This article originally appeared in the July 1924 edition of the IBICC journal
VISIT of the l.B.l.C.C. to the Works of THE AERONAUTICAL PLYWOOD COMPANY.
By the kind invitation of the Company; Wm. Mallinson, Esq., J.P., and W. J. Mallinson, Esq , J.P., a large party of our members visited the modern factory of The Aeronautical and Panel Plywood Co, Ltd, in Kingsland Road, Shoreditch, EC, on Saturday, May 3rd 1924.
The visit proved to be most interesting and instructive, and the pleasure was heightened by the courtesy of the general manager, E. Roberts, Esq., who personally explained the processes and spared no pains to satisfy the thirst for information, which the many interesting exhibits developed among the visitors. He was ably backed by his staff, who demonstrated the capabilities of the many specially constructed English and foreign machines, which were put into operation for the benefit of the party.
The factory is a modern six-storey ferroconcrete building.
The ground floor contains the glueing and press room. Here the glue mixing machine is situated in a convenient position for the presses. After the boards are built from the required number of veneers, they are placed on tables near the presses, and then stacked in the presses themselves, where hydraulic pressure quickly squeezes out the surplus glue. A stack of one and a quarter inch ply boards was in the cold press under pressure for the weekend; they were to make engine beds in aeroplanes. One of the features of this room is a large hot plate press, with two rams 21 inch diameter, which is capable of developing a total pressure on its plate equal to 600 tons.
It is fitted with a number of flat steel plates heated by steam. The ply boards are stacked between these and are subjected to heat and pressure at the same time. They are finished more rapidly by this combination, and therefore more boards can be passed through the press in a given time.
The fluid under compression, for working the pressure, is obtained from a large hydraulic accumulator, either direct or through an intensifier, when extra pressure is needed for special work. These were shown to the party, and their method of working explained.
One press in this room is large enough to deal with boards up to 16 ft. x 5 ft-.; it has specially adapted tables for dealing with large sheets. Specially shaped forms and blocks for building up work of double curvature, such as motor car tops, were seen, and some of the work from them was available for inspection. Nearby, was a machine with heated rollers for burnishing and drying veneers. By means of a lift as large as a good-sized room, the party was raised from floor to floor. This lift must greatly facilitate the movement of stock for the various operations; it can raise three tons. The party was shown into a room fitted up like a flourmill. The machines were for treating casein, which is the chief ingredient in the adhesive used in the manufacture of the ply panels. The process of preparation was carefully explained by Mr. Roberts, and the motor was switched on to show the plant in operation, and incidentally, the dust which may arise if it is not operated with care. The composition of the glue was then imparted as casein, plus water; a member of the party added “ experience.”
On another floor some large partitions were exhibited; these were faced with burr walnut and other fancy woods. The method of building the cores to obtain flat and permanently reliable surfaces was shown. American chestnut planks were sawn into strips, carefully dried, and then glued together to make a flat panel; this was faced, and then covered with veneers, one or more under the final face of fancy wood.
A very interesting machine for making the edge key joint for foundation strips was shown, and its method of working explained. The firm take a pride in ensuring that their productions are of first class quality. They have installed drying kilns for the purpose of thoroughly seasoning and drying stock and finished work.
These large rooms have means of controlling the temperature and the moisture of the air circulating in them. The three-sixteenth inch ply boards take about one week to complete, in a temperature of about 140 degs. F., other thicknesses in proportion. The boards were shown in position in stacks, carefully packed with drying strips. Machines are installed for trimming the edges of long veneers to make a joint which is almost invisible on the face. Two sheets are clamped on a guided table, which moves past a small circular saw, making about 3,000 revs per minute. The sheets then pass to an adjacent machine which joins the sawn edges and glues a paper strip over them. These machines are marvels of ingenuity for ensuring accurate work and for labour saving. The great pains taken to obtain really good work is shown in the installation of a re-drying machine; this large construction is fitted with hot plates of considerable area which work in pairs. Buckled veneers (the buckling signifies that moisture has been absorbed) are placed between the hot plates which alternately squeeze and release the veneers to cause a circulation of air and so thoroughly dry and flatten the sheets ready for glueing up. A small, well-equipped testing laboratory was also shown, together with tested specimens.
The glue mix is used for only 100 panels, a fresh lot being prepared for each batch. A sheet is selected at random from each batch, and the test pieces are cut from it, together with samples for records.
The tests consist of a tensile test on a strip, a dryness test, a moisture test, and a boiling test. Full records are kept, and it is possible to tell the date of manufacture, the mix of the glue, the men responsible, and other details from the records.
Those who visit Wembley Exhibition should look out for some very fine veneered panels in the Government building the Palace of Industry, and other buildings, the products of the Company’s associated firm, Wm. Mallinson & Sons.
A fine three-roller sander is installed for finishing the ply boards and panels; this was shown in operation, and the excellent suction plant for dealing with the resultant dust demonstrated its efficiency.
Plywood panels to size are a feature of the Company’s business; piles of these were shown, in various stages; they included many sizes and shapes. The marvel of the factory is a birch plyboard of three laminations, the total thickness being eight-tenths m.m., for use an aircraft.
A specimen board was exhibited which had been boiled for 15 minutes; it was a three layer plyboard, which had spent I3 months in cold storage, with the temperature‘ 30 degs. below Zero, and had then been on the roof in tropical and rainy weather for two months. This was a sample of the firm’s standard production “ Mallite.” They manufacture sheets up to 192 ins. by 86 ins., to any thickness from one-thirty-second of an inch. These can be fireproofed.
A cordial and hearty vote of thanks to Messrs. Mallinson, and Mr. Roberts and his staff of capable assistants for their kindness and courtesy terminated a very instructive and pleasant afternoon’s visit.
This article first appeared in the British Institute of Certified Carpenters Journal July 1924. We then reprinted it in the June 2014 issue of Cutting Edge. As part of the IOC membership, IOC members receive quarterly editions of Cutting Edge magazine and access to all back issues online.
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