Planning & Mix Preparation
Capabilities colours mixing routes rendency, temp control, trendview, lot traceability, volumes, full QA on every batch. All quality records held in perpetuity.
Our computerised planning and scheduling system is key to our ability to handle a wide variety of mixes quickly and efficiently. Once an order is received, and stocks checked, the necessary weighing, mixing and finishing processes are scheduled and displayed on our production office screens so that order progress is visible to all.
Careful ingredient preparation is essential for a high quality mix; the weighments control system delivers full lot traceability, and enables time between weighing and production to be minimised (thus reducing the scope for contamination or error) . It also ensures that relevant health and safety information is available to operators at the point of use.
Pre-warming facilities are available for polymers, to improve mixing consistency, and all polythene wrapping is removed before mixing.
Carbon black storage uses a hopper and bin system for each grade; there is no common pipework which could produce cross contamination.
Small chemicals are stored in temperature controlled cabinets to eliminate problems with moisture pick-up.
All stock items are dated and re-checked as required to ensure compliance to specification.
Internal Mixing
The company runs 3 Banbury internal mixers for production (2x 50l, 1x12l).
The mixing shops are designed to ensure that conditions can be optimised for every mix. The “masterbatch /colour” and “dedicated fluoroelastomer” mixers use dry PEEK seals, to eliminate oil contamination and aid cleaning. Air cooling is available for all compounds, as we use a number of cure systems where moisture control is a critical factor. Automated take-off to produce slab or strip is also available.
All mixers are fitted with Trendview recording software; temperature, power input, rotor speed, ram position and oil injection times are recorded for every mix . Information from this system together with information from the weighments system, rheology data and laboratory test results are stored in the company database to give a complete overview of the mixing process for every compound.
Extensive use is made of 2-stage mixing, where this can enhance compound consistency, and an invertor is used to ensure that the 1st batch of a first stage will also be the first batch of a second stage, ensuring consistency of dwell time.
Dispersion is measured for all new mixes, using a dispergrader, so that mixing routines can be adjusted where necessary to achieve optimium dispersive and distributive mixing of carbon black and other fillers.
Mill Mixing & Finishing
The mill room contains 5×60” plus 1×40” mills, with a range of friction ratios to suit different mixes and processes.
A large part of the work carried out is the second staging of internally mixed compounds; examples of products where this approach is particularly beneficial are hard, fast curing, fibre filled nitriles ( as used in down-well applications) , and very soft compounds, where cooling followed by a second breaking down stage may be required to achieve optimum dispersion.
Traditional open mill mixing is also used for small batches, coloured compounds and for “hard to handle” compounds, when appropriate. Where this requires the use of masterbatches (due to, eg, high levels of black in the mix), these are produced in-house to ensure quality.
Mills are fitted with trendview recorders to monitor power input; these mixing profiles are stored together with weightment, rheology and lab testing data to provide a complete overview of the mix.
Compounds can be supplied in sheet, strip, in barwell blanks to a given weight, or in pellet form (suitable for solvation work).
Silicones & Perfluoroelastomers
Silicones (VMQ), Fluorosilicones (FVMQ), Phenylsilicones (PVMQ) and Perfluoroelastomers (FFKM) are mixed in a separate building, in positive pressure clean room environments.
Silicone facilities include a Z-blade mixer (for mixing special additives, eg fine particulate metals) , and a custom designed mill, with variable speed and friction ratio. This enables it to be operated without using the traditional scraper blade- a potential source of contamination. The specialist bearing system prevents oil loss, and interchangeable nylon stock guides are fitted for ease of cleaning.
Colour matching is a speciality, and the colour of every batch is verified by spectrometer before dispatch.
All silicone compounds are heat sealed into polythene bags before packing for transport.
FFKM is produced in a separate clean room, and the mill is adapted to mix batch sizes from 200g to 1kg. All compounds are vacuum packed into foil bags.