Need Help With Problems When Installing Threaded Inserts Into Plastic Mouldings?|
How do I choose the correct insert?
1. What type of material is the insert going into?
2. What ‘torque’, ‘pull-out’ and ‘jack-out’ performance is required?
3. How do you intend to install the insert?
4. Does the insert need to be ‘headed’ or ‘unheaded’?
5. Choose the appropriate ‘brand’ of insert?
6. Do you require installation equipment?
(1) Application Material
The material (thermoplastic, thermoset, DMC etc) in which the insert will be installed will directly influence the choice of product, achievable performance and installation method.
(2) Types of Performance
Torque is the maximum rotating force (Nm) that can be applied to the insert before it ‘spins’ in the moulding.
Pull-out performance is the maximum force (Kg), applied in a direct line, that results in the failure of the insert from the host material.
Jack-Out is the maximum rotating force (Nm) that can be applied to the insert before it starts to be ‘pulled-out’ of the moment. This ‘failure’ is similar to Pull-Out’ and is usually found when the design of the two mating parts has not been designed properly.
The performance of any insert is also directly dependent on hole size, material and method of installation.
(3) Methods of Installation
There are two methods of installing inserts:
(a) Post-Moulded Installation
(a) Post-Moulded Installation
There are three methods of installing ‘post-moulded’ inserts – Heat/Ultrasonic; Cold; Screw-In, and each method has advantages and disadvantages. instalator The easiest to install is the ‘press-in cold’ range of inserts; the ‘press-in hot’ range of inserts uses some type of installation machine to install the inserts, but provides a higher performance. The ‘screw-in’ range of inserts uses installation equipment, is the hardest to install, but provides the best performance.
(b) Moulded-In Installation
This is the method that provides the maximum performance, but has the disadvantage of requiring the insert to be installed directly into the ‘mould tool’. This type of inserts is mainly used in thermoset or DMC mouldings where cycle times are slower, so the time taken to install the inserts is not too much of a disadvantage. The majority of inserts are ‘blind’ so as to stop plastic material going inside and contaminating the thread.
(4) ‘Headed’ or ‘Unheaded’?
The majority of inserts supplied are ‘unheaded’, due to the fact that they are usually installed ‘flush’ into a blind hole. The ‘headed’ style are used in a ‘though hole’ moulding to prevent them ‘pulling through’, when working with an oversize clearance hole in the mating part to prevent ‘jack-out’, where high tightening torques are required and for an electrical contact.
(5) Choose the appropriate ‘brand of insert?
We offer several different types of threaded inserts to suit all types of applications, materials and performance.
* Inserts for hot or cold installation into all types of thermoplastics
* Inserts for heat or ultrasonic insertion into all types of thermoplastics
* Inserts for cold installation into both thermoplastic and thermoset materials
* Inserts for screw-in installation into thermoplastic and some thermoset materials
* Inserts for moulded-in installation into thermoplastic and thermoset materials
* Inserts f or moulded-in installation into rotational mouldings
(6) Installation Equipment
We can supply installation equipment for use with the our range of inserts.
Our “Heat Installation” machine offers a solid and consistent installation of inserts by maintaining a pre-set temperature between ambient and 500Ë?C. The machine ensures a cost effective, high performance solution every time; can be used for installing both male and female inserts.
Our “Screw-In Installation” machine is a spring-loaded pneumatic arm, which is highly flexible and manoeuvrable giving a rapid clean installation for high performance inserts. The assembly can be expanded to incorporate three separate arms on a single column – allowing fast installation of multi-sized inserts into a one moulding with each arm having a dedicated insert size and pre-set installation torque. The machine has almost a 1m working envelope allowing it to accommodate insert installation into most plastic moulded products.
Our Arbor press is designed for insertion of ‘cold installed’ inserts. The simple rack and pinion operation is virtually maintenance free and delivers solid and reliable installation of inserts.
Dealing with installation problems.
This section helps users recognise installation problems and their causes. We will illustrate the common type of problems and how they can be overcome. Each problem would feature a mini case study from a customer who has experienced the problem and how they overcame the issues involved.