FIELD OF INVENTION
This invention is directed to a strengthened molded part by strengthening joinery between two materials of the molded part.
BACKGROUND/PRIOR ART
Currently any molded part involving two materials such as 2K molded, co-molded or over molded parts consist of joining of two parts of different material to obtain a single product. The two materials generally include one hard and one soft material (1 and 2). In this regard reference may be made to fig 1A, IB, 1C depicting typical section of different joineries, namely I,L and Z joinery currently provided in such molded parts.
According to the process of molding, one material is molded after another material either in the same tool or in different tools, wherein the joining of the two materials occurs owing to chemical bonding of the Jiot materials at the line of contact. Thus, joining strength of such kind of joint depends greatly upon the surface area of contact between the two materials (joinery strength a contact surface area) other than factors such as raw material type, part thickness etc. Therefore, the aforesaid joinery has strength in the series of Ib due to presence of hole and d' is auxiliary area of contact.
Upon application of force, when the tearing starts from one end, the mechanical lock provided in the joinery prevents the complete tearing. In conjunction wiLl.i the mechanical bonding an increase in the contact surface area further adds to the joinery strength.
Thus even when the force equal to breakage force as in prior art is applied, the tearing will not occur due to the following two factors:
- Increased contact surface area to improve chemical bonding.
- Provision of mechanical bonding.
Now, the advantageous features of the invention can be briefly summarized hereinbelbw:
- Strengthening of the joinery.
- Prevention of tearing.
- Longer life span.
it is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the. present invention, which is further set forth under the following claims:-

we claim:-
A strengthened molded part by strengthening joinery between two
materials of the molded part comprising of a hard material part
embedded into soft material part, wherein the hard material part is
provided with a hole adjacent to joinery of said parts which acts as a
mechanical lock.
A strengthened molded part by strengthening joinery between two
materials of the molded part as claimed in claim 1 wherein the hole is
atleast one in number along a side/circumference of the hard material
part.
A strengthened molded part by strengthening joinery between two
materials of the molded part as claimed in claim 1 or 2 wherein the hole
accommodates soft material to establish mechanical bonding between
the parts which acts as a mechanical lock.
A strengthened molded part by strengthening joinery between two
materials of the molded part as claimed in any of the proceeding claims
comprises increased contact surface area between the two parts so as to
improve chemical bonding therebetween.
A strengthened molded part by strengthening joinery between two
materials of the molded part as claimed in any of the preceding claims is
associated with the advantageous features such as herein described.
A strengthened molded part by strengthening joinery between two
materials of the molded part substantially as herein described with
reference to the accompanying drawings.