Apparatus and method for manufacturing multi-component plastic molded parts

Abstract

In a method of making multi-component plastic molded parts, using an apparatus which includes two outer platens with first half-molds, and a middle platen with second half-molds interacting with the first half-molds such as to define cavities in two parting planes for injection of a plastic melt and/or a PUR mixture, one of the first and second half-molds can move in increments relative to the other one of the first and second half-molds, thereby forming different cavities in the parting planes from cycle to cycle. In a first cycle preforms are produced in respective cavities and then held in one of the first and second half-molds as the other one of the first and second half-molds moves in increments. Further components can then be injected into cavities formed in the parting planes from cycle to cycle, while another process step can be executed from cycle to cycle in free half-molds.

1 . A method of making multi-component plastic molded parts, using an apparatus which includes two outer platens with outer first half-molds, and a middle platen with middle second half-molds interacting with the first half-molds such as to define cavities in two parting planes for injection of a plastic melt and/or a PUR mixture, said method comprising the steps of:
 allowing one of the first and second half-molds to move in increments in relation to the other one of the first and second half-molds to thereby form different cavities in the two parting planes from cycle to cycle;   producing in a first cycle preforms in the cavities respectively formed in the two parting planes between respective ones of the first and second half-molds;   holding the preforms in one of the first and second half-molds as the other one of the first and second half-molds moves in increments and injecting further components into the cavities formed in the two parting planes from cycle to cycle; and   allowing from cycle to cycle to execute a pretreatment or another process step in free ones of the first and second half-molds.   
   
   
       2 . The method of  claim 1 , wherein the middle platen has a cube-shaped or prism-shaped configuration, said moving step including the step of rotating the middle platen in relation to the outer platens about a vertical axis or a horizontal axis, with the different cavities being formed in the two parting planes from cycle to cycle. 
   
   
       3 . The method of  claim 1 , wherein the middle platen has two parallel platen areas, with one of the platen areas carrying a first plurality of the second half-molds of the middle platen, which cooperate with one of the first half-molds of the outer platens, and the other one of the platen areas carrying a second plurality of the second half-molds of the middle platen, which cooperate with another one of the first half-molds of the outer platens, said moving step including the step of linearly moving the middle platen in increments in perpendicular relationship to a longitudinal apparatus axis, with the different cavities being formed in the two parting planes from cycle to cycle. 
   
   
       4 . The method of  claim 3 , wherein the middle platen has a plate-shaped configuration. 
   
   
       5 . The method of  claim 1 , wherein one of the outer platens carries a first plurality of the first half-molds and the other one of the outer platens carries a second plurality of the first half-molds, said moving step including the step of linearly moving the outer platens in increments in relation to the middle platen. 
   
   
       6 . The method of  claim 1 , wherein one of the outer platens carries a first plurality of the first half-molds and the other one of the outer platens carries a second plurality of the first half-molds, said moving step including the step of rotating the outer platens in increments in relation to the middle platen. 
   
   
       7 . The method of  claim 1 , wherein the producing step includes the step of molding the preforms from a thermoplastic component in the two parting planes, and further comprising the step of flooding the preforms with a PUR mixture in the two parting planes in a second cycle. 
   
   
       8 . The method of  claim 1 , wherein the producing step includes the step of molding the preforms from a thermoplastic component in the two parting planes, and further comprising the step of molding a second thermoplastic component onto the preforms. 
   
   
       9 . The method of  claim 1 , wherein the producing step includes the step of molding the preforms from a first PUR mixture in the two parting planes, and further comprising the step of flooding the preforms with a second PUR mixture in the two parting planes in a second cycle. 
   
   
       10 . The method of  claim 1 , wherein the pretreatment or other process step involves one process selected from the group consisting of preheating, addition of a mold release agent, venting of the mold release agent, cleaning, addition of varnish for an In Mold Coating process, and placing and securing at least one of insertion parts and decoration materials. 
   
   
       11 . The method of  claim 10 , wherein the at least one of the insertion parts and decoration materials is selected from the group consisting of fabrics, foils, aluminum strips, and metal strips. 
   
   
       12 . The method of  claim 1 , further comprising the step of successively opening the parting planes. 
   
   
       13 . The method of  claim 12 , wherein the parting planes are opened when PUR mixtures in the two parting planes have different reaction times or the preforms in the two parting planes have different cooling periods. 
   
   
       14 . The method of  claim 1 , for the production of a pair of plastic molded parts, comprised of a right part and a left part, wherein the right part is produced in one of the parting planes; and the left part is produced in the other one of the parting planes. 
   
   
       15 . The method of  claim 1 , for the production of different plastic molded parts, wherein a main component is produced in one of the parting planes; and a plurality of accessory components are produced in the other one of the parting planes. 
   
   
       16 . The method of  claim 9 , further comprising the step of heating the half-mold with the first PUR mixture before the flooding step. 
   
   
       17 . The method of  claim 16 , wherein the heating step is executed while the preform is produced. 
   
   
       18 . The method of  claim 9 , further comprising the step of subjecting the PUR mixture to a compression during the flooding step to contract or expand the cavity formed in the respective one of the parting planes. 
   
   
       19 . The method of  claim 18 , wherein contraction or expansion of the cavity is implemented by moving half-molds or inserts in the half-molds relative to each other. 
   
   
       20 . The method of  claim 1 , wherein the execution of the pretreatment is performed by at least one operator; and further comprising the step of providing a safety device and allowing a movement of machine parts only when the at least one operator actuates the safety device. 
   
   
       21 . The method of  claim 20 , wherein the machine parts involve the middle platen or movable outer platens. 
   
   
       22 . The method of  claim 21 , further comprising the steps of defining a safety area, monitoring the safety area by light barriers, and allowing a movement of the machine parts only when the at least one operator has left the safety area and actuated the safety device. 
   
   
       23 . Apparatus for making multi-component plastic molded parts, comprising:
 two outer platens having outer half-molds;   a middle platen positioned between the outer platens; and   a clamping unit for closing and locking four of the half-molds of the outer platens and the middle platen at one time to thereby define two parting planes;   wherein the middle platen carries at least two of a first type of half-molds that are different from each other and at least two of a second type of half-molds that are different from each other so as to successively form in the parting planes with the half-molds of the outer platens different cavities while leaving free half-molds for allowing pretreatment or a further process step, and   wherein the outer half-molds are constructed for holding molded parts.   
   
   
       24 . The apparatus of  claim 23 , further comprising at least one member selected from the group consisting of injection units and PUR facility, and constructed for docking on at least one of the outer and middle platens and half-molds of the outer and middle platens. 
   
   
       25 . The apparatus of  claim 23 , wherein the middle platen has four half-molds. 
   
   
       26 . The apparatus of  claim 23 , wherein the middle platen is constructed for rotation. 
   
   
       27 . The apparatus of  claim 23 , wherein the middle platen has a cube-shaped or prism-shaped configuration and is constructed for rotation about a vertical axis or a horizontal axis so as to form, from cycle to cycle, the different cavities in the parting planes. 
   
   
       28 . The apparatus of  claim 23 , wherein the middle platen has two platen areas, said first type of half-molds being arranged on one of the platen areas and cooperate with a half-mold of one outer platen, and said second type of half-molds being arranged on the other one of the platen areas and cooperate with a half-mold of the other outer platen, said the middle platen constructed for linear movement in increments in perpendicular relationship to a longitudinal apparatus axis so as to form the different cavities in the two parting planes from cycle to cycle. 
   
   
       29 . The apparatus of  claim 28 , wherein the middle platen has a plate-shaped configuration. 
   
   
       30 . The apparatus of  claim 23 , wherein one of the outer platens is fixed and the other one of the outer platen is movable, said middle platen being movable longitudinally between the outer platens on a sliding table. 
   
   
       31 . The apparatus of  claim 23 , wherein the outer platens are movable, said middle platen being fixedly arranged between the outer platens and having a cube-shaped configuration, said middle platen having two adjacent first half-molds cooperating with one of the two movable outer platens and two adjacent second half-molds cooperating with the other one of the two movable outer platens. 
   
   
       32 . The apparatus of  claim 23 , wherein the PUR facility is docked onto each of the half-molds of the outer platens and includes two injection units and two mixing head docked onto the half-molds of the outer platens in one-to-one correspondence. 
   
   
       33 . The apparatus of  claim 23 , wherein half-molds of one of the parting planes are constructed for the production of a right part of a pair of plastic molded parts, and half-molds of the other parting plane are constructed for the production of a left part of the pair of plastic molded parts. 
   
   
       34 . The apparatus of  claim 23 , wherein half-molds of one of the parting planes are constructed for the production of a main component, and half-molds of the other parting plane are constructed for the production of at least one accessory component. 
   
   
       35 . The apparatus of  claim 30 , further comprising a safety device adapted for actuation by an operator, and a safety area monitored by light barriers, wherein a movement of a machine part can be blocked and released depending on the safety device and the safety area. 
   
   
       36 . The apparatus of  claim 35 , wherein the machine part is the middle platen. 
   
   
       37 . The apparatus of  claim 23 , further comprising at least one dummy mold provided in one of the parting planes. 
   
   
       38 . Apparatus for making multi-component plastic molded parts, comprising:
 two outer platens, each having mounted thereon a plurality of half-molds;   a middle platen positioned between the outer platens;   a clamping unit for closing and locking four of the half-molds of the outer platens and the middle platen at one time to thereby define two parting planes;   wherein the middle platen has a plurality of mold halves which are constructed to hold molded parts,   wherein the outer platens move in increments in relation to the middle platen to thereby form in increments different cavities in the two parting planes and leaving free half-molds for allowing pretreatment or a further process step.   
   
   
       39 . The apparatus of  claim 38 , further comprising at least one member selected from the group consisting of injection units and PUR facility, and constructed for docking on at least one of the outer and middle platens and half-molds of the outer and middle platens. 
   
   
       40 . The apparatus of  claim 38 , wherein the outer platens move linearly in relation to the middle platen. 
   
   
       41 . The apparatus of  claim 38 , wherein the outer platens rotate about a horizontal axis in relation to the middle platen. 
   
   
       42 . The apparatus of  claim 38 , wherein the outer platens are constructed in the form of sliding tables which are linearly movable in perpendicular relationship to a longitudinal apparatus axis. 
   
   
       43 . The apparatus of  claim 38 , wherein the outer platens are constructed in the form of rotary tables which are rotatable about a horizontal axis. 
   
   
       44 . The apparatus of  claim 38 , wherein one of the outer platens is fixed and the other one of the outer platen is movable, said middle platen being movable longitudinally between the outer platens on a sliding table. 
   
   
       45 . The apparatus of  claim 38 , wherein the outer platens are movable, said middle platen being fixedly arranged between the outer platens and having a cube-shaped configuration, said middle platen having two adjacent first half-molds cooperating with one of the two movable outer platens and two adjacent second half-molds cooperating with the other one of the two movable outer platens. 
   
   
       46 . The apparatus of  claim 39 , wherein the PUR facility is docked to each of the half-molds of the outer platens and includes two injection units and two mixing heads docked to the half-molds of the outer platens in one-to-one correspondence. 
   
   
       47 . The apparatus of  claim 38 , wherein half-molds of one of the parting planes are constructed for the production of a right part of a pair of plastic molded parts, and half-molds of the other parting plane are constructed for the production of a left part of the pair of plastic molded parts. 
   
   
       48 . The apparatus of  claim 38 , wherein half-molds of one of the parting planes are constructed for the production of a main component, and half-molds of the other parting plane are constructed for the production of at least one accessory component. 
   
   
       49 . The apparatus of  claim 38 , further comprising a safety device adapted for actuation by an operator, and a safety area monitored by light barriers, wherein a movement of a machine part can be blocked and released depending on the safety device and the safety area. 
   
   
       50 . The apparatus of  claim 49 , wherein the machine part is the middle platen. 
   
   
       51 . The apparatus of  claim 38 , further comprising at least one dummy mold provided in one of the parting planes.