GB2199837A

GB2199837A - Producing foam articles

Info

Publication number: GB2199837A
Application number: GB08700819A
Authority: GB
Inventors: Garcia Don Jose Sanchis
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-01-15
Filing date: 1987-01-15
Publication date: 1988-07-20
Also published as: GB8700819D0

Abstract

A method for producing flexible synthetic sponge products comprising mixing isocyanate and polyol in a polyurethane skimmer (1), subjecting the mixture to a froth removal process, and passing it to a dispensing head (9) for introduction into a mould. The dispensing head (9) includes an agitator and a funnel (3) for directing the flow of the mixture. A rotatable arm (4) supports the dispensing head so that it can be moved in a circular path to follow a line of moulds (6) moving in a corresponding path beneath the head. <IMAGE>

Description

"Producing Foam Articles" This invention relates to a method and apparatus for manufacturing synthetic sponge or foam" articles, particularly articles such as toys.

The advantages of toys manufactured from soft foam materials are well known, as they are resilient, easy to handle, and have no dangerous sharp edges.

Furthermore, they can be easily coloured by well-known methods.

The present invention seeks to provide a method and apparatus for producing such articles, which utilises a continuous process with a minimum number of manual operations and a maximum degree of automation.

Accordingly, the present invention provides a p p a r a t U 5 for p r o d-u c i n g synthetic sponge p r o d u c t s comprising a polyurethane skimming machine including means for removing froth from a mixture of foam-producing chemicals; a dispensing head for introducing the mixture into a mould, the dispensing head including an agitator and a funnel for directing the flow of the mixture; and a rotatable arm supporting the dispensing head so that it can be moved in a circular path to follow a line of moulds moving in a corresponding path beneath the head.

Preferably, the apparatus also includes means for automatically dispensing measured quantities of the component chemicals of the foam, into the moulds.

One embodiment of the invention will now be described by way of example, with reference to the accompanying drawing, which is a perspective view of apparatus in accordance with the invention.

Referring to the drawing, the two chemical components required to produce a tear resistant flexible foamed article are mixed in a polyurethane "skimming machine' 1 of known type in which the froth removal process takes place. The preferred components are isocyanate and polyol.

The components are then transported via ducts 2 to a dispensing head 9 and the product passes through a funnel 3 which is equipped with an agitating or mixing device. The passage of the material through the head of the machine is regulated by solenoid valves and suitably programmed timers.

As can be seen from the drawing, the head 9 and funnel 3 are supported on a radial arm 4 carried by a vertical support 5, for reasons to be explained in more detail below.

A series of moulds 6 are supported on a conveyor 8 which moves at a constant speed below the head 9, and the mixture produced in the head is dispensed into each of the moulds 6 in turn, as it passes below the head. Since the vertical mounting shaft 5 is rotatable, the radial arm 4 can be moved so that the head 9 follows the passage of each mould 6 as it passes beneath the apparatus.

The moulds are preheated to a temperature of 50 - 600C, and as the mixture settles in the mould, a chemical reaction takes place between the NCO groups of the isocyanate and the OH groups of the polyol.

The conveyor carries the moulds from the filling position into a temperature controlled tunnel 7, which is preheated to the required temperature to achieve proper curing of the product. In addition, the length of the tunnel, and the speed of the conveyor are suitably arranged so that the moulds are maintained in the proper temperature controlled condition for the required length of time.

Consequently, as each mould leaves the other end of the tunnel the completed article can be removed from the mould in its cured form. The mould is then at the correct preheated temperature, to accept the next input of material from the dispensing head 9.

It will be appreciated that the ratio of the components can be varied, to achieve finished articles of different thicknesses and flexibility.

Claims

1. A method for producing flexible synthetic sponge products comprising mixing isocyanate and polyol in a polyurethane skimmer; subjecting the mixture to a froth removal process, and passing it to a dispensing head for introduction into a mould.

2. A method according to claim 1 in which the mixture is subjected to further stirring in the dispensing head.

3. A method according to claim 1 or claim 2 in which the moulds are preheated to a temperature of 50 600C.

4. A method according to any preceding claim in which the mixture is allowed to settle in the mould until the main chemical reaction between the NGO groups of the isocyanate and the OH groups of the polyol is complete.

5. A method according to any preceding claim, also including the step of introducing a pigment into the mixture.

6. Apparatus for producing synthetic sponge products comprising a polyurethane skimming machine including means for removing froth from a mixture of foamproducing chemicals; a dispensing head for introducing the mixture into a mould, the dispensing head including an agitator and a funnel for directing the flow of the mixture; and a rotatable arm supporting the dispensing head so that it can be moved in a circular path to follow a line of moulds moving in a corresponding path beneath the head.

7. Apparatus according to claim 6 further comprising a conveyor arranged to carry the moulds on a circular path beneath the said dispensing head, and a temperature controlled tunnel through which the conveyor is arranged to pass, the speed of the conveyor and the length of the tunnel being so arranged as to allow the chemical reaction of the mixture to be completed when the moulds leave the tunnel.

8. A method for producing flexible synthetic sponge toys substantially as herein described with reference to the accompanying drawings.

9. Apparatus for producing flexible synthetic sponge toys substantially as herein described with reference to the accompanying drawings.