, mould and automation technology to every individual product.

The series features highly accurate clamping systems with linear guides and high-performance injection units which can be freely selected and combined. The servo-electric rotary table technology ensures fast and accurate positioning of preforms. Independent, parallel, high-performance injection is achieved from all injection units through the flexible drive concept based on electrically adjustable twin or triple pumps.

The COMBIMOULD series is available in 3-platen technology with clamping forces ranging from 45 to 300 t, and in 2-platen MacroPower technology from 400 to 1000 t clamping force.

High flexibility is achieved by simplicity of installation and removal of the rotary unit. Where necessary, the unit can be deactivated via the control system. This shortens changeover time. Optimal operator and mould safety are ensured by damping of the end-position control and the indexing device.  Nike Special Forces Air Force 1 Boots