Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invent
The present invention relates to a bottle made of a saturated
polyester resin provided with a vertically extending, strip-shaped projection
on the trunk or body ~hereof.
The saturated polyester resins attract public attention for use
as the materials for bottles, since they prevent soaking o~ any harmful
materials such as solvent differing from other synthetic resinous materials
conventionally used for making bottles and no poisonous gas i.s generated
when combusted af~er disposal. However, melted saturated polyester resin is
poor or deficient in fluidity as compared to other meltable materials and
tends to gelatinize to make it difficult to mould there*rom a bottle of
complicated contour and to form an embossed pattern on the outer face of the
bottle.
Furthermore, a parison made of a saturated polyester resin is
crystallized at the glass transition temperature due to the interrelation
between the temperature and the time ~o lose its elongation capacity. As a
resul~, it is necessary to maintain the temperature within an appropriate
range if the parison made of a saturated polyester resin is biaxially
oriented and it is extremely difficult to effect the desired biaxial
orientation particularly when the thickness of the parison is varied in parts.
Summary of t~e Invention:
According to the invention there is provided in a bottle made of
a saturated polyester resin having a neck and a body and formed by biaxial
orientation of a parison of said saturated polyester resin, the improvement
comprising
a vertically extending, strip-shaped projection formed on the
outer surface of said body by simultaneous biaxial orientation of a strip-
shaped piece welded on the outer surface o~ said parison and said parison.
Also according to the invention there is provided a method o.f
making a bottle made of a saturated polyester resin comprising the steps of
injection moulding a parison having an open upper end and a closed bottom end
from a saturated polyester resin material, welding a strip-shaped piece made
of the saturated polyester resin on the body of said parisonJ biaxially
orienting said parison sinn~ltaneously with said strip-shaped piece to form a
bottle made of the saturated polyester resin, with a vertically extending,
strip-shaped reinforcement formed on the body of the bottle.
Brief Description of the Drawin~s:
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
Figure 1 is a front view of a bottle made o a saturated polyester
I resin according to the present invention;
Figure 2 is a front view of the parison used for moulding the
bottle;
Figure 3 is a front view of the parison with the welded strip;~and
Figure 4 is a sactional view taken along line IV-IV in Figure 3.
Detailed Description of_the Invention:
The bottle of a saturated polyester resin according to the present
invention will be described with reference to the appended drawing. A bottle 1
comprises a trunk or body 2 rising up from the periphery of the bottom of the
bottle, a shoulder 3 at the upper end of the body 2, and a neck 4 projecting
from the center of the shoulder 3 and having a diameter smaller than that of
the body. Projecting from the base portion of the neck 4 is a flange 5 against
~3~
which the bottom edge of a cap abutsO A thread 6 for engagement with a
corresponding thread on the cap is provided on the outer face of the neckO
A projection 7a .is formed OTI the portion surrounding the base of
the neck 4 and is integrally connected with two strip-shaped projections 7b
which extend downwardly onto the bottom of the bottle at diametrically opposed
peripheral portions of the body. It should be appreciated that the body
2 which is thin and somewhat weak is reinforced by the thick projections 7a
and 7b which also serve as projected or embossed patterns.
The bottle made of a saturated polyester resin having the project-
ln ions 7a and 7b may be formed by the following procedureO A parison 8 having anopen upper end and a closed bottom end, as shown in Figure 2, is injection
moulded using a saturated polyester resin as the moulding materialO The
parison 8 has a substantially uniform thickness throughout and includes the
neck 4, the thread 6 and the flange 5 which are formed in the injection moulding
step. In order to produce transparent parison 8, it is necessary to cool the
same rapidly, immediately after the moulding step thereby to prevent crystal-
lization resulting in whiteningO As has been described hereinbefore, if the
saturated polyester resin materia.l is crystallized7 the subsequent biaxial
orientation which will be described hereinafter in detail, becomes extremely
difficult,
The strip-shaped pieces 7b' made of saturated polyester resin are
~elded on the outer face of the parison 5 at diametrically opposed peripheral
portions. The strip-shaped pieces 7b' extend vertically from the bottom of the
parison 8. An annular piece 7a' is similarly welded to the parison below the
flange 5 so that the flange is surrounded by the annular piece 7a', as shown
in Figures 3 and 4O While in the Figures there is shown a parison with welded-
~3~6~
on strip-shaped pieces 7b' having the ends covering the bottom of the parison 8,
the lengths of the strip-shaped pieces may be such that the bottom of the
parison 8 is not covered by them. It is preferable to color the strip-shaped
pieces 7_' and the annular piece 7a' by adding with a desired coloring agent
~or ornamental purposes.
The parison 8 thus welded with the strip-shaped pieces 7b' and the
annular piece 7a' is then put in blow-mou]ding mould cmd heated to a temperature
enabling biaxial orientation and yet causing no whitening. After the strip-
shaped pieces and the annular piece are conjoined to form an integral piece the
parison 8 is inflated and elongated in the longitudinal direction to form the
bottle 1. In this operation, the annular piece 7a' and the strip-shaped
pieces 7b' are Eitted in recesses provided on the wall of the blow-moulding
mould, so as to form, respectively~ the projections 7a and 7b after the biaxial
orientation operation. As a result, the projection 7a and 7b become thicker
than the other portions of the bottle 1 to reinforce the latter. Since no
recess or groove is provided at the bottom of the mould, no projecting portion
is formed at the bottom of the bottle.
If the outer face portions atpredetermined locations are heated to
a higher temperature during heating of the parison 8, such portions are crystal-
lized to form whitened patterns.
As will `be apparent from the foregoing description, the presentinvention is directed to a bottle made of saturated polyester resin and a method
of making the same, wherein thicker projections 7a and 7b are formed on the
trunk of the bottle, so that the bot*le becomes strong even when the wall of the
other portions of the bottle is thin. Mo~eover, the projections form embossed
patterns which serve as desirable ornaments. Further, the projections 7b or the
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l,ike may be easily formed by welding on strip-shaped pieces 7b' made of the
same saturated polyester resin as the body portion of the bottle, a material
that is difficult to process to form an embossed pattern. ~urthermore, by
using colored strip-shaped pieces 7b' or the like, colored projecting patterns
may be formed.
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