Process for sealing at least one well out of a number of wells provided in a plate for receiving chemical and/or biochemical and/or microbiological substances, and installation for carrying out the process

• US 5,582,665 A
• Filed: 01/25/1995
• Issued: 12/10/1996
• Est. Priority Date: 07/18/1990
• Status: Expired due to Fees

• 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): AFTERGUT, JEFFRY H
• Application Number:
  US08/378,925
• Time in Patent Office: 685 Days
• Field of Search: 156/69, 156/581, 156/582, 156/308.2, 156/308.4, 156/292, 156/251, 53/452-454, 53/478, 53/471, 53/559, 53/560, 53/900, 53/374.2, 435/288.4, 435/305.3
• US Class Current: 156/69
• CPC Class Codes: B01L 2300/044 pierceable, e.g. films, membranes
• CPC Class Codes: B01L 3/50853 with covers or lids
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/305 involving the use of cartridge heaters
• CPC Class Codes: B29C 65/7808 in the form of holes or slots B29C65/7814 takes precedence; holding or clamping means cooperating with specially formed features of at least one of the parts to be joined B29C65/7844
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• CPC Class Codes: B29C 66/24221 being circular B29C66/51 takes precedence
• CPC Class Codes: B29C 66/53461 joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73113 Thermal conductivity
• CPC Class Codes: B29C 66/73365 at least one of the parts to be joined being transparent or translucent to visible light
• CPC Class Codes: B29C 66/73521 of different thickness, i.e. the thickness of one of the parts to be joined being different from the thickness of the other part
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/8122 characterised by the composition of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
• CPC Class Codes: B29C 66/81433 being toothed, i.e. comprising several teeth or pins comprising a single tooth B29C66/81429, or being patterned
• CPC Class Codes: B29C 66/8181 characterised by the cooling constructional aspects
• CPC Class Codes: B29C 66/81831 of the welding jaws
• CPC Class Codes: B29C 66/8223 Worm or spindle mechanisms
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/8432 : Machines for making separate joints at the same time mounted in parallel or in series
• CPC Class Codes: B29C 66/849 : Packaging machines
• CPC Class Codes: B29C 66/91231 : of the joining tool
• CPC Class Codes: B29C 66/91421 : of the joining tools
• CPC Class Codes: B29C 66/91431 : the temperature being kept constant over time
• CPC Class Codes: B29C 66/91641 : the heat or the thermal flux being non-constant over time
• CPC Class Codes: B29C 66/919 : characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/949 : characterised by specific time values or ranges
• CPC Class Codes: B29C 66/954 : by measuring or controlling the thickness of the parts to be joined
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2905/12 : Iron
• CPC Class Codes: B65B 7/165 : Securing by deformation of the web material
• CPC Class Codes: B65B 9/042 : for fluent material

Abstract

A plate having wells therein for receiving chemical substances is provided with a coverplate covering said filled wells. The process for sealing the wells by providing a joining seam running around the wells provides the joining seam such that it has a profiled cross-section in order to increase the contact surface between the plate and the coverplate. To this end a welding die has a front surface provided with projecting profiled regions and being heated to a temperature in the region of the melting point of the coverplate. The welding die is placed on the coverplate means and remains there for a fixed first period. Then the welding die is pressed down through a fixed path and remains in this position for a fixed second period. Removing the welding die from the coverplate is the last step in the process.

Claims

1. A process for sealing at least one well out of a number of wells having openings facing upwards, said wells being provided in a plate means and serving to receive chemical and/or biochemical and/or microbiological substances, the openings having their orifices in the upper side of said plate means, wherein the process comprises the steps of:

a) placing said plate means with said wells facing upwards onto a receiving member having means for receiving said wells so that said plate means contacts an upper face of said receiving member,

b) placing a heat deformable coverplate from a thermoplastic resin sheet on said upper side of said plate means, at least said opening of said at least one well to be sealed being covered by an area of said coverplate, which coverplate has an upper side facing upwards, and then

c) providing a joining seam running at least around said opening of said well to be sealed and joining at least the area, covering said opening of said well with said coverplate, said joining seam having a profiled cross-section in order to increase the contact surface between said upper side of said plate means and said coverplate, by the following steps;

ba) providing a welding die member having a front face above said receiving member so that said front face thereof opposes said upper face of said receiving member,

bb) providing one of said opposing faces with a substantially flat surface and the other of said opposing faces with projecting profiled regions, wherein at least said other face is heated to a temperature which is in the region of the melting point of, at least, said coverplate,

bc) bringing the opposing faces of said welding die member and said receiving member together so that said front face of said welding die member contacts said upper side of said coverplate, said profiled regions coming into contact with one of said upper side of said coverplate or said plate means in the area around said opening;

then

bd) pressing said welding die member and said receiving member together through a fixed path so that said profiled regions at least penetrate into said coverplate; and

then

d) separating said welding die member from said receiving member.

2. The process according to claim 1, wherein said front face of said welding die member is provided with said projecting profiled regions.

3. The process according to claim 2, wherein the provision of the joining seam comprises the provision of a joining seam which is closed in itself.

4. The process according to claim 3, wherein the provision of said joining seam comprises the provision of a join which is positive-locking, at least in sections, between said plate means and said coverplate.

5. The process according to claim 3, wherein said joining seam seals said well gas-tight.

6. The process according to claim 2, wherein an individual joining seam is provided for each of said wells.

7. The process according to claim 2, wherein said receiving member is kept at a fixed temperature and said wells are brought into thermal contact with said receiving member when they are placed on the latter.

8. The process according to claim 7, wherein a holding device is placed from above onto said coverplate before said welding die member is placed in position, which holding device presses said coverplate onto said upper side of said plate means and brings said wells into thermal contact with said receiving member.

9. The process according to claim 2, wherein said plate means is produced from a thin polycarbonate film having a thickness of less than 0.5 mm, wherein said coverplate is produced from a thin polycarbonate film having a thickness of less than 0.3 mm, wherein said wells have a wall with a thickness of less than 0.08 mm and a volume smaller than 200 mm³, and wherein said temperature of said welding die member is between 250°

and 300°

.

10. The process according to claim 2, wherein said fixed path is approximately equal to the thickness of said coverplate.

11. A process according to claim 2 wherein during pressing the welding die member and receiving member together, through the action of said welding die member material of said cover plate partially penetrates into the upper side of the plate means.