Jugs have quite a complex shape, and hitherto moulding them in one piece has been considered impossible, or at least just not economic in view of the elaboration of the mould. It is the aim of this invention to offer a practical way of making a one-piece jug.

According to the present invention there is provided a method of manufacturing a jug wherein, in a first stage, a preform is moulded as a closed end cup or tube with a mouth having a handle with a free end projecting therefrom, and wherein in a second stage, the preform is blow moulded in a mould into whose cavity said free end penetrates, the expansion of the cup or tube causing it to join to the free end of the handle.

Preferably the mouth is formed with a spout.

The mouth of the preform preferably has an outer peripheral portion from which the handle projects and which is held and remains unaltered during the blow moulding stage, and an inner portion in the form of a flange extending outwardly from the tube with a detent on its upper surface. This flange can be transformed in the blow moulding stage into a throat with an interior detent, following the technique described in WO 97/19806.

However the mouth may be formed in its ultimate shape in the first stage moulding, being unaltered by the blow

moulding. In that case, if the mouth has an internal screw formation above that there will be a seat for a blow nozzle.

That means that the blow nozzle does not have to screw into the workpiece.

Generally the first stage will be injection moulding, and the injection mould can employ just two parts to form the mould cavity.

The blow moulding can be supplemented by preliminary mechanical stretching.

For a better understanding of the invention, one embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial section of a preform from which a jug is to be blow moulded, Figure 2 is an elevation, looking in the direction A of Figure 1, of the preform, Figure 3 is plan view of the preform, Figure 4 is an elevation of the completed jug, corre- sponding to the view in direction A, Figure 5 is a vertical section on the line V-V of Figure 4, Figure 6 is a vertical section on the line VI-VI of Figure 5, Figure 7 is a plan view of the jug, Figure 8 is an axial section of a jug preform and Figure 9 is an axial section of another jug preform.

The preform P of Figures 1 to 7 is an injection moulding of plastics material, its geometry being such that

it can be produced by a two part mould. It has a tube 1 tapering gradually in towards its rounded closed bottom end 2, and this tube will be blow moulded to form the body of the jug. At the mouth of the tube 1 there is an outwardly projecting flange 3 with a downwardly projecting annular skirt 4 and an upwardly projecting rim 5 which is cylindri- cal apart from a spout 6. On top of the flange 3 there are two part spiral, diametrically opposed ribs 7, and at the point opposite the spout 6 there projects from the flange 3 and the rim 5 a handle 8. This is of simple inverted L- shape, with a T-shaped cross-section.

The injection moulding and the subsequent blow mould- ing, possibly pre-assisted by mechanical stretching, are carried out as described in WO 97/19806. This bends the flange 3 down and out against the skirt 4 and transforms the ribs 7 into portions of a screw thread on the inside of a cylindrical throat 9, as best seen in Figure 5. The rim 5, spout 6 and handle 8 remain unchanged and provide the anchorage for the jug as it is expanded to its final size and shape.

The blow mould halves close together in the plane of Figure 5 with the lower end tip of the vertical leg of the handle 8 just within the cavity. These halves are shaped to make a sweeping indent 10 in the jug directly opposite the handle 8, to allow free finger access.

When the tube 1 expands it locally wraps itself around and welds to the tip of the handle 8, making that close the loop with the rest of the jug and thus making it stronger

and more secure.

As seen in Figure 7, the body of the jug in this example is substantially square with rounded corners. It will be understood that many other shapes are equally possible, consistent with releasability from a blow mould cavity. In particular, the tube 1 of the preform P may be shorter and be more appositely described as cup-like.

The preform of Figure 8 is similar in some respects to that of the previous figures. It has a closed end tube 11, tapering slightly inwards towards the base, a throat 12 with an internal screw thread 13, a stepped-out shoulder 14 above the throat and a generally cylindrical rim 15. The rim is locally deformed outwardly into a spout 16 and diametrically opposite that it has an L-shaped handle 17, the short leg 18 being radial to the rim and the long leg 19 projecting down parallel to the tube 11.

However this is injection moulded of thermoplastic material (preferably PET) in conventional fashion, the throat being in its ultimate form. Part of the mould therefore unscrews from the throat 12 when the preform has solidified.

In due course this preform is blow moulded, the tube 11 (but not the throat, rim and handle) being pre-heated. The blow nozzle seats on the shoulder 14 and penetrates a short distance into the throat 12, sealing against the slightly coned surface immediately below the turn of the shoulder 14.

Before air is injected, the heated tube may be stretched longitudinally. When blown, the tube expands to meet the

lower end of the leg 19 of the handle 17, which just pen- etrates and seals to the now-thin shell that is the main body of the jug. This final shape is indicated in broken lines.

During this blow moulding the projecting spout 16 and the handle 17 are used to hold the preform firmly against the nozzle.

The preform of Figure 9 is very similar except that instead of the almost right angled shoulder 14 there is a coned surface 20 (with a more pronounced angle compared with that of the surface below the shoulder 14) against which the blow nozzle will seal.