LIQUID SILICONE MOLDING. Contrary to popular opinion Liquid Silicone Molding (L.S.M.) is not rocket-science!! However it is distinctly different from thermoplastic injection molding and also very different from molding conventional high consistency silicone. For starters L.S.M. is a reactive molding technology and the raw materials also have low viscosity at the molding temperature. These two factors alone require distinct processing disciplines, systems and techniques without which it is difficult to succeed. However once implemented they can assure successful, sustainable high yield L.S.M. operations. Crinnis can guarantee to significantly shorten your learning curve! We provide troubleshooting, manufacturing know-how, complete turn-key systems,start-up assistance, and on-going technical support including design assistance and sourcing of LSR/ LIM tooling.

Critical areas of support include the following:

EQUIPMENT SELECTION. What is the most appropriate metering/mixing, and injection equipment for your particular needs? Which "bells and whistles" are critical and which only add unnecessary expense? Electric or hydraulic control of injection? Equipment suppliers and capabilities.

TOOLING SELECTION. Conventional (hot) runner or cold runner? Pros and cons of direct (open) gate or needle (valved) gates. Fully automatic/robotic parts removal. LSR/LIM tooling sources.Flashless tooling.

MATERIAL SELECTION. Effects of part design and tooling choice on material selection.Material suppliers and capabilities

FLEXIBLE MANUFACTURING SYSTEMS. How to optimise cost-effectively for high volume/ fully automated production or low volume production with frequent tool or material changes.

IN-PLANT TROUBLESHOOTING AND PROCESS OPTIMISATION. Identify and evaluate key machine variables and their relationships to product properties and process yields. Optimise process windows for molding products.

EMPLOYEE TRAINING. Teach key differences between LIM/LSR molding and thermoplastic molding or high consistency rubber (HCR) molding. LSR machine set-up, tooling prove out. How to establish realistic process windows and optimise product quality and process yields.

NEW PROCESS DEVELOPMENT/TOOLING EVALUATIONS. We can help in your new product and process development programs and, if necessary,will participate under appropriate"Non- Disclosure Agreements" to assure complete confidentiality. We have the latest all-electric LSR injection molding machine (110 Ton) available for your next process development program or tooling evaluation/prove-out

TURN-KEY SYSTEM DEVELOPMENT .If clients prefer, we can develop, optimise,and deliver full turn-key systems (machines, tooling, material selection, and cycle optimisation) to guarantee efficient troublefree implementation and manufacturability of parts in your plant.

RUBBER KEYPADS. We have extensive turn-key technology for rubber keypad production using liquid silicone molding and over-molding processes. This includes material and equipment recommendations together with operating know-how and assistance for all post molding operations such as screen printing, painting and laser etching, legend protection, and bonding to plastic keycaps.

ELASTOMERIC GELS. Use of elastomeric gels is growing rapidly in areas such as sports and recreation,ergonomics,orthopedics,adult-novelty products / sex toys, personal comfort, medical pads,seat pads,pressure relief pads for the foot,knee, elbow,wrist,etc..We can help from concept to full production either in a consulting capacity or with custom manufacturing services in the area of elastomeric gels. Our expertise includes product formulation, process know-how and production capabilities for both thermoset and thermoplastic based elastomer gels either as stand alone gels or combined with other materials (stretch fabrics; films; plastic and metal parts; and tough, elastic paints and barrier coatings)

SOFT-POLYMER OR ELASTOMER GEL SELECTION CRITERIA. The following considerations and areas of Crinnis expertise in soft-polymer and elastomer gel systems may be helpful to you when evaluating product and process options.

Elastomer gels can be formulated from a variety of base polymer materials including thermoset elastomers such as silicones and polyurethanes, and thermoplastic polymers typically including thermoplastic elastomers (TPE), and plasticized vinyl polymers. Selection of the best polymer-gel formulations for your particular application depends primarily upon the physical properties and performance requirements of the finished soft polymer product and/or the processing methods available or appropriate.

Crinnis provides support in the following critical areas, all of which need to be considered before deciding upon the best solution to your product and process needs.

PHYSICAL PROPERTY REQUIREMENTS. Which of the following physical properties are important ?

a) tactile properties such as durometer, or bloom penetration force

b) resilience. i.e. do you need “bounce” or are you looking for “dead” gel properties such as those optimized to minimize skin-shear and pressure points in seating or patient-positioning systems

c) properties such as surface tack i.e. do you need the gel to adhere strongly to a laminated substrate or enveloping bladder or do you need a non-tacky surface for a stand-alone gel suitable for human handling or skin contact

d) creep resistance, effect of temperature on cohesive strength, deformation under load, etc. These requirements will generally dictate whether thermoset or thermoplastic elastic gels can be used

e) resistance to bleed-out . Most soft polymer gels are dilute networks formulated from extensible/elastic polymers which form the polymer network extended with liquid diluents to reduce cost, improve processability, reduce hardness or improve conformability. Depending upon the specific combination of diluents and polymers used, together with their relative compatibilities and chemical make-up, diluents can leech out or “bleed” from the gel network. This is the case even in gels in a stand alone condition, without surface contact with any other surface material. Alternatively, diluents can show no tendency to bleed from the gel ( i.e. have a “dry-feel” surface) until they are brought into contact with other materials such as fabrics, paper etc. when the diluent can be “wicked-out” of the elastomer gel over time (i.e. known as the “french-fry” effect ) causing “staining or water-marking” of the contact fabric or paper. Bleed-out or wicking characteristics of elastomer gels are not always detrimental properties and in fact can be precisely tailored to meet specific requirements. Examples where this would be beneficial would be in the production of self-lubricating materials.

PROCESSING REQUIREMENTS. Typical considerations include the following:

a) are one-time-use, reactive-thermoset elastomeric gels best suited for your application or can thermoplastic gels facilitating reuse of scrap and/or thermal sealing techniques be advantageous?

b) what is the best metering system for reactive gels or the most practical, cost-effective melt processing equipment for hot-melt gels to meet your needs. Is off-the-shelf equipment available and if so, how do you correctly specify performance requirements?

c) If off-the-shelf equipment is not available, or even if available, would a turn-key customized system be more cost effective in the long run? All Crinnis turn-key system equipment is proved-out in our facility in the same manufacturing cell configuration and under the same manufacturing conditions with the clients’ own molds, dies, etc. prior to delivery and installation in the clients’ factory. If required, Crinnis will also provide ramp-up production capability on an interim basis prior to installation of equipment in the clients’ plant.

TOOLING REQUIREMENTS & SOURCES. Closed-tool molding or open-pour casting techniques can be satisfied using a variety of tooling materials including elastomer molds, fiberglass, and rigid thermoset resin tooling. Metal tooling options include cast or machined metal tooling, spray-metal and electroform-metal tooling. We can incorporate any of the above options into a fully turn-key molding system.

POST- MOLD FINISHING. We have developed flexible elastomeric paints and surface coatings to provide aesthetic decoration, abuse resistance or barriers to diluent bleed. Paint and coating formulations can be applied by brush, dipping and spray techniques.

Lamination and bonding techniques of thermoset and thermoplastic elastomer gels to various substrates such as fabrics, non-woven webs and films have been developed and perfected.

PROTOTYPE AND PRODUCTION SERVICES
If you currently use or are considering applications for elastomeric gel products and are looking to source production, or simply want to evaluate or prototype a concept,you can contact us with complete assurance of confidentiality.