Glass fiber mat for stampable sheet, process for the production

Details Glass fiber mat for stampable sheet, process for the production Glass fiber mat for stampable sheet, process for the production

1997-02-07

2000-05-30

Jones, Deborah

Adhesive bonding and miscellaneous chemical manufacture

Methods

Surface bonding and/or assembly therefor

156148, 156222, 156296, 156312, 428 345, 428 347, 428 74, 428113, 4282994, 4283007, 428340, 428902, 442175, 442180, 442327, 427299, B27N 300

Patent

active

060687150

DESCRIPTION:

BRIEF SUMMARY
APPLICABLE FIELD OF THE INVENTION

The present invention relates to a glass fiber mat for a stampable sheet, a production process thereof, a stampable sheet employing the glass fiber mat, a production process thereof, and a production system therefor.


BACKGROUND OF THE INVENTION

A stampable sheet is a sheet form article, in which a thermoplastic resin is impregnated in reinforcement fibers. There are various stampable sheets depending upon production processes and forms of reinforcement fibers. As production processes of the stampable sheet, a lamination method and dispersing method have been known.
The lamination method is a method in which a fiber mat first is prepared from reinforcement fibers, the fiber mat and a thermoplastic resin sheet or molten thermoplastic resin sheet are stacked, and then, the thermoplastic resin is impregnated into the fiber mat by applying heat and pressure (U.S. Pat. Nos. 3,644,909, 3,713,962 and 3,850,723).
On the other hand, the dispersing method is a method for producing the stampable sheet in which after mixing and dispersing reinforcement fibers and thermoplastic resin, the mixture is shaped into a sheet form, and heat and pressure are applied to the sheet form mixture. This method is divided into a wet method to perform mixing and dispersing in water (Japanese Examined Patent Publication (Kokoku) No. Heisei 2-48423, Japanese Examined Patent Publication No. Heisei 3-4678 and Japanese Examined Patent Publication No. Heisei 4-40372) and a dry method to perform mixing and dispersing within a special mixer without using water (Japanese Examined Patent Publication No. Heisei 3-55312, Japanese Examined Patent Publication No. Heisei 2-42058 and Japanese Unexamined Patent Publication (Kokai) No. Heisei 4-173311). In the wet method, reinforcement short fibers and thermoplastic resin powder are mixed in water, made into a sheet by a paper machine by adding a flocculating agent or a binder, and water is removed to dry and to form a sheet. A plurality of sheets are stacked as required, and heat and pressure are applied to obtain the stampable sheet. On the other hand, in the dry method, reinforcement fibers and thermo-plastic resin powder are mixed within a special mixing chamber, formed into sheet form on a belt, and heat and pressure are applied to form the stampable sheet.
The stampable sheet formed by lamination method has high impact strength since the reinforcement fibers are continuous fibers. However, it is difficult to cause local orientation due to mechanical entangling of the fibers. On the other hand, since the reinforcement fibers cannot be sufficiently filled into a rib or a boss, the design strength cannot be achieved. Therefore, freedom in designing of products is limited.
On the other hand, the stampable sheet produced by dispersing method has shorter fibers in comparison with the lamination method. This easily causes fluctuations of strength due to local orientation of the reinforcement fibers. Such sheet also has low impact strength. On the other hand, since the reinforcement fibers can be filled even into a rib or boss, designing of the products is easy.
Therefore, there have been several proposals for obtaining the features of short fiber reinforcement in a stampable sheet of long fiber reinforcement typically obtained by the lamination method.
For example, examples of attempts for improvement by impregnating a resin containing short fibers in a long fiber mat have been disclosed in Japanese Unexamined Patent Publication No. Showa 48-80172, Japanese Unexamined Patent Publication No. Showa 54-21476, Japanese Unexamined Patent Publication No. Showa 55-161618, Japanese Unexamined Patent Publication No. Showa 57-100029 and Japanese Examined Patent Publication No. Heisei 4-65854. However, in such methods, as pointed out in Japanese Unexamined Patent Publication No. Showa 64-4320, most of the short fibers are filtered by the long fiber mat to penetrate almost only resin into the mat. Then, most of the short fibers form a layer in the vicinity of the surface of the

REFERENCES:
patent: 4315789 (1982-02-01), Tongel
patent: 5565049 (1996-10-01), Simmons et al.
patent: 5681887 (1997-10-01), Ikeda et al.

Affiliated with

Also associated with

Rating

Glass fiber mat for stampable sheet, process for the production does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Glass fiber mat for stampable sheet, process for the production , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Glass fiber mat for stampable sheet, process for the production will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1907604