Process of producing plastic plates with wells by placing a film on a mold and applying hot gas

• US 5,447,679 A
• Filed: 01/15/1993
• Issued: 09/05/1995
• Est. Priority Date: 07/18/1990
• Status: Expired due to Term

• Current Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Original Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Inventors: Eigen, Manfred, Simm, Wolfgang
• Primary Examiner(s): Timm, Catherine
• Application Number:
  US07/969,825
• Time in Patent Office: 963 Days
• Field of Search: 264/544, 264/504, 264/555, 264/509, 425/387.1, 425/384
• US Class Current: 264/544
• CPC Class Codes: B29C 51/10 Forming by pressure difference, e.g. vacuum

Abstract

A process serves for producing a plate comprising at least one well havingts opening facing upwards, for receiving chemical and/or biochemical and/or microbiological substances. The process, wherein the wells are made in the plate with the aid of a molding die, comprises the steps of:

a) Applying a plastic film, which is deformable by the action of heat, on a molding block which serves as a molding die and which has the negative shape of the wells to be formed; and

b) subjecting the plastic film, for a predetermined period of time, to the action of a hot gas flow of a predetermined first temperature, the gas flow impinging upon at least an area of the plastic film covering one of the recessed portions, heating up this area and pressing it into the recessed portion so that it comes to lie flat against the latter'"'"'s inner wall which is smooth throughout.

Claims

1. Process for producing a plate member comprising at least one well having its opening facing upwards, for receiving chemical and/or biochemical and/or microbiological substances, said wells being made in the plate member with the aid of a molding die means, wherein the process comprises the steps of:

a) applying a plastic sheet of synthetic material, which sheet is deformable by the action of heat, on a molding block means which serves as said molding die means and which has recessed portions with the negative shape of the wells to be formed; and

b) subjecting said plastic sheet, for a predetermined period of time, to the action of a hot gas flow of a predetermined first temperature, the gas flow impinging upon at least an area of said plastic sheet covering one of the recessed portions, heating up this area and pressing it into said recessed portion so that it comes to lie flat against the latter'"'"'s inner wall which is smooth throughout, and

c) maintaining said molding block means at a predetermined second temperature which is lower than said predetermined first temperature, but above room temperature,

wherein said plastic sheet is a polycarbonate film having a thickness smaller than 0.5 mm, said predetermined first temperature is between 250°

C. and 300°

C., and said predetermined second temperature is between 90°

C. and 110°

C.

2. Process for producing a plate member comprising at least one well having its opening facing upwards, for receiving chemical and/or biochemical and/or microbiological substances, said wells being made in the plate member with the aid of a molding die means, wherein the process comprises the steps of:

a) applying a plastic sheet of synthetic material, which sheet is deformable by the action of heat, on a molding block means which serves as said molding die means and which has recessed portions with the negative shape of the wells to be formed; and

b) subjecting said plastic sheet, for a predetermined period of time, to the action of a hot gas flow of a predetermined first temperature, the gas flow impinging upon at least an area of said plastic sheet covering one of said recessed portions, heating up this area and pressing it into said recessed portion so that it comes to lie flat against the latter'"'"'s inner wall which is smooth throughout, and

c) maintaining said molding block means at a predetermined second temperature which is lower than said predetermined first temperature, but above room temperature, such that

the at least one well is formed with a wall having a smooth and uniform outer surface and a defined contour, which contour can be brought into direct heat-exchanging contact with a corresponding shaped counter-surface, enabling a rapid heat-exchange through said wall of said well and thus providing for a rapid temperature change of said substances, and wherein

said plastic sheet is a polycarbonate film having a thickness smaller than 0.5 mm, said predetermined first temperature is between 250°

C. and 30020 C., and said predetermined second temperature is between 90°

C. and 110°

C.

3. Process for producing a plate member comprising at least one well having its opening facing upwards, for receiving chemical and/or biochemical and/or microbiological substances, said wells being made in the plate member with the aid of a molding die means, wherein the process comprises the steps of:

a) applying a plastic sheet of synthetic material, which sheet is deformable by the action of heat, on a molding block means which serves as said molding die means and which has recessed portions with the negative shape of the wells to be formed; and

b) subjecting said plastic sheet, for a predetermined period of time, to the action of a hot gas flow of a predetermined first temperature, the gas flow impinging upon at least an area of said plastic sheet covering one of said recessed portions, heating up this area and pressing it into said recessed portion so that it comes to lie flat against the latter'"'"'s inner wall which is smooth throughout, and

c) maintaining said molding block means at a predetermined second temperature which is lower than said predetermined first temperature, but above room temperature, such that

the at least one well is formed with a wall having a smooth and uniform outer surface and a defined contour, which contour can be brought into direct heat-exchanging contact with a corresponding shaped counter-surface, enabling a rapid heat-exchange through said wall of said well and thus providing for a rapid temperature change of said substances, and wherein

said hot gas flow issues from a nozzle means having an orifice, which is maintained at a fixed distance from said plastic sheet during said predetermined period of time, and

said well displays a circular cross-section, has a volume smaller than 200 mm³ and a diameter smaller than 10 mm, said orifice of said nozzle means has a diameter approximately equal to the diameter of said well and said fixed distance corresponds approximately to said diameter of said well.

4. A process as claimed in 3, wherein said plastic sheet is a polycarbonate film having thickness smaller than 0.5 mm, said predetermined first temperature is between 250°

C. and 300°

C., and said predetermined second temperature is between 90°

C. and 110°

C.