Claims
- 1-62. Canceled.
- 63. Method of reducing the inner layer thickness and improving the layer adhesion in a multilayer injection-molded plastic article, the method comprising:
firstly molding an inner sleeve layer between a first mold cavity and core, the first mold cavity being heated to maintain an outer surface of the inner sleeve layer at an elevated temperature; transferring the core and sleeve layer to a second mold cavity and secondly molding an outer layer over the sleeve layer while the outer surface is at the elevated temperature, the outer layer having a thickness greater than the thickness of the inner sleeve layer, where the elevated temperature is selected to provide melt adhesion between the inner sleeve and the outer layer during the second molding step.
- 64. The method of claim 63, wherein the melt adhesion between the inner sleeve and outer layer includes diffusion bonding.
- 65. The method of claim 63, wherein the melt adhesion between the inner sleeve and outer layer includes chain entanglement.
- 66. The method of claim 63, wherein the sleeve forms an upper sleeve portion of the article, and the outer layer forms a lower body portion of the article.
- 67. The method of claim 66, wherein a lower end of the upper sleeve portion and un upper end of the lower body portion are joined in an intermediate portion of the article.
- 68. The method of claim 63, wherein the first molding step forms the inner sleeve as a full-length inner layer and an upper surface of the article.
- 69. The method of claim 63, wherein the first molding step forms the inner sleeve as an upper length portion of the article and an upper surface of the article.
- 70. The method of claim 63, wherein the outer layer comprises multiple outer layers.
- 71. The method of claim 63, wherein the article is a preform.
- 72. The method of claim 71, wherein the first molding step forms a neck finish portion of the preform.
- 73. The method of claim 72, wherein the neck finish portion is molded from a polymer, which crystallizes during the first molding step.
- 74. The method of claim 72, wherein the neck finish portion is molded from a first polymer material having a higher glass transition temperature than a second polymer material, which forms the outer layer.
- 75. The method of claim 63, wherein the sleeve has a weight in a range on the order of 10 to 20 percent of a total weight of the article.
- 76. The method of claim 63, wherein the sleeve has a wall thickness in a range on the order of 0.5 to 1.5 mm (0.02 to 0.06 inch).
- 77. The method of claim 76, wherein the outer layer has a wall thickness in a range on the order of 2.50 to 6.35 mm (0.10 to 0.25 inch).
- 78. The method of claim 63, wherein the inner sleeve is formed of a first material having a first melt temperature, and the outer layer includes a second layer adjacent the inner sleeve and made of a second material having a second melt temperature lower than the first melt temperature.
- 79. The method of claim 63, wherein the first mold cavity is at a first cavity temperature and the second mold cavity is at a second cavity temperature lower than the first cavity temperature.
- 80. The method of claim 79, wherein the core is at a core temperature, which is less than the first cavity temperature.
- 81. The method of claim 63, wherein the inner sleeve is formed of a first material having a first Tg, and the elevated temperature is in a range on the order of 5-20° C. below the first Tg.
- 82. The method of claim 63, wherein the sleeve is molded from a first material selected from the group consisting of homopolymers, copolymers, and blends of polyethylene naphthalate (PEN).
- 83. The method of any one of claim 63, wherein the outer layer includes at least one layer molded from a second material selected from the group consisting of polyethylene terephthalate (PET), and oxygen scavenging material, recycled PET, polyethylene, polypropylene, polyacrylate, polycarbonate, polyacrylonitrile, nylon, and copolymers and blends thereof.
- 84. The method of claim 63, wherein the article has a sidewall portion in which the inner sleeve has a first thickness (t1) and the outer layer has a second thickness (t2) and the ratio of t2:t1 is greater than on the order of 4:1.
- 85. The method of claim 63, wherein the article has a first thickness (t1) and the outer layer has a: second thickness (t2), and the ratio of t2:t1 is on the order of from 1.2:1 to 8:1.
- 86. The method of claim 63, wherein the inner sleeve is substantially crystallized and the outer layer is substantially amorphous.
- 87. The method of claim 63, wherein the inner sleeve is made of a first material and the outer layer is made of a second material, and the second material has a lower crystallization rate compared to the first material.
- 88. The method of claim 63, wherein first and second cores are provided, and wherein during a first cycle the first core is positioned in the first mold cavity to form a first inner sleeve, and the second core, having a second inner sleeve positioned thereon, is simultaneously positioned in the second mold cavity for molding a second outer layer on the second inner sleeve.
- 89. The method of claim 88, wherein the first molding step includes an initial no-action period while the second molding step proceeds in order to facilitate the transfer while the outer surface of the sleeve layer is at the elevated temperature.
- 90. The method of claim 63, wherein the sleeve is molded of a first material selected from the group consisting of polyester, polyester with nucleating agents, acrylate, polyethylene naphthalate (PEN), polycarbonate, polypropylene, polyamide, polysulfone, acrylonitrile styrene, and copolymers and blends thereof.
- 91. The method of claim 90, wherein the outer layer includes a second material selected from the group consisting of homopolymers, copolymers, and blends of any one or more of: polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and recycled PET.
- 92. The method of claim 63, wherein the article has a body portion and the method further comprises expanding the body portion of the article to form an expanded article having a substantially transparent and biaxially-oriented body portion.
- 93. The method of claim 63, wherein the method further comprises cooling the article below a first glass transition temperature of a first material in the article, reheating the article above the first glass transition temperature, and expanding the reheated article to form an expanded article.
- 94. The method of claim 63, wherein the expanded article has a high Tg or crystallized upper neck finish portion and a substantially transparent, biaxially-oriented body portion.
- 95. An apparatus for making multi-layer injection-molded plastic articles comprising:
a first mold cavity set and a second mold cavity set, each first cavity being adapted to form an inner sleeve layer and each second cavity being adapted to form an outer layer, the outer layer having a thickness greater than the thickness of the inner sleeve layer; a transfer mechanism with first and second core sets for successively positioning the first and second core sets in the first and second cavity sets; wherein the first core set is positionable in the first cavity set for molding a set of inner sleeve layers on the first core set, while the second core set is positionable in the second cavity set for molding, over a previously-molded set of inner sleeve layers on the second core set, a second set of outer layers; and means for heating the first cavity set so as to maintain an outer surface of the inner sleeve layer at an elevated temperature during transfer and molding of the outer layer thereover, the elevated temperature being selected to provide melt adhesion between the inner sleeve and outer layer.
- 96. The apparatus of claim 95, wherein the first cavity and core define a first wall thickness (t1) and the second cavity and core define a second wall thickness (t2), and wherein a ratio of t2:t1 is greater than on the order of 4:1.
- 97. The apparatus of claim 95, wherein the transfer mechanism is a rotatable turret.
- 98. The apparatus of claim 95, wherein the transfer mechanism is a reciprocating shuttle.
- 99. The apparatus of claim 95, including means for initiating molding of the outer layers in the second cavity set while maintaining a no-action period in the first cavity set in order to facilitate transfer while the outer surface of the sleeve layer is at the elevated temperature.
- 100. The method of claim 63 comprising:
injection molding a first thermoplastic material to form a first preform portion including the inner sleeve layer having an average percent crystallinity of at least about 30 percent; and injection molding a second thermoplastic material to form a second preform portion including the outer sleeve, which remains substantially amorphous.
- 101. The method of claim 100, wherein the first portion is substantially a neck portion and the second portion is substantially a body-forming portion.
- 102. The method of claim 100, wherein the second material has a lower crystallization rate compared to the first material.
- 103. The method of claim 102, wherein the first material is selected from the group consisting of polyester, polyester with nucleating agents, arylate polymers, polyethylene naphthalate (PEN), polycarbonate, polypropylene, polyamide, polysulfone, acrylonitrile styrene, and copolymers and blends thereof.
- 104. The method of claim 103, wherein the second material is selected from the group consisting of homopolymers, copolymers and blends of any one or more of: polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and recycled PET.
- 105. The method of claim 102, further comprising expanding the second portion to form a substantially transparent and biaxially-oriented body of a container.
- 106. The method of claim 63, comprising:
first molding the inner sleeve on a core positioned in the first mold cavity, the first molding step including a filling stage and a pressure boost stage but substantially no holding and cooling stage so as to maintain the outer surface of the inner sleeve at an elevated temperature for a second molding step; removing the sleeve on the core and transferring the same without substantial delay to the second mold cavity; and second molding the outer layer over the sleeve in the second mold cavity to form the multi-layer injection-molded article.
- 107. The method of claim 63, wherein the inner sleeve is made of a PEN polymer material and the elevated temperature is in range on the order of 60-120° C.
- 108. The method of claim 107, wherein the first molding step has a cycle time on the order of no greater than 8 seconds.
- 109. The method of claim 107, wherein the cycle time is in a range on the order of 4-8 seconds.
- 110. The method of claim 110, wherein the first cavity temperature is in a range on the order of 40-120° C. and the core temperature is in a range on the order of 5-80° C.
- 111. The method of claim 110, wherein the first cavity temperature is in a range on the order of 75-95° C. and the core temperature is in a range on the order of 60-70° C.
- 112. The method of claim 110, wherein the first cavity temperature is in a range on the order of 100-110° C. and the core temperature is in a range on the order of 5-15° C.
- 113. The method of claim 110, wherein the PEN polymer material has a melt temperature in a range on the order of 275-295° C. and the elevated temperature is in a range on the order of 90-110° C.
- 114. The method of claim 63, wherein the outer layer includes a PET polymer material adjacent the inner sleeve, the PET polymer material having a melt temperature in a range on the order of 260-275° C. and the second molding step being carried out at a cavity pressure in a range on the order of 55×106-103×106 N/m2 (8000-15,000 psi).
- 115. The method of claim 63, wherein the inner sleeve is made of a polyester polymer material, which is crystallized during the first molding step and the elevated temperature is in a range on the order of 80-140° C.
- 116. The method of claim 115, wherein the first molding step has a cycle time on the order of no greater than 8 seconds.
- 117. The method of claim 116, wherein the cycle time is in a range on the order of 5-8 seconds.
- 118. The method of claim 115, wherein the first cavity temperature is in a range on the order of 80-150° C. and the core temperature is in a range on the order of 5-60° C.
- 119. The method of claim 118, wherein the first cavity temperature is in a range on the order of 110-120° C. and the core temperature is in a range on the order of 5-15° C.
- 120. The method of claim 115, wherein the polyester polymer material has a melt temperature in a range on the order of 280-290° C. and the elevated temperature is in a range on the order of 115-125° C.
- 121. The method of claim 115, wherein the outer layer includes a PET polymer material adjacent the inner sleeve, the PET polymer material having a melt temperature in a range on the order of 270-285° C. and the second molding step being carried out at a cavity pressure in a range on the order of 55×106-103×106 N/m2 (8000-15,000 psi).
- 122. The method of claim 106, wherein:
the inner sleeve is made of a PEN polymer material; during the second molding step the outer surface of the sleeve is at an elevated temperature in a range on the order of 100-110° C. and the outer layer includes a first outer layer of a PET polymer material adjacent the inner sleeve, and wherein the PET polymer material has a melt temperature in a range on the order of 260-275° C. and the second molding step is carried out at a cavity pressure in a range on the order of 55×106-103×106 N/m2 (8000-15,000 psi) to achieve melt adhesion between the inner sleeve and the outer layer during the second molding step.
- 123. The method of claim 106, wherein:
an inner sleeve is made of a PEN polymer material mold; during the second molding step the outer surface of the sleeve is at an elevated temperature in a range on the order of 90-100° C. and the outer layer includes a first outer layer of a PET polymer material adjacent the inner sleeve, and wherein the PET polymer material has a melt temperature in a range on the order of 260-275° C. and the second molding step is carried out at a cavity pressure in the range on the order of 55×106-103×106 N/m2 (8000-15,000 psi) to achieve melt adhesion between the inner sleeve and the outer layer during the second molding step.
- 124. The method of claim 106, wherein:
the inner sleeve is made of a polyester polymer material, which is crystallized on the core during the first molding step; and during the second molding step the outer surface of the sleeve is at an elevated temperature in a range on the order of 115-125° C., and the outer layer includes a first outer layer of a PET polymer adjacent the inner sleeve and wherein the PET polymer material has a melt temperature in a range on the order of 270-285° C. and the second molding step is carried out at a cavity pressure in the range on the order of 55×106-103×106 N/m2 (8000-15,000 psi) to achieve melt adhesion between the inner sleeve and the outer layer during the second molding step.
- 125. The method of claim 106, wherein the sleeve has a weight in a range on the order of 10 to 20 percent of a total weight of the article.
- 126. The method of claim 106, wherein the sleeve has a wall thickness in a range on the order of 0.5 to 1.5 mm (0.02 to 0.06 inch).
- 127. The method of claim 126, wherein the outer layer has a wall thickness in a range on the order of 2.50 to 6.35 mm (0.10 to 0.25 inch).
- 128. The method of claim 106, wherein the inner sleeve is made of a PEN polymer material and the elevated temperature is in a range on the order of 60-120° C.
- 129. The method of claim 106, wherein the first molding step has a cycle time on the order of no greater than 8 seconds.
- 130. The method of claim 106, wherein the cycle time is in a range on the order of 4-8 seconds.
- 131. The method of claim 106, wherein the first cavity temperature is in a range on the order of 40-120° C. and the core temperature is in a range on the order of 5-80° C.
- 132. The method of claim 131, wherein the first cavity temperature is in a range on the order of 75-95° C. and the core temperature is in a range on the order of 60-70° C.
- 133. The method of claim 131, wherein the first cavity temperature is in a range on the order of 100-110° C. and the core temperature is in a range on the order of 5-15° C.
- 134. The method of claim 128, wherein the PEN polymer material has a melt temperature in a range on the order of 275-295° C. and the elevated temperature is in a range on the order of 90-110° C.
- 135. The method of claim 128, wherein the outer layer includes a PET polymer material adjacent the inner sleeve, the PET polymer material having a melt temperature in a range on the order of 260-275° C. and the second molding step being carried out at a cavity pressure in a range on the order of 55×106-103×106 N/m2 (8000-15,000 psi).
- 136. The method of claim 106, wherein the inner sleeve is made of a polyester polymer material, which is crystallized during the first molding step and the elevated temperature is in a range on the order of 80-140° C.
- 137. The method of claim 136, wherein the first molding step has a cycle time on the order of no greater than 8 seconds.
- 138. The method of claim 136, wherein the cycle time is in a range on the order of 5-8 seconds.
- 139. The method of claim 136, wherein the first cavity temperature is in a range on the order of 80-150° C. and the core temperature is in a range on the order of 5-60° C.
- 140. The method of claim 139, wherein the first cavity temperature is in a range on the order of 110-120° C. and the core temperature is in a range on the order of 5-15° C.
- 141. The method of claim 136, wherein the polyester polymer material has a melt temperature in a range on the order of 280-290° C. and the elevated temperature is in a range on the order of 115-125° C.
- 142. The method of claim 136, wherein the outer layer includes a PET polymer material adjacent the inner sleeve, the PET polymer material having a melt temperature in a range on the order of 270-285° C. and the second molding step being carried out at a cavity pressure in a range on the order of 55×106-103×106 N/m2 (8000-15,000 psi).
RELATED APPLICATIONS
[0001] This is a continuation-in-part of copending and commonly owned U.S. Ser. No. 08/534,126 filed Sep. 26, 1995, entitled “PREFORM AND CONTAINER WITH CRYSTALLIZED NECK FINISH AND METHOD OF MAKING THE SAME,” by Wayne N. Collette and Suppayan M. Krishnakumar, which in turn is a continuation-in-part of copending and commonly owned U.S. Ser. No. 08/499,570 filed Jul. 7, 1995, entitled “APPARATUS AND METHOD FOR MAKING MULTILAYER PREFORMS,” by Suppayan M. Krishnakumar and Wayne N. Collette, both of which are hereby incorporated by reference in their entirety.
Continuations (3)
|
Number |
Date |
Country |
Parent |
10209896 |
Aug 2002 |
US |
Child |
10887872 |
Jul 2004 |
US |
Parent |
08981467 |
Mar 1998 |
US |
Child |
10209896 |
Aug 2002 |
US |
Parent |
PCT/US96/11413 |
Jul 1996 |
US |
Child |
08981467 |
Mar 1998 |
US |
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
08534126 |
Sep 1995 |
US |
Child |
08981467 |
Mar 1998 |
US |
Parent |
08499570 |
Jul 1995 |
US |
Child |
08534126 |
Sep 1995 |
US |