WO2000053399A1

WO2000053399A1 - An elongate plastic article

Info

Publication number: WO2000053399A1
Application number: PCT/IB2000/000254
Authority: WO
Inventors: Erhard HÖNIG
Original assignee: Ttg Technology Transfer Gmbh; Saunders, Thomas, Edward
Priority date: 1999-03-10
Filing date: 2000-03-10
Publication date: 2000-09-14
Also published as: AU3183300A

Abstract

An apparatus (10) for manufacturing an elongate plastic article (12) includes a first extrusion means (30) for extruding a feedstock strip of a synthetic plastics material (32) and at least one rotatable forming element (36) for forming the feedstock strip (32) into a formed strip (42) with a desired cross sectional profile. An elongate plastic article (12) and method of manufacturing an elongate article.

Description

ONGATE PLASTIC ARTICLE

TH IS INVENTION relates to an apparatus for manufacturing an elongate

plastic article, a method of manufacturing the article, and the article when

manufactured by means of the apparatus or by the method .

According to the invention there is provided an apparatus for

manufacturing an elongate plastic article which includes

an extrusion means for extruding a feedstock strip of a synthetic

plastics material; and

at least one rotatable forming element for forming the feedstock strip

into a formed strip with a desired profile.

Further according to the invention there is provided a method of

manufacturing an elongate plastic article, which includes

extruding a feedstock strip of a synthetic plastics material; and

forming the extruded feedstock strip into a formed strip with a desired

profile by means of at least one rotatable forming element.

The, or each, forming element may be wheel-like or roller-like having

forming formations at its rim For convenience, such a forming element is

hereinafter referred to as a "roller" . It will thus be appreciated by those skilled

in the art that the or each roller may have a recessed rim in which the forming formations are located .

The invention extends still further to an elongate plastic article which

has been manufactured by means of the apparatus or by the method of the

invention .

The plastic may be a thermoplastic material and may, for example, be

PVC, polystyrene, polyurethane or any other suitable thermoplastic synthetic

plastics material.

A pair of rollers may be used which, between them, define the profile.

It will thus be appreciated that the profile of the extruded feedstock

strip is, to a large extent, irrelevant, and the desired profile is provided by the

feedstock strip being squeezed by the roller, or between the pair of rollers.

The profile of the formed article is not determined by the head or aperture of

the extrusion means.

The forming formations may include projections and recesses to provide

the surface of the rolled, profiled strip with ornamentation or a pattern as well

as the profile.

The feedstock strip may be extruded onto a substrate, the feedstock strip then being squeezed between the substrate and the roller or an upper,

forming one of a pair of rollers. The substrate may be rigid or flexible, so long

as it is able to support and carry the feedstock strip.

A region of the substrate onto which the formed strip is to be bonded

may be coated with a suitable adhesive or bonding layer.

The formed strip may be narrower than the substrate, so that the

formed strip is applied onto a part of the substrate. Instead, the formed strip

may be wider than the substrate, so that is applied over the substrate.

The substrate may have a securing formation by means of which the

elongate article may be secured to a body or surface. For example, the

substrate may have a "T"-section, with the bead thereof having ribs or teeth

to secure the leg in a groove in the surface or body.

The substrate may be supplied from a supply thereof, the substrate

having been formed in a previous operation. Instead, the substrate may be

formed in the same operation, by means of an extrusion station, with the

extruded substrate being given sufficient time to harden sufficiently to carry

and support the feedstock strip and not be deformed by the roller or the pair

of rollers. If only one roller is used, it may be freely rotatable or it may be driven.

Similarly, if a pair of rollers is used, both may be freely rotatable, one may be

freely rotatable and the other driven, or both may be driven If they are both

75 driven, then they are preferably driven at suitable rotational speeds to ensure

the same linear perimetral speed Thus, they may both have the same

effective external diameter and be driven at the same rotational speed .

A surface ornamental layer may also be applied onto an upper surface

80 of the formed strip. Conveniently, such an ornamental layer may be provided

by a foil which is passed between the strip and the, or the forming, roller.

The foil may be applied onto or over the feedstock strip, le onto only a part

of the formed strip; across the entire upper surface of the formed strip; or

over the entire upper surface of the formed strip and part or all of adjacent

85 surfaces of the substrate. The foil may be carried on a carrier which is

removed downstream of the, or the forming, roller

It will further be appreciated by those skilled in the art that the cross

sectional area of the extruded feedstock strip of feedstock material may be

90 substantially the same as that of the formed strip However, the extruded

feedstock strip may have slightly more material than that of the desired

profile, so that there is a small ribbon on either side of the formed strip. The

apparatus may then have a stripping station to remove the ribbons. 95 The elongate article may be intended to be used for a decorative or

ornamental purpose or for a structural purpose such as a picture frame.

However, the manner in which the elongate article is used, or its intended

purpose is not hereby limited.

I 00 The invention is now described, by way of examples with reference to

the accompanying drawings, in which:-

Figure 1 shows schematically a first embodiment of an apparatus in

accordance with the invention for manufacturing an elongate plastic article;

1 05

Figure 2 shows schematically an elongate article manufactured by

means of the apparatus of Figure 1 , which is a first decorative article, with

part removed to illustrate the construction better;

1 10

Figure 3 shows schematically a side view of a pair of rollers forming

part of the apparatus of Figure 1 and how a substrate and a feedstock strip

interact therewith;

I I 5 Figure 4 shows schematically a second embodiment of an apparatus in

accordance with the invention; Figure 5 shows a sectioned end view of a second decorative strip

manufactured by means of the apparatus and method of the invention;

Figure 6 shows a sectioned end view of a further decorative strip

manufactured by means of the apparatus and method of the invention;

Figure 7 shows an end portion of a plank-like article manufactured by

means of the apparatus and method, with part removed to illustrate the

construction better, which is intended to be used as a picture frame; and

Figure 8 shows schematically a side view of a roller forming part of the

apparatus used to manufacture the plank-like article shown in Figure 7 and

how the substrate and the extruded feedstock strip interact therewith.

Referring to Figure 1 , an apparatus for manufacturing an elongate

plastic article is designated generally by reference numeral 1 0. The elongate

article 1 2 is shown in Figure 2. The apparatus 10 has a first extruder 14

which extrudes a substrate 1 6 having a "T"-lιke cross section. The profile of

the substrate 1 6 is shown more clearly in Figure 2 from which it will be seen

that the substrate 1 6 has a bar 1 8 with a bead 20 The bar 1 8 has a convex

curved upper surface 22 and the bead 20 has securing ribs 24. The

substrate 1 6 is integrally extruded by the first extruder 1 4 which has an

extrusion head (not shown) with a suitably shaped aperture. The substrate 1 6 is of PVC and is flexible so that it can be bent and curved to have a

suitable spatial configuration.

The extruded substrate 1 6 coming out of the first extruder 14 passes

through a first water bath 26 where it is cooled to have mechanical strength.

Downstream of the first water bath 26 is an adhesive applicator 28

which applies a layer or coating of adhesive to the convex upper surface 22

of the bar 1 8.

The apparatus 1 0 further includes a second extruder 30. This second

extruder 30 extrudes a feedstock strip 32 that has a circular cross section as

is more clearly shown in Figure 3. The feedstock strip 32 is also of PVC.

Immediately downstream of the second extruder 30 and close enough

that the feedstock strip 32 does not cool much and remains sufficiently hot

to be moulded, there is a moulding station 34.

The moulding station 34 has a paired upper roller 36 and lower roller

38. The upper roller 36 has a concave rim 40 as is seen more clearly in Figure

3. As will be appreciated from what is said below, the concave rim 40

defines a moulding cavity together with the substrate 1 6 and the lower roller

38. Thus, the upper roller 36 is profiled to mould the feedstock strip 32 to have the desired profile As seen in Figures 2 and 3, the feedstock strip 32

is moulded ove^r the bar 1 8 of the substrate 1 6 into a formed strip 42 which

has a central lower recess in which the bar 1 8 seats, with planar lower

surfaces 44 on either side thereof The formed strip 42 also has a central

longitudinally extending convex upper region 46 with a longitudinally convex

edge section 48 on either side The central region 46 has a repeating pattern

of protrusions 50 and the edge sections 48 have corrugations 52.

As is seen in Figure 3, the concave rim 40 is complementaπly shaped

to the upper surface of the formed strip 42.

It will further be seen in Figure 3 that the lower roller 38 has a groove

54 in its rim in which the bead 20 of the substrate 1 6 is received The groove

54 is narrower than the bar 1 8 and sufficiently deep so that the lower edge

portions of the bar 1 8 seat on support surfaces 56 of the rim of the lower

roller 38 that are cylindrical.

It will further be appreciated that the upper roller has fairly sharp edges

60, and the two rollers 36 and 38 are spaced so that there is a gap of about

0,2 mm between the edges 60 and the surfaces 56.

Thus, the substrate 1 6 is fed between the two rollers 36 and 38 to

define with them a progressive moulding cavity as the rollers 36, 38 rotate and the substrate 1 6 passes between them. The feedstock strip 32 is fed

onto the substrate 1 6 and supported thereby (in this embodiment) to be

moulded into the formed strip 42 by the progressive moulding cavity.

The rollers 36, 38 are mounted to be rotatable about parallel axes 62

and 64 respectively, which are transverse to the direction of travel of the

substrate 1 6. The rollers 36 and 38 have the same effective diameters and

are driven together at the same speed .

It will be appreciated further that the feedstock strip 32 is drawn

between the rollers 36 and 38 and is squeezed to have the desired profile as

the rollers 36, 38 are rotated.

Those skilled in the art will appreciate that the substrate 1 6 is not

essential and the formed strip 42 could be formed without the substrate 1 6.

The apparatus 1 0 would then not have the first extruder 14, the first water

bath 26 and the applicator 28. The feedstock strip 32 would then be fed

between the rollers 36 and 38 and the lower roller 38 would not have the

groove 54.

Still further, it will be understood that the progressive moulding cavity

has a cross sectional area and the feedstock strip 32 has a slightly larger

cross sectional area so that there is sufficient material to fill the progressive moulding cavity and have a small excess. This small excess is then squeezed

out between the two rollers 36 and 38 to provide edge ribbons 66. These are

easily trimmed off and removed by a stripping station (not shown) .

The formed strip 42 is bonded to the substrate 1 6, bonding being

improved by the adhesive applied by the applicator 28.

The substrate 1 6 and formed strip 42 are passed through a second

water bath 68 to provide the elongate article 1 2. The elongate article 1 2

passes through a take off station 70 and it is then coiled by means of a coiling

machine (not shown) .

Referring now to Figure 4, a second embodiment of an apparatus in

accordance with the invention is designated generally by reference number

72. This second embodiment has the extruder 30, moulding station 34, water

bath 68 and take off station 70. It does not have the first extruder 14, the

first water bath 26 and the applicator 28. The substrate 1 6 is manufactured

in a separate operation and is supplied from a coil 74 to the moulding station

34, between the rollers 36 and 38. A woodgrain ornamental foil 76 is also

supplied from a coil 78 on top of the feedstock strip 32 between the

feedstock 32 and the upper roller 36. The foil 76 is bonded by heat and

pressure as it passes through the progressive moulding cavity onto the upper

surface of the formed strip 42. Referring now to Figure 5 a further flexible decorative elongate article

80 in accordance with the invention is shown . This article is similar to the

article 1 2, except that the substrate 1 6 has a bar 1 8 that is wider than the

formed strip 42, so that the progressive moulding cavity is defined by the

substrate 1 6 and the upper roller 36.

A third embodiment of a flexible decorative article 82 is shown in Figure

6. This embodiment 82 is also similar to the embodiment 1 2, with the formed

strip 42 being slightly wider than the bar 1 8.

A fourth embodiment 84 of a rigid structural elongate article is shown

in Figure 7. This article 84 has a substrate 86 that is of wood which has been

machined to have the profile shown. A portion of the upper surface thereof

is coated with an adhesive layer 88 and the formed strip 42 bonded thereto.

The formed strip 42 is formed by means of a single roller 90, as shown

in Figure 8. Thus, the substrate 86 is passed between a support surface 92

and the roller 90 and a circular feedstock strip 94 issuing from an extruder

such as the extruder 30 is fed onto the substrate 86 and moulded by the

progressive cavity formed by the substrate 86 and the roller 90. The article

84 is intended for use as a picture frame or rail.

Claims

1 . An apparatus for manufacturing an elongate plastic article which

includes

a first extrusion means for extruding a feedstock strip of a synthetic

plastics material; and

at least one rotatable forming element for forming the feedstock strip

into a formed strip with a desired cross sectional profile.

2. The apparatus as claimed in Claim 1 , in which the forming

element is a roller having forming formations along its rim.

3. The apparatus as claimed in Claim 2, in which the roller has a

recessed rim in which the forming formations are located .

4. The apparatus as claimed in Claim 2 or 3, which includes a pair

of co-operating rollers.

5. The apparatus as claimed in Claim 2 or 3, in which the roller has

projections and recesses along its rim to provide the surface of the formed

strip with ornamentation as well.

6. The apparatus as claimed in any one of the preceding claims,

which includes a substrate providing means for providing a substrate onto which the feedstock strip is extruded .

7. The apparatus as claimed in Claim 6, in which the substrate

providing means includes a second extrusion means.

8 The apparatus as claimed in Claim 6 or 7, which includes an

adhesive supply means for supplying a coating of adhesive on the substrate.

9. The apparatus as claimed in any one of the preceding claims,

which includes a decorative foil applicator for applying a layer of decorative

foil on the feedstock strip.

1 0. A method of manufacturing an elongate plastic article, which

includes

extruding a feedstock strip of a synthetic plastics material; and

forming the extruded feedstock strip into a formed strip with a desired

cross sectional profile by means of at least one rotatable forming element.

1 1 The method claimed in Claim 10, which includes

providing a substrate,

extruding the feedstock strip onto the substrate; and

forming the extruded feedstock strip to have the desired cross sectional

profile by squeezing the feedstock strip between the substrate and the 300 rotatable forming element.

1 2. The method claimed in Claim 1 0 or 1 1 , which includes extruding

the substrate.

1 3. The method claimed in Claim 1 1 , which includes the step of

305 coating a region of the substrate to which the formed strip is to be bonded

with an adhesive layer.

14. The method claimed in any one of Claims 10 to 1 3, which

includes the step of applying a layer of a decorative foil onto an upper surface

31 0 of the feedstock strip.

1 5. An elongate plastic article which has been manufactured by

means of an apparatus as claimed in any one of Claims 1 to 9.

31 5 1 6. An elongate plastic article which has been manufactured in

accordance with the method as claimed in any one of Claims 1 0 to 1 4.

1 7. An elongate plastic article which has been manufactured by

means of an apparatus as claimed in Claim 6, 7 or 8, in which the substrate

320 includes a securing formation whereby the article can be secured to a body or

surface.

1 8. The article claimed in Claim 1 7, in which the securing formation

comprises a bead which projects from an underneath surface of the substrate

and is receivable, in use, in a groove in the body or article.