GB2361661A - Nozzle - Google Patents

Abstract

A nozzle is disclosed, the nozzle 1 being particularly for use in the pouring of molten composite materials into a mould, the nozzle 1 comprising a hollow body 2 to allow the passage of molten materials there through and a plurality of outlets 5 at one end of the body 2, the outlets 5 being offset from the longitudinal axis A of the body 2. The end of the body 2 adjacent the outlets 5 may be closed and the outlets 5 may be inclined at right angles to the longitudinal axis A of the body 2, towards the closed end 4 of the nozzle 1. The nozzle 1 may include four outlets 5 equi-spaced around the closed end 4 of the body 2. Sealing means 6 may be provided around one end of the nozzle 1 to co-operate with a sleeve S of a mould M1, M2 to prevent molten material from escaping the mould M1, M2. The sealing means 6 may further comprise one or more gaskets provided around the outer periphery of the nozzle 1.

Description

2361661 NOZZLE This invention relates to a nozzle and, more particularly,

to an improved nozzle for use in the injection of liquid polymers and solid fillers, such as forming a composite moulding mixture, hereinafter called a composite material, into a mould for the production of a solid moulded article. The nozzle provides means for protecting the mould from the abrasive nature of the composite material.

Many everyday products are made by an injection moulding process. This allows objects to be mass produced thereby reducing the overall cost of production of the product. This cost saving can be passed on to the purchaser of the final product.

Presently, in such methods, a composite material is introduced into a suitably selected mould through a cylindrical nozzle which slides into a sleeve extending from the mould. The sleeve ensures that the nozzle is correctly aligned within the mould and provides a scaling surface to prevent escape of the material from the mould.

The free end of the nozzle is connected to a supply of molten composite material and upon release of valve means, this material is forced through a longitudinal bore in the nozzle and into the mould. Once the mould has been filled to the appropriate level, the valve means is closed and the nozzle is removed at a given point in the cycle. The composite material is then allowed to set, following which the mould is opened to allow the moulded product to be released.

The molten composite material used in such a process is abrasive in nature and as it is forced through the nozzle and into the mould, it impacts on the "show" face of one part of the mould. This can lead to pitting of the surface of the mould and thus lead to imperfections in the moulded product which can increase over time as the mould is used in successive operations.

2 Furthermore, repeated use of the mould can build up an area of weakness in the mould in the region where the molten composite material is forced against the mould, which reduces the effective life of the mould and therefore increases the resulting cost of manufacture of the product in question.

In most cases, in order to reduce the impact of such imperfections on the finished product, care is taken to select the point on the mould at which the molten composite material impacts the mould face to ensure that this is not in a critical area on the final product. However, this does not address the problems which are identified above and merely moves the problem to a less conspicuous area on the final product.

The present invention aims to overcome or at least mitigate the above mentioned problems associated with pouring of molten composite materials into a mould.

According to one aspect of the present invention there is provided a nozzle particularly for use in the pouring of molten composite materials into a mould, the nozzle comprising a hollow body to allow the passage of molten materials there through and a plurality of outlets at one end of the body, the outlets being off-set from the longitudinal axis of the body. This allows molten material to flow through the nozzle and into the mould without impacting upon the "show" face of the mould. Instead, the molten material is channelled into the mould in a controlled manner.

Preferably, the end of the body adjacent the outlets is closed.

Preferably also, the outlets are provided at right angles to the longitudinal axis of the body.

3 Advantageously, the outlets are inclined towards the closed end of the nozzle.

Conveniently four outlets are equi-spaced around the closed end of the nozzle, although any number of outlets may be provided depending upon the desired pouring characteristics required.

Different numbers or orientations of outlets may be selected depending upon the molten material being used.

Preferably, sealing means are provided around the closed end of the nozzle to co-operate with a sleeve of the mould to prevent molten material from escaping the mould.

Advantageously the sealing means comprises one or more gaskets provided around the outer periphery of the nozzle.

An embodiment of the present invention will now be described with reference to and as shown in the accompanying Figure which shows a schematic cross-sectional view of a nozzle 1 according to one aspect of the present invention. The nozzle comprises a generally cylindrical body 2 formed of, for example, stainless steel, which is open at one end 2a. A blind bore 3 is provided longitudinally through the body. In the embodiment shown, an end cap 4 is placed on one end of the body to close off the bore. The end cap is retained by suitable means (not shown) on the end of the nozzle.

A plurality of outlets 5 are provided in the body adjacent to the closed end thereof. In the embodiment shown 4 apertures are provided eqi-spaced around the end of the nozzle. The number of outlets may be selected depending upon the precise pouring characteristics required for the nozzle.

4 Each of the outlets in the embodiment shown is provided at a right angle to the longitudinal axis A of the body. Alternatively, the outlets may be provided at some other angle to the axis and may be inclined towards either the end of the nozzle or the body of the nozzle 5 if required.

Scaling means 6 are provided around the end of the nozzle, the scaling means in the example shown being in the form of a pair of gaskets each of which is received in a groove 7 around the outer periphery of the nozzle. The gaskets seal aganst a sleeve 8 of the mould in use so as to prevent escape of molten plastics niaterial from the mould M 1, M2.

In use, the mould parts Mi and M2 are brought together and held by suitable retaining means. The nozzle 1 is introduced through the sleeve S of the mould to a position where the outlets 5 are clear of the sleeve and the sealing means 6 are in contact with the internal surface of the sleeve. The open end of the nozzle 2a is connected to a supply of molten composite material (not shown).

The molten composite material is then caused to flow through the bore 3 in the nozzle body and exit the nozzle through the apertures 5 therein. As the end of the nozzle which feeds into the mould is closed, by the end cap 4, the molten plastics material is channelled into the mould M through the apertures 5 which prevents the molten composite material from impacting on the "show" face of the mould M2. In this way the mould is protected from the abrasive nature of the molten material. This can lead to considerable lengthening of the lifetime of the mould which has the consequence of reducing the cost of manufacturing the products in question.

It is to be understood that the body may be formed as a single piece unit with apertures formed in the closed end of the body rather than a separate body and end cap as described above. In a further embodiment, the end cap may be extended such that the apertures are formed in the side walls of the end cap. In this embodiment, a number of end caps could be produced for a single nozzle, each end cap having a different arrangement of apertures, and each being mountable on one end of the nozzle. This allows the pouring characteristics of a nozzle to be altered without changing the entire nozzle, only the end cap requiring replacement between operations.

6

Claims (8)

1. A nozzle particularly for use in the pouring of molten composite materials into a mould, the nozzle comprising a hollow body to allow the passage of molten materials there through and a plurality of outlets at one end of the body, the outlets being off set from the longitudinal axis of the body.

2. A nozzle according to claim 1 or 2, wherein the end of the body adjacent the outlets is closed.

3. A nozzle according to claim 2, wherein the outlets are inclined towards the closed end of the nozzle.

4. A nozzle according to claim 2 or 3, wherein the outlets are provided at right angles to the longitudinal axis of the body.

5. A nozzle according to any one of claims 2-4, wherein four outlets are equispaced around the closed end of the body.

6. A nozzle according to any one of the preceding claims, wherein scaling means are provided around one end of the nozzle to co operate with a sleeve of a mould to prevent molten material from escaping the mould.

7. A nozzle according to claim 6 wherein the sealing means comprises one or more gaskets provided around the outer periphery of the nozzle.

8. A nozzle substantially as hercinbefore described with reference to and as shown in the accompanying Figure.