Unlock instant, AI-driven research and patent intelligence for your innovation.

Chilled injection molding during ophthalmic lens manufacture

A lens and coolant technology, applied in home appliances, optical components, other home appliances, etc., can solve the problem of reducing the ability of polymer molds to replicate optical characteristics, increasing the cold stress of materials, orientation non-uniformity, affecting the properties of parts, etc. question

Inactive Publication Date: 2009-08-26
JOHNSON & JOHNSON VISION CARE INC
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, low mold temperatures also increase the magnitude, orientation and additional inhomogeneity of material cold stresses
Typically, these variables adversely affect the properties of the part
Several negative effects can be part warping, which will reduce the ability of the polymer mold to replicate the desired optical characteristics in subsequent lenses

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Chilled injection molding during ophthalmic lens manufacture
  • Chilled injection molding during ophthalmic lens manufacture
  • Chilled injection molding during ophthalmic lens manufacture

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0058]As shown in Table 1, Table 2 and Table 3 below, experiments have shown that lowering the mold temperature results in better dimensional stability of the part when either the polypropylene material or the Zeonor 1060R / polypropylene blend is used. In some embodiments, the improved dimensional stability is due to changes in the polypropylene morphology that provide the desired dimensionally constant polypropylene. Relatively high mold temperatures, molds using a water temperature inlet of 10°C or less with simultaneous use of 9544MED will produce molds with good mold properties at reduced cycle times.

[0059] Table 1

[0060]

[0061] Table 2

[0062] method 1

Method 2

period time

Second

2.9

2.8

Mold temperature (A side and B

side)

℃

10

7

Hold time (first / second /

third fourth)

Second

1

0.9

radius standard deviation

Micron

0.0055 ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The present invention includes molds for forming ophthalmic lenses, such as contact lens. In particular, the present invention relates to apparatus, molds and methods for fashioning mold parts used to fashion an ophthalmic lens which includes cooling a mold structure used to fashion a mold part prior to depositing a molten material into the mold structure.

Description

[0001] related application [0002] This application claims priority to US Provisional Application Serial No. 60 / 827,176, filed September 27,2006. technical field [0003] This invention relates to molds for forming ophthalmic lenses. More specifically, the present invention relates to an apparatus and method for making molds for plastic ophthalmic lenses at reduced injection molding temperatures. Background technique [0004] Typically ophthalmic lenses are manufactured by casting, in which monomeric or prepolymeric material is deposited in cavities defined between the optical surfaces of opposing mold parts. [0005] A multi-part mold for forming a hydrogel into a useful article, such as an ophthalmic lens, may include, for example, a first mold part having a convex portion corresponding to the back curve of the ophthalmic lens, and a concave surface corresponding to the front curve of the lens part of the second mold part. Here, the first mold part is generally referr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): B29D11/00B29C35/16
Inventor G·L·伯克米勒V·H·巴尔T·P·弗里曼S·F·安塞尔殷长虹J·M·托卡斯基
Owner JOHNSON & JOHNSON VISION CARE INC