Foam Rubber in the Home

New Zealand Journal of Agriculture, Volume 95, Issue 6, 16 December 1957, Page 615

Foam Rubber in the Home

By

MAUD B. STRAIN.

Home Science Extension Officer, Department of Agriculture, Dunedin A COMPARATIVE newcomer to the upholstery field, foam rubber is rapidly outpacing " ' the traditional paddings and fillings such as kapok, flock, horsehair, and feathers formerly used for the purpose. Foam rubber gives a trim, sleek look well fitted to.modern room settings and is, barring accidents, virtually indestructible. Like everything else it has its enemies; it is damaged by intense heat, strong sunlight, and grease and oil. But these are open adversaries, easily seen and guarded against, whereas the ruthless and voracious moths and carpet beetles which work in the dark and in secret have no effect on rubber.

■pOAM rubber is a soft, resilient “■ material made by whipping latex, the milk-like juice of the rubber tree, to a frothy foam and then moulding it into sheets which can be cut into shapes as desired or into permanent form. The foam sets into a honeycomb of minute interconnecting air cells held together, and supported by latex.

There are two types of foam rubber. One is cavity sheet, which is made up to about Agin. thick and which' is used ■ for : mattresses, car seats, seats and backs of chairs, and where deep upholstery is required. . The other is plain sheet, available from fin. up to in. thick and has a variety of uses. In upholstery- it is used for arm rests, occasionally on chair backs, and also

as stiffening strips to edge cavity strips where required. Foam Rubber and Sponge Rubber The terms foam rubber and sponge rubber are often used synonymously, but they refer to two different products. Foam rubber is made by whipping pure latex to a froth and baking it. It is made up of a honeycomb of interconnecting air cells which are open to .the outside air and which in use are continually expelling and drawing in air as pressure is applied or released. Because of this action good ventilation is assured, It also explains why, if foam rubber is on a solid base of either wood or metal, ventilation holes are necessary, in the base.

Sponge rubber is made differently; substances are added to the latex which make it “rise”. (This is similar to the action of baking powder in a cake mixture.) The whole is more or less filled with bubbles of gas. These bubbles are totally enclosed and do not communicate with each other or with the outside air. The more gas that is produced the greater will be the proportion of gas to rubber and the softer will be the resulting sponge. The required firmness of the product can be adjusted by the amount of raising agent used. In foam rubber the length of time of beating regulates the firmness of the product; the longer it is beaten the greater is the proportion of air to rubber and the softer it will be. Latex Chips Whipped-up rubber latex is poured into a mould and baked. The process is somewhat analagous to the making and baking of a sponge cake, and so is the result. It happens sometimes that a sponge cake is not a success, the middle part not being cooked properly. So it is with foam rubber. When this happens the unsuccessful centre part is chopped into small pieces known as latex chips. These are used in cushions and cot pillows and for other fillings. They are re-

silient and soft, but, unlike cushions of foam rubber, have no stability of shape beyond that given by the enclosing cover. Comfort and Durability If foam rubber is given proper care, it should last indefinitely. It is pure rubber which is extremely long lasting. It offers no feeling of resistance to weight. Pressure is equalised at every point of contact and there is no “pull” to where the weight is greatest; in other words it conforms to the body contours. It is not inflated, there are no springs to break down and give trouble, it it cannot sag, become matted or lumpy, and never requires remaking, it does not form dust or fluff, and it is proof against vermin, moths, carpet beetles, damp, and mould. Being porous it “breathes” through its innumerable air cell's and use automatically keeps it always aired. Foam rubber pillows are especially recommended for sufferers from hay fever, asthma, and all dust and feather allergies, because they do not create dust. There are those who find foam pillows not sufficiently compressible, but some pillows are softer and less springy than others and a little time spent searching for the right pillow is well worth the effort.

Another advantage is its use in the sick room. It is the most sanitary cushioning material available as well as being comfortable, durable, hygienic, dust free, and moth resistant. Beside its use for mattresses, pillows, cushions, and upholstery, it also forms an ideal underlay for carpets and stair treads, and insoles for shoes, shoulder pads, kneeling pads, and toys and other modern applications. Because of its inherent durability it is the most economical cushioning for upholstered furniture, especially since it retains its shape and resiliency throughout its life. Furniture fitted with foam rubber always looks shapely and inviting, and when covering fabrics have to be renewed the clearly defined contours of the foam rubber make re-covering comparatively simple. In sheet form and bonded on to some fabric such as hessian, foam rubber provides a highly resilient underlay for carpets and rugs. It lifts the carpet from the floor, protecting, it from wear and giving it longer life. The initial expense is high, but it should be regarded as a lifetime investment. It can be put down without tacking even in small pieces; pieces can be joined easily with adhesive tape. It can be removed and reinstalled without difficulty and is easy to clean.

Precautions in Use That foam rubber is long lasting is proved by the fact that mattresses that have been in use constantly for 15 years still look and act as if they were new, but care must be taken to avoid the few things that are harmful to it. Strong sunlight and. extreme heat both cause deterioration as do oil, grease, tar, and some dry-cleaning fluids.

In practice foam rubber in the home (except in small articles like toys and kneeling pads) is almost invariably covered. Mattresses usually have a strong cotton or cotton-rayon damask cover; upholstery such as seats, divans, and cushions are covered with some furnishing fabric; and shoulder pads and other lingerie accessories are encased in fabric.

Rubber upholstered furniture should not stand in strong sunlight for any length of time. A chair or seat intended for a sunny window either on the sunporch or in a room should not be upholstered with rubber.

Any oil, grease, or tar spots should be removed immediately with warm water and mild soap. If the spots are stubborn, a dry-cleaning fluid will have to used, but it must be used carefully, as these fluids soften rubber and vigorous action could cause permanent damage. The fluid should be wiped off immediately its work is done and the area sponged over to remove all traces of the cleaner. Foam rubber furniture should not be very close to a radiator or to steam pipes, and if' any rubber article is being stored, a dark, cool place is ideal. . Any accidental cuts or tears in mattresses or other foam rubber can be mended with rubber cement. Working with Foam Rubber The ease with which foam rubber can be used by amateurs for rejuvenating upholstered furniture makes almost any upholstery job possible. Working with foam - rubber requires little more than the. ability to use shears and to spread rubber cement.

A paper pattern of the shape to be cut is essential. This is placed on the foam rubber and its outline traced round with a ball-point pen. Shears dipped in water are used for cutting.

To give a good fit under compression each piece should be cut just a little bigger than the pattern. For smaller pieces about tin. all round is sufficient and for bigger cushions about gin.; for a full-length settee Ijin. will be necessary.

Foam rubber can be used over a solid base such as wood or metal, provided there are ventilation holes through which air can escape when pressure is applied. The foam rubber

is held in place with tacking strips or it may be cemented on to the base and the whole covered with a tackedon cover. In re-upholstering sprung furniture the original coil springs are readjusted and tied to keep them in position and are then covered with hessian or unbleached calico. This lessens wear on the sheet of foam rubber, which is placed on top and attached to the framework with tacking strips. A thicker foam rubber can be used similarly on top of canvas webbing. Cementing . There need be little waste of foam rubber because offcuts can be cemented together to make a piece of the desired shape or cemented to a solid base, or a tacking strip. To join foam to foam, rubber cement is brushed over both surfaces and left about 5 minutes to dry. The surfaces are then carefully brought together. Any accidental cuts can be mended in this way. Use of Tacking Tape Foam rubber should never be tacked directly; tacking tape is, used. . Tacking tape can be made at home by applying rubber cement along . one side of strips of unbleached calico, letting it dry, then cementing it to the foam rubber which has been

brushed with cement and allowed, to. dry until it is tacky. The tape is pressed into place lin. in from the edge of the foam and the uncemented half hangs free and can be tacked to the framework of the base. Edging For a square edge tacking tape is attached to the vertical edge of the foam rubber and the overhang is tacked to the base. For a rounded edge the foam rubber is cut in. oversize all round. Edging tape is cemented to the top surface lin. in from the edge. The vertical edge is. tucked under, so it lies against the base, and the tape is drawn down firmly and tacked in place. Covering When covering foam rubber with a fabric cover it is advisable to make the cover just a shade undersize, so that when the fabric has stretched in use it will be a neat fit. Tacking strips can be cemented to the foam rubber and then stitched to the cover to prevent slipping. If a plastic cover is being made, especially one that does not have a cloth backing, it is advisable to make an undercover of unbleached calico; otherwise the plasticiser in the cover may transfer itself to the . rubber, leaving the plastic stiff and brittle.