Robotised line doubles packing insulation capacity
What very few readers know is that Isomo stands for ISOlation Modern. It is a well-known brand of expanding polystyrene plates and in Belgium a generic type name is called Styrofoam. The production operation of the Isomo plates is located in Kortrijk, it was launched in 1956 and is still under the ownership of the Vereecke.
Isomo sells forty percent of its production in Belgium. Next comes France, an important outlet and a potential growth market, where the opportunities are in the small formats. This market saw quick growth last year and needed to be availed of as quickly as possible.
The problem was that the existing packing insulation line became a bottleneck for small formats and thus was not conducive to play there and earn money. But initially the working was with man and power to do the semi-manual packing quickly, so one could tap into the new market.
Since August 2011,
a new robotised line has been in operation that can handle small formats quickly and profitably. Besides doubling of the packing insulation capacity (given that this was the bottleneck), thus also the production capacity, this department could go
from three to two shifts. The result is that with this investment of half a million Euro, the rising market in France translates into significant business results.
Industry Technical & Management had a discussion about this new robot installation with Thierry Vereecke, managing director and Dieter Werniers, technical executive of Isomo, with Hans Van Essche, deputy director and Jelle Parmentier, project engineer of Fraxinus (the designer and builder of the new packaging line), and with Peter Kiekens and Annelies Vander Hulst of FANUC (the robot supplier).
Production of Isomo plates step-by-step
The raw material for polystyrene plates is expanded polystyrene. This component is an invention by BASF dating back to the 50s, but since the patent has expired, it has been brought to the market by various companies. There are two basic types: the white pure polystyrene and the black polystyrene with black carbon inclusion. This latter has better insulating properties (also sound insulation). Depending on the final properties, additives are added in the polystyrene (e.g. for making fire-proof types).
Step 1: injecting steam into a silo to larger polystyrene beads
The basic product that is supplied is
micro cells of the size of powdered sugar with an outer wall in polystyrene and pentane gas as blowing medium). When heating, the blowing medium can make
cells expand up to fifty times, wherein air is sucked into the cells.
That powder is expanded in a first batch production step by
injecting steam into a silo to larger hollow polystyrene beads, where the size of bead is a function of the steam that is supplied during expansion. The level of expansion that is realised in a function of the density that the future plate is to have.
After an initial forced drying for a specific time, these beads are stored in storage silos for further processing.
Step 2: bringing beads into a mould
In a second step, the correct weight of beads is
brought into a mould from the storage silo by air transport.
These beads are again
further expanded by air injection. Due to the limited volume (the mould height has a size of 6 x 1.2 m x 1 m), the expanded beads are pushed against each other and they
melt together to a homogeneous block containing a lot of air (around 95% of the volume), retained within the mutually adhering, closed polystyrene bead. This block insulation material is
stored on different days in the stores, until the whole reaction has completed.
Step 3: cutting the block
The third step is the
cutting of the block and it happens in three stages:
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First by density: a broad variation of densities as function of the client and the adaption, by single mm (for insulating wall paper) to some tens of cm thick (for example for wall insulation). Mostly one would try to maintain the same plate thickness for handling or restrict to the maximum three thicknesses. Consequently in the desired width (normally 1.2 m or 1 m and since recently 0.6 m).
- At the last work post, the correct lengths are cut, earlier mainly lengths of 2 m, now also increasingly a variation of lengths from 33 cm. This cutting is done mechanically using pre-stressed copper wires, which are heated using their electrical resistance.
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One thus melts the taut wire through the block, simultaneously sealing the cut layer and giving a smooth surface. Setting of the position of the wire is done manually.
The blocks go via a controlled transport conveyor through the three work posts and are automatically cut.
Final step: packing and handling insulations
Earlier, the plates were mainly of 2 m length (often used as cavity wall insulation), and for packaging these (with a plastic film to facilitate carrying a number of plates) by the end of 80s a machine was purchased.
The cut blocks are transported using a transport belt to the
packing insulation machine. The plates are unloaded there and placed on the foil machine manually; the foil is wrapped around it and welded. The packets are then manually picked up and placed on the pallet.
France, an important market for do-it-yourselfers, requested smaller plate sizes and smaller insulation packages. Adjustments such as renovation and wall insulation also use smaller plate sizes. Where one pulled out a cadence for the large plates of 60 sqm/ hour, this speed decreased for small plates to only 30 sqm/ hour. This ensured that the cutting machine had to mostly rest. In other words,
the complete production output dropped too drastically and the cost price of the small formats became too high, so one could not calculate the sale price.
In order not to allow this market to lie low, it was decided by end of 2010 to
set up a specific line for the smaller formats. Via Desco, the supplier of the first packaging machine which was found very satisfactory, Isomo came in contact with Fraxinus. He designed and built, based on Seco packaging machine, a
robot installation with which one could pack three thicknesses together.
