WO1991001208A1 - Moulding of materials, with incorporated release agents - Google Patents
Moulding of materials, with incorporated release agents Download PDFInfo
- Publication number
- WO1991001208A1 WO1991001208A1 PCT/GB1990/001126 GB9001126W WO9101208A1 WO 1991001208 A1 WO1991001208 A1 WO 1991001208A1 GB 9001126 W GB9001126 W GB 9001126W WO 9101208 A1 WO9101208 A1 WO 9101208A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- carrier
- release agent
- base material
- mould
- moulding
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
- B29C33/58—Applying the releasing agents
Definitions
- This invention relates to moulding of materials such as plastics and metals.
- a me-hod cf producing a self-releasing material for use in moulding comprising absorbing a mould-release agent into a microporous carrier and incorporating the carrier into a base material, preferably when the latter is in a molten state.
- the base material may be a plastics material to be injection or compression moulded or may be a metal intended to be diecast.
- the microporous carrier is a substance as defined in the claims of British Patent No. 1576228.
- the carrier has a density within the approximate range of 0.9 to 0.945 gm/cc 3 , a void volume of substantially 75%, a cell size within the approximate range of 0.5 to 6.0 microns, and/or a pore size within the approximate range of 0.05 to 5.0 microns.
- the base material can be a plastics, such as polypropylene, polyethylene or a polyamide (e.g. nylon) , or a metal such as aluminium or aluminium alloy.
- the carrier incorporating the release agent is mixed with the base material and the resulting mixture is then subjected to a melting operation.
- the mixture may then be moulded or cast without preliminary spraying of the mould or dies with a release agent.
- the release agent may be a lubricant or a non-oil based mould release agent.
- a microporous carrier is caused to absorb a non-oil based mould release agent of conventional' type or any form of lubricant which will have a mould releasing action. Particles of the treated carrier are then mixed either with a molten plastics or metal or, particularly in the case of a plastics material, are mixed with granules of a base plastics material in a finely divided state.
- the proportion of carrier to base material may be of the order of 1%.
- the release agent is dispersed in minute pockets throughout the finished component. Because the concentration is very low, this should have little effect on the properties of the product except at the surface where the pockets of release agent make intimate contact with the mould and provide a self-releasing function.
- a suitable form of carrier for use in the above-described process is that described and claimed in UK patent no. 1576228 and sold by Azko Chemicals under the tradename ACCUREL. This substance is capable of absorbing approximately two-thirds of its own weight of the release agent.
- microporous carrier may be used, where the base material is a polyamide plastics, polyethylene or polypropylene for example.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Abstract
A mould-release agent is absorbed into a microporous carrier, and the carrier is then incorporated into a base material (such as a plastics material) for moulding. The release agent thus becomes dispersed throughout the base material, and serves to assist release of the subsequently moulded component from the mould or die, without any need for preliminary spraying of the mould or die with a release agent.
Description
Moulding of materials, with incorporated release agents
This invention relates to moulding of materials such as plastics and metals.
In my patent application no. 8911557.0, there is disclosed a self-lubricating material capable of use in a wide range of products from bearings and gears to artificial ski slopes.
In the manufacture of articles from plastics by, for example, injection or compression moulding or in the diecasting of metals, it has hitherto been the practice to spray the mould with a release agent prior to moulding, to prevent the plastic or metal material from sticking to the mould. Applying the release agent requires an extra m -.ufacturing stage which increases the moulding cycle time and also rec ires spray equipment, adding to basic capital costs. The use of certain sprays may also be environmentally hazardous.
It is an object of the present invention to provide a method of producing materials capable of use in moulding without such spraying steps .
According to the invention there is provided a me-hod cf producing a self-releasing material for use in moulding, the method comprising absorbing a mould-release agent into a
microporous carrier and incorporating the carrier into a base material, preferably when the latter is in a molten state.
The base material may be a plastics material to be injection or compression moulded or may be a metal intended to be diecast.
Preferably, the microporous carrier is a substance as defined in the claims of British Patent No. 1576228.
Desirably, the carrier has a density within the approximate range of 0.9 to 0.945 gm/cc3, a void volume of substantially 75%, a cell size within the approximate range of 0.5 to 6.0 microns, and/or a pore size within the approximate range of 0.05 to 5.0 microns.
The base material can be a plastics, such as polypropylene, polyethylene or a polyamide (e.g. nylon) , or a metal such as aluminium or aluminium alloy.
Desirably, the carrier incorporating the release agent is mixed with the base material and the resulting mixture is then subjected to a melting operation. The mixture may then be moulded or cast without preliminary spraying of the mould or dies with a release agent.
The release agent may be a lubricant or a non-oil based mould release agent.
The invention will now be further described by way of example only.
In order to produce a self-releasing moulding material, a microporous carrier is caused to absorb a non-oil based mould release agent of conventional' type or any form of lubricant which will have a mould releasing action. Particles of the treated carrier are then mixed either with a molten plastics or metal or, particularly in the case of a plastics material, are mixed with granules of a base plastics material in a finely divided state.
Since the release agent is only required to act at the surfaces of the moulded article to release it from the mould, and since only one release operation is necessary, a very small quantity of mould release agent is required. Since a highly absorbent carrier material is available, capable of absorbing approximately two-thirds of its own weight of release agent, only a very small quantity of carrier material needs to be added to provide adequate release of the finished moulded article. The proportion of carrier to base material may be of the order of 1%.
Because of the microporous nature of the carrier, the release agent is dispersed in minute pockets throughout the finished component. Because the concentration is very low, this should have little effect on the properties of the product
except at the surface where the pockets of release agent make intimate contact with the mould and provide a self-releasing function.
A suitable form of carrier for use in the above-described process is that described and claimed in UK patent no. 1576228 and sold by Azko Chemicals under the tradename ACCUREL. This substance is capable of absorbing approximately two-thirds of its own weight of the release agent.
According to the nature of the base material, different forms of microporous carrier may be used, where the base material is a polyamide plastics, polyethylene or polypropylene for example.
The above-described method has the advantages that no modifications are needed to the mould, and the correct percentage of lubricant can readily be obtained by adding the oil-bearing microporous carrier in appropriate quantities as a masterbatch to the base material.
Claims
1. A method of producing a self-releasing matejcial for use in moulding, comprising absorbing a mould-release agent into a microporous carrier, and incorporating the .carrier into a base material.
2. A method as claimed in claim 1, wherein the microporous carrier is incorporated into the base material when the latter is in a molten state.
3. A method as claimed in claim 1, wherein the carrier incorporating the release agent is mixed with the base material, and the resulting mixture is then subjected to a melting operation.
4. A method as claimed in claim 1, 2 or 3, wherein the base material is a plastics material, such as polypropylene, polyethylene or a polyamide (e.g. nylon).
5. A method as claimed in claim 1, 2 or 3 wherein the base material is a metal, such as aluminium or aluminium alloy.
6. A method as claimed in any one of claims 1 to 5, wherein the mould-release agent is a lubricant.
7. A method as claimed in any one of claims 1 to 5, wherein the mould-release agent is non-oil based.
8. A method as claimed in any preceding claim,.-wherein the carrier has a density within the approximate range of 0.9 to 0.945 gm/cc3.
9. A method as claimed in any preceding claim, wherein the carrier has a void volume of substantially 75%.
10. A method as claimed in any preceding claim, wherein the carrier has a cell size within the approximate range of 0.5 to 6.0 microns.
11. A method as claimed in any preceding claim, wherein - the carrier has a pore size in the approximate range of 0.05 to 5.0 microns.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8916775.3 | 1989-07-21 | ||
| GB898916775A GB8916775D0 (en) | 1989-07-21 | 1989-07-21 | Moulding of materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1991001208A1 true WO1991001208A1 (en) | 1991-02-07 |
Family
ID=10660454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/GB1990/001126 WO1991001208A1 (en) | 1989-07-21 | 1990-07-20 | Moulding of materials, with incorporated release agents |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB8916775D0 (en) |
| WO (1) | WO1991001208A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108688026B (en) * | 2018-05-14 | 2021-03-26 | 贺州学院 | Thermosetting resin release agent and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB695037A (en) * | 1949-12-29 | 1953-08-05 | British Thomson Houston Co Ltd | Improved process for making resinous compositions for the manufacture of articles having a self-lubricated surface |
| GB915589A (en) * | 1960-09-09 | 1963-01-16 | Ici Ltd | Polyolefine films |
| FR1497179A (en) * | 1965-10-11 | 1967-10-06 | Nat Distillers Chem Corp | Improvements to polyolefin-based compositions which do not adhere to themselves |
| FR2195321A5 (en) * | 1972-08-05 | 1974-03-01 | Klueber Lubrication | |
| EP0206446A1 (en) * | 1985-02-13 | 1986-12-30 | British United Shoe Machinery Limited | Producing fused polymeric articles |
-
1989
- 1989-07-21 GB GB898916775A patent/GB8916775D0/en active Pending
-
1990
- 1990-07-20 WO PCT/GB1990/001126 patent/WO1991001208A1/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB695037A (en) * | 1949-12-29 | 1953-08-05 | British Thomson Houston Co Ltd | Improved process for making resinous compositions for the manufacture of articles having a self-lubricated surface |
| GB915589A (en) * | 1960-09-09 | 1963-01-16 | Ici Ltd | Polyolefine films |
| FR1497179A (en) * | 1965-10-11 | 1967-10-06 | Nat Distillers Chem Corp | Improvements to polyolefin-based compositions which do not adhere to themselves |
| FR2195321A5 (en) * | 1972-08-05 | 1974-03-01 | Klueber Lubrication | |
| EP0206446A1 (en) * | 1985-02-13 | 1986-12-30 | British United Shoe Machinery Limited | Producing fused polymeric articles |
Non-Patent Citations (1)
| Title |
|---|
| GEORGE S. BRADY "Materials Handbook", An Encyclopedia for Purchasing Agents Engineers, Executives, and Foremen, Ninth Edition, 1963, McGraw-Hill Book Company, (New York, US), see page 255, lines 27-42; page 256, lines 1-10; page 813, lines 12-16; page 831, lines 21-36 * |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8916775D0 (en) | 1989-09-06 |
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