DE2819377A1 - CONDUCTIVE PLASTIC - Google Patents

Description

Applicant: International Business Machines

Corporation, Armonk, N.Y. 10504

I bu-bd

^ Conductive plastic

The invention relates to an arrangement like the one above of claim 1 can be found.

iFor a variety of reasons, it may be useful to use Plastic Form-I Having parts available that are electrically conductive ι For example, it can be advantageous to prevent electrostatic charging j, while on the other hand it may be necessary! an insulating outer skin, e.g. in the case of a housing, is present to have. A wide field of application arises where I electrical devices and equipment are to be shielded from the radiation of electromagnetic waves, or where radiation from electrical devices is to be effectively prevented by shielding. This is especially true for devices for use in data processing systems. Please refer to the publications in "IBM Technical Disclosure Bulletin "Volume 19, No. 7, September 1976 pages 2412 and 2413 are referenced, where further details can be found find this. From this it can be seen that when using conductive plastic molded parts as the housing, certain manufacturing simplifications result for this.

But conductive plastic molded parts are not only used in electrical devices of advantage, but also for devices where heat is to be dissipated, which of course also applies to electrical ones operated facilities may also be the case. In other words, a conductive plastic molding is lost Can also be used as a replacement for cooling plates or cooling fins.

PO 975 014X, PO 977 015

809847/0715

set. Another field of application arises in heating devices for low temperature resistance heating.

When using flexible and pliable plastic molded parts flexibility and conductivity can also be combined in an advantageous manner.

U.S. Patent 3,556,855 is for a particular Use case shown in which way conductive plastic! molded parts using metal-coated glass fibers can be made as a filling insert. In detail, this serves to ensure a good dispersion of metal-coated pieces of glass fiber To achieve in plastic, a heated two-roller mill. For this purpose, the plastic is first rolled to then subsequently to add the metal-coated glass fibers, which are then broken by the continued rolling process are embedded in the plastic compound, the rolling process being continued until the initially formed Skeins have disappeared. The conductive plastic layer that results after the completion of the rolling process is made available cut to size according to a tabletted molding compound.

An electrically conductive plastic molding compound produced in this way suffers from the fact that the conductivity inevitably falls below it of a certain value, because on the one hand the mutual contact of the metallbeschichtil * i pieces of glass fiber with each other extremely bad is, and on the other hand, the glass fiber filler can not be added as much, if not the other properties of the plastic should be impaired, which not least also for the later machinability of the molding compound can be decisive.

PO 975 014X, PO 977 015

809847/0715

! The object of the invention is therefore to provide a leading To provide plastic molding compound of the type described above, in which a desired conductivity is established during manufacture without the inherent ; lent, advantageous characteristics, e.g. for processing

j the molding compound as well as the application or use of the finished ■ Molding, get lost.

According to the invention, this object is achieved, as is the case with the identifier of claim 1 can be found.

: 'According to the invention, metal-coated glass I fibers coated with plastic in a strand process,

ibzw. embedded therein to then the resulting plastic strand with a fiberglass core to provide the! molding compound to be cut into tablets.

It has been shown that when such tablets are used to create molded parts, they have an anisotropic conductivity possess, which results from the fact that the individual pieces of glass fiber are parallel to each other in the direction of flow during casting align so that no or only an extremely reduced electrical conductivity perpendicular to the direction of flow come about when creating the molding.

Molded parts with such properties are of particular advantage in certain applications. On the other hand is but it is for certain applications, such as special ones Shielding purposes advantageous when the metal-coated Pieces of fiberglass in the finished molding under random Orientation are embedded in the plastic, so that the electrical conductivity is the same in all directions Values. Investigations have been carried out on this.

PO 975 014X, PO 977 015

809847/0715

281837?

by producing test samples from transparent plastic with metal-coated fiberglass pieces embedded therein have been. The random orientation of the metal-coated fiberglass pieces appeared to be apparent when looking at the transparent Confirm plastic plate. However, on closer examination it has been shown that below the surface With random orientation of the metal-coated fiberglass ■ pieces, the fiberglass pieces embedded here are aligned parallel to one another, namely in the direction of flow To water.

Furthermore, it has been shown that the random orientation of the glass fibers on the surface of the molded part is probably due to the friction of the fluid with the shape and the resulting turbulence in the areas of the flowing j the plastic comes about. The surface hardens first j

with the randomly oriented metal-coated glass' pieces of fiber are fixed in their position fairly quickly. In the same way it can be seen that only partially filled Test pattern shape, the leading edge of the resulting plastic molded part, also an indiscriminate orientation of the has metal-coated glass fiber pieces, which is also probably due to turbulence occurring during pouring. the Internal parts of molded parts remain hot and in the molten state after casting, so that there are less turbulence consequences here are to be recorded, and the pieces of glass fiber located here generally in the direction of the flow process during casting are aligned. It should therefore be clear that molded parts with anisotropic electrical conductivity, as desired, have provided. However, if the electrical conductivity wedge of a plastic molded part is to be the same in all directions, then, according to an advantageous development of the invention, care must be taken that the metal-coated dm.

PO 975 014X, PO 977 015

809847/0715

Pieces of glass fiber during casting, sometimes in a wide variety of ways ! Directions can disperse. For this purpose, twisted glass fiber strands embedded in the tablets are used in such a way that ! When casting a molded part, both individual metal-coated pieces of glass fiber scatter in all directions and the remaining pieces of fiberglass tangle. In this way It is ensured that a good, electrically conductive connection also results in the direction perpendicular to the ■ flow direction. It can be stated here again that these fiberglass balls are in the flow direction of the plastic ! line up, but they have a sufficient thickness in the direction perpendicular to the direction of flow, which together with * the scattered, individual metal-coated pieces of glass fiber can ensure good electrical conductivity in plastic in this direction.

As already said, it is necessary for this that at tablet manufacture a twisted fiberglass core strand Applies. The metal-coated glass fibers in a tablet can be twisted in various ways be attached in order to then bring about the desired, advantageous entanglement when casting the molded part. So could E.g. the fiberglass core consists of a braided ribbon of a fiberglass web. Alternatively, a raw strand can be used made of twisted, metal-coated glass fibers to make tablets, which has been shown to be particularly good «Ate to form a ball when pouring such a mold tends. In order to provide a twisted raw spun strand, the metal-coated glass fibers are first used combined in tufts in order to then twist several tufts together, or around a central tuft with one another to interweave, as is the case with a wire rope. In contrast to this, there is a coil-like twist of

PO 975 O14X, PO 977 015

809847/0715

281937?

metal-coated glass fibers do not lead to a tangle formation a later molded part casting; This is probably due to the fact that the sink cores concerned are during the; Tablets made by virtue of the inherent tension in them: I!

! as well as the ι imposed on the glass fiber strand during extrusion Stretch tension when forces in mechanical working;

going to be free. .

The tangling effect due to the twisted, metal-coated pieces of glass fiber in the tablets can be eliminated
can be attributed to the fact that the glass fibers are only inadequately wetted during the production of tablets. Will this i

Tablets used in the casting process then mix
not the previously unwetted, metal-coated glass fibers
with the softened plastic and therefore strive to be in
to remain in their original form.

In summary, it can be said that when the molding composition according to the invention is used, a molded part with anisotropic conductivity or isotropic, depending on requirements, is advantageously obtained
Can provide conductivity.

Let further advantageous embodiments of the invention
can be found in the subclaims.

The invention will then be based on a description of the embodiment are explained in more detail.

To provide the molding composition according to the invention is the
Use of suitable, metal-coated glass fibers from
crucial importance. For this, however, it can be assumed that the selection of a certain metal for
the conductivity of the molded part to be produced does not

PO 975 014X, PO 977 015

8098A7 / 0715

281937?

- 10 -

^; is outgoing. However, there are other aspects, 'let', the use of certain metals over others depending appear conveniently on the intended application:

1. The metal should adhere well to the fiberglass. Chromium has been found to be good in this regard, however, J. the glass fibers due to the mechanical occurring in the process

ι Tensions destroyed. Aluminum shows only weak adhesion ability, whereas copper has medium adhesive properties. Zinc forms a porous coating with interruptions so that, as a result, a higher electrical resistance is recorded than it is for some applications ; purposes may be desirable. Nickel and titanium show good adhesion properties with the glass fibers and moreover have them still other desirable properties.

| 2. The metal should bond well with the one to be used Plastic. The metals in question meet these requirements.

3. The metal used must not enter into any harmful chemical reaction with the plastic used. Practical Investigations have shown nothing of the kind, but it might be conceivable that something like this could be expected in the case of beryllium-copper is.

! With regard to the plastic to be used, none have (Limitations shown.

{The metal-coated glass fibers are embedded in the plastic in such a way that the metal coating of the Glass fiber is not damaged. In contrast to this, conventional grinding processes even destroy the glass

PO 975 O14X, PO 977 015

809847/0715

j - 11 -

.fibers brought about. To provide the plastic strand with an embedded fiberglass strand is a polycarbonate plastic, e.g., dissolved in a common solution, in the present case e.g. with methyl chloride, in order to then spray the solution product onto the metal-coated glass fibers. ! The plastic strand is then dried in air, so that the solvent can escape and a solid strand of polycarbonate plastic with a fiberglass core results.

The percentage by weight of the metal-coated glass fibers in relation to the total weight of the plastic strand can be varied within wide limits vary, but it makes sense to keep them between about 20% to about 50% of the total mass. The strand is then blended into tablets to be used as a molding compound / üie-

Despite the poor adhesion of aluminum to glass fibers, caused by moisture on the glass fibers during vacuum deposition of aluminum, this combination is widely used in practice. Obviously, using a different method will produce better results. Here \ be drawn glass fiber strands from the melt and passed through the yiiniskus an aluminum smelter, where they receive the aluminum coating. A thread is formed from the aluminum-coated glass fibers and wound onto a spool. With regard to the envisaged embedding of the metal-coated

When fibers are inserted into a plastic, the thread is not provided with a sliding coating. The thread size is the same the usual ones for glass fibers, which are used for

serve to strengthen. The thickness of the metal layer coating on the glass fibers compared to the fiber thickness can be neglected.

PO 975 014X, PO 977 015

809847/0715

281937?

! To prepare for embedding the metal-coated glass fibers in plastic, a suitable binder is first applied to the glass fibers in the form of a ■ thin coating. • For this purpose, a polycarbonate plastic that is dissolved in methyl chloride can again be used, whereby after

The same order the metal-coated glass fibers prepared in this way be prepared for embedding in the polycarbonate plastic tablets by evaporating the methyl chloride. 'As mentioned above, other plastics can also be used accordingly. In the tablets to be created is (a core with a suitable number of strands of metal-coated Glass fibers provided. Basically, the ratio of glass fibers to plastic in a tablet could be determined hold regardless of how high the proportion of metal-coated glass fibers should be in the molded part to be created, because in the corresponding melting process too provided with cores Tablets Coreless tablets can be added to the extent that the desired proportion in the poured To obtain molded part.

It has been shown, however, that if too many glass fibers are present as the core in a tablet, the individual glass fibers become too different do not wet the tablet plastic so much that loose glass fibers can be observed at the ends of the tablets are. However, these loose glass fibers do not lead to adhesion with the plastic when the molded part is cast. If there are too few glass fibers in a tablet, the adhesion between the glass fiber and the plastic is also there not strong enough to be able to withstand an extrusion process in the manufacture of tablets. So it has been shown that Tablets with around 500 glass fibers are at the lower limit of the required adhesiveness, whereas tablets with around 1000 glass fibers already have insufficient wetting

PO 975 014X, PO 977 015

809847/0715

with plastic show; Show tablets with about 750 glass fibers good adhesion and good wetting.

To hold the fiberglass thread together until processing in molding compound to be able to, as described above, a thin 'plastic coating is applied, so that handling and supply i be facilitated during extrusion.

To provide tabletted molding compound, a plastic extruder is continuously fed with a glass fiber strand, ribbon, -hose fed to together with a plastic strand to be subjected to an extrusion process. The plastic is melted in the extruder, so that a plastic strand at the exit with a fiberglass core embedded therein. The plastic strand with a glass fiber core has a thickness between 3 to 6 mm and is cut into tablets of suitable length j. The tablets can have different transverse i have cuts, round, oval or rectangular. j

It is important for the invention that the metallized glass fibers are not cut into pieces of suitable length beforehand but only after they are embedded in a plastic strand. Namely, the metal-coated Glass fibers already cut to size before they are put into the tablets, then it cannot be avoided that the metal coating is damaged. Split metal coating shows stress points, which with subsequent Treatment lead to breaks, and the cut glass fibers also contain unwanted dust made of chipped pieces of glass and fragments of the metal coating. However, plastic strands with a fiberglass core are used cut into pieces, then it appears as if the plastic holds the glass fibers in place during the cutting process holds so that the metal coating on the glass fibers does not

PO 975 014X, PO 977 015

809847/0715

is seriously damaged in the area of the interfaces.

The relationship between tablet length and fiber length can be found in the table below.

i SAMPLE ABC p_ E

! Tablets- 3mm 6mm 10mm 12mm 19mm! length

^ Fiber length 0.2-0.3 1 mm 5 mm 5 mm

i mm

ι Samples A and B apply to molded parts made from tablets ! that are cut off with j metal-coated glass fibers are provided. It turns out that in all cases during the melting process to create the 'Molded the metal-coated glass fibers in shorter

(Lengths are broken to match the original fiberglass length in the tablet. This effect will be the Attributed to mixing process, which goes hand in hand with the casting process and is desirable in itself in order to ensure good distribution to achieve the metal-coated glass fibers in the finished molded part. As the length of the mixing process increases the breaking of the glass fibers apparently continues, but it has been found that for sufficient Mixture during a casting process, no harmful breaking of the glass fibers is recorded if the original glass fiber length about 10 mm, but preferably about 12 mm. It should be emphasized, however, that the glass fibers are so long should be as possible in order to improve the conductivity conditions in the formed part accordingly. Samples A and B do not show sufficient conductivity; Pattern C shows useful conductivity; whereas the Samples D and E produce satisfactory conductivity

PO 975 014X, PO 977 015

809847/0715

; Tablets longer than 20 mm are common 'Melting equipment is rather unwieldy. In and of itself, it is, as I said, »customary to reinforce plastic with glass fibers}, By adjusting the glass fiber content to 50 percent by weight. Investigations have shown that meta-coated | te glass fibers with plastic with a proportion of up to 43 years

i can combine weight percent? but that such an i

ι L

I plastic strand with further increase in the weight fraction j Jan glass fibers are becoming more and more fragile. However, | ! furthermore shown that at 43 percent by weight metal-!

I- i

[layered glass fibers additionally not metallized Allow glass fibers to be added without causing later brittleness. Is the amount of metal-coated glass fibers in the Range between 12 and 15%, then usable results Values for using the finished part as an electrical resistance! In general, it can be said that the conductivity increases with an increase in the weight percent of metal-coated glass fibers grows. Tablets can therefore have up to 50 percent by weight of metal-coated glass fibers, in which case it is desirable will use such tablets with other tablets that do not contain fiberglass cores, to melt a molded part which then contains about 43 weight percent or less metal-coated glass fibers. On the other hand, tablets can of course also be produced with the respectively desired weight percentage of metal-coated Glass fibers for the molded part to be created are provided by correspondingly the number of glass fiber strands or the total cross-section is adjusted in the case of extruded tablets. Optimal properties in terms of electrical Conductivity and other physical properties result when the proportion of metal-coated glass fibers corresponds to about 25% in the molded part. On the other hand, there are also applications where these conductive plastics are not so much

PO 975 014X, PO 977 015

809847/0715

for shielding but only to provide a only minimal conductivity is required, such as with apparatus for electrostatic replication.

With regard to the materials used, it can also be pointed out that plastics other than polycarbonates are also used can be used, such as urethane elastomers and thermoplastic plastics. The metal coating of the glass fibers can be improved if the aluminum used for this purpose contains 2 to 3% antimony to prevent the formation of oxides. ; dung, as is known per se, is alloyed. When pulling through; the glass fibers are pulled through the liquid aluminum incus ! Generally the glass fibers only up to three quarters of their circumference; covered with the aluminum layer, in which case normally in a reheating process, the aluminum to run . is brought over the entire circumference of the glass fiber. For the inventive use of the glass fibers, however, this Reheating process can be suppressed, namely has shown that up to three-fourths of its circumference can be metal-coated glass fibers for the purposes of the invention are completely sufficient.

Examples of plate-shaped molded parts are then given, which are used to investigate the shielding properties serve against electromagnetic radiation. These plates are made with uniform dimensions of 75 χ 150 χ 6 mm. ; represents. The test results should also tell the difference between molded parts with parallel aligned metal-coated Show glass fibers and those with coiled metal-coated glass fibers. Table II brings so In pattern 1, a molded part that is created from tablets, the mutually parallel, metal-coated glass fibers exhibit. Included in all samples are the tablets

PO 975 014X, PO 977 015

809847 / 071S

and the molded parts produced have about 25 percent by weight of me- j

tall-coated glass fibers. The tablets are uniform ί

18 mm long, the components of the glass and the metal j

Coating are also identical. The general test ■

conditions are comparable so that the better ab- j

Screen results in the molding pattern using for;

Manufacture used tablets with twisted glass, ' fibers or with glass fiber braids for the tangling effect, which occurs when the tablets melt, back!

are feasible. ;

Tabel II Reference base example 1 2 pattern 3 Example 2 Example ; Pattern 1 Template ; Pattern 4 Pattern 5 frequency 21-22 (MHz) 16 19th 20-21 18th 18th 12th 16 19th 21-23 18-19 18-19 20th 15-16 18-19 22-25 18th 19-20 30th 18-19 23-24 23-25 18-21 21-22 70 29-32 31-34 25-26 33 100

All values in db!

For the pattern as a reference base 1, there are three pattern plates
Polycarbonate base has been melted with 25 percent by weight of metal-coated glass fibers, the glass fibers being present in the form of unwound strands. The shielding effect is below 20 db up to 70 MHz. The shielding effect increases to around 30 db with increasing frequency up to 100 MHz. Beyond that, no measurement results are available. The conductivity of this test pattern is suitable for a variety of purposes, in particular when anisotropic conductivity is desired. The shielding effect can also be described as sufficient in many cases.

PO 975 014X, PO 977 015

8098A7 / 071S

j - 18 -

However, it cannot be ruled out that shielding effects More than 20 db can be required for 6 mm thick molded parts!

• For Example 1, tablets are coated with metal-glass _fiber: used which are held together by a binder coating in the form of tufts each containing glass fibers, but without being twisted thereby. Eight tufts of glass fibers form a braided band with a total of 800 glass fibers. The braid corresponds to a hose like him ^; is used as an outer conductor for coaxial cables. The braid has 8 crossovers per 25.4 mm, but it can be assumed that any suitable number of such crossovers can be used as well. Two of these braids are used for the production of polycarbonate tablets, thus containing 1,600 glass fibers, so that a weight proportion of 25% of metal-coated glass fibers results. The shaped patterns created on the basis of such tablets show relatively large vortex structures, which also reflect the flow path of the plastic in the melt form. One of the pattern plates has been ground to increase the contrast between the metallized glass fibers and the surrounding plastic, and it has been found that the glass fibers appear to have a random three-dimensional orientation on the surface which is generally independent of the turbulence structures. The individual patterns have been broken approximately parallel to the plastic flow direction and transversely to the plastic flow direction in order to determine the distribution of the metallized glass fibers. Both glass fiber balls and individual glass fibers have been identified. This shows that the original glass fiber lengths are generally retained in the balls, whereas individually occurring glass fibers over the entire length range

PO 975 014X, PO 977 015

809847/0715

to be found between dust particles up to approximately the full length as present in the original tablets j are. The balls appear to consist generally of parallel, tightly packed glass fibers, with the braid structure j

door is no longer visible in the melted test samples.j Both individual glass fibers and the balls seem to be aligned in the {flow direction of the plastic in the moldi The balls hit one another at random! ^! term spacing of about 6 mm in the plastic. The ball dimension is also about 6 mm. j

As pattern 2, two pattern plates are melted, consisting of a mixture of tablets, one of which has a type two braids of metal-coated glass fibers, as described ^ !, are provided with 50% metallized glass fibers in one stretched strand as included in the reference sample. This means that these sample plates have 12.5 percent by weight metallized Glass fibers in braid form with a total weight fraction of 25% of the metal-coated glass fibers. As the table shows, there is a considerable improvement in the shielding effect .

For sample 3, three sample panels are melted and checked according to the procedure described for sample 2, with the exception of that the tablet mixture of 75% tablets, containing a mesh of metallized glass fibers, and 25% tablets, containing stretched, untwisted metallized glass fibers. That is, the melted pattern plates are 18% by weight metallized glass fibers in the form of a braid and 7% metallized glass fibers in the form of an untwisted strand. It turns out that these plates make one Shielding effect with more than 20 db over the entire test frequency range demonstrate.

PO 975 014X, PO 977 015

8098A7 / 071S

In example 2 there are metallized glass fibers in the form of 13 tufts, each containing 100 metal-coated glass fibers, used. One of these tufts forms a soul consisting of twisted glass fibers. Six of the named Tufts are wound clockwise around the soul tuft and the remaining six are counterclockwise around the inner seven tufts coiled. Owns this fiberglass strand therefore a total of 1300 metal-coated glass fibers. This serves as the core for tablets that have a Have a proportion of 25 percent by weight of metal-coated glass fibers. The fiberglass strand has about a quarter turn per 25.4 mm. Although this corresponds to only three quarters of a turn along the length of a tablet, they show ! Tufts at the end of the cut an interlocking of the fibers so that they do not diverge. However, it can be estimated that an extra eight turns per 25.4 mm are desirable. To prevent the fluff that occurs when a If the mechanical stress is too low, it is likely .because relative movement of the glass fibers of a tuft at low Stress can occur and the glass fibers rub against each other should be applied to the metal-coated

Glass fibers constantly exert minimal mechanical tension. The maximum stress is due to the permissible tensile stress of the fiber optic strand. It appears that (within these limits the tension on the tufts is not critical, as long as the tension is the same for all tufts.

In sample 4, there are three sample plates with the help of the tablets used in this example, i.e. without the help of others Tablets, melted. This means that these plates have about 20 percent by weight of metal-coated glass fibers in Have the shape of a twisted glass strand. Although the plates show test results that are suitable for some frequencies

PO 975 014X, PO 977 015

809847/0715

are less than the samples for example Λ ₍ the results are better than with the reference basis for sample 1. However, with other frequencies the results are much better, so that the use of twisted metal-coated fiberglass strands is preferable. The test plates are then an-f approximately at right angles to the direction of flow of the plastic and also parallel to this direction of flow to determine the position of the glass fibers and the fiber ball Tablets have braid strands I. The coils seem to correspond to the original j tufts with about 100 metal-coated glass fibers

Then there are plastic tablets like those in the example 2 have been used for melting a housing of a data terminal station, with the product test being satisfactory Has shown results.

For sample 5 of example 3, three sample plates made from a mixture of tablets, of which 75% contain twisted glass fiber strands, as described in example 2, and 25% glass fiber braids, as described in example 1, have been melted. The sample plates show results that are essentially comparable to the results for sample 4. A sample plate has been broken up and the broken corner has been examined microscopically. The plate shows both single glass fibers and balls of glass fibers. There is no difference between balls whose starting basis is made of woven braids and whose starting basis is based on twisted threads. Again, these results suggest that twisted braids are preferable for most shielding purposes.

PO 976 01 4X, PO 977 015

809847/0715

^! - 22 -

: As already stated, the tablets are for the above Listed examples created by extrusion with polycarbonate as a plastic base, but can just as well ■ also use other plastics, as they are usually used with Unmetallized glass fibers are used to reinforce molded parts.

PO 975 014X, PO 977 015

809847/0715

Claims (11)

PATENT CLAIMS Tableted molding compound for the production of conductive molded parts / in particular shielding housings for electrical Devices in which the individual tablets are at least 1 mm long / metal-coated glass fibers with a weight fraction between about 20% to about I. Contain 50% of the respective total tablet mass / j characterized in that the tablets manufactured by means of extrusion j are at least 5 mm long and j of the order of 3 mm thickness each in their longitudinal direction made of plastic-soaked and plastic embedded strands of metal-coated glass fibers. 2. Tableted molding composition according to claim 1, characterized in that the tablets and the glass fiber strands have a length of about 10 to about 18 mm. 3. Tableted molding composition according to claim 1 and / or 2, characterized in that the glass fiber strand consists of a web of about 500 to about 1000, but preferably 750, metal-coated glass fibers consists. 4. Tableted molding composition according to claims 1 to 3, characterized in that the weight fraction of metal-coated Glass fibers between about 25% to about 43% of the respective total tablet mass, preferably however, is about 25%. PO 975 014X, PO 977 015 809847/0715 5. Tableted molding composition according to one or more of claims 1 to 4, characterized in that the | metal-coated glass fibers in the core of a tablet ', are arranged / that when creating a j Partly scattered as individual fibers
and partly to form balls
close, the thickness of which is considerably greater than that of a single glass fiber, so that a fiber-to-fiber contact perpendicular to the flow direction of the softened plastic occurs in the finished molded part. 6. Tableted molding composition according to claims 1 to 5, characterized in that the metal-coated Glass fibers in the core of a tablet in the form of a glass fiber tuft with individual glass fibers lying around it are present. 7. Tableted molding composition according to claims 1 to 6, characterized in that the core of a tablet consists of a tuft of metal-coated glass fibers, which consists of several smaller tufts
metal-coated glass fibers is surrounded. 8. Tableted molding composition according to claim 7, characterized in that the glass fiber tufts consist of one
inner tufts with outer tufts wound around them. 9. Tableted molding composition according to claim 7 and / or 8,
characterized in that the core of a tablet consists of an inner tuft of glass fibers with in first
Direction of winding tufts of fiberglass and PO 975 014X, PO 977 015 ~~ 809847/0715 281837? ί - 3 - j consists of tufts of fiberglass wound around it in the opposite direction. 10. Tableted molding composition according to claims 1 to 5, j characterized in that the tablet core consists of glass fiber tufts combined to form a braided band consists. 11. Tableted molding composition according to claims 1 to 5, j characterized in that the tablet core consists of glass fiber tufts combined to form a braided tube consists. PO 975 014X, PO 977 015 809847/0715